Biology 1081 Exam 3
What initiates the movement of the chromosomes to the poles in prometaphase?
"capturing" by microtubules of the kinetochores
A protein kinase that is active only when attached to a particular cyclin
(Cyclin-dependent kinase) Cdk
A human genetic disease caused by a sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue
(Duchenne) muscular dystrophy
It is predictable that half of the human babies born will be male and half will be female because A of the segregation of the X and Y chromosomes during male meiosis B of the segregation of the X chromosomes during female meiosis C all eggs contain an X chromosome D Both 1 and 2
A
Mature nerve cells are incapable of cell division. These cells are probably in a. G1 b. the S phase c. G2 d. mitosis
A
Meiosis is used primarily a. to produce haploid gametes b. by animals but not plants c. for asexual reproduction d. to take a pause from the cell cycle
A
Nucleoli are present during _____. a. interphase b. prophase c. metaphase d. prometaphase e. anaphase
A
Spindle fibers attach to kinetochores during _____. a. prometaphase b. telophase c. anaphase d. interphase e. metaphase
A
The bacterial genome exist as a: a. single, circular, double stranded DNA molecule. b. single, circular, double stranded RNA molecule. c. single, linear, double stranded DNA molecule. d. many, circular, double stranded DNA molecules.
A
The members of a homologous pair of chromosomes a. are identical in size and appearance b. contain identical genetic information c. separate to opposite poles of the cell during mitosis d. are found only in haploid cells e. are present only after the S phase
A
What number and types of chromosomes are found in a human somatic cell? a. 44 autosomes and 2 sex chromosomes b. 21 autosomes and 2 sex chromosomes c. 22 autosomes and 1 sex chromosome d. n chromosomes e. 45 autosomes and 1 sex chromosome
A
Where do cells spend most of their time? a. Interphase b. Mitosis c. Cytokinesis d. Meiosis
A
Which of the following is an explanation for independent assortment, a factor in producing genetic variability? a. In anaphase I, how one pair separates does not affect how any other pair separates. b. Chromosomes are divided into daughter cells in a random fashion. c. In prophase I, which chromosomes pairs with which other one is completely random. d. Chromosomes can have different functions in various types of cells of the same organism.
A
Which of the following is not true of homologous chromosome pairs? a. They come from only one of the individual's parents b. They usually contain slightly different versions of the same genetic information c. They segregate from each other during meiosis I d. They synapse during meiosis I e. Each contains two sister chromatids at the beginning of meiosis I
A
_____ is a carcinogen that promotes colon cancer. a.fat b.UV light c.estrogen d.a virus e.testosterone
A
A ___% frequency of recombination in such testcrosses is observed for any two genes that are located on different chromosomes and thus cannot be linked
50
Genes can have a max value of __% recombination frequency
50
If a female was a carrier for sex-linked color blindness, what percentage of her male children would also be color blind? 0% 25% 50% 100%
50
When 50% of all offspring are recombinants, geneticists say there is a ___% frequency of recombination
50
Cleft chin is a sex-linked dominant trait. A man with a cleft chin marries a woman with a round chin. What percent of their female progeny will show the cleft chin trait? 0 25 50 75 100 What percent of their male progeny will show the cleft chin trait?
50 0
In your group: How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? 4 8 16 32 64
8
In guppies, fan tail is dominant to flesh tail, and rainbow color is dominant to pink. F1 female guppies are crossed with flesh-tailed, pink-colored males, and the following progeny are observed: 401 fan-tailed, pink-colored; 399 flesh-tailed, rainbow-colored; 98 flesh-tailed, pink-colored; and 102 fan-tailed, rainbow-colored guppies. Assuming that the F1 female guppies have both dominant alleles on one chromosome, the map distance between these two genes is 80 cM 25 cM 0.8 cM 20 cM None of the above
80
All of the following animal cells are diploid except a.gametes. b. muscles. c. nerves. d. skin. e. reproductive organ.
A
Calico cats are usually female, but rare males may be found Group question #33: How does this usually happen? A. Male is XXY B. Male is XYY C. Male is Y D. Male is XX
A
Centromeres divide and sister chromatids become full-fledged chromosomes during _____. a. anaphase b. interphase c. metaphase d. telophase e. prometaphase
A
Cytokinesis often, but not always, accompanies _____. a. telophase b. prometaphase c. metaphase d. interphase e. anaphase
A
If an XY human had a deletion of the SYR gene, they would A develop as a female. B have both male and female characteristics. C have ambiguous genitalia. D develop as a male.
A
Crossing over involves the exchange of genetic material between a. sister chromatids b. males and females c. sex chromosomes d. homologous chromosomes
D
Cytokinesis occurs right after a. prophase b. G2 c. anaphase d. telophase
D
During recombination there must be at least one crossing over per chromosome, but not more than two to three. The three genes involved in recombination in humans, MLH1, MLH3 and BLM have been found to suppress tumors. Mutations in these genes can cause excessive recombination, and ultimately lead to colon cancer and to Bloom's syndrome, which also results in cancer-prone individuals recombination. Which of the following is most likely false? a. Both strands of a DNA molecule are cut during recombination b .Cancer cells caused by excessive recombination fail to stop dividing c. Homologous chromosomes without recombination will still be genetically different from each other d. Centromeres are only found in chromosomes in Metaphase I, not in Metaphase II
D
During which phase of the cell cycle are mitochondria and chloroplasts distributed equally among daughter cells? a. G2 b. M c. C d. There is no mechanism to distribute mitochondria and chloroplasts equally among daughter cells.
D
Huntington's disease is caused by an autosomal dominant allele. It is a lethal disease, but it persists in the human population. Which of the following statements best describes why? A Huntington's disease is sex-linked and every human has at least one X chromosome; thus, the chances are extremely high for this allele to be maintained in the human population. B Huntington's disease can present symptoms so mild that they appear to lack dominant expression of the allele in some individuals; in those cases, the allele is passed on to the offspring. C While lethal to a parent, Huntington's disease will not be lethal to the offspring since it can skip a generation. D Huntington's disease presents symptoms in humans after many have already reproduced; therefore, they are unaware that they passed on Huntington's disease. E Huntington's disease can be treated in humans that are heterozygous for the condition, but individuals who are homozygous cannot receive treatments; thus, they pass on the alleles to their offspring.
D
If an XX individual had the translocation of an SYR gene to one of their X chromosomes, they would A 'develop as a female. B have both male and female characteristics. C have ambiguous genitalia. D develop as a male.
D
In which of these phases are the cells haploid? Interphase (a) Meiosis I (B) Meiosis (C) a. A and B b. A c. A and C d. B and C
D
Linked genes are genes that A assort independently B segregate equally in the gametes during meiosis C always contribute the same trait to the zygote D are found on the same chromosome
D
The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a A C = C bond. B hydrogen bond. C hydrophobic bond. D phosphodiester bond. E peptide bond.
D
Vinblastine is an antimicrotubule drug used to treat certain kinds of cancer, including Hodgkin's lymphoma, non-small cell lung cancer, breast cancer, head and neck cancer, and testicular cancer. Vinblastine was first obtained from C. roseus. It binds to tublin, thus interfering with microtubule assembly. Which of the following is most likely false? a. Stem cells in the bone marrow, which produce our white blood cells through mitosis, are inhibited. This is why it is used to treat lymphoma, a cancer of white blood cells. b. Vinblastine treatment prevents proper kinetochore function. c. Vinblastine is capable of binding to protein. d. Cancer cells treated with vinblastine typically get arrested (stuck) in S phase.
D
Which of the following DNA sequences is complementary to 5' ATGGTCAGT 3'? A 5' ATGGTCAGT 3' B 5' TGACTGGTA 3' C 5' TACCAGTCA 3' D 5' ACTGACCAT 3'
D
Which of the following is essentially the reverse of prophase? a. Anaphase b. Interphase c. Metaphase d. Telophase e. Cytokinesis
D
Which of the following is not a component of nucleic acids? A organic nitrogenous bases B sugar C phosphate D protein
D
Which of the following is true of sister chromatids? a. They are replicated chromosomes still joined together at the centromere b. They are nearly identical in mitotic chromosomes c. They are nearly identical in meiotic chromosomes d. Both A and B are true e. A, B, and C are all true
D
a hyperactive version of a protein in a stimulatory pathway, such as ___ (a G protein), functions as an oncogene protein
Ras
A gene that codes for a G protein that relays a growth signal from a growth factor receptor on the plasma membrane to a cascade of protein kinases, ultimately resulting in stimulation of the cell cycle
Ras gene
In 1952, Alfred Hershey and Martha Chase performed experiments showing that DNA is the genetic material of a phage known as T2. Tagged protein with radioactive isotope of __ in one batch of T2. Tagged DNA with radioactive isotope of ____ in second batch
S P
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated
S phase
In the absence of ___, the gonads develop into ovaries
SRY
___, the pairing of homologous chromosomes, occurs during ___.
Synapsis prophase I
All of the kinetochores of all chromosomes must be attached to the mitotic spindle before anaphase will begin. T/F
T
In single-celled eukaryotes that undergo binary fission, mitosis is part of the process. T/F
T
The requirement that a cell must be attached to a substratum in order to initiate cell division
anchorage dependence
a chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number
aneuploidy
referring to the arrangement of the sugar-phosphate backbones in DNA double helix
anti-parallel
Kinases (vary/are constant) in concentration in the cell
are constant
A radial array of short microtubules that extends from each centrosome toward the plasma membrane in an animals cell undergoing mitosis
aster
A chromosome that is not directly involved in determining sex; not a sex chromosome
autosome
most imprinted genes are on ___
autosomes
Name the three structures composing the spindle?
centrosomes spindle microtubules asters
wild-type flies have ___ bodies and ___-sized wings
gray normal
A local regulator that acts on nearby cells to stimulate cell proliferation and differentiation
growth factor
A protein that must be present in the extracellular environment (culture medium or animal body) for the growth and normal development of certain types of cells
growth factor
Anaphase II is essentially the same as mitotic anaphase except that the cell is ___
haploid
Metaphase II is essentially the same as mitotic metaphase except that the cells are ____
haploid
The events of prophase II are essentially the same as those of mitotic prophase except that prophase II cells are ___
haploid
Meiosis in the sporophyte produces___ cells called ___
haploid spores
Unlike a gamete, a ___ ____ doesn't fuse with another cell but divides mitotically, generating a multicellular haploid stage called the ___
haploid spore gametophyte
The transmission of traits from one generation to the next
heredity
eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed
heterochromatin
a small protein with a high proportion of positively charged amino acids that binds to the negatively charged DNA and plays a key role in chromatin structure
histone
one from the mother and one from the father form a..
homologous pair
The separation of ___ during ___ accounts for the segregation of the two alleles of a gene into separate gametes
homologs anaphase I
A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci
homologs (homologous chromosomes; homologous pair)
the situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele
incomplete dominance
Alleles of genes on nonhomologous chromosomes... during gamete formation refers to the law of...
independent assortment
During ____ in animal cells, the single centrosome duplicates, forming two centrosomes
interphase
During ____ the centrosome duplicates and the chromosomes are not condensed.
interphase
During____, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase.
interphase
The period in the cell cycle when the cell is not dividing.
interphase
an aberration in chromosome structure resulting from reattachment of a chromosomal fragment in reverse orientation to the chromosome from which it originated
inversion
A display of the chromosome pairs of a cell arranged by size and shape
karyotype
MPF acts both directly as a ____ and indirectly by activating other ___
kinase
Each of the two sister chromatids of a duplicated chromosome has a ____, a structure made up of proteins that have assembled on specific sections of DNA at each centromere
kinetochore
What structure attaches sister chromatids to the spindle? Where is it attached to the sister chromatids? What is it made of?
kinetochore centrosome proteins
A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes ___ map
linkage
Genes located close enough together on a chromosome that they tend to be inherited together
linked genes
A cancerous growth containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites; can impair the functions of one or more organs
malignant tumor
the inheritance of traits controlled by the genes present in the mitochondria and plastids depends solely on the ___ parent because the zygote's cytoplasm containing these organelles comes from the ___
maternal egg
Meiosis or mitosis? crossing over occurs in...
meiosis
Meiosis or mitosis? homologous pairs at the metaphase plate
meiosis
Meiosis or mitosis? synapsis occurs in...
meiosis
Typical mode of cell division for eukaryotic gametic cells?
meiosis
cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell by the splitting of homologous pairs
meiosis I
cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell by the splitting of sister chromatids
meiosis II
Nonkinetochore microtubules from opposite poles overlap each other extensively during ____
metaphase
stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the ___ plate
metaphase
A tumor-suppressor gene that codes for a specific transcription factor that promotes the synthesis of proteins that inhibit the cell cycle
p53 gene
: An offspring with a phenotype that matches one of the true-breeding parental
parental type
The cell plate enlarges until its surrounding membrane fuses with the ____ ____ around the perimeter of the cell
plasma membrane
1 gene affect many phenotypes refers to....
pleiotropy
the ability of a single gene to have multiple effects
pleiotropy
an additive effect of two or more genes on a single phenotypic character
polygenic inheritance
many genes affects 1 phenotype refers to...
polygenic inheritance
The two alleles for each gene separate during gamete formation Refers to the law of
segregation
Once activated, the M checkpoint complex sets off a chain of molecular events that activates the enzyme ___
separase
The enzyme that cleaves cohesins, allowing sister chromatids to separate
separase
A chromosome responsible for determining the sex of an individual
sex (chromosome)
Two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms
sister chromatids
Any cell in a multicellular organism except a sperm or egg or their precursors
somatic cell
In the alternation of generations, meiosis produces ___
spores
The ___ is the diploid, multicellular stage of the plant that produces haploids by meiosis.
sporophyte
The multicellular diploid stage is called the ___
sporophyte
the diploid multicellular organism in alternation of generations
sporophyte
the pairing and physical connection of duplicated homologous chromosomes during prophase I of meiosis
synapsis
a zipper-like strucutre composed of proteins, which connects two homologous chromosomes tightly along their lengths
synaptonemal complex
During ___ both nuclear envelopes and nucleoli re-form
telophase
Nuclei re-form during ____
telophase
stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun
telophase
Cytokinesis in plant cells, which have cell walls, is different. Instead, during ____, vesicles derived from the ___ ___ move along microtubules to the middle of the cell, where they coalesce, producing a ___ ___
telophase Golgi apparatus cell plate
Phase when: begins when each half of the cell has a complete haploid set of duplicated chromosomes each chromosome is composed of two sister chromatids one or both chromatids include regions of nonsister chromatid DNA
telophase I
Phase when: nuclei form, the chromosomes begin decondensing, and cytokinesis occurs
telophase II
breeding an organism of unknown genotype with a homozygous individual to determine the unknown genotype
testcross
In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?
0
for a dihybrid cross between two heterozygotes YyRr, what is the probability of the genotype YYRR?
1/16
for a dihybrid cross between two heterozygotes YyRr, what is the probability of the genotype YyRR?
1/8
In your group: In a two-point cross to map genes A and B, you obtained 98 recombinant flies out of a total of 730 progeny. How far apart are these genes? 11.8 cM 13.4 cM 98 cM 632 cM
13 (13.4 CM)
You are studying meiosis in an organism that has 28 chromosomes as its diploid number. How many chromosomes will each nucleus have after meiosis I, but before cytokinesis? 7 14 28 56
14
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes. 32 8 30 64 16
16
At the end of telophase I and cytokinesis there are ___ haploid cells.
2
Diploid organisms use meiosis for the development of gametes. Meiosis consists of how many rounds of nuclear division? One Two Three Four
2
It has been found that at a certain locus of the human genome, 200 different alleles exist in the population. Each person has at most _______ alleles at this locus 1 2 100 200 400
2
If a double-stranded DNA molecule contains 30 percent T, it must contain _______ percent G.
20
down syndrome is caused by an extra chromosome __. It is a ___ condition
21 aneuploid
You are studying meiosis in an organism that has 28 chromosomes as its diploid number. How many chromosomes will the cell have after meiosis II, but before cytokinesis? 7 14 28 56
28
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. Of the 16 possible gamete combinations in the dihybrid cross, how many would be the phenotype white, tall None 1 3 9
3
____ haploid cells are present at the end of telophase II and cytokinesis.
4
the DNA backbones of a double helix run in opposite _' S _' directions
5 3
when do the sister chromatids separate in meiosis?
anaphase II
After telophase I of meiosis, but before cytokinesis I, the chromosomal makeup of each daughter cell is A diploid, and the chromosomes are each composed of a single chromatid. B diploid, and the chromosomes are each composed of two chromatids. C haploid, and the chromosomes are each composed of a single chromatid. D haploid, and the chromosomes are each composed of two chromatids.
B
All zygotes are a.multicellular. b. diploid. c. animals. d. clones. e. gametes.
B
Asexual reproduction _____. a.leads to a loss of genetic material b.produces offspring genetically identical to the parent c is limited to single-cell organisms d.is limited to plants e.requires both meiosis and mitosis
B
Chromosomes start to condense & the spindle starts to form in: a. anaphase b. prophase c. prometaphase d. telophase e. metaphase
B
Double-stranded DNA looks a little like a ladder that has been twisted into a helix, or spiral. The steps of the ladder are A individual nitrogenous bases B pairs of bases C alternating bases and phosphate groups D alternating sugars and bases E alternating bases, sugars, and phosphates
B
During meiosis, the sister chromatids separate during a.anaphase I b.anaphase II c.the S phase d,.synapsis e.telophase II
B
E. coli, which doubles every 20 minutes weighs 10^-12 g, while the Earth 6 x 10^24 kg. At this rate, how long before E. coli would outweigh the Earth? a. 1-2 days b. 1 week c. 1 month d. 1 year e. 1 decade
B
Each chromosome has a ___________, a point of constriction that bind specific proteins and holds two sister chromatids together. a. DNA strand b. centromere c. node d. synapse
B
Generally, mitochondrial genes are inherited through _______ A Paternal inheritance B Maternal inheritance C Maternal and Paternal inheritance D None of these
B
Group question 34: If the GC content of Mycoplasma is 30%, with a genome size of 1.1 Mbp (1,100,000 base pairs) and the average size of a bacterial gene is 1000 base pairs, roughly how many genes are in Mycoplasma? A. 10,000 B. 1000 C. 300 D. 100
B
How is genetic linkage related to the principle of independent assortment? A If two alleles assort independently than they are linked B If two loci are linked then they do not assort independently C Linked loci are present on homologous chromosomes D Linked loci are present on sister chromatids
B
Human papillomavirus (HPV) can integrate its DNA into the DNA of cells it infects. One gene it contains codes for a protein which binds to the p53 protein and inactivates it. This allows for repeated cell division, resulting in warts. Certain HPV types can cause persistent infection of the cervix, which can eventually result in invasive cervical cancer. When they sequenced Henrietta Lack's genome in 2013, with the permission of her family, they found that the HPV virus had inserted itself next to a human oncogene Myc. This is thought to have resulted in the aggressive cancer which killed her at such a young age. Which of the following is most likely true of Henrietta Lacks? a. Each of her parents had 30 to 40 copies of the p53 gene, but she had fewer since she ended up getting cancer. b. She had two copies of the p53 gene, one on each of two homologous copies of chromosome #8, one from her mom and one from her dad. c. The main protective function of her p53 gene, prior to being infected by HPV, was to prevent premature death of cancerous cells, thereby delaying the spread of cancer. d. Her p53 gene coded for the sugar hyaluronan, which causes cells to clump together to form cancerous tumors.
B
In humans, if a non-disjunction event led to an individual with a genotype of XXY, they would A be female because they have two X chromosomes. B be male because they have a Y chromosome. C display no sexual characteristics. D not survive.
B
In your group: Examine the following recombination data and determine the proper order of the genes on the Drosophila X chromosome. Assume y is in the 0.0 position. Recombination Gene 1 Gene 2 frequency Yellow (y) vermilion (v) 0.322 Vermilion miniature (m) 0.030 White (w) vermilion 0.297 Yellow white 0.010 White minature 0.327 A y m v w B y w v m C y m w v D y w m v
B
Irene and William are having their first child. Irene knows her blood type is A, but William does not know his blood type. However, William knows that his mother and father were B. Their first child is a boy named Gregory. Gregory has type O blood. Irene and William do not understand how this happened. You could explain this to them using which of the following choices? A Irene's genotype is AA, and William's genotype is OO; thus, Gregory expresses the phenotype of O. B Irene's genotype is AO, and William's genotype is BO; thus, Gregory expresses the phenotype of O. C Because his parents were both type B, William could not be the father of Gregory. D Gregory's blood type will need to be checked after his first month of life if the parents want to know his blood type. It takes about a month for the blood type to develop in a newborn child.
B
Plant cells typically achieve cytokinesis by a. binary fission. b. forming a cell plate across the middle of the cell. c. forming a cleavage furrow that pinches the cell into two. d. chromosome condensation. e. chromosome elongation.
B
Sequencing of the gene that codes the FtsZ protein indicates that it is evolutionarily related to the gene coding tubulin. FtsZ has also been found in eukaryotic chloroplasts and mitochondria, where it is responsible for organelle division. Similar to tubulin, FtsZ has a plus and minus end, forms hollow tubes, and is assembled in the presence of GTP. Unlike microtubules, however, movement does not appear to involve a motor protein. In what metabolic process studied in this class was GTP formed? a. Fermentation b. Citric acid cycle c. Pyruvate Oxidation d. Glycolysis
B
The DNA double helix is similar to a twisted ladder. What makes up the sides holding the rungs together? A phosphate groups only B alternating units of phosphate groups and sugars C sugars only D purines and pyrimidines
B
The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? a. spindle formation b. cleavage furrow formation and cytokinesis c. DNA synthesis d. spindle attachment to kinetochores e. cell elongation during anaphase
B
The strands that make up DNA are antiparallel. This means that A the base pairings create unequal spacing between the two DNA strands. B the 5´-to-3´ direction of one strand is counter to the 5´-to-3´ direction of the other strand. C the twisting of the DNA molecule has shifted the two strands. D purines bond with purines and pyrimidines bond with pyrimidines.
B
The two copies of each chromosome in body cells are called a. sister chromatids. b. homologous chromosomes. c. sister chromosomes. d. daughter chromosomes. e. genes.
B
Which of the following would be most likely to lead to cancer? a.hyperactivity of a proto-oncogene and activation of a tumor-suppressor gene b.amplification of a proto-oncogene and inactivation of a tumor-suppressor gene c.failure of a proto-oncogene to produce a protein and amplification of a tumor-suppressor gene d.hyperactivity of both a proto-oncogene and a tumor-suppressor gene e.failure of both a proto-oncogene and a tumor-suppressor gene to produce proteins
B
Y-linked genes include a gene that produces hairy pinnae (the external ear). A male with hairy pinnae will pass this trait A to his sons and daughters B only to his sons C only to his daughters D only to his grandsons E to all his children if the mother is a carrier
B
name of tumor-suppressor gene associated with breast cancer
BRCA (1 or 2)
In the ovaries, ___ chromosomes are reactivated in the cells that give rise to eggs, such that following meiosis, every female gamete (egg) has an active X
Barr-body
A method of asexual reproduction by "division in half."
Binary fission
A same-sex couple wants to have a child in which they both contribute genetically to the offspring. Assuming it was technically possible to replace the DNA found in a sperm with female DNA, or DNA found in the egg with male DNA, what other scientific obstacle must be overcome? A sex determination B translocation events C genetic imprinting D nondisjunction events
C
Animal cells typically achieve cytokinesis by a. binary fission. b. forming a cell plate across the middle of the cell. c. forming a cleavage furrow that pinches the cell into two. d. chromosome condensation. e. chromosome elongation.
C
At the end of meiosis and cytokinesis, each of the four resulting cells contains a. one full set of chromosomes, each with two chromatids. b. two full sets of chromosomes, each with two chromatids. c. one full set of chromosomes, each a single chromatid. d. two full sets of chromosomes, each a single chromatid. e. a different number of chromosomes.
C
Fourteen percent of the DNA nucleotides from a certain organism contain T. What amounts of the other bases would you expect to be present in this particular DNA? A 14 % A, 0% C, 36 % G B 14 % A, 36 % C, 14 % G C 14 % A, 36 % C, 36 % G D 14 % T, 38 % C, 36 % G E 14 % T, 36 % C, 36 % U
C
If a bacterial population has 1000 cells and divides every 30 minutes, how many cells will there be in two hours? a. 3,000 b. 4,000 c. 16,000 d. 30,000 e. 60,000
C
If a human female has two Barr bodies, it is almost certain that A her father had at least one Barr body. B her mother also had two Barr bodies. C she developed from a fertilized egg with 3 X chromosomes. D she is actually a male with female characteristics. E she is genetically a normal fertile female.
C
In Griffith's transformation experiments, A mice infected with live R form caused pneumonia and death in mice. B the R form transformed the S form into a virulent variety of the bacteria. C mice infected with both heat-killed S form and live R form caused pneumonia and death in the mice. D the S form lacked an enzyme involved in the manufacture of the polysaccharide coat, leading to the abnormally smooth colonies.
C
In addition to showing that DNA carries genetic information, the experiments using mice and Streptococcus demonstrated that A eukaryotic cells may be genetically transformed B DNA is a double helix C DNA may be taken up by bacterial cells and be active D DNA binds to the cell wall of the bacterium E DNA is present in bacteriophage.
C
In humans, the male has an X and Y sex chromosome. The human female has two X chromosomes. In birds, the female has a Z and a W sex chromosome while the male has two Z chromosomes. Which of the following statements is accurate about which parent controls the gender of the offspring? A In humans and birds the male controls the gender of all the offspring. B In humans and birds the female controls the gender of all the offspring. C In humans the male controls the gender of the offspring, and in birds the female controls the gender. C In humans the female controls the gender of the offspring, and in birds the male controls the gender.
C
In sex-linked inheritance of a recessive gene, all A male offspring of a normal male and a heterozygous female carrier would show the trait. B female offspring would be carriers. C male offspring who receive the mutant X chromosome would show the trait. D female offspring who receive the mutant X would show the trait.
C
In tomatoes, tall is dominant to short, and smooth fruits are dominant to hairy fruits. A plant homozygous for both dominant traits is crossed with a plant homozygous for both recessive traits. The F1 progeny are tested and crossed with the following results: 78 tall, smooth fruits; 82 dwarf, hairy fruits; 22 tall, hairy fruits; and 18 dwarf, smooth fruits. These data indicate that the genes are A linked, but do not cross over B linked and show 10 percent recombination C linked and show 20 percent recombination D linked and show 40 percent recombination
C
Organisms generally have many more genes that assort independently than the number of chromosomes. This phenomenon is due to A independent assortment. B segregation. C crossing over. D epistasis. E pleiotropy.
C
The opposing nitrogenous bases (and therefore the two strands of the DNA double helix) are held together by A weak van der Waals forces B covalent bonds C hydrogen bonds D Both a and b E Both a and c
C
The two strands in the DNA molecule contain nitrogen bases which are A identical. B parallel. C complementary. D the same in all species. E exact copies of the protein they make.
C
Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of micro-tubules, its effectiveness must be related to: a. inhibition of regulatory protein phosphorylation. b. inhibition of DNA synthesis. c. disruption of mitotic spindle formation. d. suppression of cyclin production. e. myosin denaturation and inhibition of cleavage furrow formation.
C
What is occurring during S phase? a. Nothing, the cell is resting b. Cytokinesis c. DNA synthesis d. Nuclear division
C
What is the best evidence telling you whether this cell is diploid or haploid? A. The cell is diploid because each chromosome consists of two chromatids. b. The cell is haploid because the chromosomes are not found in pairs. c. The cell is diploid because it contains two sets of chromosomes.
C
White eyes is a recessive sex-linked trait in fruit flies. If a white-eyed female fruit fly is mated to a red-eyed male, their offspring should be A 50 percent red-eyed, 50 percent white-eyed for both sexes B all white-eyed for both sexes C all white-eyed males, all red-eyed females D all white-eyed females, all red-eyed males
C
Chromosomes become visible during _____. a. interphase b. metaphase c. anaphase d. prophase e. prometaphase
D
A membrane-bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis
Cell plate
The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane
Cleavage
The first sign of cleavage in an animal cell
Cleavage furrow
a shallow groove around the cell in the cell surface near the old metaphase plate
Cleavage furrow
____ generally begins during anaphase or telophase, and the spindle eventually disassembles by depolymerization of microtubules
Cytokinesis
A chromatid is a. one of the pairs of homologous chromosomes. b. a homologous chromosome. c.a newly replicated bacterial chromosome. d. one-half of a newly replicated eukaryotic chromosome.
D
A human cell containing 22 autosomes and a Y chromosome is a. a somatic cell of a male b. a somatic cell of a female. c. a zygote. d. a sperm. e. an egg.
D
Case Report: A 52-year-old woman with renal failure had her immediate family undergo tissue compatibility testing in preparation for kidney transplantation. The results suggested that the patient could not be the biological mother of two of her three sons, who had her husband's markers and a unique collection of markers instead of one of the expected maternal markers She inherited the 1 marker of her father (who was 1,2) and the 3 marker of her mother (who was 3,4). Her husband typed 5,6. Of her three sons, one was 1,6 but the other two were both 2,5. Clues came from typing of her other tissues which revealed both 1,3 and 2,4. Group Question #32: All of the following are possible explanations for the case result data, except: A All of her cells were XX because two of her father's sperm cells successfully carried his X chromosome B Her father produced both 1-containing and 2-containing sperm, and the 1-sperm fertilized a 3-egg and the 2-sperm fertilized a 4-egg. C The patient's mother had simultaneously ovulated two eggs, one containing marker 3 and the other with marker 4. D DAs the patient developed into a fetus, only one of the fertilized eggs survived and led to the development of all of her organs, including her ovaries.
D
Chromosome number is reduced during meiosis because the process consists of a. two cell divisions without any chromosome replication b. a single cell division without any chromosome replication c. two cell divisions in which half of the chromosomes are destroyed d. two cell divisions and only a single round of chromosome replication
D
The process by which a DNA molecule is copied; also called DNA synthesis
DNA replication
A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in a.anaphase. b. prophase. c. G2. d. metaphase. e. G1.
E
Which life cycle stage is found in plants but not animals? a. Unicellular diploid b. Gamete c. Multicellular diploid d. Zygote e. Multicellular haploid
E
Which of these is NOT a carcinogen? a.fat b.cigarette smoke c.testosterone d.UV light e.all of the above are carcinogens
E
no fertilization occurs in alternation of generations. T/F
F
Bacteria do not have chromosomes. T/F
F (In bacteria, most genes are carried on a single bacterial chromosome that consists of circular DNA molecule and associated proteins)
In prokaryotes, binary fission does involve mitosis. T/F
F (In prokaryotes, binary fission does not involve mitosis)
The regulatory molecule in the M checkpoint is a Cdk. T/F
F (complex composed of several proteins, but not cyclin-Cdk complex)
the law of independent assortment applies only to genes located on different chromosomes. T/F
F (genes far enough away from each other on a chromosome act as though they are located on different chromosomes through recombination)
In the alternation of generations, meiosis produces gametes. T/F
F (haploid cells that then divide by mitosis, giving rise to a multicellular haploid)
Binary fission never involves mitosis. T/F
F (it does in eukaryotes)
Most cells of the human body are in the ___ phase
G0
What happens if the G1 checkpoint does not receive a go-ahead signal?
G0
A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly
G0 phase
For many cells, which checkpoint has been deemed the most important?
G1 (because when passed, usually G1, S, G2, and M phases are completed and the cell divides)
The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins
G1 phase
The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs
G2 phase
a human genetic disease caused by a dominant allele; characterized by uncontrollable body movements and degradation of the nervous system; usually fatal 10 to 20 years after the onset of symptoms
HD (Huntington's disease)
____ often accounts for about 90% of the cell cycle.
Interphase
A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle
Kinetochore
The phase of the cell cycle that includes mitosis and cytokinesis
M (mitotic) phase
Cyclin combines with Cdk, producing ___ during G2
MPF
During anaphase, the cyclin component of ___ is degraded, terminating the M phase
MPF
Which Cdk is responsible for triggering the cell's passage into the M phase?
MPF
When enough ___ molecules accumulate, the cell passes through the G2 checkpoint and begins ___
MPF mitosis
___ causes ___ of various proteins of the nuclear lamina, which promotes fragmentation of the nuclear envelope during ___ of mitosis
MPF phosphorylation prometaphase
___ promotes mitosis by ____ various proteins
MPF Phing (phosphorylating)
a protein complex required for a cell to progress from late interphase to mitosis. The active form consists of cyclin and a protein kinase
MPF (maturation-promoting factor)
An imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located
Metaphase plate
A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella
Microtubule
A process of nuclear division in eukaryotic cells conveniently divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase.____ conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei
Mitosis
Are centrioles essential for cell division?
No (if destroyed, a spindle still forms; plant cells don't even have them)
A gene found in viral or cellular genomes that is involved in triggering molecular events that can lead to cancer
Oncogene
Phase when: Early on, each chromosome pairs with its homolog, aligned gene by gene, and crossing over occurs The DNA molecules of non-sister chromaitds are broken (by proteins) and are rejoined to each other
Prophase I
A normal cellular gene that has the potential to become an oncogene
Proto-oncogene
____ can become ____ when a mutation or other genetic change increases the activity of the encoded protein.
Proto-oncogenes oncogenes
When do the homologous pairs separate during meiosis?
anaphase I
Turner syndrome has genotype:
X
Which genotype produces "normal" females, but maybe taller than average?
XXX
Klinefelter syndrome has genotype:
XXY
Which genotype produces "normal" males, but maybe taller than average?
XYY
At the end of _____ and cytokinesis there are four haploid cells. a.telophase II b.prophase I c.interphase d.prophase II e.anaphase I
a
Centromeres divide and sister chromatids become full-fledged chromosomes during _____. a.anaphase b.interphase c.metaphase d.telophase e.prometaphase
a
During _____ a spindle forms in a haploid cell. a.prophase II b.telophase I and cytokinesis c.metaphase II d.anaphase II e.prophase I
a
During _____ sister chromatids separate. a.anaphase II b.prophase I c.prophase II d.metaphase I e.interphase
a
Group Question: The likelihood that a child will inherit cystic fibrosis if his or her parents each have one recessive gene is approximately: a 1 in 4 (25%) b 2 in 4 (50%) c 3 in 4 (75%) d 4 in 4 (100%)
a
Group Question: The word "autosomal" refers to the fact that the recessive gene is found on: a Chromosomes that are not related to determining the individual's gender. b Chromosomes that are related to determining the individual's gender. c Chromosomes that are mutated. d Chromosomes that are damaged.
a
Homologous chromosomes migrate to opposite poles during _____. a.anaphase I b.prophase II c.telophase II and cytokinesis d.metaphase I e.metaphase II
a
In Mendel's experiments, if the allele for tall (T) plants was incompletely dominant over the allele for short (t) plants, what offspring would have resulted from crossing two Tt plants? a 1/4 tall; 1/2 intermediate height; 1/4 short b 1/2 tall; 1/4 intermediate height; 1/4 short c All the offspring would have been tall d All the offspring would have been of intermediate height
a
In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele also causes the tigers to be cross-eyed. If two tigers heterozygous for this allele mate and produce offspring, what percentage can be expected to be white and/or cross-eyed a 25% will be white and the same 25% will be cross-eyed b 25% will be white and 25% will be cross-eyed, but not necessarily the same 25% due to independent assortment c 50% will be both white and cross-eyed d Because it is a recessive allele, none of the offspring in the F1 generation will be white or cross-eyed
a
Meiosis I produces _____ cells, each of which is _____. a.two ... haploid b.four ... haploid c.two... identical to the other d.two... diploid e.four ... diploid
a
Mistakes can be made during crossing over in meiosis, causing mutations. DNA also can be damaged by UV light or chemicals such as formaldehyde, all of these causing double-strand breaks in DNA. BRCA1 can repair these breaks using homologous recombination, in which repair proteins utilize homologous intact sequence from a sister chromatid (in G2), from a homologous chromosome (in G1), or on the same chromosome (if there are duplicate copies of the gene on the chromosome). This repair takes place within the cell nucleus, with the DNA wrapped around the histone proteins. Use of the homologous chromosome for repair requires searching around in the nucleus for the homologous gene. What other potential disadvantage does use of the homologous chromosome have, as opposed to use of the sister chromatid? A. The gene may not have the exact same sequence. B. The gene may be from a gamete C. The sister chromatid only contains female copies of the gene D. DNA repair requires four sister chromatids
a
Nucleoli are present during _____. a. interphase b. prophase c. metaphase d. prometaphase e. anaphase
a
Spindle fibers attach to kinetochores during _____. a.prometaphase b.telophase c.anaphase d.interphase e.metaphase
a
The phenotypic ratio for a testcross with a homozygous individual and a heterozygous individual is ______. a 1:1 b 2:1 c 3:1 d 1:2:1
a
The totality of the alleles present in an organism is called its a. genotype b. heterozygote c. homozygote d. phenotype e. pleiotropy
a
True breeding plants a. produce the same offspring when crossed for many generations b result from a monohybrid cross c result from a dihybrid cross d result from crossing over during prophase I of meiosis
a
Unattached earlobes are a dominant trait. Finn and Maggie both have unattached earlobes but their daughter, Celia, does not. If Finn and Maggie have a second child, what is the probability that it will have attached earlobes? a 1⁄4 b 1⁄2 c 3⁄4 d 1⁄8
a
During ____ sister chromatids separate and migrate to opposite poles.
anaphase II
When oxygen is released as a result of photosynthesis, it is a direct by-product of _____. A) splitting water molecules B) chemiosmosis C) the electron transfer system of photosystem I D) the electron transfer system of photosystem II
a
Phase when: breakdown of proteins holding the sister chromatids together at the centromere allows the chromatids to separate The chromatids move toward opposite poles as individual chromosomes
anaphase II
When are the centromeres separated in meiosis?
anaphase II
On the cytoplasmic side of the furrow is a contractile ring of ____ ___ associated with molecules of the protein ____
actin microfilaments myosin
What two molecules are involved in the contracting of the ring or cleavage furrow during animal cytokinesis? ____ ____ ____
actin microfilaments myosin
At the end of ____, duplicate groups of chromosomes have arrived at opposite ends of the elongated parent cell
anaphase
During ____: microtubules shorten poles move apart
anaphase
In a dividing animal cell, the nonkinetochore microtubules are responsible for elongating the whole cell during ____
anaphase
stage of mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell
anaphase
____ begins suddenly when the cohesion holding together the sister chromatids of each chromosome are cleaved by an enzyme called _____
anaphase separase
During ____, the region of kinetochore overlap is reduced as ____ ____ attached to the microtubules walk them away from one another, using energy from ATP
anaphase motor proteins
During ___ sister chromatids remain attached at their centromeres, and homologous chromosomes move to opposite poles.
anaphase I
During ____ homologous chromosomes, consisting of sister chromatids, migrate to opposite poles.
anaphase I
Phase when: breakdown of proteins that are responsible for sister chromatid cohesion along chromatid arms allows homologs to separate
anaphase I
Phase when: sister chromatid cohesion persists at the centromer, causing chromatids to move as a unit toward the same pole
anaphase I
Phase when: the homologs move toward opposite poles, guided by spindle apparatus
anaphase I
Group Question: An individual with cystic fibrosis must have parents that: a Both have two dominant genes. b Both have at least one recessive gene. c One has one recessive gene, but the other has two dominant genes. d Have cystic fibrosis.
b
How are sister chromatids and homologous chromosomes different from each other? a.They are not different. Homologous chromosomes and sister chromatids are both identical copies of each other. b.Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication. c.Homologous chromosomes are identical copies of each other. One sister chromatid comes from the father, and one comes from the mother. d.Homologous chromosomes are closely associated with each other in both mitosis and meiosis. Sister chromatids are only associated with each other during mitosis. e.Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis.
b
Human gametes are produced by _____. a.asexual reproduction b.meiosis c.mitosis d/the cell cycle e.fertilization
b
Meiosis and mitosis are both processes that involve nuclear division. What is the difference between the two? a. Mitosis is nuclear division, resulting in haploid gametes. Meiosis is nuclear division, resulting in diploid somatic cells. b. Mitosis is nuclear division, resulting in diploid somatic cells. Meiosis is nuclear division, resulting in haploid gametes. c. Mitosis is nuclear division, resulting in diploid gametes. Meiosis is nuclear division, resulting in haploid somatic cells. d. Mitosis is nuclear division, resulting in syngamy. Meiosis is nuclear division, resulting in zygotes.
b
Mendel referred to the trait that was expressed in the hybrid, F1 or first filial generation as a recessive. b dominant. c codominant. d independent. e epistatic.
b
Which of the following statements about crossing over is false? a Crossing over takes place between non-sister chromatids. b Crossing over takes place between sister chromatids. c Recombination nodules may be observed. d Sites of crossing over are called chiasmata.
b
Yellow-seeded plants might be homozygous or heterozygous. We could find out which by crossing these plants with a true breeding yellow-seeded plants. b true breeding green-seeded plants. c heterozygous yellow-seeded plants. d true breeding white-flowered plants. e true breeding purple-flowered plants.
b
A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division; has two centrioles
centrosome
A virus that infects bacteria
bacteriophage
A dense object lying along the inside of the nuclear envelope in the cells of female mammals, representing a highly condensed, inactivated X chromosome
barr body
A mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable of surviving at a new sit and generally remain at the site of the tumor's origin
benign tumor
By which mode do prokaryotic cells typically divide?
binary fission
mutant flies have __ bodies and wings much ___, called ___ wings
black smaller vestigial
All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs? a.Proto-oncogenes are unavoidable environmental carcinogens. b.Proto-oncogenes are genetic junk that has not yet been eliminated by natural selection. c.Proto-oncogenes are necessary for the normal control of cell growth and division. d.Cells produce proto-oncogenes as a by-product of mitosis. e.Proto-oncogenes protect cells from infection by cancer-causing viruses.
c
At the end of cytokinesis II of meiosis, each of the four resulting cells contains a one full set of chromosomes, each with two chromatids. b two full sets of chromosomes, each with two chromatids. c one full set of chromosomes, each a single chromatid. d two full sets of chromosomes, each a single chromatid. e a different number of chromosomes.
c
Crossing spherical-seeded pea plants with wrinkled-seeded pea plants resulted in progeny that all had spherical seeds. This indicates that the wrinkled-seed trait is a. neutral b dominant c recessive d environmental
c
Spindle microtubules grow out of ____ during mitosis
centrosomes
Height and eye colors are two examples of continuous variation in humans. Whereas in pea plants the tall allele is dominant over the short allele, there are no intermediate heights in peas. Which of the following is the best explanation for the differences described above? a The intermediate size pea plant seeds are aborted within the seedpod and thus will never develop. b The intermediate size pea plant seeds have deleterious alleles that prevent them from germinating. c Many genes, rather than one gene for a characteristic, control some variations in species. d These variations in humans are affected by lack of dominance in the alleles that control these traits.
c
In a typical Mendel experiment on pea-seed color, if the dominant yellow seed-bearing parent plant was crossed with the recessive green seed-bearing plant, the F2 generation will show what ratio of each kind? a 1 yellow: 3 green b 1 yellow: 1 green c 3 yellow: 1 green d seeds with patches of green and yellow color
c
In dogs, erect ears and barking while following a scent are due to dominant alleles; droopy ears and silence while following a scent are due to recessive alleles. A dog homozygous dominant for both traits is mated to a droopy-eared, silent follower. The expected F1 phenotypic ratios should be a 9:3:3:1 b 8:8 or 1:1 c 16:0 d 4:8:4 or 1:2:1
c
In pea plants, the gene for yellow seeds, Y, is dominant to the allele for green seeds, y. A plant with green seeds must have the genotype a YY b Yy c yy d XY
c
In the ABO blood type system, a A, B, and O are codominant b A, B, and O are incompletely dominant c A and B are codominant d O is incompletely dominant to A and B e A is dominant to B, and B is dominant to O
c
One difference between mitosis and meiosis I is that a. homologous chromosome pairs synapse during mitosis b. chromosomes do not replicate in the interphase preceding meiosis I c. homologous chromosome pairs synapse during meiosis but not during mitosis d. spindles composed of microtubules are not required during meiosis e. sister chromatids separate during meiosis but not during mitosis
c
Traits that are carried on the X chromosome are said to be ________________. a autosomal b gametal c sex-linked d alleles
c
When the two haploid gametes contain two different alleles of a given gene, the resulting offspring is called a discrete. b a haploid. c heterozygous. d homozygous. e a fused allele.
c
Which of the following statements about Mendelian genetics is false? a Alternative forms of genes are called alleles b A locus is a gene's location on its chromosome c Only two alleles can exist for a given gene d A genotype is a description of the alleles that represent an individual's genes e Individuals with the same phenotype can have different genotypes
c
An ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two
cell cycle
A cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle
cell cycle control system
The reproduction of cells
cell division
Cytokinesis in plant cells involves the formation of a ___ ___
cell plate
(plant cell cytokinesis)...Two daughter cells result, each with its own plasma membrane. Meanwhile, a new ___ ___ arising from the contents of the ___ ___ has formed between the daughter cells.
cell wall cell plate
A structure in the centrosome of an animal cell composed of a cylinder of microtubule triplets arranged in a "9+0" pattern
centriole
what are centrosomes made of?
centrioles, which are made of microtubules
During anaphase ____ come apart, and sister chromatids become full-fledged chromosomes, which migrate to opposite poles of the cell.
centromeres
A control point in the cell cycle where stop and go-ahead signals can regulate the cycle
checkpoint
the X-shaped, microscopically visible region where crossing over has occurred earlier in prophase I between homologous nonsister chromatids become visible after synapsis ends, with the two homologs remaining assocaited due to sister chromatid cohesion
chiasamata
The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, ____ exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope
chromatin
A cellular structure consisting of one DNA molecule and associated protein molecules
chromosome
A prokaryotic cell often has a singular, circular____, which is found in the nucleoid, a region that is not enclosed by a membrane.
chromosome
A eukaryotic cell typically has multiple, linear____, which are located in the nucleus
chromosomes
What does the M checkpoint check for?
chromosomes attached to spindle fibers
Cytokinesis in animal cells involves the formation of a ___ ___
cleavage furrow
the situation in which the phenotypes of both alleles are exhibited in the heterozygote because both alleles affect the phenotype in separate indistinguishable ways
codominance
What protein holds sister chromatids together until anaphase?
cohesin
a complex that regulates the separation of sister chromatids during cell division, either mitosis or meiosis
cohesin proteins
the situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable
complete dominance
Pairing of homologous chromosomes is followed by ____, the exchange of genetic material between nonsister chromatids of homologous chromosomes
crossing over
The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis Accounts for the recombination of linked genes
crossing over
genetic recombination is another term for
crossing over
the reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis
crossing over
A cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle
cyclin
To be active, a kinase must be a attached to a ___
cyclin
The fluctuating activities of different ___-___ complexes are of major importance in controlling all the stages of the cell cycle and give the go-ahead signals at some checkpoints as well
cyclin Cdk
a human genetic disorder caused by a recessive allele for a chloride channel protein; characterized by an excessive secretion of mucus and consequent vulnerability to infection; fatal if untreated
cystic fibrosis
The division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II.
cytokinesis
Phase when: in some species, chromosomes decondense and a nuclear envelope form
cytokinesis I
A dominant allele K is necessary for normal hearing. A dominant allele M on a different locus results in deafness no matter which other alleles are present. If a kkMm individual is crossed with a Kkmm individual, _______ percent of the offspring will be deaf. 0 25 50 75 e None of the above
d
Huntington's disease is dom/rec auto/sex?
dom auto
A test cross can be used to do all of the following except a determine whether an individual that displays a dominant phenotype is homozygous for the trait. b determine whether an individual that displays a dominant phenotype is heterozygous for the trait. c gather genotype information from phenotype information. d identify the chromosome on which a gene is located.
d
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids. a.metaphase II b.interphase c.telophase d.telophase I e.telophase II
d
At the end of the first meiotic division, each chromosome consists of a Chiasmata b. a homologous chromosome pair c. dour copies of each DNA molecule d. two chromatids e. a pair of polar microtubules
d
Between the two divisions of meiosis there is a. a full cell cycle. b a pairing of homologues. c replication of some parts of the chromosomes. d no S phase. e random combination among chromatids.
d
Checkpoints receive signals: a. only externally b. only internally c. only when something wrong has occurred d. both externally and internally
d
Chromosomes become visible during _____. a. interphase b. metaphase c.anaphase d.prophase e.prometaphase
d
Cyclin-dependent kinase (Cdk) is _____. A) inactive, or "turned off," in the presence of cyclin B) present only during the S phase of the cell cycle C) the enzyme that catalyzes the attachment of chromosomes to microtubules D) an enzyme that attaches phosphate groups to other proteins
d
During _____ chromosomes align single file along the equator of a haploid cell. a.metaphase I b.prophase I c.anaphase I d.metaphase II e.telophase I and cytokinesis
d
During _____ the cell grows and replicates both its organelles and its chromosomes. a.S b.cytokinesis c.mitosis d.interphase e.G1
d
During prophase a homologous pair of chromosomes consists of _____. a.one chromosome and four chromatids b.four chromosomes and two chromatids c.two chromosomes and two chromatids d.two chromosomes and four chromatids e.one chromosome and two chromatids
d
Group Question: A person with cystic fibrosis must have: a Two working CTFR genes. b One working CTFR gene and one faulty gene. c One working CTFR gene and one completely nonworking gene. d Two CTFR genes that are not working correctly.
d
Group Question: A person without cystic fibrosis must have: a One dominant CTFR gene and one recessive CTFR gene b Two dominant CTFR genes c Two recessive CTFR genes d They can have options A or B
d
Group Question: By applying the information included in the passage, the likelihood that a child will inherit cystic fibrosis if his or her parents both have cystic fibrosis is approximately: a 1 in 4 (25%) b 2 in 4 (50%) c 3 in 4 (75%) d 4 in 4 (100%)
d
If meiosis produces haploid cells, how is the diploid number restored for those organisms that spend most of their life cycle in the diploid state? A) DNA replication B) reverse transcription C) synapsis D) fertilization
d
In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short plants, and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of the F2 generation are both tall and heterozygous? a 1⁄4 b 1⁄3 c 2⁄3 d 1⁄2
d
In alternation of generations, what is the diploid stage of a plant that follows fertilization called? a.chiasmata b.spore c.gametophyte d.sporophyte e.karyotype
d
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What combinations of gametes could be produced by a heterozygote for both the traits a PpTt only b Pp, Tt c P, p, T, t d PT, Pt, pT, pt
d
The ABO blood groups in humans are determined by a multiple allelic system in which A and B are codominant, and are dominant to O. If an infant born to a type O mother also is type O, possible phenotypes for the father are a O or A b A or B c O only d O, A, or B e impossible to determine
d
What number and types of chromosomes are found in a human somatic cell? a.22 autosomes and 1 sex chromosome b.45 autosomes and 1 sex chromosome c.n chromosomes d.44 autosomes and 2 sex chromosomes e.21 autosomes and 2 sex chromosomes
d
Which of the following is not true of sister chromatids? a. They arise by replication during S phase b. They segregate from each other during each mitotic anaphase c .They usually contain nearly identical versions of the same genetic information d. They segregate from each other during meiosis I e. They are joined during prophase and metaphase at their common centromere
d
Which statement about an individual that is homozygous for an allele is false? a Each of its cells possesses two copies of that allele b Each of its gametes contains one copy of that allele c It is true-breeding with respect to that allele d Its parents were necessarily homozygous for that allele e It can pass that allele to its offspring
d
an aberration in chromosome structure due to fusion with a fragment from a homologous chromosome
duplication
An allele that is present but unexpressed is a redundant. b dominant. c functional. d epistatic. e recessive.
e
Cytokinesis often, but not always, accompanies _____. a. interphase b. metaphase c. prometaphase d. anaphase e. telophase
e
During _____ both the contents of the nucleus and the cytoplasm are divided. a.G1 b.S c.mitosis d.G2 e.the mitotic phase
e
a deficiency in a chromosome resulting from the loss of a fragment through breakage
deletion
a mutational loss of one ore more nucleotide pairs from a gene
deletion
The phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another
density-dependent inhibition
zygotes are haploid or diploid?
diploid
For what purpose(s) might a karyotype be prepared? Choose the best answer. a.for prenatal screening, to determine if a fetus has the correct number of chromosomes b.to determine whether a fetus is male or female c.to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations d.The first and second answers are correct. e.The first three answers are correct.
e
In cocker spaniels, black color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s). If the offspring between BBss and bbss individuals are mated with each other, what fraction of their offspring will be expected to be black and spotted? a 1⁄16 b 9⁄16 c 1⁄9 d 3⁄16 e 3⁄4
e
Normal human gametes carry _____ chromosomes. a.23 pairs of b.46 pairs of c.46 d.5 e.23
e
One of the main reasons genes assort independent of one another is that a they produce unrelated traits. b they produce related traits. c they are on the same chromosome. d they are different alleles. e they are on different chromosomes.
e
a type of gene interaction in whcih the phenotypic expression of one gene alters that of another independently inherited gene
epistasis
the less condensed form of eukaryotic chromatin that is available for transcription
euchromatin
A haploid reproductive cell, such as an egg or sperm. ____ unite during sexual reproduction to produce a diploid zygote
gametes
the haploid multicellular organism in alternation of generations
gametophyte
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses
gene
a proto-oncogene that made multiple copies of a gene--in excess--thus normal growth-stimulating proteins are in excess
gene amplification
An ordered list of genetic loci (genes or other genetic markers) along a chromosome ___ map
genetic
General term for the production of offspring with combinations of traits that differ from those found in either parent
genetic recombination
The genetic material of an organism or virus; the complete complement of an organism's or virus's genes along with its noncoding nucleic acid sequences
genome
a phenomenon in which expression of an allele in offpsring depends on whether the allele is inherited from the male or female parent
genomic imprinting
Phase when: both chromatids of one homolog are attached to kinetochore microtubules from one pole; those of the other homolog are attached to the microtubules from the opposite pole
metaphase I
Phase when: pairs of homologous chromosomes are now arranged at the middle, with one chromosome in each pair facing each pole
metaphase I
The random arrangement of chromosome pairs at ____ accounts for____ ____ of the alleles for two or more genes located on different homolog pairs
metaphase I independent assortment
Phase when: because crossing over occurred earlier, the two sister chromatids of each chromosome are not genetically identical
metaphase II
Phase when: the kinetochore of sister chromatids are attached to microtubules extending from opposite poles
metaphase II
Phase when: the sister chromatids are positioned at the middle of the cell
metaphase II
The spread of cancer cells to locations distant from their original site
metastasis
Inactivation of an X chromosome involves modification of the DNA and the proteins bound to it, called histones, including the attachment of ___ groups to DNA nucleotides
methyl
____ of DNA nucleotides is the cause of gene inactivation
methylation
What are asters made of?
microtubules
An aster, a radial array of short ____, extend from each ____
microtubules centrosome
Typical mode of cell division for eukaryotic somatic cells?
mitosis
gametes are formed by ___ in alternation of generations
mitosis
An assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis
mitotic spindle
organism that's heterozygous with respect to a single gene of interest
monohybrid
cross between two organisms heterozygous for the character being followed or the self-pollination of a heterozygous plant
monohybrid cross
diploid cell with only one copy of a chromosome
monosomic
referring to a phenotypic character that is influenced by multiple genes and environmental factors
multifactorial
Traits alternative to the wild type, such as the white eyes, are called ____ phenotypes
mutant
the number of chromosomes in a single set is represented by _
n
an error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other
nondisjunction
In effect, when a single crossover occurs, end portions of two ___ chromatids trade places
nonsister
the basic, bead-like unit of DNA packing in eukaryotes, consisting of a segment of DNA wound around a protein core composed of two copies of each of four types of histone
nucleosome
The duplicated centrosomes remain near the ___ during ____
nucleus interphase
While joined, two sister chromatids make up how many chromosomes?
one
A defective version of a protein in an inhibitory pathway, such as ___ (a transcription activator), fails to function as a tumor suppressor
p53
a chromosomal alteration in which the organism possesses more than two complete chromosome sets. It is the result of an accident of cell division
polyploidy
stage of mitosis, in which the nuclear envelope fragment and the spindle microtubules attach to the kinetochores of the chromosomes
prometaphase
During_____, some of the spindle microtubules attach to the kinetochores. These are called ___ ____
prometaphase kinetochore microtubules
By the end of_____, the two ____, one at each pole of the spindle, are at opposite ends of the cell
prometaphase centrosomes
The events of ____ include the attachment of spindle fibers to____.
prometaphase kinetochores
Chromosomal condensation occurs during which phase of mitosis?
prophase
Events of ___ include the condensation of chromatin and the dispersal of nucleoli.
prophase
stage of mitosis, in which the chromatin condenses into discrete chromosomes visible with a light microscrope, the mitotic spindle begins to form, and the nucleolus disappears but the nucleus remains intact
prophase
the centrosomes move apart during ____ and ____ of ____
prophase prometaphase mitosis
Phase when: Centrosome movement, spindle formation, and nuclear envelope breakdown occur Chromosomes condense
prophase (I)
Chromosomal condensation occurs during which phase of meiosis?
prophase I
Homologous chromosomes pair during ____.
prophase I
Phase when: Each homologous pair has one or more X-shaped regions called chiasmata where crossovers have occurred
prophase I
Phase when: Later on, microtubules from one pole or the other will attach to the two kinetochores, one at the centromere of each homolog the homologs will then move towards the middle plate
prophase I
Phase when: another spindle apparatus forms
prophase II
Phase when: later on, chromosomes, each composed of two sister chromatids associated at the centromere move towards the middle plate
prophase II
an enzyme that catalyzes the hydrolytic breakdown of proteins into peptides or amino acids.
protease
Enzymes that activate or inactive other proteins by phosphorylating them
protein kinases
What are the two regulatory molecules involved in the cell cycle control system?
protein kinases cyclins
cytosine is a
purine
thymine is a
purine
adenine is a
pyrimidine
guanine is a
pyrimidine
a heritable feature that varies continuously over a ranger than in an either-or fashion
quantatative character
An offspring whose phenotype differs from that of the true-breeding P generation parents
recombinant
a chromosome created when crossing over combines DNA from two parents into a single chromosome
recombinant chromosome
___ eyes are the wild type for fruit flies
red
A change in genotype and phenotype due to the assimilation of external DNA by a cell. When the external DNA is from a member if a different species, ____ results in horizontal gene transfer
transformation
The conversion of a normal cell into a cell that is able to divide indefinitely in culture, thus behaving like a cancer cell. (Malignant ___ may also describe the series of changes in a normal cell in an organism that change it into a malignant (cancerous) cell.
transformation
A proto-oncogene that has moved to new locus, under new control
translocation
an aberration in chromosome structure resulting from attachment of a chromosomal fragment to a nonhomologous chromosome
translocation
diploid cell with three copies of a chromosome
trisomic
the mitotic spindle elongates by incorporating more subunits of the protein ___
tubulin
A gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer
tumor-suppressor gene
Differences between members of the same species
variation
Cell wall material carried in ____ collect inside the cell plate as it grows
vesicles
An infections particle incapable of replicating outside of a cell, consisting of an RNA or DNA genome surrounded by a protein coat (capsid) and, for some, a membranous envelope
virus
The phenotype most commonly observed in natural populations; also refers to the individual with that phenotype
wild type
female sex chromosomes
xx
male sex chromosomes
xy
