Are Any of Your Relatives Blue?
When was the structure of DNA discovered?
1953
A karyotype is
A visual inspection of chromosomes
thymine and cytosine (T, C)
pyrimidines
Alternate forms of a gene for the same trait are called
alleles
Human Ox Wheat Germ E. coli Sea Urchin
% A % G % C % T 30.4 19.6 19.9 03.1 29.0 21.2 21.2 28.7 28.1 21.6 22.7 27.4 24.7 26.0 25.7 23.6 32.8 17.7 17.3 32.1
Base pairing is complementary
(A/T, G/C)
When true-breeding (pure) varieties were crossed,
, all offspring in the F1 generation showed one of the two original phenotypes for each trait
Chargaff's Rules indicated some regularity
- Amounts of each base vary among species - Percentage of all bases are not equal - G = C; A = T - G + C does not necessarily equal A + T
Enzymes lower the activation energy required to make the reaction go
- Bind and bring reactants (substrates) into close proximity - Put reactants into the necessary orientation - Exert thermodynamic strain on the bonds
3. Put the (now) two molecules back together
- Connect any loose ends along the new chain - Each new molecule consists of one original and one new strand - semiconservative replication
two sister chromatids
- Formed from DNA replication during the S phase - Will separate during Anaphase of Mitosis and Anaphase II of Meiosis
Self-replication
- Genetic information must be passed from one generation to the next; this requires that there be an inherent mechanism for accurate copying of the information
homologous chromosomes
- Inherited from different parents - Stay separate and assort independently during Mitosis - Come together as tetrads during Prophase I of Meiosis - Separate during Anaphase I of Meiosis
4 kinds of bases, 2 purines and 2 pyrimidines
- Purines: Adenine (A) and Guanine (G) - Pyrimidines: Thymine (T) and Cytosine (C) - Uracil (U) occurs in RNA instead of Thymine
1. Take the double-helix apart
- Separate the two strands - unzip the helix - DNA separates stands in the middle - Involves breaking the hydrogen bonds holding base pairs together
Functional complexity
- The genetic material must contain sufficient complexity to encode the huge variety of traits that exist in an individual
Mutability
- There must be some capacity for mutation, or change, in the genetic information. These changes, once they occur, must be faithfully copied and passed on
2. Make a copy of everything
- Use each strand as a template for making a copy of the other - Add new nucleotides to a growing chain - The energy comes from 2 phosphates and sugar and connects loose ends, end up with 2 DNA molecules
The chromatin packaging is hierarchical and dynamic
- only when it is most tightly packed is the chromatin visible as chromatids and chromosomes
DNA replication steps
1) Helicase- unwinds the parental double helix (origins of replication) 2) DNA topoisomerase - upstream of helices alleviating torsional strain. The enzyme complex expands the replication bubble in both directions. 3) Single-strand binding proteins (SSBP) stabilize unwound DNA, aided by DNA gyrase. 4) Primase synthesizes a short RNA primer for DNA polymerase to bind to in the 5' to 3' direction to start replication on each strand. 5) DNA polymerase synthesizes the leading strand in 5' to 3' direction while the lagging strand is made discontinuously by primase making short pieces and then DNA polymerase extending these to make Okazaki fragments. 6) DNA ligase joins the Okazaki fragments together
Meiosis II Phases
1. Begins with chromosomes without going another round of DNA replication 2. Centrioles duplicate and begin moving to opposite poles 3. Prophase II: sister chromatids condense while spindle starts to form, envelope disappears 4. Prometaphase II: sister chromatids attach to opposite spindle poles by kinetochore microtubules 5. Metaphase II: spindle aligns the sister chromatids along the metaphase plate 6. Anaphase II: sister chromatids separate and they move toward the poles 7. Telophase II: chromosomes decondense and envelope reforms 8. Cytokinesis II: Cleavage furrows separate two daughter cells into 4 haploid daughter cells
Cell cycle
1. Duplicate the genetic material and cell components (make enough for 2 cells) 2. Separate the two sets of genetic material (and any other cell components) 3. Divide the parent cell into two daughter cells Cell division in prokaryotes (as well as mtDNA and cpDNA) occurs through binary fission
Apoptosis steps
1. cell shrink/pull away from neighboring cells 2. the nucleus fragments, the plasma membrane develops blisters 3. the cell fragments are engulfed by white blood cells
Chances of FF, Ff, fF from the preceding list to arrive at 3/4or 75%. The chance of offspring without freckles (only the ff genotype is
1/4 or 25%
If a cell has 22 chromosomes the haploid number would be
11
If each codon were composed of only 1 nucleotide, for how many amino acids (out of the 20) would there NOT be a code for?
16
f each codon were composed of only 1 nucleotide, for how many amino acids (out of the 20) would there NOT be a code for?
16
What is the expected genotypic ratio of a Mendelian monohybrid cross involving individuals with the following genotypes (Tt X Tt)?
1:2:1
What is the expected genotypic ratio of a Mendelian dihybrid cross when both parents are heterozygous for both of their traits?
1:2:1:2:4:2:1:2:1
Each individual inherits
2 factors, one from each parent, from each trait
Each individual inherits
2 factors, one per percent
A typical eukaryotic cell contains over
2 m of DNA
Density studies suggested
2 or 3 chains
The X chromosome contains over
2000 genes
Normally, humans have _____ pairs of autosomes.
22
The normal number of autosomes for a human is_____________ pair(s) and the normal number of sex chromosomes is_____________ pair(s), for a total of 23 pairs of chromosomes.
22 1
Each base is rotated
36 degrees to the right
What is the expected phenotypic ratio of a Mendelian monohybrid cross involving individuals who have the following genotypes (Ww X Ww)?
3:1
If codons were composed of only 2 nucleotides each, how many amino acids (out of the 20) would there NOT be a code for?
4
The outcome of meiosis, which includes two nuclear divisions, is______________ (2 /4) daughter cells with the______________ (haploid / diploid) chromosome number.
4 haploid
The outcomes of meiosis.
4 daughter cells haploid daughter cells
in the second generation in a dihybrid cross there are
4 variations
Human cells contain ___ chromosomes
46
Nucleotides have
5 and 3 prime ends and are antiparallel
The chains have distinct
5' and 3' ends, and run antiparallel
Which of the following are components of a nucleotide?
5-carbon sugar Phosphate Nitrogen-containing base
How many phenotypes are possible for human blood type? How many genotypes are possible?
6
What is the expected phenotypic ratio of a Mendelian dihybrid cross when both parents are heterozygous for both of their traits?
9:3:3:1
Chromatid
A DNA molecule, each half of the chromosome
Eukaryote
A cell that contains a nucleus and membrane bound organelles
dihybrid cross
A cross between individuals that have different alleles for the same gene
monohybrid cross
A cross between individuals that involves one pair of contrasting traits
tumor suppressor genes
A gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer.
G0 phase of interphase
A nondividing state occupied by cells that have left the cell cycle, continue to perform everyday processes
poptosis
A programmed cell death, acts to decrease the number of cells, occurs when unwanted tissue develops.
Prokaryote
A unicellular organism that lacks a nucleus and membrane bound organelles
recessive allele
An allele that is masked when a dominant allele is present
GMOs
An organism whose genetic material has been precisely and specifically altered (engineered) using recombinant DNA technology and in a way that does not occur naturally. - Inserting genes from other species (often unrelated) - transgenic organisms - Altering the sequence of existing genes - gene editing, gene therapy - Enhancing expression or knock-out of existing genes
Allele
An particular form of a gene.
Choose ALL possible outcomes in a cell that cannot pass the G1 checkpoint because its DNA is damaged.
Apoptosis will occur if the DNA cannot be repaired. The cell may move into G0 if DNA repair is not possible. The p53 protein will attempt to initiate DNA repair.
Centromere
Area where the chromatids of a chromosome are attached
The concept of______________ illustrates how combinations of traits segregate when gametes are produced, and thus end up in offspring as a result of fertilization
Assortment
Prior to Mendel, most people believed in the theory of
Blended inheritance
RNA interference (iRNA)
Blocking gene expression by means of an miRNA silencing complex. first discovered in worms. Evolved from eukaryotic organisms as a protection against viruses.
1st step of spindle apparatus: Prophase
DNA condensed into visible chromosomes; spindle apparatus forms; the nuclear membrane breaks down.
Interphase
Cell grows, performs its normal functions, and prepares for division; consists of G1, S, G2, G0 phases
2nd step of binary fission prokaryote
Chromosome and DNA is replicated
Cytokinesis in animal cells
Cleavage furrow forms and deepens, and a contractile ring separates the contents into two cells
DNA length is measured in
Constant diameter
Mendel carried out hand pollination of individual plants to create
Controlled crosses
A chromatid, which is found in the cell at the beginning of the S phase, is composed of
DNA
A transgenic organism contains foreign
DNA
James Watson and Francis Crick contributed greatly to our knowledge of the structure of the molecule known as
DNA
The genetic material of all organism is called __________.
DNA
The purpose of mRNA is to carry information from______________ to the_______________
DNA Ribosomes
During the 1940s, scientists considered which two molecules most likely to be genetic material?
DNA protein
Chromatin is composed of
DNA and protein.
The enzyme responsible for unwinding and unzipping the DNA strands during DNA replication is
DNA helicase.
Prior to the 1950s, it was unclear whether
DNA or proteins carried the genetic information in the cell
The enzyme responsible for maintaining the complimentary natures of the DNA strands during DNA replication is
DNA polymerase.
The process of copying one DNA double helix is called
DNA replication
The synthesis of new DNA double helix molecules from a pre-existing parent molecule is called
DNA replication
Recombinant DNA (rDNA)
DNA that has been formed artificially by combining genetic material from different sources (often different species).
Who was unaware of Mendel's work?
Darwin
The following were direct contributions of the work of James Watson and Francis Crick
Determined that sugars and phosphates formed backbones in the DNA Determined that nucleotides were paired inside the double helix Discovered the double helix shape of deoxyribonucleic acid
In flamingos, coloration is a result of their
Diet
Mendel's first law: segregation
Diploid organisms inherit a pair of factors (alleles), one from each parent, and these segregate randomly during production of gametes such that each gamete has an equal chance of receiving either allele (but not both).
Mendel's 2 laws of inheritance apply to all generic traits in
Diploid, sexually-reproducing organisms
Linus Pauling
Discovered the alpha helix structure of proteins, thought DNA was triple stranded
The following were direct contributions of the work of James Watson and Francis Crick.
Discovered the double helix shape of deoxyribonucleic acid Determined that nucleotides were paired inside the double helix Determined that sugars and phosphates formed backbones in the DNA
Mendel showed that the genetic factors were_______ and _________ as they were passed from one generation to the next
Discrete maintained their identity
sources of generic variation:
During prophase 1, synapsis causes crossing-over and genetic recombination - each chromatid breaks into a mixture of material and paternal pieces During anaphase 1, one member of each homologous chromosome pair randomly ends up in a given daughter cell - independent assortment After Meiosis 2, each daughter cell contains only one copy of each chromosome/gene/factor -segregation Punnett Squares model the twin processes of meiosis and fertilization
Mendel's 2nd law: independent assortment
Each gene (pair of alleles) assorts into gametes independently of other genes at separate loci, such that a gamete can contain any combination of factors that occur in the parent.
restriction enzymes
Enzyme that cuts DNA or a virus at a specific sequence of nucleotides (the sticky ends)
5th step of binary fission prokaryote
Except for mutation, the daughter cells are identical
True or false: Most sex linked genes are located on the Y chromosome.
False. Reason: Incorrect. The Y chromosome has far fewer genes than the X chromosome. As such, most sex linked traits are X linked.
Damaged DNA in a cell can prevent the cell from passing which of the checkpoints?
G1
Many traits are controlled by more than one
Gene
Golden rice
Genetically modified rice that produces edible beta-carotene, which the body can turn into vitamin A for nutrient deficiencies
Meiosis 1: Anaphase 1
Homologous pairs of identical sister chromatids separate and move toward opposite poles of the cell
FF Ff ff
Homozygous dominant Heterozygous Homozygous recessive
Sister chromatids are those are produced through DNA replication
Identical except for mutation(identical)
translation steps
Initiation. mRNA in cytoplasm binds to a ribosome (mRNA) Start codon (AUG) Elongation. tRNAs anticodons bind to the codons on the mRNA sequence Termination. the amino acids on the RNA bind to each other to form a long chain, or protein
Mendel compared observed results to those predicted by the
Laws of probability
locus
Location of a gene on a chromosome
Mendel used ____ for his experiments
Mathematical models
Which of the following contributes least to genetic variety?
Mitosis
Mitosis vs. Meiosis
Mitosis: Prophase: No pairing of chromosomes Metaphase: Duplicated chromosomes at metaphase plate Anaphase: Sister chromatids separate, becoming daughter chromosomes that move to the poles Telophase/Cytokinesis: two diploid cells, identical to the parental cell occurs in somatic(body) cells during development, one round of the M phase; 1 diploid parent cell produces 2 diploid daughter cells, homologous chromosomes stay distinct; sister chromatids separate during anaphase, except for mutation, daughter cells are genetically-identical Meiosis: Prophase 1: pairing of homologous chromosomes Metapahse 1: Homologous duplicated chromosomes at metaphase plate Anaphase 1; sister chromatids separate in anaphase 2 Telophase 1: Two Haploid daughter cells occurs in germ cells and produces gametes, two rounds of the M phase with no DNA replication in-between; 1 diploid parent cell produces 4 haploid daughter cells, homologous chromosomes come together in Meiosis 1 to form tetrads; this reduces the number of chromosomes by half(diploid-to-haploid), homologous chromosomes separate during
All of the historical uses of biotechnology.
Modify bacteria to produce new drugs. Improve the nutritional value of crops. Produce plants that can withstand climate change.
One of the uses of CRISPR.
Modify the pig genome to make hearts for humans.
A certain gene has 5 possible alleles throughout a population. The trait controlled by this gene has/is ______.
Multiple alleles.
Inversions, translocation, deletions, and duplications are types of chromosomal
Mutations
Pea flowers are an example of
Non genetic influences and PH of soil
The short segments of DNA that are formed on the lagging strand during replication are called_______________ fragments.
Okazaki
Each trait examined was controlled by one pair of factors with
One allele dominant and one recessive (here, tall allele dominant over short)
Which of the following is true about a homologous chromosome pair?
One came from "mom" and one from "dad."
codominant alleles
Pairs of alleles that both affect and express the phenotype when present in the phenotype of a heterozygote
Mendel studied transmission(inheritance) of different traits in
Peas
Meiosis 1: Interkinesis
Period of time between Meiosis 1 and 2
Because Mendel was known about the actual "stuff" being passed from one generation to the next, he had to use
Phenotypes to infer something about the underlying genotypes. "Stuff" was genes.
Human genes are
Polygenic
cell division
Process by which a cell divides into two new daughter cells
1st step of binary fission prokaryote
Prokaryote is attached to the cell membrane
In eukaryotes, the DNA is packaged with
Proteins to form chromatin
The diagram used for estimating genetic probability is called a
Punnett Square
Centromeres
Region of a chromosome where the two sister chromatids attach
Which scientist's X-ray diffraction data helped to demonstrate the double helix structure of DNA?
Rosalind Franklin
Who took a picture of DNA?
Rosalind Franklin
Early examples of GMO's
Selective breeding in dogs, livestock and food domestication (horses, cows, corn, potatoes, wheat, rams, bananas)
The two traits were controlled by
Separate genetic factors, each following the mono hybrid model
Homologous chromosomes/chromatids are those that are inherited from two parents
Similar (same genes, different alleles)
Most alleles don't show
Simple dominant: recessive expression
Why did early molecular geneticists know that the genetic material needed to be a stable molecule?
So it could be passed from one generation to the next. So it could be replicated accurately.
3rd step of spindle apparatus: Metaphase
Spindle microtubules grow out and attach to the chromosomes; chromosomes jostle around until they are lined up along the metaphase plate
autosomal
all the other genes in the body that are not sex-linked.
cell separation
Technique used to separate transfused cells from autologous or patient cells
Adenine
The base that pairs with Thymine in DNA
G2 phase of interphase
The cell accumulates proteins necessary to divide the cell
G1 phase of interphase
The cell replicates it's organelles(mitochondria and ribosomes) and accumulates materials to replicate the chromosomes
What can also modify an expression of a trait?
The environment
Cell Duplication
The genetic material and cell components (make enough for 2 cells)
Meiosis 1: Metaphase 1
The homologous chromosome pair align at the metaphase plate, called independent assortment
The ploidy level
The number of centromeres
When F1 individuals were crossed with each other,
The original phenotypes appeared in the F2 generation in roughly a 3:1 ratio
When F1 individuals were backcrossed with a true breeding short,
The phenotypic ratio was roughly 1:1
gene cloning
The production of multiple copies of a gene. Scientists do it for a particular protein, alter genotypes, produce large quantities of a gene's protein product like insulin
2nd step of spindle apparatus: Prometaphase
The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes.
3rd step of binary fission prokaryote
The two copies are pulled apart as the cell grows out from the midline
A and B blood types exits to show that
The types of alleles (proteins) you have
M phase of interphase (Mitotic)
This stage includes mitosis, the division of the nucleus and genetic material, and cytokinesis, the division of the cytoplasm(which doesn't happen in all cells) during mitosis the sister chromatids of each chromosome separate becoming daughter chromosomes that are distributed to two daughter nuclei, when cytokinesis is complete, two daughter cells are identical to the mother cell
Who continued Mendel's research
Thomas Hunt Morgan
It took one hundred years
To understand Inheritance
Mendel's laws describe the
Transmission of genotypes on sexually-reproducing organisms
True or false: All three major types of RNA are produced by transcription of DNA.
True
True or false: Environmental factors may influence the expression of some genes.
True
True or false: The development of cancer always involves gene mutation.
True
1. Substitution - single base exchange 2. Insertion - addition of one or more bases 3. Deletion - removal of one or more bases
Types of mutations include
Select all of the choices that apply to a gene carrier.
Typically has a heterozygous genotype. Possesses but does not express the allele in question.
All gametes are
Unique
Most sex-linked traits are genes only on the__________ chromosome.
X
Analysis of this pedigree indicates that the genetic trait in question is
X-linked recessive.
analysis of this pedigree indicates that the genetic trait in question is
X-linked recessive.
females have ____ chromosomes
XX
cytokinesis in plant cells
a cell plate forms, followed by a new cell membrane, and finally a new cell wall forms
Peter has a gene that encodes blue eyes, while Karin has a gene for green eyes. Alternate forms of genes such as blue versus green for one trait are called
allele
The haploid number of chromosomes is
a condition in which only one kind of each chromosome is present inside the cell.
Backcross
a cross between an F1 genotype and either of the parental genotypes
growth factors
a hormone that stimulates the growth and division of a cell or cells
The cell cycle is
a set of orderly stages that occur between one cell division and the next
During the final stage of translation, a release factor binds to
a stop codon
particulate theory of inheritance
a theory proposed by Mendel. it states that traits are inherited as discrete units that remain unchanged as they are passed from parent to offspring
Meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
Gene
a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
Which of the following are genotypes of "true-breeding" organisms?
aabbcc AABBCC
The characteristics that researchers suspected the genetic material would have prior to the discovery that the genetic material was DNA.
ability to store information accurate replication passes from one generation to the next
Somatic cells are
able to undergo mitosis. body cells
The level of packaging can control whether certain regions of DNA are
active and genes are expressed
The_______________ of an enzyme are highly specific, and a function of their 3D shapes
active site
2 hydrogen bonds between
adenine and thymine, weaker
On a pedigree, a filled in square represents an
affected male.
When true breeding pure varieties were crossed,
all offspring of the F1 generation showed one of the two original phenotypes.
a given gene can have 2 or more forms known as
alleles , that result in the production of different versions of the protein that the gene encodes.
Dominant allele
an allele that is fully expressed in the phenotype of a heterozygote(Uppercase)
Avastin
an anti-angiogenic drug that is used to cut off the capillary networks to tumors and other cancers
cells that are green or isn't on proteins
aren't expressed on a chart
Mitosis is
asexual reproduction
During independent____________ , homologous chromosomes segregate in a random manner.
assortment
During independent______________ , homologous chromosomes segregate in a random manner.
assortment
A chromosome that is not associated with determining gender in an individual is called a(n)
autosome
Any chromosome other than sex chromosomes are called
autosome
Human chromosome 3 is classified as an
autosome.
Humans normally have 22 pairs of___________ and one pair of____________ chromosomes.
autosomes sex
A cell that contains a pair of each type of chromosome unique to the species is called _____.
diploid
All that apply or are associated with the term plasmid.
bacterial DNA vector
First GMO patent in 1980
bacterium with an appetite for crude oil, ready to gobble up spills.
The idea that crossing a plant with red flowers with one with white flowers would yield only plants with pink flowers is referred to as the ______ concept.
blending
Somatic cells
body cells
The repeating sequence of events in eukaryotes that involves cell growth and cell division is called the________________________.
cell cycle
At the beginning of the S phase, each chromosome is composed of a single, unreplicated DNA molecule called a
chromatid
Crossing-over sometimes occurs between nonsister___________ of a tetrad during meiosis.
chromatids
Chromosomes are made of
chromatids, when visible consist of two replicated chromatids
Eukaryotic chromosomes are composed of____________ , which is a mixture of DNA and protein.
chromatin
To fit within the cell, and prevent damage, DNA is packaged with proteins
chromatin
eukaryotic chromosomes are composed of
chromatin(combination of DNA and protein)
When the backbone of the DNA molecule breaks it is referred to as a
chromosomal mutation.
S phase of interphase
chromosome replication occurs, then each chromosome consists of two sister chromatids
Restriction enzymes are used to
cleave the vector DNA.
Proto-oncogenes
code that encodes proteins that promotes the cell cycle and prevents apoptosis
Q1 and Q2 are different alleles of a single gene and are both completely expressed in a heterozygous individual. This type of inheritance is termed
codominance
Jim has type AB blood. To have type AB blood he inherited an "A" allele from one parent and a "B" allele from the other parent. This is an example of
codominance.
A(n)____________ is a three-nucleotide sequence in mRNA that codes for a particular amino acid.
codon
Genotype
combination of alleles in a get Ben individual Ex: Aa, BB, AaBB
Hershey and Chase
concluded that the genetic material of the bacteriophage was DNA, not protein. Made the model of DNA
Which of these are removed from a mRNA during processing in the nucleus?
copies of introns
BT crops
crops that have been genetically modified to contain the Bt gene. This gene expresses a protein that is toxic to many crop-eating pests. The gene was transferred from a soil bacterium called Bacillus thuringiensis (hence Bt).
GMO examples
crops, animals, drugs, pest-resistant plants, useful bacteria. (bacterium to corn)
The further genes are apart from each other the more often they will_________ over.
cross
In meiosis,_____________________________ occurs during prophase I and results in new mixtures of genes; while during metaphase I________________________ results in new mixtures of chromosomes
crossing over independent assortment
The two events that are key to genetic variation are
crossing over. independent assortment.
What is division of cellular cytoplasm called?
cytokinesis
An individual of genotype QqBb bred with an individual of genotype QqBb. This is an example of a(n) cross.
dihybrid
A _____ is an experiment during which two individuals are bred that have two traits that have two variations for each trait
dihybrid cross
Select all of the chromosomal mutations that can occur.
deletion translocation inversion duplication
Coat color in Himalayan rabbits is influenced by the temperature at which the animal is reared. This is an example of a trait that is
determined by both genotype and environment.
A human body cell has 23 pairs of chromosomes, or 46 total chromosomes; thus, with regard to humans, 23 is the haploid (n) chromosome number and 46 is the______________ , or 2n, chromosome number.
diploid
In humans, mitosis produces cells that are
diploid.
The genetic units for underlying traits are passed as
discrete factors (I.e., not blended)
A__________ allele masks the expression of an alternate form of that same gene.
dominant
The term____________allele means that this allele will mask the recessive allele when they are together in the same organism.
dominant
DNA is a
double helix, with bases facing inward
during meiosis, crossing over sometimes occur between the nonsister chromatids of a tetard.
during crossing over, the chromatids exchange genetic material, and genes.
Treatments of certain cancers and genetic disorders are uses of genetic
engineering
ASE
enzyme
Sister chromatids contain
exactly the same genetic information.
Which contains instructions for the production of a polypeptide?
exon
The coding portions of a gene that are joined during mRNA processing are called
exons
Which of the following are spliced together to produce a mRNA transcript that will undergo translation?
exons
Signals that tell a cell to divide are more likely to be ______ signals.
external
The concept of segregation refers to how different alleles for a pair of traits are passed from parents to offspring.
false
True or false: Gene cloning refers to cloning of whole organisms.
false
Unlike what most people believed at the time, Mendel showed that blended inheritance was true.
false
The insertion or deletion of one or more bases, causing a change of the mRNA codon-reading sequence is called a(n)_____________ mutation.
frameshift
A mutation that results in a different reading frame for the codons is called a
frameshift mutation.
These factors must separate randomly when
gametes are produced, and combine randomly when fertilization occurs
The type of cloning through which identical copies of a functional unit of DNA are made is called___________ cloning.
gene
A certain gene excerpt has the sequence AAGGGTAACGA, then changes to CCGGGTAACGA. What just happened?
gene mutation
The expression of selected_____________ accounts for the specialization of cells like white blood cells, muscle fibers, and nerve cells.
genes
The expression of selected________________ accounts for the specialization of cells like white blood cells, muscle fibers, and nerve cells.
genes
Crossing over is most likely to occur between
genes that are far apart.
Oncogenes
genes that cause cancer
Producing large quantities of a gene product, such as insulin, and to learn how a cloned gene codes for a particular protein are examples of why biologists clone
genes, DNA
Genetic engineering involves manipulation of the)_____________ of organisms.
genes, genome
The ability to manipulate the genes of organisms is called
genetic engineering.
Inheritance patterns are studied in the field of
genetics
The science that helps to explain the process of inheritance patterns is called
genetics
The complete genetic makeup of any organism or virus is called its
genome
Chocolate Labrador retrievers have brown fur. The combination of alleles that produce the brown fur represents the dogs'
genotype
The alleles responsible for a trait are referred to as an organism's
genotype
Enzyme Less energy than reactants
go downhill
operon
group of genes operating together
Zmmap
grown in tobacco, cured healthcare workers in 2014 who had ebola
The enzyme that unwinds the DNA double helix so that replication can occur is called DNA
helicase
If an organism has two different alleles for the same gene it is considered ______ for that gene.
heterozygous
Recessive genes are typically masked when an individual is__________ for the gene. When two members of an allelic pair are different. Ex: genotype Hh
heterozygous
The X and Y chromosome are not
homologous
A pair of chromosomes that are alike and come together in synapsis during prophase of the first meiotic division are
homologous.
An organism carrying two dominant alleles of a particular gene would be considered dominant for that trait.
homozygous
An individual with the genotype HH, would be considered ______ for that trait.
homozygous dominant
Genes that are active in most of the body's cells are called _____ genes.
housekeeping
Bases on opposite strands are connected by
hydrogen bonds (2 or 3)
During mitosis, sister chromatids are
identical to one another. the components of a replicated chromosome.
A characteristic______________ of dominance is that heterozygotes display an intermediate phenotype that is between that of the individuals homozygotic for both alleles.
incomplete
A heterozygote displaying a third variation of a trait - a phenotype in between that of individuals homozygotic for both alleles - is an example of
incomplete dominance.
double heterozygote
individual with two mutant alleles each at a different locus
During the binding of substrates, the 3D shape of the enzyme changes, which induces strain
induced-fit
So, the genetic material must be able to store the
information needed to run the cell, and be able to pass that information to the next generation
Polygenic____________ occurs when a trait is governed by two or more genes or sets of alleles.
inheritance
frameshift mutation examples
insertion and deletion
All of the following that describes the geneticist, Gregor Mendel.
integrated mathematics in his studies followed the scientific method closely careful, deliberate, note-taker
Epistasis
interaction between alleles in which one allele hides the effects of another allele
Signals that ensure that stages of the cell cycle follow one another in the normal sequence are more likely to be ______ signals.
internal
The noncoding portions of a gene that are removed from the mRNA copy during processing are called
introns
A female that is heterozygous for an X-linked recessive trait
is a carrier of the condition.
Three alleles for the same gene control the inheritance of ABO blood types, by determining which antigens will be expressed on the surface of red blood cells. The resulting four blood types are A, B, AB and O. Select all of the true statements about the inheritance of human blood types
is codominantly expressed. has multiple alleles.
A visual inspection of the chromosomes is called a
karyotype
The locus of an allele refers to its
location on a pair of chromosomes.
Alleles of a gene are typically located at the same____________ on homologous chromosomes.
locus
dedifferentiated
lose their specialized identity
Which structure carries genetic information from the DNA to the ribosome?
mRNA
During ______, crossing-over sometimes occurs between nonsister chromatids of a tetrad.
meiosis
The process that occurs within the reproductive organs of the human body in order to produce gametes is called
meiosis
Crossing over is an event that distinguishes
meiosis from mitosis.
The type of nuclear division that occurs as part of sexual reproduction, in which the daughter cells receive the haploid number of chromosomes in varied combinations is
meiosis.
During which phase of meiosis are you most likely to observe independent assortment?
metaphase I
The purpose of _______ is to produce two genetically identical daughter cells.
mitosis
Within most tissues of the human body, a process called_____________ occurs to produce new cells.
mitosis
nuclear division that stays constant
mitosis
Most traits result from a
mixture of genetic and non genetic influences
Males inherit their X chromosomes from ?
mom
An individual of genotype Qq is bred with an individual of genotype Qq is an example of a(n) cross.
monohybrid
An individual of genotype Qq is bred with an individual of genotype Qq is an example of a_____________ cross.
monohybrid
An experiment during which two heterozygous F1 individuals are bred and produce two different phenotypes for a single trait is termed a
monohybrid cross
The allele that causes Duchenne muscular dystrophy remains in the population because the allele is passed from a carrier_____________ to a carrier_____________
mother daughter
The recessive allele that causes Duchenne muscular dystrophy remains in the population because the allele is passed from carrier
mother to carrier daughter.
Some genes are controlled by genes on
mtDNA or cpDNA or are sex-linked
A chromosomal_____________ occurs when the backbone of the DNA molecule breaks.
mutation
A chromosomal___________occurs when the backbone of the DNA molecule breaks.
mutation
A gene___________ is a permanent change to the base sequence of DNA.
mutation
Cancer generally develops as a result of
mutation events in either proto oncogenes or tumor suppressor genes.
Meiosis 1: Telophase 1 and Cytokinesis
nuclear membranes reform, the cell separates into 2 daughter cells
At the lowest level, the DNA double helix is wrapped around a core of proteins to form a
nucleosome
DNA is composed of units called__________ , each of which contains a phosphate group, a 5-carbon sugar, and one of 4 nitrogen-containing bases.
nucleotides
A sugar-phosphate backbone links
nucleotides on the same chain
DNA was a long, thin polymer of
nucleotides, (deoxyribose sugar + phosphate group + base)
When proto-oncogenes mutate, they become cancer-causing genes, called ______.
oncogenes
Each trait examined was controlled by one pair of factors, with
one allele dominant and one recessive (here, tall allele dominant over short)
Homozygote
organism that inherits two alleles of the same type for a given gene ex: AA, aa
Heterozygote
organism that inherits two different alleles for a given gene ex: Aa
The idea developed by Mendel that proposed that inheritance involves the reshuffling of the same genes from generation to generation is called the____________ theory of inheritance.
particulate
A chart which depicts a family's history with regard to a particular genetic trait is called a
pedigree
A chart which depicts a family's history with regard to a particular genetic trait is called a(n)_________ chart.
pedigree
The bases are flat and stacked like coins
perpendicular to the sugar-phosphate backbone
cells get their energy from
phosphate groups
The blending concept of inheritance indicates that if a red flowered plant was crossed with a white flowered plant, all offspring of this cross would have___________ flowers
pink
An accessory ring of DNA in bacteria, often used as a vector in gene cloning, is a
plasmid
A mutation that results in a difference of one base from the original DNA sequence is called a point mutation.
point
A mutation that results in a difference of one base from the original DNA sequence is called a(n)___________ mutation.
point
A mutation that results in one base in the DNA being replaced by a different base is called a
point mutation.
A condition in which two or more sets of alleles control genetic patterns is controlled by _____ inheritance.
polygenic
The enzyme that assists with complementary base pairing and adding new nucleotides to the growing strand during DNA replication is DNA
polymerase
The technique that uses DNA polymerase with heating/cooling cycles to produce billions of copies of a particular piece of DNA is called
polymerase chain reaction
Two categories of DNA
purines (9-membered double rings with nitrogen at 1,3,7 and 9 positions) and pyrimidines (six membered rings with nitrogen at 1 and 3 positions).
In the 1940s, scientists had concluded that the genetic material was most likely either
protein or DNA.
Hershey and Chase used radioactive sulfur in order to label______________ during the experiments that demonstrated that DNA was the genetic material.
proteins
adenine and guanine (A, G)
purines
Erwin Chargaff determined that the number of___________ like guanine and adenine always equal the number of________________ like cytosine and thymine.
purines pyrimidines
The findings of Erwin Chargaff regarding DNA composition.
pyrimidines = purines G=C A = T
The result of the Hershey and Chase experiment that demonstrated DNA to be the genetic material.
radioactive DNA is taken up by bacteria
Alleles that are represented by a lower case letter are termed
recessive
Use the pedigree to answer the following question. This pedigree reflects a X-linked____________ condition.
recessive
Hereditary methemoglobinemia
recessive loss-of-function mutation in the gene for the enzyme diaphorase (blue skin)
A segment of DNA containing genes from both mice and humans would be called________ DNA
recombinant
The type of DNA that contains DNA from two or more different sources is called ______ DNA.
recombinant
X-ray diffraction suggested a
regular helix
During what cellular process do Okazaki fragments form?
replication
The production of two DNA copies from a single original DNA molecule is called DNA
replication
The particulate theory of inheritance involves
reshuffling of the genes from generation to generation.
The three events that distinguish meiosis from mitosis are
separation of homologous chromosomes. crossing over. homologous chromosomes synapse.
Enzymes are not part of the reaction - they contribute no atoms - so are
reusable
Gregor Mendel was a mathematician and also kept very detailed notes on his observations. These characteristics helped him be a
scientist, biologist
These combinations of factors must
segregate randomly when gametes are produced, so individuals can inherit any combination of alleles for the two factors
These factors must
separate randomly when gametes are produced, and combine randomly when fertilization occurs
Which nucleic acid is the physical carrier of individual amino acids?
tRNA
A coding portion of a DNA template strand has the sequence AGAACC. Assuming no modifications, what would be the sequence of the amino acids in the protein product? (Use the mRNA codon table.
serine - tryptophan
X and Y linked genes are generally referred to as_____________ linked genes.
sex
X and Y chromosomes are classified as
sex chromosomes.
Autosomes are any chromosomes other than___________chromosomes.
sex, allosome
traits controlled by genes located on an X or Y chromosome is said to be
sex-linked.
Meiosis is a type of nuclear division that occurs as a part of___________ reproduction, and the resulting daughter cells have the_____________ number of chromosomes, 23, in humans.
sexual haploid
Meiosis is
sexual reproduction
RNA
single-stranded nucleic acid that contains the sugar ribose
4th step of spindle apparatus: Anaphase
sister chromatids are separated and moved to opposite poles of the cell
Replicated chromosomes are composed of
sister chromatids.
Two chromosomes that are attached and have identical sequences of genes are called
sister chromatids.
mitochondria
site of genetic information
Body cells, which are cells that do not undergo meiosis to become sperm or oocytes, are also called___________ cells.
somatic
Body cells, which are cells that do not undergo meiosis to become sperm or oocytes, are also called____________ cells.
somatic
5th step of spindle apparatus: Telophase
spindle disappears and the nuclear envelope components reassemble around the daughter chromosomes, the polar spindles are still visible, after telophase the chromosomes decondense and a nucleolus appears in each daughter nucleus
The codon near which the small ribosomal subunit attaches to the mRNA molecule to be translated, which codes for methionine (AUG) is called the____________ codon.
start
During translation initiation, the small ribosomal subunit and initiator tRNA attach in the vicinity of the
start codon
The single-stranded but complementary ends of DNA, which are ready to bind foreign DNA to vector DNA in recombinant DNA production, are called " ____________ends".
sticky
Single-stranded, but complementary ends of two DNA molecules are called
sticky ends
Translation ends when a(n)__________ codon binds to a release factor.
stop
During meiosis I, occurs such that homologous chromosomes come together and line up side by side.
synapsis
The process by which homologous chromosomes come together and line up side by side is termed
synapsis
Meiosis 1: Prophase 1
synapsis occurs and spindle appears and the homologous chromosomes come together side by side and crossing over
The specific type of nucleic acid bearing anticodons for the amino acid sequence is abbreviated
tRNA
true-breeding
term used to describe organisms that produce offspring identical to themselves if allowed to self-pollinate(same phenotype)
If an individual showing a dominant phenotype, but an unknown genotype, is crossed with a homozygous recessive individual for that trait, this would be considered a
test cross
Mendel bred an unknown plant displaying a dominant phenotype with an individual showing the recessive phenotype; then, he analyzed the offspring to determine the unknown genotype, is crossed with a homozygous recessive individual. This experiment is called a
testcross
Mitosis is the portion of the cell cycle in which
the cell divides its DNA.
4th step of binary fission prokaryote
the cells divide in two at the midline
sum rule of probability
the chance of an event that can occur in more than one way is the sum of the individual chances
The genome is
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes
Cytokinesis is the portion of the cell cycle during which
the cytoplasm and organelles of the cell are divided.
Humulin
the first intermediate-acting insulin that was genetically modified to be commercial medicine, grown form yeast.
Proto-oncogenes and tumor suppressor genes control
the movement of a cell through the cell cycle.
When F1 individuals were crossed with each other
the original phenotypes appeared in the F2 generation in roughly a 9:3:3:1 ratio
locus
the physical location of a gene on a chromosome
The phenotypic ratio is the same as you would predict by taking
the product of the 2 phenotypic ratios from the monohybrid crosses
Mitosis produces daughter cells that have
the same number of chromosomes as the parent cell.
Phenotype
the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment. Ex: wrinkled seeds, pink flowers
A Punnett square is a diagram used
to estimate genetic probabilities in offspring.
All of the following that are reasons why a scientist may want to clone a gene.
to use the gene for gene therapy to learn how the gene codes for a protein to produce large quantities of the gene's protein product
Molecules of mRNA, tRNA, and rRNA are produced by the process of
transcription
The process by which an RNA strand is synthesized from a DNA template strand is called
transcription
The production of mRNA from a DNA template occurs during
transcription.
Genetically modified organisms that have had foreign DNA inserted into their genome are said to be___________ organisms.
transgenic
Organisms that have had a foreign gene inserted into their genome are called
transgenic organisms.
The process of_______________ uses mRNA, tRNA, and ribosomes to synthesize proteins.
translation
Polypeptides and proteins are produced during the process of
translation.
All of the uses of genetic engineering.
treatments of genetic disorders cancer treatments
The genetic code is said to be a(n) _______________code, because a set of three nucleotide bases codes for a particular amino acid.
triplet
The genetic code is said to be a(n)____________ code, because a set of three nucleotide bases codes for a particular amino acid.
triplet
In almost all cases, there is a 50:50 chance that a given allele in an individual is passed to a gamete.
true
Mendel's laws say the chance of inheriting certain pair of traits is the product of the chance of inheriting each one separately.
true
Sexually-reproducing organisms generally have two copies of each genetic factor (gene), one inherited from each parent.
true
When two pea plants with round, yellow seeds breed, they produce many offspring all with round, yellow seeds. This population is considered ________.
true breeding
The balance between what two types of genes determines if cell division does or does not occur.
tumor suppressor genes and proto-oncogenes
Crossing-over occurs between the
two non-sister chromatids of a homologous pair.
On a pedigree, an unfilled circle represents an
unaffected female.
Thomas Hunt Morgan
used Drosophila melangaster (fruit flies) to confirm the existence of sex-linked traits (chromosomes)
A piece of DNA that can be manipulated such that foreign DNA can be added to it is called a
vector
A plasmid is often used in biotechnology applications as a(n)____________ to transfer foreign genetic material.
vector
Rosalind Franklin's X-ray diffraction photograph demonstrated that DNA
was a double helix.
in 1986, a hepatitis B vaccine was grown in
yeast