Genetics Flashcard Round-Up
Gal3p
- Transducer found in cytoplasm - Binds galactose and moves into nucleus to bind GAL4/ GAL80
Effects of Epistasis
- distinct phenotypic classes are produced - assort independently of one another during gamete formation - either allele (+ or -) may be present without consequence to the phenotype - all P1 involve homozygous outcomes: A-B-, A-, aaB-, aabb
Remodeling of nucleosome core particle
- exchange of histone variants
Erasers
- histone and lysine demethylases
Transcription and translation
- occurs in the nucleus where the mRNA takes a copy of DNA - occurs in the cytoplasm with the help of ribosomes - purpose is to produce proteins throughout the body ; DNA codes for that
To execute a successful mapping cross, three criteria must me met:
- the genotype of the organism producing the crossover gametes must be heterozygous at all loci under consideration - genotypes of all gametes can be accurately determined by observing the phenotypes of the resulting offspring - sufficient number of offspring must be produced
For linked genes A, B, and C, the map distance A-B is 5 map units and the map distance B-C is 25 map units. If there are 10 double crossover events out of 1000 offspring, what is the interference?
0.2 ( The coefficient of coincidence is 0.01/0.0125 = 0.8, so the interference is 1 - 0.8 = 0.2.)
Part C - Experimental prediction: Comparing autosomal and sex-linked inheritance You now know that inheritance of eye color in fruit flies is sex-linked: The gene encoding eye color is located on the X chromosome, and there is no corresponding gene on the Y chromosome. How would the inheritance pattern differ if the gene for eye color were instead located on an autosome (a non-sex chromosome)? Recall that for autosomes, both chromosomes of a homologous pair carry the same genes in the same locations. Suppose that a geneticist crossed a large number of white-eyed females with red-eyed males. Consider two separate cases: Case 1: Eye color exhibits sex-linked inheritance. Case 2: Eye color exhibits autosomal (non-sex-linked) inheritance. (Note: In this case, assume that the red-eyed males are homozygous.)
1 Eye color exhibits sex linked inheritance -100 Fm osp,100 red eyes + 0 white - 0 male osp 0 red eyes+ 100 white -100 female Osp 100 red eyes+ 0white -100Male osp 100 red eyes+0 white
Assume that the genes from the previous example are located along the chromosome in the order X, Y, and Z. What is the probability of recombination between genes X and Z?
30% Recombination frequencies between linked genes along a chromosome are additive, so the recombination frequency between genes X and Z is 25 + 5 = 30.
If two genes on the same chromosome exhibit complete linkage, what is the expected F2 phenotypic ratio from a selfed heterozygote with the genotype a+b+ ⁄⁄ ab?
3:1 (Each parent produces two types of gametes, a+b+ and ab, giving the simple Mendelian ratio of 3 a+b+ : 1 ab.)
Kleinfelter's Syndrome
47 XXY, nondisjunction during miosis long legs, short trunk gynecomastia Hypogonadism Tall height
Excision repair
A DNA-repair process where enzymes remove a damaged portion of DNA, synthesize a replacement section in place, and attach it to the neighboring DNA segments
high frequency recombination
A HFR strain, caused by the presence of a chromosomally integrated F factor.
R plasmids
A bacterial plasmid carrying genes that confer resistance to certain antibiotics.
Missense mutation
A base-pair substitution that results in a codon that codes for a different amino acid.
chromosome theory of inheritance
A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.
Endoplasmic Reticulum
A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.
Mutation
A change in a gene or chromosome.
Chromosomal mutation
A change in the chromosome structure, resulting in new gene combinations.
deletion
A change to a chromosome in which a fragment of the chromosome is removed.
traits
A characteristic that an organism can pass on to its offspring through its genes.
punnett square
A chart that shows all the possible combinations of alleles that can result from a genetic cross
Mutagens
A chemical or physical agent that interacts with DNA and causes a mutation.
BrdU
A chemical that identifies newly-divided cells
Aneuploidy
A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number.
monosomic
A chromosomal condition in which a particular cell has only one copy of a chromosome, instead of the normal two.
Turner syndrome
A chromosomal disorder in females in which either an X chromosome is missing or part of one X chromosome is deleted
Klinefelter syndrome
A chromosomal disorder in which males have an extra X chromosome, making them XXY instead of XY.
triploid
A chromosomal mutation where an organism has three sets of chromosomes (3n) instead of two (2n)
deoxyribonuclease (DNase)
A class of enzymes that breaks down DNA into oligonucleotide fragments by introducing single-stranded or double-stranded breaks into the double helix.
yeast artificial chromosome (YAC)
A cloning vector that has telomeres and a centromere that can accommodate large DNA inserts and uses the eukaryote yeast as a host cell.
sliding clamp loader
A component of the DNA polymerase III holoenzyme consisting of five subunits that attach a circular protein complex to the polymerase in an ATP-dependent reaction.
monohybrid cross
A cross between two individuals, concentrating on only one definable trait
dihybrid cross
A cross between two individuals, concentrating on two definable traits
nucleoid
A dense region of DNA in a prokaryotic cell.
pedigree
A diagram that shows the occurrence of a genetic trait in several generations of a family.
spermatogonium
A diploid cell that can undergo mitosis to form more spermatogonium, and can also be triggered to undergo meiosis to form sperm.
biotechnology
A form of technology that uses living organisms, usually genes, to modify products, to make or modify plants and animals, or to develop other microorganisms for specific purposes.
conditional knockout
A gene that can be selectively deactivated either in specific tissues and/or at a specific stage of development.
tumor suppressor genes
A gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer.
reporter gene
A genetic marker included in recombinant DNA to indicate the presence of the recombinant DNA in a host cell.
Actin
A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells.
Action spectrum
A graph that profiles the relative effectiveness of different wavelengths of radiation in driving a particular process.
r-determinant
A group of genes for antibiotic resistance carried on R factors
resistance transfer factor (RTF)
A group of genes for replication and conjugation on the R factor
Polyadenylation signal sequence
A hexanucleotide sequence of mRNA, usually AAUAAA, that identifies the location of 3' pre-mRNA cleavage and polyadenylation
Cosmic rays
A highly energetic atomic nucleus or other particle traveling through space at a speed approaching that of light.
insulin
A hormone produced by the pancreas or taken as a medication by many diabetics
PKU
A human metabolic disease caused by a mutation in a gene coding for a phenylalanine processing enzyme (phenylalanine hydroxylase), which leads to accumulation of phenylalanine and mental retardation if not treated; inherited as an autosomal recessive phenotype.
southern blotting
A hybridization technique that enables researchers to determine the presence of certain nucleotide sequences in a sample of DNA.
cytoplasm
A jellylike fluid inside the cell in which the organelles are suspended
genome-wide association studies
A large-scale analysis of the genomes of many people having a certain phenotype or disease, with the aim of finding genetic markers that correlate with that phenotype or disease.
DNA ligase
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.
Chromatin remodeling
A mechanism for epigenetic gene regulation by the alteration of chromatin structure.
blue-white screening
A method of selecting the desired recombinant bacteria (out of millions of cells) that contain an inserted gene from foreign DNA.
DNA microarray
A microarray of immobilized single-stranded DNA fragments of known nucleotide sequence that is used especially in the identification and sequencing of DNA samples and in the analysis of gene expression (as in a cell or tissue).
folded fiber model
A model of eukaryotic chromosome organization in which each sister chromatid consists of a single chromatin fiber composed of double-stranded DNA and proteins wound like a tightly coiled skein of yarn
spectral karyotyping
A molecular cytogenetic technique that allows the visualization of all the chromosomes at once using different colored markers for each chromosome
Silent mutation
A mutation that changes a single nucleotide, but does not change the amino acid created.
Nonsense mutation
A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.
Null mutation
A mutation that results in complete absence of function for the gene
Negative control
A negative control is a control group in an experiment that uses a treatment that isn't expected to produce results.
prophase 2
A new spindle forms around the chromosomes
dissociation (Ds)
A nonautonomous transposable element named by Barbara McClintock for its ability to break chromosome 9 of maize but only in the presence of another element called Activator (Ac).
telophase 2
A nuclear membrane forms around the chromosomes in each of the 4 new cells.
SWI/SNF
A nucleosome remodeling complex. A group of proteins that associate to move nucleosomes away from promoter sequences to facilitate transcription; a coactivator.
Apyrimidinic site
A nucleotide residue in a DNA molecule from which a prymide base has been lost or removed
nucleus
A part of the cell containing DNA and RNA and responsible for growth and reproduction
alternate segregation
A pattern of chromosome segregation that can occur following reciprocal balanced translocation that leads to the production of viable gametes.
carrier
A person whose genotype includes a gene that is not expressed in the phenotype.
prophage
A phage genome that has been inserted into a specific site on the bacterial chromosome.
temperate phage
A phage that is capable of reproducing by either the lytic or lysogenic cycle.
virulent phage
A phage that reproduces only by a lytic cycle.
F factor
A piece of DNA that can exist as a bacterial plasmid. The F factor carries genes for making sex pili and other structures needed for conjugation, as well as a site where DNA replication can start. F stands for fertility.
Ti plasmid
A plasmid of a tumor-inducing bacterium that integrates a segment of its DNA into the host chromosome of a plant; frequently used as a carrier for genetic engineering in plants.
Polynucleotides
A polymer consisting of many nucleotide monomers in a chain; nucleotides can be those of DNA or RNA.
Positive control
A positive control is a control group in an experiment that uses a treatment that is known to produce results.
Sanger sequencing
A procedure in which chemical termination of daughter strands help in determining the DNA sequence.
Electrophoresis
A process where DNA fragments are separated according to size using electrical charges
Ubiquitin
A protein that attaches itself to faulty or misfolded proteins and thus targets them for destruction by proteasomes
motor proteins
A protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell.
Base analogs
A purine or pyrimidine that differs in chemical structure from those normally found in DNA or RNA
Nonhomologous end joining
A quick-and-dirty mechanism for repairing double-strand breaks in DNA that involves quickly bringing together, trimming, and rejoining the two broken ends; results in a loss of information at the site of repair.
Transcription factors
A regulatory protein that binds to DNA and affects transcription of specific genes.
transcription factor
A regulatory protein that binds to DNA and affects transcription of specific genes.
gene
A segment of DNA on a chromosome that codes for a specific trait
plasma membrane
A selectively-permeable phospholipid bilayer forming the boundary of the cells
General transcription factors
A set of proteins that bind to the promoter of a gene whose combined action is necessary for transcription.
genomic library
A set of thousands of DNA segments from a genome, each carried by a plasmid, phage, or other cloning vector.
Triplet code
A set of three-nucleotide-long words that specify the amino acids for polypeptide chains.
single nucleotide polymorphism (SNP)
A single base-pair site in a genome where nucleotide variation is found in at least 1% of the population.
Apurinic site
A site in DNA that is missing a purine base
plasmid
A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome
kinetochore
A specialized region on the centromere that links each sister chromatid to the mitotic spindle.
recognition sequence
A specific sequence of nucleotides at which a restriction enzyme cleaves a DNA molecule
restriction site
A specific sequence on a DNA strand that is recognized as a cut siteby a restriction enzyme.
inducer
A specific small molecule that inactivates the repressor in an operon.
Alpha helix
A spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure.
centrosome
A structure in animal cells containing centrioles from which the spindle fibers develop.
polymerase chain reaction (PCR)
A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.
chronic villus sampling (CVS)
A technique for diagnosing genetic and congenital defects in a fetus by removing and analyzing a sample of the fetal portion of the placenta
genetic engineering
A technology that includes the process of manipulating or altering the genetic material of a cell resulting in desirable functions or outcomes that would not occur naturally.
Transport proteins
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.
Zinc finger motif
A type of DNA-binding motif in regulatory proteins that incorporates zinc atoms in its structure.
mRNA
A type of RNA, synthesized from DNA, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein.
epistasis
A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.
Base pair substitution
A type of point mutation; the replacement of one nucleotide and its partner in the complementary DNA strand by another pair of nucleotides.
Base substitution
A type of point mutation; the replacement of one nucleotide and its partner in the complementary DNA strand by another pair of nucleotides.
Beta pleated sheet
A type of protein secondary structure; results from hydrogen bonding between polypeptide regions running antiparallel to each other.
palindrome
A word or an expression that is spelled the same backward and forward
26. Trisomy 21, or Down syndrome, occurs when there is a normal diploid chromosomal complement but one (extra) chromosome 21. Although fertility is reduced in both sexes, females have higher fertility rates than males. Van Dyke et al. (1995; Down Syndrome Research and Practice 3(2): 65-69) summarize data involving children born of Down syndrome individuals. Assume that children are born to a female with Down syndrome and a normal 46-chromosome male. What proportion of the offspring would be expected to have Down syndrome? A. One-half of the offspring would be expected to have Down syndrome. B. All the children would be expected to have Down syndrome. C. Two-thirds of the offspring would be expected to have Down syndrome. D. None of the offspring would be expected to have Down syndrome. E. One-third of the offspring would be expected to have Down syndrome.
A. One-half of the offspring would be expected to have Down syndrome.
22. In Drosophila, an individual female fly was observed to be of the XXY chromosome complement (normal autosomal complement) and to have white eyes as contrasted with the normal red eye color of wild type. The female's father had red eyes, and the mother had white eyes. Knowing that white eyes are X-linked and recessive, in what parent and at what stage did nondisjunction occur to produce this XXY, white-eyed female fly? Select all that apply. A. meiosis I in the mother B. meiosis II in the mother C. meiosis I in the father E. meiosis II in the father
A. meiosis I in the mother B. meiosis II in the mother
7. Name the general category into which double-stranded circular extrachromosomal DNA elements such as F factors, ColE1, and R would fall. A. plasmid B. partial diploid C. plaque D. capsid E. r-determinant
A. plasmid
19. The phenomenon in which one crossover decreases the likelihood of crossovers in nearby regions is called A. positive interference. B. chiasma. C. mitotic recombination. D. negative interference. E. reciprocal genetic exchange.
A. positive interference.
7. The genes for mahogany eyes and ebony body are approximately 25 map units apart on chromosome 3 in Drosophila. Assume that a mahogany-eyed female was mated to an ebony-bodied male and that the resulting F1 phenotypically wild-type females were mated to mahogany, ebony males to obtain an F2 generation. A.) Which of the following phenotypes would be expected in the F2 offspring? B.) If 1000 F2 offspring are obtained, how many flies of each phenotype are expected? __wild type : __ mahogeny : __ ebony : __ mahogeny, ebony (Remember the two genes are 25 mu apart on the same chromosome. In order to determine how many offspring of each type are produced, you must determine if the F1 females carries both mutations on one chromosome, and wildtype alleles on the other or if she carries one mutation and one wildtype allele on each chromosome.) Enter your answer as the number of flies of each phenotype separated by a colon.
A.) All Phenotypes: - wild type - mahogeny-eyed - ebony-bodied - mahogeny-eyed, ebony-bodied B.) Ratios are: 125 Wild type :375 Mahogeny :375 Ebony :125 Ebony/Mahogeny
18. Assume that the genes for tan body and bare wings are 15 map units apart on chromosome 2 in Drosophila. A tan-bodied, bare-winged female was mated to a wild-type male and that the resulting F1 phenotypically wild-type females were mated to tan-bodied, bare-winged males to obtain an F2 generation. A.) What phenotypes would be expected in the F2 offspring? B.) If 1000 F2 offspring are obtained, how many flies of each phenotype are expected? ___ wild-type : ____ tan : ___ bare : ____ tan, bare (Remember the two genes are 15 mu apart on the same chromosome. In order to determine how many offspring of each type are produced, you must determine if the F1 females carries both mutations on one chromosome, and wildtype alleles on the other or if she carries one mutation and one wildtype allele on each chromosome.) Enter your answer as the number of flies of each phenotype separated by a colon.
A.) All Phenotypes: - wild-type - tan body - bare wings - tan body, bare wings B.) Ratios are: 425 Wild type: 75 Tan: 75 Bare: 425 Tan/Bare
1. In Drosophila, assume that the gene for scute bristles (s) is located at map position 0.0 and that the gene for ruby eyes (r) is at position 15.0. Both genes are located on the X chromosome and are recessive to their wild-type alleles. A.) A cross is made between scute-bristled females and ruby-eyed males. Phenotypically wild F1 females were then mated to homozygous double mutant males, and 1000 offspring were produced. What phenotypes are expected in these offspring? B.) How many of each phenotype are expected if 1000 offspring were obtained? __ wild type: __ scute : __ ruby : __ scute, ruby (Remember the two genes are 15 mu apart on the same chromosome. In order to determine how many offspring of each type are produced, you must determine if the F1 females carries both mutations on one chromosome, and wildtype alleles on the other or if she carries one mutation and one wildtype allele on each chromosome.) Enter your answer as the number of flies of each phenotype separated by a colon.
A.) All phenotypes: - Wild type females - Wild type males - Scute-bristled females - Scute-bristled males - Ruby-eyed females - Ruby-eyed males - Scute-bristled, ruby-eyed females - Scute-bristled, ruby-eyed males B.) Ratios are: 75 Wild Type: 425 Scute: 425 Ruby: 75 Scute/Ruby
6. Assume that investigators crossed a strain of flies carrying the dominant eye mutation Lobe on the second chromosome with a strain homozygous for the second chromosome recessive mutations smooth abdomen and straw body. The F1 Lobe females were then backcrossed with homozygous smooth abdomen, straw body males, and a F2 generation was obtained (table). A.) Which gene is in the middle? A. straw body B. smooth abdomen C. Lobe B.) What is the coefficient of coincidence?
A.) C. Lobe B.) 0
22. In the fruit fly, Drosophila melanogaster, a spineless (no wing bristles) female fly is mated to a male that is claret (dark eyes) and hairless (no thoracic bristles). Phenotypically wild-type F1 female progeny were mated to fully homozygous (mutant) males, and 1000 progeny were obtained (see table). A.) Which gene is in the middle? A. spineless B. claret C. hairless B.) With respect to the three genes mentioned in the problem, what are the genotypes of the homozygous parents used in making the phenotypically wild F1 heterozygote? Choose two answers, one for each parent. A. cl h+ sp / cl h+ sp B. cl+ h+ sp+ / cl+ h+ sp+ C. cl+ h+ sp / cl+ h+ sp D. cl h sp+ / cl h sp+ E. cl+ h sp / cl+ h sp F. cl h+ sp+ / cl h+ sp+ G. cl+ h sp+ / cl+ h sp+ H. cl h sp / cl h sp C.) What is the map distance between claret and hairless? D.) What is the map distance between hairless and spineless? E.) What is the map distance between claret and spineless? F.) What is the coefficient of coincidence?
A.) C. hairless B.) Answers: C. cl+ h+ sp / cl+ h+ sp D. cl h sp+ / cl h sp+ C.) 30 map units D.) 10 map units E.) 40 map units F.) Coefficient of Confidence = 1
human papilloma virus
Abbreviated HPV and also known as plantar warts; a virus that can infect the bottom of the foot and resembles small black dots, usually in clustered groups.
genome scanning
Allows analysis of DNA for dozens or hundreds of disease alleles
Activation domain
Allows for binding of several transcription factors and other important regulatory proteins
Replication slippage
Also known as slipped-strand mispairing, is a form of mutation that leads to either a trinucleotide or dinucleotide expansion or contraction during DNA replication. A source of spontaneous mutation
reverse transcription PCR
Amplifies sequences corresponding to RNA. Reverse transcriptase is used to convert RNA into complementary DNA, which can then be amplified by the usual polymerase chain reaction
null allele
An allele whose effect is the absence either of normal gene product at the molecular level or of normal function at the phenotypic level.
alternative lengthening of telomeres (ALT)
An alternative pathway that some cancer cells use to replace lost telomere ends by using DNA recombination.
bacterial artificial chromosome (BAC)
An artificial version of a bacterial chromosome that can carry inserts of 100, 000 to 500, 000 base pairs.
DNA helicase
An enzyme that unwinds the DNA double helix during DNA replication
SOS repair system
An error-prone process whereby a bypass polymerase replicates past DNA damage at a stalled replicating fork by inserting nonspecific bases
Intragenic mutation
An existing gene can be randomly modified by changes in its DNA sequence, through various types of error that occur mainly in the process of DNA replication
Avian Influenza
An infectious disease of birds with some strains capable of crossing the species barrier and causing severe illness in humans that come in contact with bird droppings or fluids
Human Genome Project
An international collaborative effort to map and sequence the DNA of the entire human genome.
Hemoglobin
An iron-containing protein in red blood cells that reversibly binds oxygen.
secondary oocyte
An oocyte in which the first meiotic division is completed. The second meiotic division usually stops short of completion unless fertilization occurs.
heterozygous
An organism that has two different alleles for a trait
homozygous
An organism that has two identical alleles for a trait
Phenotype
An organism's physical appearance, or visible traits.
phenotype
An organism's physical appearance, or visible traits.
Myoglobin
An oxygen-storing, pigmented protein in muscle cells.
transgenic animals
Animals that contain genes transferred from other animals, usually from a different species
5-azacytidine
Anti-leukemic drug that is inserted in DNA as a cytosine analog and binds irreversibly to cytosine methyltransferase, depleting this enzyme and causing demethylation of DNA which promotes tumor cell differentiation. Used to treat myelodysplastic syndrome.
1. A recessive gene for red-green color blindness is located on the X chromosome in humans. Assume that a woman with normal vision (her father is color blind) marries a color-blind male. What is the likelihood that this couple's first son will be color blind? A. 75% B. 50% C. 25% D. 0% E. 100%
B. 50%
10. Assume that you are told that a particular organism, Drosophila, has the XO chromosome complement. You are also told that the autosomal complement is a normal 2n. You know that in humans the XO complement is female determining. Would you be correct in assuming that the Drosophila sex for XO is also female? Choose the answer that includes the correct explanation. A. Yes, because sex determination in humans and insects is essentially the same. B. No, the chromosomal basis for sex determination in Drosophila based on the balance between the number of X chromosomes and haploid sets of autosomes. C. No, sex determination in Drosophila is dependent on the presence or absence of the Y chromosome. D. Yes, the presence of an X chromosome determines a female in both organisms. E. No, it takes two X chromosomes to produce a female in humans and a Y chromosome to produce a male in Drosophila.
B. No, the chromosomal basis for sex determination in Drosophila based on the balance between the number of X chromosomes and haploid sets of autosomes.
4. The condition that exists when an organism gains or loses one or more chromosomes but not a complete haploid set is known as ________. A. polyploidy B. aneuploidy C. euploidy D. triploidy E. trisomy
B. aneuploidy
7. To which of the following does the term heteroplasmy refer? A. a circumstance that is homologous to incomplete dominance B. cells with a variable mixture of normal and abnormal organelles C. conditions in which the germ plasm is a mixture of dominant and recessive genes D. various stages of development of mitochondria and chloroplasts E. heterozygous individuals with more than one gene pair involved
B. cells with a variable mixture of normal and abnormal organelles
8. In Drosophila, an individual female fly was observed to be of the XXY chromosome complement (normal autosomal complement) and to have white eyes as contrasted with the normal red eye color of wild type. The female's mother and father had red eyes. The mother, however, was heterozygous for the gene for white eyes. Knowing that white eyes are X-linked and recessive, in which parent and at what stage did nondisjunction occur to produce this XXY, white-eyed female fly? Select all that apply. A. meiosis I in the mother B. meiosis II in the mother C. meiosis I in the father D. meiosis II in the father
B. meiosis II in the mother
17. Approximately one in 5000 humans either have a mitochondrial DNA disorder or are at risk for developing such a disorder. What future approach involving nuclear transplantation might be available to treat mtDNA-based human disorders? A. nuclear activation B. mitochondrial swapping C. mitochondrial activation D. mitochondrial suppression E. nuclear disintegration
B. mitochondrial swapping
13. Direction of shell coiling in Lymnaea peregra is strongly and most directly influenced by_______. A. the phenotype of the mother B. the genotype of the mother C. the genotype of the father D. the phenotype of the father E. the genotype of the embryo itself
B. the genotype of the mother
13. A genomic condition that may be responsible for some forms of fragile X syndrome, as well as Huntington disease, involves ________. A. plasmids inserted into the FMR-1 gene B. various lengths of trinucleotide repeats C. multiple breakpoints fairly evenly dispersed along the X chromosome D. single translocations in the X chromosome E. multiple inversions in the X chromosome
B. various lengths of trinucleotide repeats
Part D - The effect of a fourth gene on fur color In the same mouse species, a fourth unlinked gene (gene P/p) also affects fur color. For mice that are either homozygous dominant (PP) or heterozygous (Pp), the organism's fur color is dictated by the other three genes (A/a, B/b, and C/c). For mice that are homozygous recessive (pp), large patches of the organism's fur are white. This condition is called piebaldism. In a cross between two mice that are heterozygous for agouti, black, color, and piebaldism, what is the probability that offspring will have solid black fur along with large patches of white fur?
Because each gene segregates independently, you need to determine the probability of each genotype independently and then multiply the four probabilities together. The probability of offspring with solid color (aa) is 1/4; the probability of offspring with black fur (BBor Bb) is 3/4; the probability of colored fur (CCor Cc) is 3/4; and the probability of piebald, or white patches (pp), is 1/4. The combined probability is1/4 x 3/4 x 3/4 x 1/4 = 9/256.
Part B - Lethal alleles and epistasis In addition to A and a, the "agouti" gene has a third allele, AY . Here is some information about the inheritance of the AY allele. The AY allele is dominant to both A and a. The homozygous genotype (AYAY ) results in lethality before birth. The heterozygous genotypes (AYA or AYa) result in yellow fur color, regardless of which alleles are present for the B/b gene. (This effect exhibited by the AY allele is known as epistasis--when the expression of one gene masks the expression of a second gene.) In a mating of mice with the genotypes AYaBb x AYaBb , what is the probability that a live-born offspring will have yellow fur?
Because the presence of the AY allele is epistatic to (masks expression of) the B/b gene, the B/b gene does not need to be taken into consideration in this problem. For the AYa x AYa cross, 1/4 of the offspring would have the AYAY genotype, which is lethal before birth. For the live-born offspring, 2/3 would be AYa, and thus have yellow fur.
In mice, agouti fur is a dominant trait resulting in individual hairs having a light band of pigment on an otherwise dark hair shaft. A mouse with agouti fur is shown here, along with a mouse with solid color fur, which is the recessive phenotype (A = agouti; a = solid color). A separate gene, which is not linked to the agouti gene, can result in either a dominant black pigment or a recessive brown pigment (B = black; b = brown). A litter of mice from the mating of two agouti black parents includes offspring with the following fur colors: solid color, black solid color, brown (sometimes called chocolate) agouti black agouti brown (sometimes called cinnamon) What would be the expected frequency of agouti brown offspring in the litter?
Because the two traits are determined by unlinked genes, they assort independently. As a result, you need to use the multiplication rule to calculate the probability of agouti brown offspring (A_ bb) from AaBb parents. The probability of A_offspring is 3/4, and the probability of bb offspring is 1/4. The combined probability is therefore 3/4 x 1/4 = 3/16.
A=Autosomal recessive B X-linked Recessive
Begin a pedigree analysis by determining the inheritance mode of the condition. Is the condition recessive or dominant? Dominant conditions require that an affected individual have at least one affected parent. An affected offspring of two unaffected parents indicates a recessive condition. (This is the case for both conditions A and B.) Is the condition autosomal or X-linked? An affected female offspring of two unaffected parents indicates an autosomal recessive condition. (This is the case for condition A.) If the condition were X-linked, the male parent would be affected. To distinguish between rare X-linked and autosomal recessive conditions, choose the simpler mode for the observed pattern—that is, the mode that requires fewer unrelated individuals to carry a rare allele. In this example, the autosomal recessive mode would require two unrelated horses (II-1 and II-5) to carry a rare recessive allele for condition B, whereas the X-linked recessive mode requires only one. Therefore, the X-linked recessive mode is a better choice for condition B.
Shelterin complex
Binds to the end of the telomere Involved in formation of heterochromatin and T-loop (TRF2)
homozygous recessive
Both alleles (factors) for a trait are the same and recessive (aa)
Hybridization
Breeding technique that involves crossing dissimilar individuals to bring together the best traits of both organisms
In bacteriophages and bacteria, the DNA is almost always organized into circular (closed loops) chromosomes. Phage λ is an exception, maintaining its DNA in a linear chromosome within the viral particle. However, as soon as this DNA is injected into a host cell, it circularizes before replication begins. What advantage exists in replicating circular DNA molecules compared to linear molecules, characteristic of eukaryotic chromosomes?
By having a circular chromosome, there are no free ends to present the problem of linear chromosomes, namely, complete replication of terminal sequences.
12. One form of hemophilia is caused by a sex-linked recessive gene. Assume that a man with hemophilia marries a phenotypically normal woman whose father had hemophilia. What is the probability that their first son will have hemophilia? A. 1/16 B. 1/8 C. 1/2 D. 1/4 E. 3/4
C. 1/2
5. Trisomy 21, or Down syndrome, occurs when there is a normal diploid chromosomal complement but one (extra) chromosome 21. While there is reduced fertility in both sexes, females have higher fertility than males. Van Dyke et al. (1995; Down Syndrome Research and Practice 3(2):6569) summarize data involving children born of Down syndrome individuals. Given the fact that conceptuses with 48 chromosomes (four #21 chromosomes) are not likely to survive early development, what percentage of surviving offspring would be expected to have Down syndrome if both parents have Down syndrome? A. None of the surviving offspring would be expected to have Down syndrome. B. All the children would be expected to have Down syndrome. C. Two-thirds of the surviving offspring would be expected to have Down syndrome. D. One-half of the surviving offspring would be expected to have Down syndrome. E. One-third of the surviving offspring would be expected to have Down syndrome.
C. Two-thirds of the surviving offspring would be expected to have Down syndrome.
14. Through the study of mitochondrial disorders, scientists have suggested a link between the decline of mitochondrial function and aging. What process appears to be involved in this suspected phenomenon? A. recombination among mtDNAs of different mitochondria B. recombination of mtDNA and nuclear DNA C. accumulation of mutations in the mtDNA D. decline of mutations in the nuclear genome E. accumulation of sporadic mutations in the nuclear genome
C. accumulation of mutations in the mtDNA
18. Name two forms of recombination in bacteria. A. auxotrophic and prototrophic B. lytic and lysogenic C. conjugation and transduction D. insertion and replication E. mixed and generalized
C. conjugation and transduction
16. Forms of inheritance that do not follow typical Mendelian patterns and that appear to be more influenced by the parent contributing the most cytoplasm to the embryo are grouped under the general heading of ________. A. neo-Mendelian inheritance B. sex-linked inheritance C. extrachromosomal inheritance D. dominance and/or recessiveness E. suppressive inheritance
C. extrachromosomal inheritance
13. Assume that a cross is made between AaBb and aabb plants and that the offspring fall into approximately equal numbers of the following groups: AaBb, Aabb, aaBb, aabb. These results are consistent with the following circumstance: A. hemizygosity. B. incomplete dominance. C. independent assortment. D. alternation of generations. E. complete linkage.
C. independent assortment.
6. The clearing made by bacteriophages in a "lawn" of bacteria on an agar plate is called a ________. A. prophage B. host range C. plaque D. clear zone E. lysogenic zone
C. plaque
14. A bacteriophage that is capable of entering either a lytic or lysogenic cycle is called a(n) ________. A. virulent bacteriophage B. episome C. temperate bacteriophage D. plasmid E. plaque-forming unit
C. temperate bacteriophage
coefficent of coincidence
C= observed DCO/expected DCO
Loss of function mutation
Causes the complete or partial absence of normal function.
meiosis
Cell division that produces reproductive cells in sexually reproducing organisms
centrioles
Cell organelle that aids in cell division in animal cells only
metaphase 2
Centromeres of chromosomes line up randomly at the equator of each cell.
DNA repair
Collective term for the enzymatic processes that correct deleterious changes affecting the continuity or sequence of a DNA molecule.
X-gal
Compound that causes marked bacteria to turn blue.
13. One form of hemophilia is caused by a sex-linked recessive gene. Assume that a man with hemophilia marries a phenotypically normal woman whose father had hemophilia. What is the probability that they will have a daughter with hemophilia? (Note: In this problem, you must include the probability of having a daughter in your computation of the final probability.) A. 1/16 B. 3/4 C. 1/2 D. 1/4 E. 1/8
D. 1/4
10. What is the expression pattern of dominant-negative mutations in petite strains of yeast? A. Expression of mutant mitochondria resembles expression of wild-type mitochondria. B. Expression of wild-type mitochondria is enhanced. C. Mitochondrial membranes become hyperpolarized. D. The function of wild-type mitochondria is suppressed. E. Mitochondria show enhanced capacity of oxidative phosphorylation.
D. The function of wild-type mitochondria is suppressed.
23. What term is applied when two genes fail to assort independently, that is, they tend to segregate together during gamete formation? A. discontinuous inheritance B. dominance and/or recessiveness C. Mendelian inheritance D. linkage E. tetrad analysis
D. linkage
3. Assume that a cross is made between AaBb and aabb plants and that the offspring occur in the following numbers: 106 AaBb, 48 Aabb, 52 aaBb, 94 aabb. These results are consistent with the following circumstance: A. sex-linked inheritance with 30% crossing over. B. linkage with 50% crossing over. C. independent assortment. D. linkage with approximately 33 map units between the two gene loci. E. 100% recombination.
D. linkage with approximately 33 map units between the two gene loci.
1. Bacteriophages engage in two interactive cycles with bacteria. What are these cycles? A. heteroduplex and homoduplex B. insertion and replication C. auxotrophic and prototrophic D. lytic and lysogenic E. negative and positive
D. lytic and lysogenic
2. Temperate phages are those that can enter either the ________ or ________ cycle. A. complementing; competing B. former; nonformer C. functional; nonfunctional D. lytic; lysogenic E. virulent; avirulent
D. lytic and lysogenic
12. One explanation for organelle inheritance is that ________. A. chloroplasts, for example, are completely dependent on the nuclear genome for components B. mitochondria and chloroplasts lack DNA and are therefore dependent on the maternal cytoplasmic contributions C. organelles such as mitochondria are always wild type D. mitochondria and chloroplasts have DNA that is subject to mutation E. None of the answers listed are correct.
D. mitochondria and chloroplasts have DNA that is subject to mutation
Random mutations
DNA changes through rare mistakes as the chromosome replicates
bacterial transduction
DNA transferred from one bacterium to other via virus
DNA replication
DNA unzips into two parts and splits with the cell In it's new home each side of the DNA strand attack to matching nucleotides to create 2 exact copies It is important in puberty and other times of growth as it is the reproducing of your cells
Unscheduled DNA synthesis
Damage to DNA requires cell to manufacture new DNA to compensate for loss or damage
Polygenic
Describes a characteristic that is influenced by many genes
acrocentric
Describes a chromosome whose centromere is placed very close to, but not at, one end.
Phenotypic variation
Differences in appearance or function that are passed from generation to generation
alleles
Different forms of a gene
Erwin Chargaff
Discovered that DNA composition varies, but the amount of adenine is always the same as thymine and the amount of cytosine is always the same as guanine.
Cytokinesis
Division of the cytoplasm during cell division
9. The sex of birds, some insects, and other organisms is determined by a ZW chromosomal arrangement in which the males have like sex chromosomes (ZZ) and females are ZW (similar to XY in humans). Assume that a recessive lethal allele on the Z chromosome causes death of an embryo in birds. What sex ratio would result in the offspring if a cross were made between a male heterozygous for the lethal allele and a normal female? A. 1:1 male to female B. 3:1 male to female C. 4:1 male to female D. 1:2 male to female E. 2:1 male to female
E. 2:1 male to female
2. The condition known as cri-du-chat syndrome in humans has a genetic constitution designated as ________. A. heteroplasmy B. triploidy C. 45, X D. trisomy E. 46, 5p-
E. 46, 5p-
21. Klinefelter syndrome in humans, which leads to underdeveloped testes and sterility, is caused by which chromosomal condition? A. triploidy B. 47, 21+ C. 47, XYY D. 45, X E. 47, XXY
E. 47, XXY
The Protenor mode of sex determination is the ________. A. scheme based on F plasmids inserted into the FMR-1 gene B. scheme based on single translocations in the X chromosome C. XO/YY scheme D. hermaphroditic scheme E. XX/XO scheme
E. XX/XO scheme
14. Based on the classic experiments of Creighton and McClintock with maize, crossing over involves a physical exchange between chromatids. What particular chromosomal characteristic allowed their experiments to succeed? A. three chromosomes with identical structure B. a missing chromosome C. colored bands along the lengths of a chromosome D. an extra chromosome E. a chromosome with a unique cytological marker
E. a chromosome with a unique cytological marker
32. Although the most frequent forms of Down syndrome are caused by a random error, nondisjunction of chromosome 21, Down syndrome occasionally runs in families. The cause of this form of familial Down syndrome is ________. A. a maternal age effect B. an inversion involving chromosome 21 C. too many X chromosomes D. a chromosomal aberration involving chromosome 1 E. a translocation between chromosome 21 and a member of the D chromosome group
E. a translocation between chromosome 21 and a member of the D chromosome group
17. Assume that a man who carries an X-linked gene has children. Assuming normal meiosis and random combination of gametes, the man would pass this gene to ________. A. all of his children B. all of his sons C. half of his sons D. half of his daughters E. all of his daughters
E. all of his daughters
9. Which of the following organelles are involved in the general category of organelle heredity? A. lysosomes and peroxisomes B. factors and episomes C. golgi and rough endoplasmic reticulum D. golgi and nuclei E. mitochondria and chloroplasts
E. mitochondria and chloroplasts
15. The maternal effect in Lymnaea is such that the genotype of the egg determines the direction of shell coiling regardless of the genotype of the offspring. Apparently, the cause of this spectacular maternal effect results from ________. A. genophores present in the egg cytoplasm B. allelic substitution as demonstrated from RNA injection experiments C. the F factor exerting its influence on the centrosome D. colicins "poisoning" one of the cleavage centers E. orientation of the spindle apparatus in early cleavage
E. orientation of the spindle apparatus in early cleavage
X rays
Electromagnetic radiation having a very short wavelength; can penetrate substances such as skin and muscle.
restriction enzymes
Enzyme that cuts DNA at a specific sequence of nucleotides
Photoreactivation repair
Enzymes called photolyases use light energy to break the extra bonds in a pyrimidine dimer Enables UV-damaged fungi to recover from exposure to sunlight Humans do not have this type of repair
DNA polymerases
Enzymes that add complementary nucleotides to each of the original strands
16. T/F Normally in humans, all the sons of a male showing a sex-linked phenotype will inherit the trait.
False
17. T/F An individual with Patau syndrome would be called a triploid.
False
17. T/F The cross GE/ge×ge/ge produces the following progeny: GE/ge 404; ge/ge 396; gE/ge 97; Ge/ge 103. From these data one can conclude that the G and E loci assort independently.
False
19. T/F To produce recombinants in bacteria, one crossover is better than two.
False
2. T/F Dosage compensation is accomplished in humans by inactivation of the Y chromosome.
False
2. T/F Exchanges occur between homologous chromosomes, but never between sister chromatids.
False
20. T/F In Drosophila, the female is the heterogametic sex.
False
21. T/F Familial Down syndrome can be caused by a translocation between chromosomes 1 and 14.
False
21. T/F Linkage (viewed from results of typical crosses) always occurs when two loci are on the same chromosome.
False
24. T/F Individuals with familial Down syndrome are trisomic and have 47 chromosomes.
False
28. T/F Inversions suppress crossing over by providing a chemical imbalance because of breakpoints within certain genes.
False
30. T/F Assume that an organism has a haploid chromosome number of 7. There would be 14 chromosomes in a monoploid individual of that species.
False
31. T/F An autotriploid may arise when three sperm cells are involved in fertilization of a single egg.
False
7. T/F In general, inversion and translocation heterozygotes are as fertile as organisms whose chromosomes are in the standard arrangement.
False
7. T/F In humans, the male is the homogametic sex.
False
8. T/F Lysogeny is a process that occurs during transformation and conjugation.
False
8. T/F Translocations may be pericentric or paracentric.
False
9. T/F Inversions and translocations are without evolutionary significance.
False
9. T/F Restriction fragment length polymorphisms (RFLPs), microsatellites, and single-nucleotide polymorphisms (SNPs) were used by Morgan and Sturtevant to discover linkage in Drosophila.
False
Crossing over during prophase I of meiosis occurs between alleles on sister chromatids
False (Crossing over during meiosis occurs between alleles on nonsister chromatids. )
To construct a mapping cross of linked genes, it is important that the genotypes of some of the gametes produced by the heterozygote can be deduced by examining the phenotypes of the progeny. True False
False (To construct a mapping cross of linked genes, it is important that the genotypes of all of the gametes produced by the heterozygote can be deduced by examining the phenotypes of the progeny, taking into consideration that the homozygote produced only recessive gametes. Gametes and their genotypes can never be observed directly.)
ABO blood groups
Genetically determined classes of human blood that are based on the presence or absence of carbohydrates A and B on the surface of red blood cells. The ABO blood group phenotypes, also called blood types, are A, B, AB, and O.
gardasil
HPV vaccine
Eye color in Drosophila is an X-linked trait. White eyes is recessive to red eyes. If a Drosophila male has white eyes, which of the following must also be true? -All his male siblings from the same parents must also have white eyes. -His mother had at least one white allele. -Some of his female siblings from the same mating must also have white eyes. -His father must also have had white eyes.
His mother had at least one white allele. (Because this male had white eyes, he must have inherited a white allele from his mother.)
meiosis 1
Homologous chromosomes separate
A human female with Turner syndrome (47,X) also expresses the X-linked trait hemophilia, as did her father. Which of her parents underwent nondisjunction during meiosis, giving rise to the gamete responsible for the syndrome?
If the father had hemophilia, it is likely that the Turner syndrome individual inherited theX chromosome from the father and no sex chromosome from the mother. If nondisjunction occurred in the mother, during either meiosis I or meiosis II, an egg with no X chromosome can be the result.
Would an experiment similar to that performed by Hershey and Chase work if the basic design were applied to the phenomenon of transformation? Explain why or why not.
In an in vitro experiment like that of Avery et al., in theory, the general design would be appropriate: in that some substance, if labeled, would show up in the progeny of transformed bacteria. However, since the amount of transforming DNA is extremely small compared with the genomic DNA of the recipient bacterium and its progeny, it would be technically difficult to assay for the labeled nucleic acid. In addition, it would be necessary to know that the small stretch of DNA that caused the genetic transformation was actually labeled.
Preimplantation Genetic Diagnosis (PGD)
In assisted reproductive technology, the determination of genetic abnormalities in the embryo before it is transferred to the uterus
Mendel's 9:3:3:1 dihybrid ratio
In every F1 x F1 fertilization event, each zygote has an equal probability of receiving one of the four combinations from each parent.; an ideal ratio based on probability events involving segregation, independent assortment, and random fertilization.
Which of the following statements about three linked genes that are spaced very close together along a chromosome is most likely to be true? -Interference will be a significant factor in the number of crossovers observed. -Interference and the number of hidden double crossovers will significantly affect the number of crossovers observed. -The number of hidden double crossovers will be very large. -Interference is not likely to affect the number of crossovers observed.
Interference will be a significant factor in the number of crossovers observed. ( Interference effects are more likely when crossovers are confined to a small region.)
Catabolism
Metabolic pathways that break down molecules, releasing energy.
mtDNA
Mitochondrial DNA. Evolve rapidly. Maternally inherited only so trace the maternal line of inheritance through time
Somatic mosaicism
Mutation arises from mitotic errors after fertilization and propagates through multiple tissues or organs
Suppressor mutation
Mutation that hides or suppresses the effect of another mutation at a site that is distinct from the site of the original mutation
Frameshift mutation
Mutation that involves the insertion or deletion of a nucleotide in the DNA sequence
Somatic mutations
Mutations that occur in body cells, aren't passed to offspring, and don't affect the gametes
Gene mutations
Mutations that produce changes in a single gene
X linked mutations
Mutations within genes located on the X chromosome
Trinucleotide repeat sequences
Normal individuals may have fewer than 30 repeats. Over 20 disorders exhibit over 200 repeats Fragile-X syndrome Huntington Disease (HD) Myotonic dystrophy (MD)
H substance
One or two terminal sugars are added O blood types (ii) only have the H substance protruding from red blood cells
Intergenic mutation
One that is in a non-coding region These mutations are thus likely to be neutral, but there are many exceptions as there are a great many functional non-coding regions in the genome
Transversion
Purine to pyrimidine Pyrimidine to purine
Ribonucleotides
RNA nucleotides
In the absence of the repressor-operator interaction, _________ transcribes the structural genes, and the enzymes necessary for lactose metabolism are produced.
RNA polymerase
Transposable element
Segment of DNA that can move spontaneously within or between chromosomes.
interrupted mating technique
Separates conjugating bacteria so that only recipient cells are observed; demonstrated that certain genes are transferred and recombined sooner than others
segregation
Separation of alleles during gamete formation
DNA markers
Sequence variations among individuals in a specific region of DNA that are detected by molecular analysis of the DNA and can be used in genetic analysis.
Core promoters
Sequences within the promoter essential for transcription initiation
After salivary gland cells from Drosophila are isolated and cultured in the presence of radioactive thymidylic acid, autoradiography is performed, revealing polytene chromosomes. Predict the distribution of the grains along the chromosomes.
Since polytene chromosomes are formed by multiple rounds of DNA replication without strand separation, you would expect grains along the entire length of each polytene chromosome.
German measles results from an infection of the rubella virus, which can cause a multitude of health problems in newborns. What conclusions can you reach from a viral nucleic acid analysis that reveals an A + G/U + C ratio of 1.13?
Since uracil is present rather than thymine, the genetic material is RNA. Assuming that the value of 1.13 is statistically different from 1.00, purines outnumber pyrimidines; therefore, the nucleic acid is single stranded. Overall, one can conclude that rubella is a single-stranded RNA virus.
origin of replication
Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.
microtubules and microfilaments
Small, thin proteins that help support and give structure to a cell. A cells cytoskeleton.
DNA storage
Store the isolated DNA in TE buffer
Alkylating agents
Synthetic chemicals containing alkyl groups that attack DNA, causing strand breaks
CVNs could be associated with
T1 diabetes, cardiovascular disease
TBP
TATA binding protein
TAFs
TBP associated factors
BRE
TFIIB recognition element
Fluorescence in situ hybridization (FISH)
Technique used to detect a given nucleotide sequence within intact cells on a microscope slide
Ames test
Test in which special strains of bacteria are used to evaluate the potential of chemicals to cause cancer.
DNA methylation
The addition of methyl groups to bases of DNA after DNA synthesis; may serve as a long-term control of gene expression.
Postranscriptional modification
The additions of a cap and tail to an RNA molecule, and RNA splicing so that the mRNA is ready for translation
Haploinsufficiency
The appearance of a mutant phenotype in an individual cell or organism that is heterozygous for a normally recessive trait
Mismatch repair
The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides.
For linked genes A, B, and C, the fraction of single crossovers for genes A and B is 0.1, the fraction of single crossovers for genes B and C is 0.3, and the fraction of double crossovers is 0.03. Which of the following statements is true? -The distances between A and B and B and C are approximately equal. -Interference has affected the number of double crossovers. -The distance between A and B is greater than the distance between B and C. -The distance between A and B is less than the distance between B and C.
The distance between A and B is less than the distance between B and C. (The frequency of crossover events decreases as the distance between genes decreases. )
chance deviation
The effect of random events on frequency of genotypes and phenotypes
quaternary structure
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
Monogenic
The hereditary passing on of traits determined by a single gene
ij x kL A_XBXb x A_XBy IV-3 Show diseas IV4=? 1 ProBBlt IV4 in Condt A=1/36 2----------------------------B=1/2
The new information allows you to be certain about two requirements that previously could only be assigned probabilities: You now know that individual III-4 has the genotype X B X b , meaning that she received an X b chromosome from II-4. You also now know that individual IV-4 is a male, meaning that he received a Y chromosome from III-5. This new information changes the probability calculations because you know that these two requirements have been met (thus, they have a probability of one -- certainty). The only requirement that is unchanged is that of III-4 passing on an X b chromosome to IV-4 -- the probability is still 1/2.
log phase
The period of exponential growth of bacterial population.
fusion protein
The protein product of a gene created by the fusion of two distinct genes or portions of genes.
Absorption spectrum
The range of a pigment's ability to absorb various wavelengths of light.
What is the effect of a rare double crossover (a) within a chromosome segment that is heterozygous for a pericentric inversion; and (b) within a segment that is heterozygous for a paracentric inversion?
The rare double crossovers within the boundaries of a paracentric or pericentric inversion produce only minor departures from the standard chromosomal arrangement as long as the crossovers involve the same two chromatids.
cell cycle
The regular sequence of growth and division that cells undergo
Deamination
The removal of an amino group from an organism, particularly from an amino acid
prometaphase
The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes.
gene amplification
The selective synthesis of DNA, which results in multiple copies of a single gene, thereby enhancing expression.
cytosol
The semifluid portion of the cytoplasm.
Starch gel electrophoresis
The separation of a mixture of electrically charged molecules in an electric field.
Transcription start site
The site at which the first RNA nucleotide is added; also known as the +1 site.
Minor groove
The smaller of two unequal grooves on the outside of a DNA duplex.
When two plants belonging to the same genus but different species are crossed, the F1 hybrid is more viable and has more ornate flowers. Unfortunately, this hybrid is sterile and can only be propagated by vegetative cuttings. Explain the sterility of the hybrid and what would have to occur for the sterility of this hybrid to be reversed.
The sterility of interspecific hybrids is often caused by a high proportion of univalents in meiosis I. As such, viable gametes are rare and the likelihood of two such gametes "meeting" is remote. Even if partial homology of chromosomes allows some pairing, sterility is usually the rule. The horticulturist may attempt to reverse the sterility by treating the sterile hybrid with colchicine. Such a treatment, if successful, may double the chromosome number, and each chromosome would then have a homolog with which to pair during meiosis.
bivalent
The structure formed by the pair of homologous chromosomes during crossing over. Also called a tetrad because it consists of four chromatids.
nutrigenomics
The study of how nutrition interacts with specific genes to influence a person's health
s phase
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
middle lamella
The thin film between the cell walls of adjacent plant cells.
Exon shuffling
The variation in the patterns by which RNA may produce diverse sets of exons from a single gene.
Transmission
The way a microbial organism moves from one host to another
11. T/F Positive interference occurs when a crossover in one region of a chromosome reduces crossovers in nearby regions.
True
12. T/F A symbiotic relationship between a phage and a bacterium apparently occurs in the process of lysogeny.
True
12. T/F In Drosophila melanogaster (2n = 8), a fly with seven chromosomes could be called a haplo-IV.
True
14. T/F An individual with Turner Syndrome has no Barr bodies.
True
14. T/F Gene duplications provide an explanation for the origin of gene families.
True
17. T/F Viral mutations and variants are often categorized by changes in host range and/or plaque morphology.
True
18. T/F A pericentric inversion includes the centromere.
True
18. T/F An individual with Klinefelter syndrome generally has one Barr body.
True
19. T/F Chorionic villus sampling (CVS) is sometimes preferred to amniocentesis because results can be provided earlier in the pregnancy.
True
2. T/F It appears as if the direction of shell coiling in Lymnaea peregra is influenced by the orientation of the first cleavage division.
True
20. T/F An expected meiotic pairing configuration in a triploid would be a trivalent.
True
22. T/F Familial Down syndrome is caused by a translocation involving chromosome 21.
True
23. T/F rDNA in eukaryotes is typically redundant.
True
24. T/F Normally in humans, all the sons of a female homozygous for a sex-linked recessive gene will inherit that trait.
True
25. T/F A position effect occurs when a gene's expression is altered by virtue of a change in its position. One might expect position effects to occur with inversions and translocations.
True
27. T/F Assume that a species has a diploid chromosome number of 24. The term applied to an individual with 36 chromosomes would be triploid.
True
29. T/F The chromosomal aberration that causes cri du chat syndrome can be referred to as a segmental deletion.
True
3. T/F An example of organelle heredity involves pigmentation in Mirabilis jalapa.
True
3. T/F Assume that an organism has a diploid chromosome number of 14. There would be 28 chromosomes in a tetraploid.
True
3. T/F Cotransduction of genes is an indication that the genes are linked.
True
4. T/F An Hfr cell can initiate chromosome transfer from one E. coli to another.
True
4. T/F If two gene loci are on nonhomologous chromosomes, genes at these loci are expected to assort independently.
True
5. T/F A typical XX human female has one Barr body per cell.
True
6. T/F A paracentric inversion is one whose breakpoints do not flank the centromere.
True
6. T/F It is safe to say that a maternal effect is caused by the genotype, not the phenotype, of the parent producing the egg.
True
8. T/F Direction of shell coiling in Lymnaea peregra is influenced by a maternal effect.
True
8. T/F The cross GE/ge×ge/ge produces the following progeny: GE/ge 404; ge/ge 396; gE/ge 97; Ge/ge 103. From these data one can conclude that there are 20 map units between the G and E loci.
True
9. T/F Lysogeny is most likely associated with transduction.
True
In a gene mapping cross, the term Frac NCO refers to the fraction of gametes that have the same genotypes as the parental gametes. True False
True ( Frac NCO refers to the fraction of gametes that have not undergone crossing over and thus their genotypes reflect those of the parental gametes)
For X-linked traits in Drosophila, the male phenotype is determined by the maternally inherited allele.
True (Males inherit only one X chromosome. That chromosome is contributed by the female parent.)
UGG
Tryptophan (Trp)
Double stranded break repair
Two major pathways, non-homologous end joining and homologous recombination, are used to repair double-stranded breaks in DNA (that is, when an entire chromosome splits into two pieces).
Pics from 8 ii4a=Aa, 4b=XBXb ii5c-A_, 5d-XBY II7e-A_, 7f-XBY ii8g-AA, 8h-XBXB III4i-A_, 4J-XBX_ III5k-A_ , 5I-XBY
Use these rules when assigning genotypes for X-linked recessive conditions: Males have only one allele for every X-linked gene. Affected males have the recessive allele, and non-affected males have the dominant (wild-type) allele. Unaffected females with affected sons are heterozygous (carriers). Unaffected females with affected fathers are heterozygous. All sons of affected females will be affected. All daughters of affected females will be heterozygous. Use these rules when assigning genotypes for autosomal recessive conditions: Unaffected parents with an affected offspring are both heterozygous. Unaffected offspring of one affected parent will be heterozygous. Unaffected offspring of two heterozygous parents may be homozygous dominant or heterozygous.
Northern blot analysis
Used to determine whether gene is actively being expressed in given cell or tissue Used to study patterns of gene expression in embryonic tissues, cancer, and genetic disorders
RNA viruses
Usually single stranded, may be double stranded, may be segmented into separate RNA pieces
Single nucleotide polymorphisms
Variation in a DNA sequence occurring when a single nucleotide in a genome is altered
tobacco mosaic virus (TMV)
Virus that affects many species of plants e.g. tomatoes Symptoms: a mosaic pattern on the leaves - parts of the leaves become discoloured The discolouration prevents the plant from photosynthesising as well, thus the virus affects growth
Single cell sequencing
We can now sequence the genome from a single cell Involves isolating DNA from single cell and executing whole genome amplification Produces sufficient DNA to be sequenced
Short interspersed elements
What are SINEs
Complementation
When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The nonmutated virus complements the mutated one by making functional protein that serves both viruses.
complementation
When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The nonmutated virus complements the mutated one by making functional protein that serves both viruses.
Part A - Experimental technique: Reciprocal crosses When Gregor Mendel conducted his genetic experiments with pea plants, he observed that a trait's inheritance pattern was the same regardless of whether the trait was inherited from the maternal or paternal parent. Mendel made these observations by carrying out reciprocal crosses: For example, he first crossed a female plant homozygous for yellow seeds with a male plant homozygous for green seeds, and then crossed a female plant homozygous for green seeds with a male plant homozygous for yellow seeds. Unlike Mendel, however, Morgan obtained very different results when he carried out reciprocal crosses involving eye color in his fruit flies. The diagram below shows Morgan's reciprocal cross: He first crossed a homozygous red-eyed female with a white-eyed male, and then crossed a homozygous white-eyed female with a red-eyed male.
When Morgan crossed a homozygous red-eyed female with a white-eyed male, all of the offspring had red eyes. However, in the reciprocal cross (homozygous white-eyed female with a red-eyed male), all of the females had red eyes while all of the males had white eyes.
Part B - Experimental results: The F2 generation In one of Morgan's experiments, he crossed his newly discovered white-eyed male with a red-eyed female. (Note that all of the females at that time were homozygous for red eyes because the allele for white eyes had not yet propagated through Morgan's flies.) All of the F1 flies produced by this cross (both males and females) had red eyes.
When a homozygous red-eyed female was crossed with the white-eyed male (w+w+ × wY), the resulting F1 females were w+w and the F1 males were w+ Y. Crossing the F1 males and F1 females would yield these results: All the F2 females would have red eyes, although some would be homozygous (w+w+ ) and others would be heterozygous (w+w). Half the F2 males would have red eyes (w+ Y), and half would have white eyes (wY).
Autosomal mutations
Within genes located on the autosomes
the egg surface is equally receptive to ________ sperm
X and Y
A new phenotype results from
a change in functional activity of the cellular product specified by that gene.
phosphodiester bond
a chemical bond of the kind joining successive sugar molecules in a polynucleotide.
nucleolar organizer region
a chromosomal region containing the genes for rRNA; most often found in physical association with the nucleolus
inversion
a chromosome rearrangement in which a segment of a chromosome is reversed end to end
shugoshin
a class of proteins involved in maintaining cohesion of the centromeres of sister chromatids during mitosis and meiosis.
Enhancer RNA
a class of relatively short non-coding RNA molecules (50-2000 nucleotides) transcribed from the DNA sequence of enhancer regions.
plaque
a clearing in a bacterial lawn resulting from lysis by phages
CRISPR
a collection of DNA sequences that tells Cas9 exactly where to cut
agricultural biotechnology
a collection of scientific techniques, including genetic engineering, that are used to create, improve,or modify plants, animals, and microorganisms.
5-methyl cytosine
a component of DNA that has been modified by addition of a methyl group
dimer
a compound whose molecules are composed of two identical monomers
Temperature sensitive mutation
a conditional mutation that produces a mutant phenotype at one temperature range and a wild-type phenotype at another
clon
a culture of cells derived from a single cell
translesion synthesis
a damage-tolerance mechanism in eukaryotes that uses bypass polymerases to replicate DNA past a site of damage
segmental deletion
a deletion of a small, terminal portion of a chromosome
inversion heterozygote
a diploid individual that carries one normal chromosome and a homologous chromosome with an inversion
Fragile X Syndrome
a disorder produced by injury to a gene on the X chromosome, producing mild to moderate mental retardation
Autism Spectrum Disorder (ASD)
a disorder that appears in childhood and is marked by significant deficiencies in communication and social interaction, and by rigidly fixated interests and repetitive behaviors
dispersive replication
a disproved model of DNA synthesis suggesting more or less random interspersion of parental and new segments in daughter DNA molecules
Chromosome territory
a distinct, nonoverlapping area where each chromosome is located within the cell nucleus of eukaryotic cells
Autotriploids
a failure of all chromosomes to segregate during meiotic divisions can produce a diploid gamete
Genomic stability
a feature of every organism to preserve and faithfully transmit the genetic material from generation to generation or from one somatic cell to another
D-DNA
a form of DNA
trinucleotide repeats
a form of mutation associated with the expansion in copy number of a nucleotide triplet in or near a gene
Beta globin gene
a gene belonging to a family of closely related genes that encode a globin polypeptide that is part of hemoglobin
MLG1
a gene encoding 2/3 extracellular mixed-Llnked glucanases
hemizygous
a gene present on the X chromosome that is expressed in males in both the recessive and dominant condition
MT2A gen
a gene that encodes the protein Metallothionein-2
Phenylketonuria
a genetic disorder in which the essential digestive enzyme phenylalanine hydroxylase is missing
Sickle cell anemia
a genetic disorder that causes abnormal hemoglobin, resulting in some red blood cells assuming an abnormal sickle shape
sickle cell anemia
a genetic disorder that causes abnormal hemoglobin, resulting in some red blood cells assuming an abnormal sickle shape
Ribosomal proteins
a group of proteins that along with rRNA molecules make up the ribosomes of prokaryotes and eukaryotes
ribosomal proteins
a group of proteins that along with rRNA molecules make up the ribosomes of prokaryotes and eukaryotes
gene editing
a highly precise type of genetic engineering in which DNA is inserted, deleted or replaced in the genome of an organism using engineered nucleases
agarose gel
a jelly-like slab used to separate molecules on the basis of molecular weight
DNA ligase
a linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain.
X-inactive specific transcript (XIST)
a locus in the X chromosome inactivation center that controls inactivation of the X chromosome in mammalian females
spermatozoa
a mature sperm cell
genic balance theory
a mechanism explaining sex-determination in Drosophila
Chromatin remodeling
a mechanism for epigenetic gene regulation by the alteration of chromatin structure.
Intrinsic termination
a mechanism in prokaryotes that involves the formation of a G-C rich hairpin loop followed by 6 or more U's in a RNA and results in the termination of transcription and release of the RNA transcript.
RNA sequencing
a method of analyzing large sets of RNAs that involves making cDNAs and sequencing them
prototroph
a microorganism that does not require any organic growth factors
auxotroph
a microorganism that requires an organic growth factor
nucleoside monophosphate (NMP)
a monomer of the growing nucleic acids; hydrolysis of two phosphates from NTP produces a NMP and a pyrophosphate plus released energy
recognition complex (ORC)
a multi-subunit DNA binding complex (6 subunits) that binds in all eukaryotes and archaea in an ATP-dependent manner to origins of replication
Mediator
a multiprotein complex that functions as a transcriptional coactivator in all eukaryotes
Nutritional mutation
a mutation affecting a synthetic pathway for a vital compound, such as an amino acid or vitamin; microorganisms with a nutritional mutation must be grown on medium that supplies the missing nutrient.
heterogeneous trait
a mutation at any one of a number of genes can give rise to the same phenotype
neutral mutation
a mutation that has no effect on survival or reproduction
loss-of-function mutation
a mutation that in turn makes the gene non functional
incomplete dominance
a pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a blending of the parental traits.
X inactivation center (Xic)
a region on the X chromosome where inactivation begins
Trans acting factors
a regulatory protein that binds to a regulatory element in the DNA and exerts a trans effect
trans acting factors
a regulatory protein that binds to a regulatory element in the DNA and exerts a trans effect
promoter region
a regulatory region a short distance upstream from the 5' end of a transcription start site that acts as the binding site for RNA polymerase. A region of DNA to which RNA polymerase binds in order to initiate transcription.
EcoRI
a restriction enzyme that specifically cuts DNA with sequence GAATTC and creates sticky ends
International Human Epigenome Consortium
a scientific organization, founded in 2010, that helps to coordinate global efforts in the field of Epigenomics
cistron
a section of a DNA or RNA molecule that codes for a specific polypeptide in protein synthesis
bacterial transformation
ability of bacteria to alter their genetic makeup by uptaking foreign DNA from another bacterial cell and incorporating it into their own
Epimutation
abnormal transcriptional repression of active genes and/or abnormal activation of usually repressed genes caused by errors in epigenetic gene repression
guanosine triphosphate (GTP)
an energy transfer molecule similar to ATP that releases free energy with the hydrolysis of its terminal phosphate group
RNA replicase
an enzyme that can produce RNA from an RNA template
beta-galactosidase
an enzyme that catalyzes the conversion of lactose into monosaccharides
DNA Polymerase V
an enzyme that catalyzes the formation of the DNA molecule.
diploid organism
an organism that has two copies of its genome it each cell. The paired genomes are said to be homologous.
cellular reproduction
an original cell divides and produces two identical daughter cells
all sons recieve this from their mother
an x; the mothers are homozygous
DNA fingerprinting
analysis of sections of DNA that have little or no known function, but vary widely from one individual to another, in order to identify individuals
Kinetochores
anchor on the sister chromatid that attaches to the fiber that pulls the sister chromatids apart.
The most accurate maps are constructed from experiments in which genes
are relatively close together
Bacterial mRNAs
are transcribed and translated simultaneously.
Haplotype
area of linked genetic variations in the human genome
fragile sites
areas on chromosomes that develop distinctive breaks or gaps when cells are cultured
how to determine gene order
arrangement of alleles observed DCO phenotypes
prereplication complex (pre-RC)
assembles at replication origins
chi square x^2 analysis
assesses how closely the observed frequencies fit the pattern of the expected frequencies and is referred to as a "goodness-of-fit" test
single-stranded binding proteins (SSBs)
bind to each side of the DNA ladder keeping it from bonding back together during DNA replication
Immunoglobulins
bind with specific antigens in the antigen-antibody response
cAMP-CAP complex
binding of cAMP to CAP. binds to CAP site. increases rate of transcription.
double cross overs
can occur between two homologs counteracting each other - can lead to us underestitmating the distance between genes
Regulatory mechanisms
can operate at various stages after transcription
regulatory mechanisms
can operate at various stages after transcription
Uncontrolled cellular proliferation
cancer is unchecked cell division
variation by mutation
capacity to serve as a source of variation among individuals
Chromosome conformation capture
captures interactions between one locus and all other genomic loci. It involves a second ligation step, to create self-circularized DNA fragments, which are used to perform inverse PCR
loss of function mutation
causes a complete or partial loss of function
gain of function mutation
causes the appearance of a new trait or function or causes the appearance of a trait in inappropriate tissue or at an inappropriate time
diploid number
cell condition in which two of each type of chromosome are present
mitosis
cell division in which the nucleus divides into nuclei containing the same number of chromosomes
Pre-initiation complex
cluster of transcription factors and other proteins that recruit RNA polymerase II for transcription of a DNA template
Chromatin
clusters of DNA, RNA, and proteins in the nucleus of a cell
Polyploidy
condition in which an organism has extra sets of chromosomes
mosaicism
condition in which regions of tissue within a single individual have different chromosome constitutions; some areas of the body express only the maternally derived alleles, and others express only the paternally derived alleles.
F+ cells
conjugation E. coli, sex factor (F: fertility) Cells serving as donors of parts of their chromosomes.
Wolffian and Mullerian ducts
connect the gonads to the body wall
sibship line
connects all siblings
DNA topoisomerases
create a nick in the helix to relieve supercoils created during replication
genetically modified organisms
crops that carry new traits that have been inserted through advanced genetic engineering methods
testcross
cross between an organism with an unknown genotype and an organism with a recessive phenotype
Hybridization
crossing dissimilar individuals to bring together the best of both organisms
intragenic recombination
crossing over within a gene
subcloning
cutting of DNA into smaller fragments in order to separately clone subsections of the sequence
Ribosome
cytoplasmic organelles at which proteins are synthesized
lod score method
demonstrates linkage with genes of great distance apart
dNTPs
deoxynucleotide triphosphates
D-DNA
deoxyribose DNA
Position effect
dependence of the expression of a gene on the gene's location in the genome
position effect
dependence of the expression of a gene on the gene's location in the genome
Core promoter elements
determine the accurate initiation of transcription by RNA Polymerase II
Triplet binding assay
determines specific codon assignments in which ribosomes bind to a single codon of three nucleotides, and the complementary amino acid-charged tRNA will be able to bind .
epigenesis
development resulting from ongoing, bidirectional exchanges between heredity and all levels of the environment
restriction map
diagram that shows the lengths of fragments between restriction sites in the strand of DNA
forked-line method
diagram using product law of probabilities to predict genotypic and phenotypic frequencies
ddNTP
dideoxyribonucleoside triphosphate lack a hydroxyl group (OH) at 2' and 3'
copy number variation (CNV)
difference among individual organisms in the number of copies of any large DNA sequence (larger than 1000 bp).
genetic variation
differences among individuals in the composition of their genes or other DNA segments
sexual dimorphism
differences in physical characteristics between males and females of the same species.
Isoaccepting tRNAs
different tRNAs that accept the same amino acid but have different anticodons
alleles
different versions of a gene
secondary spermatocytes
differentiate into spermatids (immature gametes)
kinases
digest fibrin clots
Jacob and Monod
discovered how DNA controls protein synthesis in a cell
Alzheimer disease
disease of structural changes in the brain resulting in an irreversible deterioration that progresses from forgetfulness and disorientation to loss of all intellectual functions, total disability, and death
Sickle cell trait
disorder in which individuals show signs of mild anemia only when they are seriously deprived of oxygen; occurs in individuals who have one dominant allele for normal blood cells and one recessive sickle-cell allele
heteromorphic chromosomes
dissimilar, such as XY in mammals that characterize one sex or the other in a wide range of species "sex chromosomes"
Codominant inheritance is characterized by
distinct expression of the gene products of both alleles
Karyokinesis
division of the nucleus
in drosophila the y chromosome ______ play a role in sex determination
doesn't
uppercase letter
dominant allele
segregation
during the formation of gametes, the paired unit factors segregate randomly so that each gamete gets one or the other with equal likelihood.
hyperchromic shift
during unwinding, the viscosity of DNA decreases and UV absorption increases
Epimutations
dysfunctional epigenetic changes
result of meiosis
each haploid cell receives 1 member of each homologous pairs of chromosomes
nucleoside triphosphate
each nucleotide that is added to a growing DNA strand
Unambiguous
each possible codon can code for one amino acid only
tetranucleotide hypothesis
early theory of DNA structure proposing that the molecule is composed of repeating units, each consisting of the four nucleotides represented by adenine, thymine, cytosine, and guanine
mitochondrial swapping
egg from mother with defect egg from normal female - insertion of nucleus from donor
Reporter genes
encode proteins that are easy to detect and assay
lacZ
encodes B-galactosidase
why is mtDNA important?
encodes for ribosomal polypeptides essential to oxidative respiration
col plasmid
encodes one or more proteins that are highly toxic to bacterial strains that do not harbor the same plasmid
TERT gene
encodes telomerase revere transcirptase which is for telomeres in DNA replication
mutations can be advantageous...
enhancing their fitness
glycolytic pathway
enzymatically converts glucose through several steps (9)into pyruvic acid and provides a small amount of ATP
Pol alpha enzyme
enzyme complex found in eukaryotes that is involved in initiation of DNA replication
tryptophan synthetase
enzyme encoded by the trp genes; made up of 5 different proteins
Testis Determining Factor (TDF)
enzyme produced by "switch" on Male chromosome that leads to the development of gender
RNA polymerase
enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
Polynucleotide phosphorylase
enzyme that catalyzes production of synthetic mRNAs
ribonuclease (RNase).
enzyme that degrades RNA
DNA Polymerase II
enzyme that proofreads the daughter strand of replicated DNA and corrects any base pairing errors
studies of monosomic and trisomic disorders help to increase understanding of
genetic balance essential for normal develipment
Transfection
genetic engineering, or transformation, of mammalian cell lines
negative control
genetic expression occurs unless it is shut off by some form of a regulator molecule
homologs carry
genetic info for more than one trait
genotype
genetic makeup of an organism
gene knockout
genetic manipulation in which one or more of an organism's genes are prevented from being expressed
the process of ______ _______ in bacteria provided the basis for the development of ________ ________ methodology
genetic recombination chromosome mapping
clones
genetically identical cells or individuals.
hot spots
genome regions where there are mutations at high frequency.
GWAS
genome wide association studies
CIMP
genomic instability phenotype with a high amount of promoter methylation
polytene chromosomes
giant chromosomes consisting of many identical chromatids lying in parallel register
single-crystal X-ray analysis
gives higher resolution and greater structural detail
Tubulin
globular protein subunit forming the hollow cylinder of microtubules
HDACs
histone deacetylases are enzymes that catalyze the removal of acetyl functional groups from the lysine residues of both histone and nonhistone proteins.
HDACs
histone deacetylases remove acetyl groups from histones
H-NS proteins
histone-like nucleoid-structuring bacterial protein play a role in the formation of nucleoid structure and affect gene expression under certain conditions
HU proteins
histone-like protein acts similarly to a histone by inducing negative supercoiling into circular DNA with the assistance of topoisomerase
eukaryotic proteins
histones and non-histones
cohesin
holds sister chromatids together
in diploid organisms chromosomes exist in
homologous pairs
gene interaction
interaction between genes at different loci that affect the same characteristic
adaptation hypothesis
interaction of bacteriophage and bacterium is essential to acquisition of immunity to phage
interphase
interval between divisions
cyclic adenosine monophosphate (cAMP)
intracellular second messenger that mediates hormone action
Kearns-Sayre Syndrome (KSS)
involves paralysis of the eye muscles, degeneration of the retina, heart disease, hearing loss, diabetes, and kidney failure.
Fingerprinting
involves the enzymatic digestion of the protein into peptide fragments
in situ molecular hybridization
involves the molecular hybridization between an isolated fraction of radioactively labeled DNA or RNA probes and the DNA contained in the chromosomes of a cytological preparation
mutant allele
is a variant that arises when a gene undergoes a mutation, or change.
lactose metabolism
lactose in environment causes E coli to express the genes involved in the absorption and metabolism of lactose
Discontinuous DNA synthesis
lagging strand is in the wrong direction poly to attach to the DNA and replicates the other direction once it reaches where DNA has already been replicated, it detaches.
DNA libraries
large collections of known DNA sequences
Termination factor, rho
large hexameric protein that physically interacts with the growing RNA transcript to terminate transcription
autopolyploids are ___ than diploids
larger
hypomethylation
leads to a decrease of methylation of DNA meaning more genes are activated thus activation of oncogenes
adjacent segregation
leads to unbalanced gametes duplicated and deleted for regions of the chromosome
Z-DNA
left handed helix
Euchromatin
less condensed form of eukaryotic chromatin that is available for transcription.
Bacteriophage lambda
linear dsDNA genome
linked genes are arranged in a _____ along the chromosome and that a variable frequency of exchange occurs between any two genes during gamete formation.
linear sequence
complete linkage
linkage between genes that are located close together on the same chromosome with no crossing over between them
Assume that a cross is made between AaBb and aabb plants and that the offspring occur in the following numbers: 106 AaBb, 48 Aabb, 52 aaBb, 94 aabb. These results are consistent with ________.
linkage with approximately 33 map units between the two gene loci
lncRNAs
long, non-coding RNAs, few functions
Looped domains
loops of supercoiled DNA that serve to compact the chromosomes
denaturation
loss of normal shape of a protein due to heat or other factor
dosage compensation
mechanism in which X chromosome inactivation equalizes gene expression between males and females.
cell cycle checkpoints
mechanisms that monitor the preparedness of a eukaryotic cell to advance through the various cell cycle stages
minimal medium
medium containing only inorganic salts, a carbon source, and water
MRNA
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
mRNA
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
G1 gap
metabolic activity and vigorous growth (interphase)
transacetylase
metabolizes certain disaccharides other than lactose
gene targeting
method for altering the sequence of a specific gene by introducing the modified version on a vector
semiconservative replication
method of DNA replication in which parental strands separate, act as templates, and produce molecules of DNA with one parental DNA strand and one new DNA strand
plaque assay
method used to measure the number of viral particles present in a sample
decoy model
mimics effector targets to trap the pathogen into a recognition event
TFIIB, TFIID, TFIIE, TFIIF, TFIIH
minimal PIC includes RNA polymerase II and six general transcription factors:
these structures contain their own genetic info
mitochondria and chloroplasts
Transposable sequences
mobile and can potentially move to different locations within the genome
transposable elements
mobile pieces of DNA that can copy themselves into entirely new areas of the chromosomes
transformation
modification of a cell or bacterium by the uptake and incorporation of exogenous DNA
Histone code
modification of histone proteins, such as the addition or removal of phosphate groups, methyl groups, or acetyl groups, that encode information affecting how genes are expressed
repressor molecule
molecule involved in gene regulation by binding to DNA and preventing gene transcription.
sequencing by synthesis
monitors identify which of 4 nucleotides is being added to complementary strand
Nucleotide
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
galactose
monosaccharide, milk sugar
loss of a chromosome
monosomy
Epigenetic modifications can silence multiple genes, making them ___________ in transforming normal cells into malignant cells than sequential mutations of single genes.
more effective
multigene trait
more than 1 gene specifying a given phenotype
Copy number variants
mutations that either create extra copies of a gene on one chromosome or result in the deletion of genes
cell division cycle mutations
mutations that exert an effect at one or another stage of the cell cycle
nutritional mutations
mutations that prevent synthesis of nutrient molecules
embryonic lethals
mutations with phenotypes causing death at the embryonic or larval stage
Noncoding RNA
ncRNA - forms an extensive and sophisticated genome regulatory network
Mullerian inhibiting substance
necessary for the degeneration of the Mullerian ducts
flies that are double mutants and thus homozygous for both brown and scarlet lack would have
neither of the pigments; they have both functional enzymes
In aerobically cultured yeast, a petite mutant is isolated. To determine the type of mutation causing this phenotype, the petite and wild-type strains are crossed. Such a cross has three potential outcomes.
neutral, segregational, suppressive
mitosis does not produce these
new recombinant chromatids
embyronic stem cells
not specialized and are the easiest cells to manipulate
maternal effect
nuclear genotype of mom affects phenotype of progeny through substances present in egg
N-DNA
nucleic DNA
Repetitive DNA
nucleotide sequences, usually noncoding, that are present in many copies in a eukaryotic genome. The repeated units may be short and arranged tandemly (in series) or long and dispersed in the genome.
episomes
plasmids that can integrate into the genome
Diplococcus pneumonia
played a central role in demonstrating that genetic material consists of DNA.
Kozak sequence
plays a role in the initiation of translation (mRNA binding to ribosomes). A mutation three bases upstream of the start codon is assoicated with thalasemmia.
end-replication problem
polymerase cannot replicate the 5' (beginning) end of the new strand because that's where the primer was. DNA strands lose 50-200 bases per replication
allopolyploidy
polyploidy resulting from contribution of chromosomes from two or more species
termination region
portion of gene that regulates the cessation of the transcription
nucleolus organizer region (NOR)
portions of DNA that encode rRNA
locus
position of a gene on a chromosome
Hermaphroditic
possessing both the male and the female reproductive organs
Hemizygosity
possession of a single allele at a locus. Males of organisms with XX-XY sex determination are hemizygous for X-linked loci because their cells possess a single X chromosome.
chaperonins
protein molecules that assist the proper folding of other proteins
sequence maps
provide the finest level of mapping detail because they pinpoint the nucleotide sequence of genes on a chromosome
the alignment of each tetrad prior to the first anaphase is _________
random
sister chromatid exchanges
recombination events between sister chromatids in mitosis
Degeneracy
redundancy of the genetic code; that is, most amino acids are encoded by several codons
Proofreading
refer to the error-correcting processes
Epigenetic
referring to the effects of environmental forces on the expression of an individual's, or a species', genetic inheritance.
lysogenized
refers to bacterial cells that contain phage nucleic acid
secondary sex ratio
reflects the proportion of each sex that is born
primary sex ratio
reflects the proportion of males to females conceived in a population
Enhancer model
region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur
Promoters
region of DNA that indicates to an enzyme where to bind to make RNA
male-specific region of the Y (MSY)
region of Y chromosome that does not synapse with X
Cis-acting DNA elements
regions of non-coding DNA which regulate the transcription of neighboring genes.
Alternative splicing
regulated process during gene expression that results in a single gene coding for multiple proteins
alternative splicing
regulated process during gene expression that results in a single gene coding for multiple proteins
Gene regulation in bacteria can also occur through the interactions of ______ molecules with specific regions of a nascent mRNA, after ______ has been initiated.
regulatory transcription
cis acting site
regulatory region located on the same strand as the gene cluster
outcomes from a hypothesis
reject or fail to reject
LOD score analysis
relies on probability calculations to demonstrate linkage between two genes in organisms in which linkage analysis relies primarily on pedigrees
DNA Pol I
removes RNA nucleotides of primer from 5' end and replaces them with DNA nucleotides
DNA polymerase I
removes RNA nucleotides of primer from 5' end and replaces them with DNA nucleotides
If all lactose is metabolized, none is available to bind to the ______, which is again free to bind to operator DNA and to repress transcription.
repressor
Silencers
repressor proteins that may bind to DNA sequences and inhibit the start of transcription
Gal80p
repressor; binds GAL4p and blocks activation
storage of information
requires the molecule to act as a repository of genetic information that may or may not be expressed by the cell in which it resides
small noncoding RNAs
sRNAs
ENCODE project
search for functions performed by noncoding DNA
metaphase
second phase of mitosis, during which the chromosomes line up across the center of the cell
The binding of these regulatory molecules alters the _____ structure of the mRNA, leading to premature transcription termination or repression of ________.
secondary translation
Cloverleaf model of tRNA
secondary structure, series of paired stems and unpaired loops
Hfr characteristics
specific nature of recombination nonrandom gene transfer pattern
Promoter
specific region of a gene where RNA polymerase can bind and begin transcription
kinetochore fibers
spindle fibers that extend from centrosome to centromere
in flowering plants this stage is the predominant phase
sporophyte
male
square
sex unkown
square rotated 45 degrees
7-methylguanosine (m7G) cap
ssential for mRNA translation and cell viability from yeast to mammals
TFIIA
stabilizes binding of TFIIB and TBP to the promoter
blastocyst
stage of early development in mammals that consists of a hollow ball of cells
template DNA
stand of original DNA that transcription occurs on
AUG
start codon
primers
starting point for DNA synthesis, short structures of nucleotides
Meselson-Stahl Experiment
states that DNA replication was semiconservative
Gilbert and Muller-Hill
that the IPTG-binding, or repressor, protein binds only to DNA containing the lac region and does not bind to lac DNA containing an operator-constitutive OC mutation.
G bands
the chromosomal banding pattern that is observed when the chromosomes have been treated with the chemical dye Giemsa
One gene one protein hypothesis
the genetic info contained in one gene of a DNA molecule isused to make one molecule of mRNA by transcription; the genetic info in that mRNA molecule is then used to make one protein by translation
Bacteriophage T2
the genetic material in phage T2 is DNA, not protein.
Wobble hypothesis
the hypothesis that some tRNA molecules can pair with more than one mRNA codon, tolerating some variations in the third base, as long as the first and second bases are correctly matched
One gene one polypeptide chain hypothesis
the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway
1:1 sex ratio
the idea that there is a 1 XY: 1 XX result of offspring
Template binding
the initial step in prokaryotic gene transcription
haploid number
the number of homologous pairs in a diploid cell.
sex ratio
the number of males per 100 females in the population.
Linking number
the number of times that two strands of a closed, circular DNA duplex cross over each other
Antiparallel
the opposite arrangement of the sugar-phosphate backbones in a DNA double helix.
translocation
the process in which a segment of a chromosome breaks off and attaches to another chromosome.
Spermatogenesis
the production of sperm cells
Oogenesis
the production, growth, and maturation of an egg, or ovum
RNAP II binds to
the promoter
Lyon hypothesis
the proposal that dosage compensation in mammalian females is accomplished by partially and randomly inactivating one of the two X chromosomes
Fibroin
the protein of silk fibers
Release factor
the protein that binds to the stop codon during termination of translation
independent assortment
the random distribution of the pairs of genes on different chromosomes to the gametes
extension
the reaction temperature is between 65 and 75 DNA polymerase uses primers to synthesize new DNA strands
dicentric bridge
the region between the two centromeres in a dicentric chromosome
expression platform
the region of a riboswitch that changes conformation in response to a ligand molecule binding to the aptamer.
aptamer
the region of a riboswitch that serves as a receptor for a ligand; binding of the ligand to the aptamer triggers conformational changes in the expression platform that influence gene expression.
Branch point
the representation on a phylogenetic tree of the divergence of two or more taxa from a common ancestor
Y chromosome
the sex chromosome found only in males. When paired with an X chromosome from the mother, it produces a male child.
sex-determining region Y (SRY)
the sex-determining region of the Y chromosome, found near the chromosome's pseudoautosomal boundary. Accumulated evidence indicates that this gene's product is the testis-determining factor (TDF)
Transcription start site
the site at which the first RNA nucleotide is added; also known as the +1 site.
Protein targeting
the sorting and transportation of proteins from the site of synthesis on ribosomes to compartments in the cell where they are needed
Two genes that are separated by 10 map units show a recombination percentage of 10%. -True -False
true (One map unit is equal to 1% recombination between two genes; 10 map units would be equal to 10% recombination between the genes.)
Genome transplantation
true test of the functionality of a synthetic genome
dideoxynucleotide
type of nucleotide used during DNA sequencing to terminate synthesis
mutant strains
unable to grow unless supplemented with specific substances (vitamins or amino acids)
chlamydomonas
unicellular green algae
unique genes
unique to one strain of a species
Replicon
unit of replication, consisting of DNA from the origin of replication to the point at which replication on either side of the origin ends.
CpG island
unmethylated CG dinucleotides found in clusters near gene promoters.
Eukaryotic DNA
unwinds in multiple areas as DNA is replicated
Regulation of transcription in eukaryotes
upstream control elements (UCEs), core promoter w/ bindings sites for transcription complex, and a TATA box
subunit vaccines
use antigenic fragments to stimulate an immune response
FMR1
x-linked gene most commonly causing intellectual disabilities in males
Short tandem repeats
(STR) simple sequence DNA containing multiple tandemly repeated units of two to five nucleotides. variations in STRs act as genetic markers in STR analysis, used to prepare genetic profiles
recombination
(genetics) a combining of genes or characters different from what they were in the parents
haploid
(genetics) an organism or cell having only one complete set of chromosomes
PCR
(polymerase chain reaction) multiple copies of a specific segment of DNA
Avery, MacLeod, and McCarty's conclusion
"The evidence presented supports the belief that a nucleic acid of the desoxyribose*
FISH
"maps" the genetic material in a person's cells. This test can be used to visualize specific genes or portions of genes.
CAAT box
(GGCCAATCT) essential eukaryotic promoter sequence involved in binding transcription factors
Alteration of the DNA path
- DNA pulled of nucleosome
Leber's Hereditary Optic Neuropathy (LHON)
- Defect in *NADH dehydrogenase* (complex I of the electron transport chain) - causes *progressive loss of central vision and blindness* - Though inherited through *mitochondrial DNA*, for unknown reasons *affects males more* than females.
have a severe impact on that organism
- mtDNA does not have the structural protection from mutations - DNA repair mechanisms for mtDNA are limited - mitochondria concentrate highly mutagenic reactive oxygen species (ROS) generated by cell respiration.
Alteration of DNA histone contacts
- sliding exposes DNA
bZIP motif
- the BASIC segment and leucine zipper
Readers
- tudor domain, MBT, chromodomain
Environmental agents for epigenetic change
-- nutrition, exposure to chemicals, and physical factors, such as temperature
time mapping
-Chromosome of Hfr strain transferred linearly -Gene order and distance between genes can be predicted -Served as basis for first genetic map of E. coli
DTC genetic testing
-Direct to consumer genetic tests are NOT regulated by the FDA -Consumers usually do not have enough knowledge about genetics to understand the results -Genetic counselors may not be provided
limitations of PCR
-is prone to error, which in turn causes mutations in the PCR fragments that are made. -the specificity of the fragments can mutate to the template DNA, due to nonspecific binding of primers -prior information on the sequence is necessary in order to generate the primers.
mRNA localization
-mRNA is transported along microtubules to the cytoplasm to be translated -RNA binding proteins recognize sequences in 3' UTRs and attach them to the microtubules for transport -the availability of the RNA-binding proteins and the speed of transport are points of regulation
L1 family
-most common LINE -6400 bp long and repeated up to 100,000 times -Retrotransposons
CpG dinucleotide
-most common site for mutation causes -spontaneous deamination of methylated cytosines -mutation hotspot with 8.5 timex greater mutation rate over other dinucleotides -not all CpG duos have the methyl group on Cytosine (making it 5-methylcytosine) ****IF YOU deaminate cytosine= no biggie; efficiently recognized and repaired, you get uracil ****IF YOU deaminate 5-methylcytosine = TROUBLE; not recognized, you get thymine
Tumor supressor genes
-prevent uncontrolled cell growth -repair damaged DNA -control cell anchorage (absent in cancers)
GR gene
-produces protein that binds stress hormone cortisol -allows rapid recovery from stress when active
quantitative real time PCR
-uses fluorescently labeled PCR products -almost immediate results
Whole Exome Sequencing (WES)
-uses similar technology as WGS, but targets only protein-coding regions of DNA that are most likely to have a functional role -these sequencing changes are the cause of many well-known genetic diseases
Probabilities range from ____ to _____.
0 (event is certain not to occur) 1 (event is certain to occur)
transformation process
1. entry of a foreign DNA into recipient cell 2. recombination between foreign DNA and its homologous region in recipient chromosome
mapping bacterial genes
1. interrupted conjugation 2. transformation 3. transduction
why organelle heredity?
1. organelles involved in gene products 2. large amounts of these are made in progeny
Genes X, Y, and Z are linked. Crossover gametes between genes X and Y are observed with a frequency of 25%, and crossover gametes between genes Y and Z are observed with a frequency of 5%. What is the expected frequency of double crossover gametes among these genes?
1.25% The probability of a double crossover is the product of the probabilities of the single crossovers: 0.25 x 0.05 = 0.0125, or 1.25%.
dominant epistasis
12:3:1; when the dominant allele of one gene masks the effects of either allele of the second gene
telophase 1
2 daughter cells are formed, each daughter cell contains only one chromosome of the homologous pair.
t B In a three‑point mapping experiment for the genes y‑w‑ec, the following percentages of events are observed: NCO events: 65% SCO events between y and w: 15% SCO events between y and ec: 17% DCO events: 3% What is the map distance between y and ec?
20 map units ( The map distance between any two genes is the sum of the percentages of all detectable recombination events between them, so 17 + 3 = 20.)
with the human species n =
23
A site, P site, E site
3 binding sites of ribosomes
Initiation, elongation, termination
3 stages of transcription
Splice acceptor
3' end of intron
triploid
3n
Turner Syndrome
45 XO, female hypogonadism, hypothyroid, short, webbed neck
diploid number in humans
46
diploid number of humans
46
Splice donor
5' end of intron
Dispersed core promoters
70% of mammalian genes. Common in plants. Multiple sites spread over 50-200nt - form different length 5' UTRs Lack known elements. Some rich in GU, but others not
how many chloroplast genes are there?
92
recessive epistasis
9:3:4 ratio; when the recessive allele of one gene masks the effects of either allele of the second gene
Typical ratios resulting from epistatic interactions in dihybrid crosses would be ________.
9:3:4, 9:7
Enhancers
A DNA sequence that recognizes certain transcription factors that can stimulate transcription of nearby genes.
A-DNA
A complex molecule containing the genetic information that makes up the chromosomes.
karyotype
A display of the chromosome pairs of a cell arranged by size and shape.
cell plate
A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.
Keratin
A fiber protein that is the principal component of hair, skin, and nails is:
2-deoxyribose
A five-carbon sugar found in DNA.
Deoxyribose
A five-carbon sugar that is a component of DNA nucleotides
Heterokaryon
A fungal mycelium that contains two or more haploid nuclei per cell.
Hemizygous
A gene present on the X chromosome that is expressed in males in both the recessive and dominant condition
Spliceosome
A large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends of an RNA intron, releasing the intron and joining the two adjacent exons.
cDNA library
A limited gene library using complementary DNA. The library includes only the genes that were transcribed in the cells examined.
Neutral mutation
A mutation that has no effect on the organism
TATA box
A promoter DNA sequence crucial in forming the transcription initiation complex.
Myosin
A protein present in muscle fibers that aids in contraction and makes up the majority of muscle fiber
mitochondrial DNA
A small amount of DNA that is located in the mitochondria of cells. Mitochondrial DNA is inherited only through the mother.
bacteriophage
A virus that infects bacteria
10. Methods for determining the linkage group and genetic map in humans involve which of the following? A. DNA markers B. chiasmatype and classical analyses C. twin spots and tetrad analysis D. zygotene and pachytene DNA synthesis E. tetrad analysis and bromodeoxyuridine
A. DNA markers
15. In humans, the genetic basis for determining the sex "male" is accomplished by the presence of ________. A. a portion of the Y chromosome B. one X chromosome C. sets of autosomes D. high levels of estrogen E. a balance between the number of X chromosomes and the number of haploid
A. a portion of the Y chromosome
23. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is inherited as an X-linked recessive gene in humans. A woman whose father suffered from G6PD marries a normal man. A.) What proportion of their sons is expected to have G6PD? Enter your answer as a fraction. B.) If the husband were not normal, but were G6PD deficient, would you change your answer in part (a)? A. yes B. no
A.) 1/2 B.) B. no
Initiation codon
AUG (methionine)
Open reading frame
AUG followed by a number of codons and a stop codon in the same reading frame
heterozygote
Aa or aA
Wobble hypothesis
Ability of the tRNAs to recognize more than one codon; the codons differ in their third nucleotide.
Electromagnetic spectrum
All of the frequencies or wavelengths of electromagnetic radiation
Epigenetic changes to the nervous system occur in
Alzheimer disease, Parkinson disease, Huntington disease, and in schizophrenia and bipolar disorder.
Alkaptonuria
An autosomal recessive trait with altered metabolism of homogentisic acid. Affected individuals do not produce the enzyme needed to metabolize this acid, and their urine turns black.
Reverse transcriptase
An enzyme encoded by some certain viruses (retroviruses) that uses RNA as a template for DNA synthesis.
Peptidyl transferase
An enzyme in the ribosome responsible for peptide bond formation during translation.
Endonuclease
An enzyme that cleaves its nucleic acid substrate at internal sites in the nucleotide sequence.
Aminoacyl tRNA synthetases
An enzyme that joins each amino acid to the appropriate tRNA.
Exonuclease
An enzyme that removes successive nucleotides from the end of a polynucleotide molecule
Mitochondria
An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.
Somatic cells
Any cells in the body other than reproductive cells
centromere
Area where the chromatids of a chromosome are attached
Mendel
Augustinian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics (1822-1884)
19. For an individual with the XXY chromosomal composition, the expected number of Barr bodies in interphase cells is ________. A. variable B. one C. three D. zero E. two
B. one
Nucleosomes
Bead-like structures formed by histones and DNA
Part C - The effect of a third gene on fur color In the same mouse species, a third unlinked gene (gene C/c) also has an epistatic effect on fur color. The presence of the dominant allele C (for color), allows the A/a and B/b genes to be expressed normally. The presence of two recessive alleles (cc), on the other hand, prevents any pigment from being formed, resulting in an albino (white) mouse.
Because the C/c gene is epistatic to both the A/a and B/b genes, any offspring with the cc allele combination will be albino. Otherwise, the A/a and B/b genes are expressed normally. AaBbcc-Albino, AaBBCC-Agouti Black Aabbcc-Albono AAbbCc Agouti Brown aaBbCc-Solid color, Black AABBcc-Albino
NAFLD
Become the most common liver disease in North America. It affects about 30% of the general population, but 70% of the obese.
4. In Drosophila, sex is determined by a balance between the number of haploid sets of autosomes and the number of ________. A. nucleolar organizers B. centromeres C. X chromosomes D. telomeres E. Y chromosomes
C. X chromosomes
15. Recently, a gene located on chromosome 3 in humans, FHIT, has been shown to be associated with the significant human malady known as ________. A. Klinefelter syndrome B. "mad-cow" disease C. cancer D. XYY/XY mosaicism E. Huntington disease
C. cancer
Tautomeric shifts
Can change the bonding structure, allowing noncomplementary base pairing May lead to permanent base-pair changes and mutations
Reactive oxidants
Can produce 100+ different types of chemical modifications
Carcinogens
Cancer causing agents
chloroplasts
Capture energy from sunlight and use it to produce food for the cell
cpDNA
Chloroplast DNA Genes encode products involved in photosynthesis and translation
Closed chromatin
Chromatin in which regulatory DNA is covered by nucleosomes, thus restricting the access of regulatory proteins to the sequences rendering genes in closed chromatin transcriptionally silent.
Open chromatin
Chromatin in which the association of DNA with nucleosomes is relaxed in regions containing regulatory sequences, allowing access by regulatory proteins
prophase 1
Chromosomes become visible; nuclear envelope breaks down; crossing-over occurs.
homologous chromosomes
Chromosomes that have the same sequence of genes and the same structure
Chromatin
Clusters of DNA, RNA, and proteins in the nucleus of a cell
Transcription factors
Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.
Initiation of DNA synthesis
Complementary RNA primer is first made to which DNA is added. 5' to 3' direction of synthesis. RNA primer is replaced with DNA under DNA polymerase I
CJD
Creutzfeldt-Jakob disease (Mad Cow disease)
3. The Lygaeus mode of sex determination is the ________. A. XO/YY scheme B. XX/XO scheme C. hermaphroditic scheme D. XY/XX scheme E. scheme based on single translocations in the X chromosome
D. XY/XX scheme
16. Transduction is a form of recombination in bacteria that involves ________. A. physical contact between the bacteria involved B. fertility factors C. 5-bromouracil D. bacteriophages E. plasmids
D. bacteriophages
10. Max Delbrück presented the first evidence that bacteria are capable of spontaneous mutation. What is the name of the test that Delbrück used to demonstrate this phenomenon? A. prototrophic test B. logarithmic test C. lag test D. fluctuation test E. auxotrophic test
D. fluctuation test
5. What relatively recent scientific advancement has made mapping by linkage or classical genetic mapping approaches virtually obsolete? A. negative interference B. the use of synteny C. positive interference D. the genome sequence of a species E. the inclusion of the X and Y chromosome in SNP experiments
D. the genome sequence of a species
Central dogma of genetics
DNA -> RNA -> Protein
Information flow
DNA -> RNA -> Protein
Spacer DNA
DNA between genes without coding function
DBD
DNA binding domain
Topoisomers
DNA conformations that differ with regard to supercoiling
organelle heredity
DNA contained in mitochondria or chloroplasts determines certain phenotypic characteristics of the offspring
double-stranded breaks (DSBs)
DNA damage often arises as a result of normal cellular processes; can also be caused by environmental exposure
Supercoiled DNA
DNA is further twisted to save space
Open configuration
DNA is unmethylated and histones are acetylated Genes can be transcribed
epigenetic modifications alter chromatin structure by several mechanisms:
DNA methylation, reversible covalent modification of histones, and action of short and long RNAs, all without changing the sequence of genomic DNA.
DNMTs
DNA methyltransferases
Recombinant DNA
DNA produced by combining DNA from different sources
CpG islands
DNA regions rich in C residues adjacent to G residues. Especially abundant in promoters, these regions are where methylation of cytosine usually occurs.
Base excision repair
DNA repair that first excises modified bases and then replaces the entire nucleotide
Insulators
DNA sequence elements that prevent inappropriate interactions between adjacent chromatin domains
autonomously replicating sequences (ARSs)
DNA sequence that confers the ability to replicate; contains an origin of replication
Minisatellites
DNA sequences composed of 10 to 1000 base pairs that are scattered throughout the genome
Mutation hot spots
DNA sequences that appear to be highly susceptible to mutation
Noncoding regions
DNA sequences that do not hold instructions to make proteins
Template strand
DNA strand that provides the template for ordering the sequence of nucleotides in an mRNA transcript.
Heterochromatin
DNA that is densely packed around histones. The genes in heterochromatin are generally inaccessible to enzymes and are turned off.
Luria delbruck fluctuation test
Demonstrated mutations are not adaptive but occur spontaneously and randomly
Genetic analysis
Determination of the function of cell RNAs and proteins based on the phenotype of cells in which the gene encoding the RNA or protein is mutated
Restriction Fragment Length Polymorphisms (RFLPs)
Differences in DNA sequence on homologous chromosomes that can result in different patterns of restriction fragment lengths (DNA segments resulting from treatment with restriction enzymes).
robertsonian translocation
Down syndrome with 46 chromosomes
15. Assume that a cross is made between AaBb and aabb plants and that all the offspring are either AaBb or aabb. These results are consistent with the following circumstance: A. codominance. B. hemizygosity. C. incomplete dominance. D. alternation of generations. E. complete linkage.
E. complete linkage.
20. What two terms apply to the fusion of cultured human and mouse cells that produces cell lines that are useful in assigning a gene to a particular human chromosome? A. positive and negative B. single and double C. lod score and pod score D. forward and reverse E. heterokaryon and synkaryon
E. heterokaryon and synkaryon
11. Direction of shell coiling in the snail Lymnaea peregra is conditioned by a form of extrachromosomal inheritance known as ________. A. epistasis B. heteroplasmy C. independent assortment D. sex-linked inheritance E. maternal effect
E. maternal effect
Eukaryotic elongation factors
EF1A, EF1B, EF2
Gamma rays
Electromagnetic waves with the shortest wavelengths and highest frequencies
UV radiation
Energy from the sun that damages DNA structure, increases mutation rate, and causes skin cancer. [D Period DK]
Ionizing radiation
Enough energy to dislodge electrons from atoms, forming ions; capable of causing cancer (gamma, X-rays, UV)
RNA polymerase
Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
Recombinase
Enzyme that catalyzes site-specific recombination
Nondisjunction
Error in meiosis in which homologous chromosomes fail to separate.
Dominant negative mutation
Exerts a dominant effect. A heterozygote produces a nonfunctional altered protein that also prevents the normal gene product from functioning
Long interspersed elements
Expression of these elements leads to genetic instability.
Pyrimidine dimers
Extra bonds formed between thymine or cytosine in DNA (cause of mutations)
recipient cells when mated with HFR cells are _____
F-; remain
1. T/F Poky strains in yeast result from suppressive mutations in chloroplast DNA.
False
10. T/F The term aneuploidy is synonymous with the term segmental deletion.
False
11. T/F The "interrupted mating technique" provides a genetic map in Drosophila.
False
12. T/F Mendel predicted that some genes will be carried in the same chromosome.
False
13. T/F In a bacterial cross in which the donor (Hfr) is a+b+ and the recipient strain (F-) is a-b-, it is expected that recombinant bacteria will all be a+b+.
False
15. T/F A plaque is a substance that causes mutation in bacteria.
False
16. T/F Assume that a species has a diploid chromosome number of 24. The term applied to an individual with 25 chromosomes would be triploid.
False
4. T/F Inheritance of the green and white patches phenotype in Mirabilis jalapa (four o'clocks) is an example of maternal influence.
False
5. T/F Mitochondrial mutations are passed equally to offspring by both males and females.
False
5. T/F R plasmids often contain genes for antibody production.
False
Evidence of a role for methylation in eukaryotic gene expression is based on several observations.
First, an inverse relationship exists between the degree of methylation and the degree of expression. Large transcriptionally inert regions of the genome, such as the inactivated X chromosome in female mammalian cells (see Chapter 7), are often heavily methylated.
FDA
Food and Drug Administration
nucleolus
Found inside the nucleus and produces ribosomes
FMRP
Fragile X Mental Retardation Protein
Somatic cell hybridization
Fusion of somatic cells of different types.
cell cycle order
G1, S, G2, M
GAL gene
GAL (Galanin And GMAP Prepropeptide) is a Protein Coding gene.
Point mutation
Gene mutation involving changes in one or a few nucleotides.
GINA
Genetic Information Nondiscrimination Act
Transposable elements
Genetic element that has the ability to move (transpose) from one site on a chromosome to another.
HBB gene
Hemoglobin beta gene that is mutated to cause sickle cell anemia
H2A
Histamine 2 antagonist
pilli
Hollow tubes used to move cells or exchange DNA between bacteria by conjunction.
anaphase 1
Homologous chromosomes separate
sister chromatids
Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.
western blotting
Identifies antibodies in a patient's serum; confirms HIV infection
An alien organism was investigated. When DNA replication was studied, a unique feature was apparent: No Okazaki fragments were observed. Create a model of DNA that is consistent with this observation.
If the DNA contained parallel strands in the double helix and the polymerase would be able to accommodate such parallel strands, there would be continuous synthesis and no Okazaki fragments. Several other possibilities exist. If the DNA were replicated as single strands, the synthesis could begin at the free ends and there would be no need for Okazaki fragments.
Adaptive mutations
Improve fitness of an organism, increasing its survival
Holliday structure
In DNA recombination, an intermediate stage seen in transmission electron microscope images as an X-shaped structure showing four single-stranded DNA regions.
Bacterial transcription and translation
In a bacterial cell, which lacks a nucleus, mRNA produced by transcription is immeadiately translated without additional processing.
DNA polymerase III
In charge of synthesizing nucleotides onto the leading end in the classic 5' to 3' direction.
Polymerase switching
In eukaryotes, the switch that occurs from DNA synthesis by the polymerase alpha-primase complex to DNA synthesis by the processive replicative polymerase that carries out the bulk of DNA elongation
DNA in human mitochondria encodes 22 different tRNA molecules. However, 32 different tRNA molecules are required for translation of proteins within mitochondria. Explain.
In many cases, molecular components of mitochondria are recruited from the cytoplasm, having been synthesized from nuclear genes.
HTH motif
In proteins, the helix-turn-helix (HTH) is a major structural motif capable of binding DNA
independent assortment
Independent segregation of genes during the formation of gametes
in order for a human disorder to be attributable to genetically altered mitochondria, several criteria must be met
Inheritance must exhibit a maternal rather than a Mendelian pattern. The disorder must reflect a deficiency in the bioenergetic function of the organelle. There must be a mutation in one or more of the mitochondrial genes.
Thalassemia
Inherited defect in ability to produce hemoglobin, leading to hypochromia
Protein domains
Ion channels, membrane-spanning regions, secretion, and export signals
Tautomers
Isomers that can interconvert by exchanging the location of a proton.
Core promoter
Located immediately upstream of the eukaryotic promoter, DNA sequences to which the basal transcription apparatus binds.
prenatal genetic testing
Many genetic disorders are diagnosed prenatally using cytogenetic, biochemical, and recombinant DNA testing Samples are obtained from amniocentesis and chorionic villus sampling (CVS)
unit factors in pairs
Mendel's first postulate: Genetic characteristics are controlled by pairs of unit factors (alleles of genes)
Anabolism
Metabolic pathways that construct molecules, requiring energy.
mitochondrial replacement therapy
Methods that combine the nuclear DNA of a woman carrying a mtDNA mutation with DNA of a sperm and the egg cytoplasm of a healthy donor, allowing her to give birth to a child free from mitochondrial disease.
DNA transposons
Mobile genetic elements that move without making an RNA intermediate.
poly A tail
Modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides.
Xeroderma pigmentosum
Mutated single strand nucleotide excision repair gene, which prevents repair of thymidine dimers.; Dry skin w/ melanoma and other cancers ("children of the night").
Adduct forming agents
Mutation-causing chemicals
Homologous recombination repair
Occurs during the late S or early G2 phase of the cell cycle
Continuous DNA synthesis
Occurs only in the leading strand towards the replication fork
first polar body
One of the products of meiosis I in oogenesis; contains half the chromosomes but little of the cytoplasm.
Termination codon
One of the three codons (UAA, UAG, UGA) that signal the termination of translation of a polypeptide.
sex-determining chromosomes
Only pair of non-homologous chromosomes in an individual XX - female XY - male
metaphase 1
Paired homologous chromosomes line up across the center of the cell
synapsis
Pairing of homologous chromosomes at meiosis
Which of the following statements about gamete formation during meiosis is false? -Complete linkage results in the formation of only parental gametes. -Recombinant gametes contain combinations of alleles not found in the parent cell. -Parental gametes contain the same combinations of linked genes as found in the parent cell. -Parental gametes can be formed only if there is no crossing over during meiosis.
Parental gametes can be formed only if there is no crossing over during meiosis. ( If crossing over occurs, half of the gametes formed are parental and the other half are recombinant.)
Mutagenic
Pertaining to producing a mutation.
Intercalating agents
Planar molecules that mimic base pairs and are able to slip in between the stacked nitrogen bases at the core of the DNA double helix, resulting in insertion or deletion of a single nucleotide pair. A source of induced mutation.
Imprinting disorders
Prader-Willi syndrome Angelman syndrome
Heteroplasmy
Presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrial inherited disease
Translation
Process by which mRNA is decoded and a protein is produced
mRNA splicing
Process that removes introns from pre-mRNAs and joins exons together.
Gain of function mutation
Produces a new trait or causes a trait to appear in inappropriate tissues or at inappropriate times in development
Proximal promoter elements
Promoter sequences other than the core promoter
Protein stability
Proteins an be disrupted by a number of external stress factors including temperature, pH, removal of water, presence of hydrophobic surfaces, presence of metal ions and high shear. The loss of secondary, tertiary or quaternary structure due to exposure to a stress factor is called denaturation.
Elongation factors
Proteins involved in the elongation phase of translation, assisting ribosomes in the synthesis of the growing peptide chain.
gene expression microarrays
Quantify variation in gene expression among individuals performing different behaviors.
telomerase RNA component (TERC)
RNA component of telomerase
RNA homopolymers
RNA molecules containing only one type of ribonucleotide
antiterminator confirmation
RNA polymerase has transcribed the unbound ligand-binding site, and in the default conformation, the expression domain adopts an antiterminator conformation.
Spontaneous mutations
Random change in the DNA due to errors in replication that occur without known cause
DNA glycosylases
Recognize the alterations and cleave the base from the sugar; specific glycosylases for each type of altered base
AP endonuclease
Recognizes apurinic/apyrimidinic site (abasic site) and cleaves behind it to base excise repair
Induced mutations
Refers to those mutations in the DNA resulting from exposure to toxic chemicals or to radiation
Single gene mutations
Relatively small changes in DNA structure that occur within a particular gene
Nucleotide excision repair pathway
Repair lesions that cause distortions in normal shape of DNA (bulky lesions)
Telomeres
Repeated DNA sequences at the ends of eukaryotic chromosomes.
Germ cells
Reproductive cells that give rise to sperm and ovum
Long terminal repeat
Required for integration of retroviruses, their promoter activity may lead to expression of host genes.
Postreplication repair
Responds after damaged DNA has escaped repair and has failed to be completely replicated
Dominant mutation
Results in a mutant phenotype in a diploid organism, even when the wild-type allele is also present
Recessive mutation
Results in a wild-type phenotype when present in a diploid organism and the other allele is wild type
3 major epigenetic mechanisms:
Reversible modification of DNA by addition or removal of methyl groups, chromatin remodeling by the addition or removal of chemical groups to histone proteins, and regulation of gene expression by noncoding RNA molecules
Rho dependent termination
Rho protein recognizes specific DNA sequences and causes a pause in the RNA polymerase
B-DNA
Right-handed helical structure of DNA that exists when water is abundant; the secondary structure described by Watson and Crick and probably the most common DNA structure in cells.
Familial Down syndrome is caused by:
Robertsonian translocation
Interspersed retrotransposons
SINES (Alu), LINES (L1)
allele specific oligonucleotides
Short, single-stranded fragments of DNA used as probes to identify alleles that differ by a single oligonucleotide
Computer-automated high-throughput DNA sequencing
Since early 1990s, DNA sequencing has been done through computer-automated Sanger reaction-based technology Generates large amounts of sequence DNA Enabled rapid progress of Human Genome Project
daughter chromosomes
Sister chromatids that are separated by mitosis
restriction sites
Specific site where a restriction enzyme cuts the DNA
chiasma
The X-shaped, microscopically visible region representing homologous chromatids that have exchanged genetic material through crossing over during meiosis.
transmission genetics
The branch of genetics concerned with the mechanisms by which genes are transferred from parent to offspring.
mRNA stability
The life span of the mRNA and can be used to control gene expression
host range
The limited range of host cells that each type of virus can infect and parasitize.
Depurination
The loss of a purine base from a nucleotide
in vitro fertilization
The most common assisted reproduction procedure, in which a woman's eggs are mixed with sperm in culture dishes (in vitro) and then carefully inserted into a woman's uterus.
Leading strand
The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' to 3' direction.
wild type allele
The non-mutant form of a gene, encoding the normal genetic function. Generally, but not always a dominant allele.
Mutation rates
The number of new mutant alleles per given number of gametes
Protein folding
The physical process by which a polypeptide folds into its characteristic three-dimensional structure, which is essential to the protein's function.
Beta globin
The polypeptide chain of hemoglobin that is designated beta and that when deficient or defective causes various anemias (as beta-thalassemia or sickle-cell anemia).
Mutation rate
The probability of a gene mutating during or between DNA replications
selective breeding
The process of selecting a few organisms with desired traits to serve as parents of the next generation
Shine dalgarno sequence
The prokaryotic ribosome-binding site on mRNA, found 10 nucleotides 5' to the start codon.
Homogametic sex
The sex (male or female) that produces gametes that are all alike with regard to sex chromosomes. For example, in the XX-XY sex-determining system, the female produces only X-bearing gametes.
Reading frame
The way a cell's mRNA-translating machinery groups the mRNA nucleotides into codons
anneal
To be capable of combining with complementary nucleic acid by a process of heating and cooling
Retrotransposons
Transposable elements that move within a genome by means of an RNA intermediate, a transcript of the retrotransposon DNA.
Patau Syndrome
Trisomy 13
Edwards Syndrome
Trisomy 18
1. T/F Nondisjunction is viewed as a major cause of aneuploidy.
True
11. T/F Doubling the chromosomes of a sterile species hybrid with colchicine or cold shock is a method used to produce a fertile species hybrid (amphidiploid).
True
11. T/F In Drosophila, sex is determined by the ratio of the number of X chromosomes to the number of haploid sets of autosomes.
True
16. T/F The cross GE/ge×ge/ge produces the following progeny: GE/ge 404; ge/ge 396; gE/ge 97; Ge/ge 103. From these data one can conclude that the recombinant progeny are gE/ge and Ge/ge.
True
Stop codons
UAA, UAG, UGA
Photoreactivation enzyme
UV light can fuse two thymine bases together, so an endonuclease enzyme will correct the damage
Free radicals
Unstable molecules that cause biochemical aging, especially wrinkling and sagging of the skin.
biopharming
Use of genetically engineered animals to act as biofactories for producing drugs, vaccines, antibodies, hormones, industrial chemicals such as plastics and detergents, and human body organs.
compensation loop
Where the unpaired region of a normal homolog must "buckle out" after an intercalary deletion.
bar mutation
X-linked trait for bar eyes in drosophila
chiasmata
X-shaped regions where crossing over occurred.
replication fork
Y-shaped region on a replicating DNA molecule where new strands are growing.
Zika
ZIKV infection
heteroduplex
a DNA double helix composed of single strands from two different DNA molecules
cloning vectors
a DNA molecule that can accept foreign DNA, be transferred to a host cell, and get replicated in it
amplicon
a DNA sequence that has been amplified by PCR
dideoxy chain termination method
a DNA sequencing method in which target DNA is denatured and annealed to an oligonucleotide primer, which is then extended by DNA polymerase using a mixture of deoxynucleotide triphosphates (normal dNTPs) and chain-terminating dideoxynucleotide triphosphates (ddNTPs)
expression vectors
a DNA vector, such as a plasmid, that carries a DNA sequence for the expression of an inserted gene into mRNA and protein in a host cell
Methylation
a biochemical process that influences behavior by suppressing gene activity and expression
primary oocyte
a cell that divides to form the polar body and the secondary oocyte
primary spermatocyte
a cell that divides to form two secondary spermatocytes
miRNA
a class of functional RNA that regulates the amount of protein produced by a eukaryotic gene
reciprocal cross
a cross in which the phenotypes of the male and female are reversed compared with a prior cross
Molecular disease
a disease caused by a mutated gene
Nonmutant bacteria are able to repair
a great deal of UV-induced damage
complementation group
a group of mutations that affect the same gene
Agarose gel
a jelly-like slab used to separate molecules on the basis of molecular weight
Spliceosome
a large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends of an RNA intron, releasing the intron and joining the two adjacent exons.
inversion loop
a loop formed by meiotic pairing of homologs in an inversion heterozygote
triphosphates (NTPs)
a molecule containing a nitrogenous base bound to a 5-carbon sugar, with three phosphate groups bound to the sugar. It is an example of a nucleotide.
Nucleoid
a non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.
sex-limited inheritance
a pattern of inheritance in which phenotypic expression is limited to one sex
Genomic imprinting
a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent
lycopene
a pigment responsible for the red color of tomatoes and other red-hued vegetables; a phytochemical that may act as an antioxidant in the body.
Protoplasts
a plant or bacterial cell without its cell wall
Polypeptides
a polymer of amino acids joined together by peptide bonds.
Autoradiography
a procedure that locates radioactive substances in a slice of tissue; the radiation exposes a photographic emulsion or a piece of film that covers the tissue
Natural selection
a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
whole genome sequencing
a process that determines the nucleotide sequence of an entire genome
Initiation factor
a protein required for the correct initiation of translation
Elongation factor
a protein that breaks the high-energy bonds of the molecule GTP to provide energy for ribosome movement and elongation of a growing polypeptide chain.
Bombay phenotype
a rare variant of the ABO antigen system in which affected individuals do not have A or B antigens and thus appear to have blood type O, even though their genotype may carry unexpressed alleles for the A and/or B antigens
Active site
a region on an enzyme that binds to a protein or other substance during a reaction.
Trans-acting factors
a regulatory protein that binds to a regulatory element in the DNA and exerts a trans effect
Utilization site (rut)
a sequence of RNA in bacteria upstream of the terminator region which serves as a binding site for the protein known as rho factor. This sequence is necessary in rho-dependent termination of DNA transcription in bacteria
Collinear
a set of loci in two different species which are located on the same chromosome in each, and are conserved in the same order
chromosomal sex determination
a sex determination system such as that of most mammals, in which the sex of an individual is determined by the combination of sex chromosomes it possesses.
primer
a short segment of DNA that acts as the starting point for a new strand
monomer
a simple compound whose molecules can join together to form polymers
Degenerate
a single amino acid may be coded for by more than one codon
Pleiotropy
a single gene having multiple effects on an individuals phenotype
polycistronic mRNA
a single molecule of messenger RNA that is formed by the transcription of a group of functionally related genes located next to one another along bacterial DNA.
Nonoverlapping
a single nucleotide may not be included in more than one codon
Transcription factory
a small area of the nucleus that contains high concentrations of RNA polymerase and everything else needed for transcription. DNA "travels" to these factories
corepressor
a small molecule that cooperates with a repressor protein to switch an operon off
Initiator tRNA
a special type of transfer ribonucleic acid (RNA) that initiates protein synthesis by binding to the amino acid methionine and delivering it to the small ribosomal subunit.
null hypothesis
a statement or idea that can be falsified, or proved wrong
Nucleosomes
a structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones.
gene drive
a system that biases inheritance patterns independent of selective advantage to alter target populations
fluctuation test
a test used in microbes to establish the random nature of mutation or to measure mutation rates
GloFish
a transgenic strain of zebrafish, contain a red fluorescent protein from sea anemones
Ribozyme
a type of RNA that can act as an enzyme
Lytic cycle
a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses
lytic cycle
a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open, releasing new viruses
lysogenic
a viral reproductive cycle in which the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA
Bacteriophage
a virus that infects bacteria
filterable agent
a virus; too small to be filtered out like bacteria
(female) the daughter cells resulting from two meiotic divisions get ____ amounts of genetic material and ______ amounts of cytoplasm
a) equal b) unequal
during sexual reproduction _________ gametes then combine at fertilization to reconstitute the ________ complement found in parental cells
a) haploid b) diploid
the first division of oocytes starts in ________ but arrests in _________, meiosis resumes ________
a) the embryo b) prophase 1 c) before ovulation
homozygous recessive genotype
aa
homozygote
aa or Aa
Processivity
ability of a polymerase to remain attached to the template
Gene regulation
ability of an organism to control which genes are transcribed in response to the environment
antiterminator hairpin
absence of tryptophan
Histone modifications
acetylation, methylation, phosphorylation
Gal4p
activator
lysostaphin
acts on the crossbridge of certain staphylococcus species only
recombination frequencies between linked genes are
addative
Histone modification
adding chemical modifications to proteins called histones that are involved in packaging DNA
Acetylation
addition of an acetyl group, CHCO3, to an organic molecule. chromatin less compact so that transcription can occur.
Poly A polymerase
adds poly A tail at the end of RNA
HbA
adult hemoglobin
when is the diploid number reestablished?
after fusion of two gametes at fertilization
In the Meselson-Stahl experiment, which of the three modes of replication could be ruled out after one round of replication? after two rounds?
after one round of replication in the 14N medium, the conservative scheme can be ruled out. After one round of replication in 14N under a dispersive model, the DNA would be of intermediate density, just as it is in the semiconservative model. However, after the next round of replication in 14N medium, the density of the DNA is between the intermediate and "light" densities, thus ruling out the dispersive model.
Eukaryotic release factors
aids stop codons in the termination of translation
complementation group
all mutations present in any single gene
autosomal
all the other genes in the body that are not sex-linked.
Metastable epialleles
alleles that are variably expressed in genetically identical individuals due to epigenetic modifications established during early development and are thought to be particularly vulnerable to environmental influences
amphidiploid
allopolyploid consisting of two combined diploid genomes
Chromosome-banding techniques
allow researchers to distinguish chromosomes of similar sizes with similar centromere positions
cryo-EM
allows detailed 3D reconstruction of phage particles.
complementation analysis
allows the determination of whether two mutations yielding similar phenotypes are on the same gene or on separate genes
alleles
alternative versions of a gene
constitutive enzymes
always present, always produced in equal amounts or at equal rates, regardless of the amount of substrate
Proteins
amino acids
BLAST
an algorithm and program for comparing primary biological sequence information, such as the amino-acid sequences of proteins or the nucleotides of DNA and/or RNA sequences
colchicine
an alkaloid that will inhibit polymerization of microtubules
recessive lethal allele
an allele that negatively affects the survival of a homozygote
temperature-sensitive allele
an allele whose product is functional only at certain temperatures common in: siamese cat, himalayan bunny
synthetic genome
an artificially constructed genome for artificial cells or designer organisms
nucleosome core particle
an eight-protein particle formed by the combination of two molecules each of H2A, H2B, H3, and H4, around which DNA winds for almost two turns.
Polymerase
an enzyme that brings about the formation of a particular polymer, especially DNA or RNA.
Telomerase
an enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
Primase
an enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.
DNA helicase
an enzyme that unwinds the DNA double helix during DNA replication
inducible enzymes
an enzyme whose transcription can be stimulated by an abundance of its substrate (as opposed to repressible enzyme). Usually in catabolism.
equilibrium dialysis
an experimental technique that can be used to determine the affinity of an antibody for antigen and its valency
trihybrid cross
an individual or strain that is heterozygous for three pairs of genes
Autopolyploidy
an individual that has more than two chromosome sets that are all derived from a single species
X-ray diffraction analysis
an instrumental technique used to determine dimensions of a crystal structure by measuring the diffraction patterns caused by x-rays impinging on the crystal
hermaphrodite
an organism that has both male and female reproductive organs
probe
any DNA or RNA sequence that is complementary to some part of the target gene to be identifies in a library
autosomes
any chromosome that is not a sex chromosome
permease
any protein that aids in the movement of a specific type of molecule across a cell membrane
Proximal promoter element
any regulatory sequence in eukaryotic DNA that is located close to (within 200 base pairs) a promoter and binds a specific protein thereby modulating transcription of the associated protein coding gene
Holoenzyme
apoenzyme + cofactor
when a single character is being studied, a ratio that is expressed in 16 parts suggests that two gene pairs
are "interacting" in the expression of the phenotype under consideration.
Long interspersed elements
are a group of non-LTR (long terminal repeat) retrotransposons that are widespread in the genome of many eukaryotes
Coiled chromatin fibers
are compacted into a chromatid (700 nm) to make the chromosome 1400 nm. Packing ratio of 500 to 1.
HAT enzymes
are enzymes that acetylate conserved lysine amino acids on histone proteins by transferring an acetyl group from acetyl-CoA to form ε-N-acetyllysine
initiation of transcription
attachment of RNA polymerase to the promoter RNA polymerase binds to a promoter start (start!)
When more than two haploid sets of chromosomes are present, these may be derived from different species
aullotetraploidy
When more than two haploid sets of chromosomes are present, these may be derived from the same species
autoploidy
these often have one chromosome
bacteria and viruses
partial diploid
bacterial cell that possesses two copies of genes, including one copy on the bacterial chromosome and the other on an extra piece of DNA (usually a plasmid); also called merozygote.
colicins
bacteriocins produced by E. coli
MS2
bacteriophage that produces 4 proteins using overlapping genes
Puff
bands of polytene chromosomes become enlarged at certain times to form swellings
Nucleoside
base + sugar
5-BU
base analog, substituting for thymine in DNA, and can induce DNA mutation in the same way as 2-aminopurine
half of the tetrad, before anaphase 1, will
be pulled to one pole, the other the opposite
Chromomeres
beadlike thickenings that form during prophase
Termination
begins when RNA polymerase binds to a promoter sequence near the beginning of a gene
cell-free protein-synthesizing system
begins with a cell extract, or lysate, containing all the essential factors for protein synthesis: ribosomes, tRNAs, amino acids, and other molecules essential to translation , but with organelles and cell membranes removed
respiratory proteins
bind oxygen at high concentrations; release oxygen at low concentrations
Activators repressors
bind to DNA close to the promoter and either activate or repress the activity of RNA polymerase
Poly A binding proteins
bind to and stabilize poly-A tail *Involved in mRNA stability and translation*
Transcriptional activators
bind to regulatory DNA sequences and stimulate transcription
repression loop
binding of repressor to operators O1 and O3 creates repression loop Prevents access of RNA polymerase to promoter
DnaA
binds to the origin of replication and is responsible for the initial steps in unwinding the helix
autosomal dominant
both M and F are affected; M may transmit to M; each generation has at least one affected parent; and one mutant allele may produce the disease.
BRCA1
breast cancer gene 1
Transcription components
building blocks (three phosphates for energy) template strand, and enzymes (rna polymerase and transcription factors)
Adapter mode
can be ligated to the ends of other DNA or RNA molecules
Cis acting elements
can only influence expression of adjacent genes on the same DNA molecule
Transposable
capable of being interchanged
Exome Aggregation Consortium
cataloged genetic variation from exome sequences
Enzymes
catalysts for chemical reactions in living things
Ribozymes
catalytic RNA molecules that function as enzymes and can splice RNA
RNAPs
catalyze transcription
progenitor cells
cells of the ventricular zone that divide and give rise to cells of the CNS
telocentric
centromere at end
metacentric
centromere in middle
submetacentric
centromere slightly off center
receptor molecule
certain protein molecules in the cell membrane that can receive chemical messages from other cells
chromosome mutation
change in chromosome structure
branch migration
changes amount of hybrid DNA present
Posttranscriptional modification
changes made to pre-mRNA molecules during conversion to mature mRNA. These include the addition of a methylated cap at the 5' end and a poly-A tail at the 3' end, excision of introns, and exon splicing.
isoropylthiogalactoside
chemical analogs of lactose sulfur-containing analog
gratuitous inducers
chemical analogs of lactose which induce transcription
Hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Ordered genetic code
chemically similar amino acids often share one or two middle bases (hydrophillic or hydrophobic for example)
Biochemistry
chemistry dealing with chemical compounds and processes in living plants and animals
CVS
chorionic villus sampling
dicentric chromatid
chromatid with two centromeres
sex chromosomes
chromosomes that determine the sex of an individual
female
circle
Pre initiation complex
cluster of transcription factors and other proteins that recruit RNA polymerase II for transcription of a DNA template
Transcription factors
collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.
northern blotting
combines gel electrophoresis of mRNA followed by hybridization with a probe on a membrane
adenosine triphosphate (ATP)
compound used by cells to store and release energy
consensus sequence
comprises the most commonly encountered nucleotides found at a specific location in DNA or RNA.
Hershey and Chase
concluded that the genetic material of the bacteriophage was DNA, not protein.
trisomy 21
condition in which an individual has three number 21 chromosomes, resulting in Down syndrome
transgenic organisms
contain at least one gene from another species
repressible
contain genes coding for anabolic enzymes; several genes in a series are turned off by the product synthesized by the enzyme
Eukaryotic gene expression
contain introns; one gene per mRNA molecule; transcription in nucleus, translation in cytoplasm; initiation begins at AUG codon preceded by 5' cap (methylated GTP) that binds the ribosome; many modifications while mRNA is in nucleus: introns are removed and exons are spliced together; a 5' cap and poly-A tail is added
balancer chromosomes
contain multiple overlapping inversions as well as a marker mutation that produces a visible dominant phenotype
bacterial genomes
contained in a single circular chromosome
X-degenerative region
contains old Y-linked homologs that are in the process of degenerating
lactose operon
contains three structural genes, each coding for an enzyme that aids in lactose metabolism
lactose (lac) operon
control system that manages the regulation of lactose metabolism. It is composed of three DNA segments, including a regulator, a control locus, and a structural locus.
operon model
controls gene expression in bacteria
Sigma factor
controls the binding of RNA polymerase to the promoter
Phenylalanine hydroxylase
converts phenylalanine to tyrosine
aromatase
converts testosterone to estradiol
Replication
copying process by which a cell duplicates its DNA
rearranging of genetic info in a diploid organism has this effect
could change viability
Peptide bond
covalent bond formed between amino acids
Nirenberg, Matthaei
cracked the genetic code, determined what codons (nitrogen bases) code for what amino acids
progenitor cell
daughter cell of a stem cell whose own daughter cells are restricted to follow specific lineages
inactivated vaccines
dead organisms injected into patient to build immunity
Together, the cell-free system for protein synthesis and the availability of synthetic mRNAs provided a means of
deciphering the ribonucleotide composition of various codons encoding specific amino acids
Translation
decoding of a mRNA message into a polypeptide chain
Parkinson disease
degeneration of neurons in the basal ganglia, occurring in later life and leading to tremors, weakness of muscles, and slowness of movement
terminal deletion
deletion at end of chromosome
intercalary deletion
deletion from the interior of the chromosome
Cri du chat
deletion on chromosome 5
sex chromatin body (Barr body)
densely staining DNA-positive mass seen in the somatic nuclei of mammalian females. Discovered by Murray Barr, this body represents an inactived X chromosome
attenuation
dilution or weakening of virulence of a microorganism, reducing or abolishing pathogenicity
phenotypic expression is not always the _____ reflection of the _________
direct genotype
RNA editing
direct alteration of one or more nucleotides in an mRNA that has already been synthesized
A
dominant; describes a trait that covers over, or dominates, another form of that trait.
structure of mtDNA
double stranded; closed circle
DPE
downstream promoter element
PAE mutations
due to paternal age
DNA gyrase
enzyme that temporarily breaks the strands of DNA, relieving the tension caused by unwinding the two strands of the DNA helix
Biological catalysts
enzymes
replication in mitochondria is dependent on ___ encoded by nuclear DNA.
enzymes
Topoisomerases
enzymes that relieve twists and kinks in a DNA molecule by breaking and rejoining the strands.
A condition in which one gene pair masks the expression of a nonallelic gene pair is called ________.
epistasis
males produce _____ numbers of X and Y bearing sperm
equal
the number of chromosomes in each gamete is ______ to the haploid number
equal to
DNA Polymerase IV
error Prone, last resort polymerase
Nondisjunction
error in meiosis in which homologous chromosomes fail to separate.
General transcription factors
essential for the transcription of all protein-coding genes
ELSI program
ethical, legal, and social implications focuses on privacy, fairness, and other factors in research
_____ cells contain much more DNA, this DNA is complexed with nucleosomes
eukaryotes
_____ chromosomes are linear rather than circular
eukaryotic
Heterochromatin
eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.
Probes
evaluate whether treatment effects are evident before treatment occurs
homologous recombination
exchange of genetic information between homologous DNA molecules.
dominant negative mutation
exerts a dominant effect; heterozygote produces a nonfunctional altered protein that also prevents the normal gene product from functioning
Conditional mutations
expressed only under certain environmental conditions
Extrons
expressed sequence of DNA; codes for a protein
triplo X
extra X chromosome in females, tall stature, irregular menstrual cycle, intellectually a little slower than siblings,
regulator quantity
facilitates isolation, they used a regulator quantity (Iq)(Iq) mutant strain that contains about ten times as much repressor as do wild-type E. coli cells.
Because transcription occurs only when the repressor ____ ___ ______ to the operator region, regulation is said to be under negative control.
fail to bind
14/21 translocation
familial down syndrome
DNA Pol IV
family Y DNA pol; bypass replication
Alu family
family of repetitive elements in primate genomes, including the human genome. Modern Alu elements are about 300 base pairs long and are therefore classified as short interspersed nuclear elements (SINEs) among the class of repetitive DNA elements
when the loci of two linked genes are _____, the number of recombinant gametes approaches, but ____ 50 percent
far apart, but does not exceed
Thus, it is evident that if four or five genes are being mapped, even ___ triple and quadruple crossovers can be expected to occur
fewer
synthetic biology
field of biology involved in engineering new functions from living systems
ootid
final product of oogenesis; following a period of maturation, becomes an ovum
prophase
first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus
F1
first filial generation
vertical gene transfer
flow of genetic information from one generation to the next
riboswitches
folded RNAs that act as switches regulating protein synthesis in response to environmental conditions
G2 gap
follows the S phase where the cell, having replicated its DNA, preps for mitosis
parental inheritance
for each character, an organism inherits one allele from each parent
why are chromosomal aberrations neccessary?
for the evolutionary process
P-DNA
form of DNA; less tightly coiled and more extended and having the phosphate backbone on the outside
heteroduplex DNA molecules
formed during genetic recombination and can be produced in vitro in DNA hybridization
Pseudogenes
former genes that have accumulated mutations over a long time and no longer produce functional proteins
terminator hairpin
forms in presence of tryptophan; ribosome proceeds through sequence
lampbrush chromosomes
found in oocytes of most vertebrae and the spermatocytes of insects. These are large with extensive DNA looping.
Eukaryotic polymerases fundamental requirements for DNA synthesis:
four deoxyribonucleoside triphosphates, a template, and a primer
spermatids
four haploid cells that are formed when a diploid reproductive cell divides meiotically
multiple-copy genes
functional genes present in more than one copy
synkaryon
fused gametic or somatic nuclei of two different species
somatic cell hybridization
fusion of somatic cells of different types.
recombinant gametes
gametes containing new combinations of alleles due to crossing over at prophase 1 of meiosis
H2A.Z
gene expression, chromosome segregation
hypostatic
gene that is masked
repressor gene
gene that prevents a nonallele from being transcribed
The chromosomal theory of inheritance states that
genes are on chromosomes
selectable marker gene
genes carried by plasmids for certain traits, often for antibiotic resistance
structural genes
genes that code for proteins
operons
genes that coordinate the regulation of gene expression
constitutive mutations
genes with these mutations produce enzymes regardless of lactose presence/absence
In the absence of _____ and under inducible conditions, CAP exerts positive control by binding to the CAP site, facilitating __________ binding at the promoter, and thus transcription.
glucose RNA-polymerase
sedimentation equilibrium
gravity is balanced by Brownian movement
the ___ the distance between two genes on a chromosome, the ____ the frequency of crossing over is between them.
greater, higher
GFP
green fluorescent protein
Next generation sequencing
group of automated techniques used for rapid DNA sequencing
Anticodon
group of three bases on a tRNA molecule that are complementary to an mRNA codon
gene families
groups of related genes in an organism's genome.
In sea urchin DNA, which is double stranded, 17.5 percent of the bases were shown to be cytosine (C). What percentages of the other three bases are expected to be present in this DNA?
guanine = 17.5%; adenine and thymine both each = 32.5%
GTP
guanosine triphosphate
gRNA
guide RNA RNA editing
meiosis leads to the formation of gametes; in plants _______ are produced
haploid spores
tetramer
have 2 alpha and 2 beta chains: forms quaternary structure
knock in animals
have a human gene inserted to replace their own counterpart
disruption of any mitochondrial gene by mutation may potentially
have a severe impact on that organism
mitochondrial mutations
have been linked to many disease and the aging process
spindle fibers
help pull apart the cell during replication and are made up of microtubules
Huntington disease
hereditary disorder marked by degenerative changes in the cerebrum leading to abrupt involuntary movements and mental deterioration
carriers
heterozygous individuals who carry the recessive allele but are phenotypically normal
phenotypic expression
how one looks and sometimes acts (partially determined by heredity or genotype but can also be influenced by environment)
heterokaryon
hybrid cell contains two nuclei in a common cytoplasm
secondary protein structure
hydrogen bonding of the peptide backbone causes the amino acids to fold into a repeating pattern
monozygotic twins
identical twins
Substitution editing
identities of individual nucleotide bases are altered; prevalent in mitochondria and chloroplast RNA derived in plants
in what instance would a breakage and rejoining be heritable
if the alteration is in germ cells involved in the formation of a gamete
Triplet codons
in RNA, a three-base "word" that codes for one amino acid
competence
in bacteria, transient state which the cell can bind and internalize exogenous DNA molecules making transformation possible
DNA Polymerase III
in charge of synthesizing nucleotides onto the leading end in the classic 5' to 3' direction.
GC box
in eukaryotes the region in the promoter containing 5' GGGCGG 3' sequence which is a binding site for transcriptional regulatory proteins
proband
in genetics research, the individual displaying the trait or characteristic being studied
reductional division
in meiosis I, homologous chromosomes are separated generating haploid daughter cells
CCL3L1
increase in this gene imparts an HIV suppressive effect during infection = diminish progression to AIDS
as sample size _______ the average deviation from the expected results decreases.
increases
As the distance between the two genes ___, the proportion of recombinant gametes ___ and that of the parental gametes ____
increases increases decreases
chromosome maps
indicate relative location of genes on chromosome
The enzymes responsible for lactose metabolism are thus __________, and lactose serves as the _________.
inducible inducer
Prions
infectious protein particles that do not have a genome
mastitis
inflammation of the breast
autosomal dominant
inheritance pattern of a dominant allele on an autosome; impacts both sexes
Silencers
inhibit transcription
catabolite repression
inhibits cells from using carbon sources other than glucose
G1 cyclins
initiate cell cycle
DNA-based vaccines
inject into muscle tissue, which expresses for a short time
Global hypomethylation may cause genomic ________ and the large-scale chromosomal changes that are a characteristic feature of _______.
instability cancer
thermocyclers
instruments that can be programmed to automatically adjust and cycle through the required temps.
lag phase
intense activity preparing for population growth, but no increase in population
paracentric inversion
inversion that does not include the centromere
pericentric inversion
inversion that includes the centromere
UV light
invisible light that lies beyond violet. Has higher energy and shorter wavelengths than visible light does.
DNA Pol II
involved in DNA repair processes
IIR cells & IIS virulent cells
involved in early DNA experiments
mixed infection experiments
involves infecting the same bacterial culture with 2 distinct mutant phage strains
General recombination
involves large regions of sequence homology between recombining DNA molecules.
E-DNA
is collected from a variety of environmental samples such as soil, seawater, snow or even air rather than directly sampled from an individual organism. As various organisms interact with the environment, DNA is expelled and accumulates in their surroundings.
single cell RNA sequencing
isolate DNA and RNA from the same cells
Spliced
joining together; unite by weaving
neutral petites
lack most of their mitochondrial DNA; when mated with wildtype, the wildtype give their mitochondria so all cells display a normal phenotype.
supressive petites
lack only small segments of mtDNA
acentric chromatid
lacks a centromere
In the presence of _______, the concentration of the enzymes responsible for its metabolism increases rapidly from a few molecules to thousands per cell.
lactose
a zygote receives a ____ number of organelles through the egg,
large
RNA polymerase I
located in the nucleolus and synthesizes rRNA
RNA polymerase III
located in the nucleus and synthesizes tRNA and some rRNA
q arm
long arm of chromosome
Polypeptide chain
long chain of amino acids linked by peptide bonds
Protein structure
long chains of amino acids
LINE sequence
long interspersed retrotransposable elements, respectively, that invade new genomic sites using RNA intermediates.
fMet
mRNA start codon (AUG) codes for N-formylmethionine in proks that stimulates neutrophil chemotaxis
ZZ/ZW
male is homogametic, female is heterogametic
following conception more _______ were than ____ were born
males; females
traits are influenced by
many gene products
bicoid
maternal effect gene dealing with protein concentration in Drosophila during embryogenesis.
cosanguinity
mating between closely related people
inducer molecule
may bind to the repressor protein and alters its conformation (cannot bind to operator)
Svedberg coefficient (S)
measurement of RNA's density, mass and shape
Myoclonic epilepsy with ragged red fibers (MERRF)
mitochondrial disease, mutation in tRNA gene, affects neurons and muscle cells (that require large amounts of ATP), heteroplasmy
single celled organisms use this process to reproduce
mitosis - asexual reproduction also: protozoans, and some fungi, algae
fungi and plants proliferate by ___________ cell division
mitotic
Monoallelic expression MAE
mitotically stable, epigenetically controlled allele-specific expression of autosomal genes, with the initial non-predetermined ('random') choice of the transcriptional activity of the two alleles maintained in a given clonal cell lineage
biopharmeceutical
most successful and widespread application of recombination DNA technology by the biotech industry
chromatin assembly factors (CAFs)
move along with the replication fork and assemble new nucleosomes
Metastatic
moves from site of origin to secondary site in body
Chloroplast Mutations
mt- parent transmits mitochondrial info
Ampliconic region
multicopy testis-specific genes with no X-linked homologs
reciprocal classes
mutant alleles found on a single chromosome while wild type alleles are found on the other homolog
auxotroph
mutant that requires a growth factor
lethal alleles
mutated genes that are capable of causing death.
Frameshift mutation
mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide
amniocentesis
needle puncture of the amniotic sac to withdraw amniotic fluid for analysis
Binding of a trans-acting element at a cis-acting site can regulate the gene cluster either - or +
negatively (by turning off transcription) or positively (by turning on transcription of genes in the cluster).
noncrossover
no crossing over occurs, most common result in offspring
Short interspersed elements
non-autonomous, non-coding transposable elements that are about 100 to 700 base pairs in length
ncRNAs
non-protein-coding RNAs that play a role in gene expression
complementary gene interaction
nonallelic gene interaction or epistasis where dominant alleles at heterozygous loci may complement each other by masking recessive alleles at respective loci
Introns
noncoding segments of nucleic acid that lie between coding sequences.
NIPGD
noninvasive prenatal genetic diagnosis
linked genes are _____ to undergo independent assortment
not free
insertion/deletion editing
nucleotides are added to or subtracted from the total number of bases
genetic anticipation
number of repeats increases in future generations causing symptoms to be worse
degrees of freedom
number of scores that can vary in the calculation of a statistic
sister chromatid exchanges
occur during mitosis but do not produce new allelic combinations
spontaneous mutations
occur in the absence of a mutagen
tertiary protein structure
occurs when certain attractions are present between alpha helices and pleated sheets
linkage
occurs when different traits are inherited together more often than they would have been by chance along; it is assumed that these traits are linked on the same chromosome
Initiation
occurs when the enzyme RNA polymerase binds to a promoter signals the DNA to unwind enzyme is now ready to make a strand of mRNA with a complementary sequence of bases.
temperature dependent sex determination
occurs when the sex of an individual is determined by the temperature at which eggs develop
prognostic
of or pertaining to prognosis; predictive of something in the future; a forecast or prediction; an omen or portent; sign.
organelle hereditary comes from
often, maternal parent thru ooplasm to offspring causing the results of reciprocal crosses to vary
Commaless
once translation begins, codons are read with no break
nonsister chromatids
one maternal and one paternal chromatid of a homologous pair
homolog
one of a pair of chromosomes having corresponding loci
Guide model
one of the models that is noteworthy, however google does not know what it is and I am too lazy to look in the book again
Alphoid family
one of the most recognized satellite DNA sequences in humans found mainly in centromere regions
chromosome inactivation
one of the x chromosomes stops working in each of the females body cells
Anticodon loop
one of three loops on a tRNA which contains the 3 nucleotides that allow it to align specifically with mRNA. Contains the anticodon
inheritance of traits is controlled by
only one set of genes
the result of complete linkage is
only parental gametes
C banding
only the centromeres are stained
Inducible
operon is turned ON by substrate: catabolic operons - enzymes needed to metabolize a nutrient are produced when needed
transduction studies can determine the _________ genes
order of 2-3 linked
chimeras
organisms that contain cells from two different lineages
Whereas promoters are _____ specific, an enhancer can be inverted, relative to the gene it regulates, _____ a significant effect on its action.
orientation without
oriC
origin of replication in E. coli
Epigenome
overall pattern of chromatin modifications possessed by each individual organism
CDKN2A
p16, blocks G1->S phase Melanoma, pancreatic cancer
harlequin chromosomes
paired human sister chromatids stained to reveal sister chromatid exchanges
P1
parental generation
hereditary deafness
partial or complete loss of hearing discovered at birth
Receptors
parts of the cell membrane that receive the neurotransmitter and initiate or prevent a new electric signal
intersexes
people with an anatomy that appears intermediate between male and female
stationary phase
period of equilibrium; microbial deaths balance production of new cells
diagnostic
pertaining to or establishing a diagnosis
phage vectors
phages that carry pieces of bacterial DNA during transduction
telophase
phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin
linkage ratio
phenotypic ratio of two linked traits resulting from two heterozygous individuals
minor alterations of genetic info can result in
phenotypic variation
this action is essential to genetic recombination
physical contact between cells of two strains
nucleoside diphosphates (NDPs)
pivotal molecules in a plethora of cellular processes
sporophyte stage
plant life cycle stage that begins when an egg is fertilized by a sperm
gametophyte stage
plant life cycle stage that begins when cells in reproductive organs undergo meiosis and produce haploid cells
GM crops
plants that have been genetically altered through biotechnology
polyploidy occurs more in
plants, fish, lizards, amphibians
PGD
preimplantation genetic diagnosis
heteroplasmy
presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrial inherited disease
Scrapie
prion disease in sheep
dihybrid ratios
probability that two of more independent events will occur simultaneously is equal to the product of the probability that each will occur independent.
gene expression
process by which a gene produces its product and the product carries out its function
Genetic expression
process by which information from a gene is used in the synthesis of a functional gene product
RNA splicing
process by which the introns are removed from RNA transcripts and the remaining exons are joined together.
crossing over
process in which homologous chromosomes exchange portions of their chromatids during meiosis.
Transformation
process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria
transformation
process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria
cotransformation
process in which two or more genes are transferred together during cell transformation
5-methylcytosine
produced by DNA methyltransferase after replication
antithrombin
produced by liver, slowly inactivates thrombin
vaccine proteins
produced in plants
bioreactors
production of compounds using engineered biofilms
Spermatogenesis
production of sperm
NIH Roadmap Epigenomic Project
project with the goal of producing a public resource of human epigenomic data to catalyze basic biology and disease-oriented research
Core enzyme
prokaryotic RNA polymerase consisting of α, α, β, and β' but missing σ; this complex performs elongation
Whereas ____ must be immediately upstream of the genes they regulate, the position of an enhancer is _____; it will function the same whether it is upstream, downstream, or within a gene.
promoters not critical
embryonic development depends on
proper timing regulated gene expression levels
Sliding DNA clamp
protein complex that keeps DNA polymerase bound to DNA during replication.
Chromatin remodeling complexes
protein machines that use the energy of ATP hydrolysis to change the position of the DNA wrapped around nucleosomes
Writers
protein methyltransferase, histone acetyltransferase
Histones
protein molecules around which DNA is tightly coiled in chromatin
catabolite activator protein (CAP)
protein that functions in catabolite repression. When bound with cAMP, CAP binds to the promoter of certain operons and stimulates transcription.
Rh antigens
proteins on the surface of red blood cells, antibodies against these proteins agglutinate red blood cells that express the proteins
Chaperones
proteins that assist in protein folding during posttranslational processing
Heat shock proteins
proteins that help maintain integrity of other proteins that would normally be denatured in extreme heat.
cyclins
proteins that regulate the timing of the cell cycle in eukaryotic cells
molecular motors
proteins that use energy to move and perform mechanical work
translocations
rearrangements of chromosomes due to the insertion of genetic material from one chromosome to another.
a
recessive; describes a trait that is covered over, or dominated, by another form of that trait and seems to disappear.
merozygote
recipient cell that is temporarily diploid as result of transfer process
F- cells
recipient cells lacking F factor
Ubiquitin ligases
recognizes specific protein substrates and attach a ubiquitin tag. The proteins are then degraded to an appropriate size and coupled with the major histocompatibility I protein complex in the ER so they can be presented to CD8+ T cells.
rDNA
recombinant DNA
sebelipase alfa
recombinant enzyme purified from the egg whites of transgenic hens
intergenic recombination
recombination between genes
duplication
repeats a segment
genetic recombination in bacteria
replacement of one or more genes in the chromosome of one cell with those from a genetically distinct cell
Polymerase II
replaces RNA primers with DNA
lower case letter
represents recessive allele
infectious heredity
results from a symbiotic or parasitic association with a microorganism
single crossovers
results in genetic recombination. the chromatids involved in this single crossover exchange alleles at a given locus. Results in 2/4 recombinants.
allosteric repressor
reversibly changes shape and cannot bind to operator
Middle repetitive DNA
ribosomal RNA genes
RRNA
ribosomal RNA; type of RNA that makes up part of the ribosome
rRNA
ribosomal RNA; type of RNA that makes up part of the ribosome
intellecutal property
rights dealing with genomics and biotechnology
Oligonucleotides
segments of nucleic acid that are 50 nucleotides or less in length
selfing
self-fertilization in plants
primary protein structure
sequence of amino acids
Variable number tandem repeats
sequences can repeat a few or many times in tandem
palindrome sequence`
sequences of base pairs that read the same but in the opp direction on complementary strands; on MSY
Microsatellites
sequences of repeated base pairs of DNA, usually no more than two to six. If repeated excessively, they are often associated with neurological disorders, such as Huntington's chorea.
Triplets
sequences of three nitrogen bases each in DNA, known as codons in mRNA
endopolyploidy
several rounds of DNA replication without separation of replicate chromosomes
SARS
severe acute respiratory syndrome
SRY gene
sex determining region of the Y chromosome
sry gene
sex determining region of the Y chromosome
terminalization
shifting of the chiasmata from their original position at the centromere toward the chromosome end or telomere.
p arm
short arm of chromosome
Okazaki fragments
short fragments of DNA that are a result of the synthesis of the lagging strand during DNA replication.
SINE sequence
short interspersed retrotransposable elements, respectively, that invade new genomic sites using RNA intermediates.
Satellite DNA
short sequences of DNA that are tandemly repeated as many as 10 million times in the DNA; much of it is located in the telomeres
Signs of Turner Syndrome
short stature, delayed puberty, infertility, heart defects, and certain learning disabilities.
Consensus sequences
short stretches of DNA that appear, with little variation, in many different genes.
Tandem repeats
short, adjacent segments of DNA within a gene that are repeated several times
HbS
sickle cell hemoglobin
Epigenetic mechanisms can replace mutations as a way of _______ individual tumor-suppressor genes or activating oncogenes.
silencing
short tandem repeats
simple sequence DNA containing multiple tandemly repeated units of two to five nucleotides.
SNPs
single nucleotide polymorphisms
anaphase 2
sister chromatids separate
meiosis 2
sister chromatids separate
Ribosomes
site of protein synthesis
ribosomes
site of protein synthesis
origin of replication
site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.
codominance
situation in which both alleles of a gene contribute to the phenotype of the organism
sRNAs
small RNA molecules that regulate translation in trans by base-pairing with sites on mRNAs that can hide or expose the ribosome binding site
plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome
snRNAs
small nuclear RNAs, function in a variety of nuclear processes, including the splicing of pre-mRNA
snRNPs
small nuclear ribonucleoproteins
segregational petites
small percent of mutations are result of nuclear mutations
pseudoautosomal region
small region on the X and Y chromosomes that contains homologous gene sequences
SLC30A8 gene
solute carrier family 30, member 8 gene
White eye color is an X-linked trait in one line of fruit flies. White eyes is recessive to red eyes. If a red-eyed female and a white-eyed male are crossed, _______. some of their male progeny may have white eyes
some of their male progeny may have white eyes (If the female is heterozygous, approximately half of the male progeny will have white eyes.)
random fertilization
source of genetic variation caused by the unlimited number of possible sperm & egg combinations
UGA
stop codon
What is the *leading cause of streptococcal mastitis* in dairy cattle in North America?
streptococcus uberis
polyribosome
string of ribosomes simultaneously translating regions of the same mRNA strand during protein synthesis
Histone tails
strings of amino acids that protrude from the histone proteins in the nucleosome
Polyribosomes
strings of ribosomes that work together to translate a RNA message.
Collagen
structural protein found in the skin and connective tissue
tetrad
structure containing four chromatids that forms during meiosis
gonadal ridges
structure that appears at approximately 5 weeks' gestation and becomes either ovaries or testes
Protein function
structure, enzymes, cell signaling
Epigenics
study of heritable changes in gene expression that are not caused by changes in the DNA sequence
genomics
study of whole genomes, including genes and their functions
Ribose
sugar in RNA
Reverse transcription
synthesis of DNA from an RNA template
reverse transcription
synthesis of DNA from an RNA template
DNA Pol V
synthesize DNA only in 5'->3' direction, can only add new dNTP's to a primer strand, cant initiate otherwise, cleaves off 2 phosphate (pyrophosphate), all primers are 5-8 nucleotides long and primase lies them down
C-DNA
synthesized from a single-stranded RNA
symptoms of Kleinfelter syndrome
tall, low testosterone and reduced muscle mass, facial/body hair, produce little or no sperm
Southern Blot Analysis
technique in which labeled probes are used to detect specific DNA fragments that have been separated by gel electrophoresis
molecular hybridization
technique used to identify specific DNAs in complex mixtures such as libraries
Assisted reproductive technologies
technologies that assist infertile couples to conceive a child
recombinant DNA technology
technology that combines genes from different sources into a single DNA molecule
Melting temperature
temperature at which a membrane transitions from being highly ordered to very fluid
genetic linkage
tendency for genes located close together on the same chromosome to be inherited together
transgenic
term used to refer to an organism that contains genes from other organisms
medulla develops into
testis
Polyadenylation
the addition of multiple adenine nucleotides to the 3' end of a newly synthesized mRNA molecule
maternal influence
the aggregate of all psychological effects mothers have on their children
Haploinsufficiency
the appearance of a mutant phenotype in an individual cell or organism that is heterozygous for a normally recessive trait
sex determination
the biological mechanism that determines whether an organism will develop as a male or female
personal genomics
the branch of genomics focused on sequencing individual genomes
recombiant DNA technology
the combination of DNA from two or more sources into a product
Genome
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes
genome
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes
Senescence
the condition or process of deterioration with age
Euploidy
the correct number of chromosomes in a species
synteny testing
the correlation of the pres/abs of each chromosome with the pres/abs of each gene product
Posttranslational modification
the covalent and generally enzymatic modification of proteins during or after protein synthesis.
expressivity
the degree to which a genotype is expressed in an individual
bacterial conjugation
the direct transfer of genetic material (DNA) from one bacterial cell to another
a given phenotype often varies depending on
the environment the organism is in
adenyl cyclase
the enzyme found inside cells, associated with hormone receptors, that converts ATP to cAMP.
Core enzyme
the enzyme responsible for catalysis in a multipart holoenzyme
telomerase reverse transcriptase (TERT)
the enzyme within telomerase that uses RNA as a template to make DNA
Chain elongation
the formation of peptide bonds between successive amino acid residues
chain elongation
the formation of peptide bonds between successive amino acid residues
One gene one enzyme hypothesis
the function of a gene is to dictate the production of a specific enzyme
transgenes
the genes that have moved between organisms
The coiling pattern of the progeny snails is determined by
the genotype of the parent producing the egg, regardless of the phenotype of that parent.
bipotential gonad
the gonad of the developing embryo that is capable of differentiating along two developmental pathways toward the development of either a testis or the ovary
sperm cells made during spermatogenesis contain
the halpoid number of chromosomes and equal cytoplasm amounts
Transgenerational inheritance
the heritable transmission to future generations of environmentally-caused phenotypes
genetic background
the impact of the collective genome of an organism on the expression of a gene under investigation
The variations in the gene products encoded in the cpDNA of different plants again attest to
the independent evolution that occurred within chloroplasts
extranuclear inheritance
the inheritance of genetic material that is not found within the nucleus
interference (I)
the inhibition of further crossover events by a crossover event in a nearby region of the chromosome, causes this reduction
Major groove
the larger of the two grooves in the DNA double helix
CEN region
the minimal region of the centromere that supports the function of chromosomal segregation
Transcription
the organic process whereby the DNA sequence in a gene is copied into mRNA
Nuclein
the original name given to DNA when it was discovered in the nucleus of cells by Friedrich Miescher in 1869
three point mapping
the parent must be heterozygous for all three genes under consideration
conservative replication
the parental molecule serves as a template for the synthesis of an entirely new molecule
x linkage
the pattern of inheritance resulting from genes located on the X chromosome
penetrance
the percentage of individuals with a particular genotype that actually displays the phenotype associated with the genotype.
positive interference
the phenomenon in which a crossover that occurs in one region of a chromosome decreases the probability that another crossover will occur nearby
gene redundancy
the phenomenon in which an inactive gene is compensated for by another gene with a similar function
negative interference
the phenomenon in which one crossover increases the likelihood of crossovers in nearby regions is called
genetic anticipation
the phenomenon in which the severity of symptoms in genetic disorders increases from generation to generation and the age of onset decreases from generation to generation.
Centromeres
the point on a chromosome by which it is attached to a spindle fiber during cell division.
dominant lethal allele
the presence of just one copy of the allele results in the death of the individual
pre-mRNAs
the primary transcript of a eukaryotic gene prior to processing to produce an mRNA.
sum law
the probability of obtaining any single outcome, where that outcome can be achieved by two or more events, is equal to the sum of the individual probabilities of all such events
Aminoacylation
the process by which a tRNA molecule is bound to its corresponding amino acid
Imprinting
the process by which certain animals form attachments during a critical period very early in life
sexual differentiation
the process by which males and females develop distinct reproductive anatomy
Transdifferentiation
the process by which stem cells from one tissue differentiate into cells of another tissue.
expression of information
the process by which the information encoded in a gene is used to direct the assembly of a protein molecule.
Bidirectional replication
the process in which DNA replication proceeds outward from the origin in opposite directions
disjunction
the separation of chromosomes during the anaphase stage of cell division
leader sequence
the sequence at the 5' end of an mRNA that is not translated into protein
Universal
the set of DNA and RNA sequences that determine the amino acid sequences used in the synthesis of an organism's proteins
Methylome
the set of nucleic acid methylation modifications in an organism's genome or in a particular cell.
heterogametic sex
the sex (male or female) that produces two types of gametes with respect to sex chromosomes. For example, in the XX-XY sex-determining system, the male produces both X-bearing and Y-bearing gametes.
Lagging strand
the strand in replication that is copied 3' to 5' as Okazaki fragments and then joined up.
Coding strand
the strand of DNA that is not used for transcription and is identical in sequence to mRNA, except it contains uracil instead of thymine
Linker DNA
the string between beads of DNA on histones. wrapped around a single histone, called linker histone - may not really have to know..
Epigenetics
the study of environmental influences on gene expression that occur without a DNA change
third generation sequencing
the techniques used are even faster and less expensive than the previous
cooperative binding
the tendency of the protein subunits of hemoglobin to affect each other's oxygen binding such that each bound oxygen molecule increases the likelihood of further oxygen binding.
anaphase
the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles
Phosphorylation
the transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation.
Exon shuffling
the variation in the patterns by which RNA may produce diverse sets of exons from a single gene.
endosymbiotic theory
theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms
why would a mutation be diluted for a zygote?
there are many mitochondria that lack the mutation
Focused core promoters
there is either a single transcription start site or a distinct cluster of start sites in a short region of several nucleotides
Ovalbumin gene
this gene has 8 exons and 7 introns
Poly A binding protein
this protein binds to the 3' end of mature RNA, preventing premature degradation
Trinucleotide
three joined nucleotides
multiple alleles
three or more forms of a gene that code for a single trait
Codon
three-nucleotide sequence on messenger RNA that codes for a single amino acid
why does meiosis need to occur?
to increase the level of genetic variation in the next generation
RNA polymerase II
transcribes mRNA
Information flow
transcription DNA to RNA translation RNA to protein = central dogma
when RNA polymerase is blocked
transcription ceases
Transcriptional repressors
transcription factors that turn down/off gene expression levels
postive control
transcription occurs only if a regulator molecule directly stimulates RNA production
TRNA
transfer RNA; type of RNA that carries amino acids to the ribosome
tRNA
transfer RNA; type of RNA that carries amino acids to the ribosome
horizontal gene transfer
transfer of genes between cells of the same generation
Retrotransposons
transposable elements that move within a genome by means of an RNA intermediate, a transcript of the retrotransposon DNA.
siRNA
triggers degradation of other RNA molecules
gain of a chromosome
trisomy
True or false: protein is abundant in the cytoplasm, whereas DNA is not
true
true or false: mutations in mtDNA occur at a rate that is at least tenfold higher than in nuclear DNA
true
trp operon
tryptophan binds to the repressor protein and enables it to repress gene transcription.
Supercoiling
twisting in the opposite direction to the turns of the double helix during the first stage of mitosis.
autosomal recessive
two copies of an abnormal gene must be present in order for the disease or trait to develop
when 1/16ths are seen in the ratios of crosses where the inheritance pattern is unknown it often means
two gene pairs are controlling the observed phenotypes
If crossing over does not occur within the inverted segment of the inversion loop, the homologs will segregate, which results in
two normal and two inverted chromatids that are distributed into gametes.
Dinucleotide
two nucleotides covalently bonded together by a phosphodiester bond
Overlapping genes
two or more genes in which part or all of one gene is embedded in the other
requirement for DCOs
two separate and independent events or exchanges must occur simultaneously
yeast
unicellular fungi
RNA heteropolymers
used calculated frequencies of ribonucleotides and found mRNA triplet compositions
deletion testing
used to provide a rough and quick localization of each mutation Benzer studied
Detergent deoxycholate
useful for disrupting and dissociating protein interactions
DNA Pol III
using parental DNA as a template, synthesizes new DNA strand by adding nucleotides to an RNA primer or a pre-existing DNA strand
attenuated vaccine
vaccine composed of a weakened form of the pathogen that is generally unable to cause disease
single nucleotide polymorphism
variation in a DNA sequence occurring when a single nucleotide in a genome is altered
SNPs
variations in the DNA sequence that occur when a single nucleotide in the genome is altered
the point of origin _______ from strain to strain
varies
hepatitis B virus
virus that causes inflammation of the liver; transmitted through any body fluid, including vaginal secretions, semen, and blood
Hydrophobic
water hating
Hydrophilic
water loving
primordial germ
what kind of cells develop and seed the developing gonads destined to become spermatogonia or oogonia?
Hairpin secondary structure
when the new RNA transcript folds back on itself and is held together by hydrogen bonds
product law
when two independent events occur simultaneously, the probability of the two outcomes occurring in combination is equal to the product of their individual probabilities of occurrence
Monosome
when two subunits are associated with each other in a single ribosome
Dominance/Recessiveness
when two unlike unit factors responsible for a single character are present in a single individual, one unit factor is dominant to the other, which is said to be recessive
threshold effect
whereby normal phenotypic expression occurs anytime a minimal level of gene product is attained
operator region
with which genetic region does the repressor protein interact?
Epigenetic cancer therapy
works by altering cell expression
superfemale
xxx
snRNA
• Found only in the nucleus of eukaryotes and functions to remove introns from mRNA
