BIO EXAM 3

Missense Mutation

A base-pair substitution that results in a codon that codes for a different amino acid.

Chromosome Theory of Inheritance

A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.

Haploid

A cell containing a single set of chromosomes n cell For humans, our number is n=23

Diploid

A cell containing two complete sets of homologous chromosomes, one from each parent. 2n cell

cytokinesis in a plant cell

A cell is treated with a drug that prevents the formation of vesicles. Which of the following processes depends on the formation of vesicles and would therefore be blocked?

before it is about to divide

A cell replicates its entire chromosomal DNA only __________.

Frameshift Mutation

A change in the genetic material that involves the insertion or deletion of one or more nucleotides in a gene, resulting in a change in the triplet grouping of nucleotides.

Mutagen

A chemical or physical agent that interacts with DNA and causes a mutation.

is caused by a recessive allele

A child with cystic fibrosis can be born to two parents who do not have the disease. This is because the disease _____.

Sex Chromosome

A chromosome that determines whether an individual is male or female.

Cytokinesis

A cleavage furrow forms in an animal cell during _____.

Cell Cycle Control System

A cyclically operating set of proteins that triggers and coordinates events in the eukaryotic cell cycle.

Punnett Square

A diagram used in the study of inheritance to show the results of random fertilization

Mitotic Spindle

A football-shaped structure formed of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis and meiosis.

the position of mRNA in the egg cell

A fruit fly's head-to-tail axis is established by __________.

the information for making a polypeptide

A gene is usually _____.

DNA ... RNA ... protein

A gene made of __________ is transcribed into __________ and then translated to form a __________.

The Law of Segregation

A general rule in inheritance (originally formulated by Gregor Mendel) that individuals have two alleles for each gene and that when gametes form by meiosis, the two alleles separate, each resulting gamete ending up with only one allele of each gene; also known as Mendel's first law of inheritance.

Law of Independent Assortment

A general rule in inheritance (originally formulated by Gregor Mendel) that when gametes form during meiosis, each pair of alleles for a particular characteristic segregate independently of other pairs; also known as Mendel's second law of inheritance.

particular nucleotide sequence in the genome that varies from person to person

A genetic marker is a __________.

substitution of one nucleotide

A geneticist found that a particular mutation had no effect on the polypeptide encoded by a gene. This mutation probably involved __________.

Character

A heritable feature that varies among individuals within a population, such as flower color in pea plants or eye color in humans

92

A human bone marrow cell in the prophase stage of mitosis contains 46 chromosomes. Therefore, there are a total of __________ sister chromatids in this cell.

DNA Polymerase

A larger molecular complex that assembles DNA nucleotides into polynucleotides using a preexisting strand of DNA as a template Add only to the 3' end of the strand Can also repair DNA

Testcross

A mating between an individual of unknown genotype and a homozygous recessive individual Used to determine the unknown genotype

Cross

A mating of two sexually reproducing individuals; often used to describe a genetics experiment involving a controlled mating.

Binary Fission

A means of asexual reproduction in which a parent organism, often a single cell, divides into two individuals of about equal size. Used by prokaryotes

Silent Mutation

A mutation in a gene that changes a codon to one that codes for the same amino acid as the original codon. The amino acid sequence of the resulting polypeptide is thus unchanged.

Nonsense Mutation

A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.

G0 Phase

A nondividing state in which a cell has left the cell cycle.

Tetrad

A pair of homologous chromosomes

Chiasma

A place where two homologous chromatids are attached to each other

the enzyme RNA polymerase

A promoter is a specific binding site for _____.

RNA would remain in the nucleus as it would be unable to move through the nuclear pores, thus blocking translation of the gene

A scientist is investigating a new drug that blocks the action of the enzyme responsible for splicing mRNA molecules. If this drug is effective, which of the following statements will be true?

Triplet Code

A set of three-nucleotide-long words that specify the amino acids for polypeptide chains.

Gamete

A sex cell Each has a single set of chromosomes (22 autosomes plus a sex chromosome)

the mechanisms of transcriptional control

A similar protein is found in both a bacterial cell and a single-celled eukaryote. However, the prokaryote seems to produce a much higher amount of the protein. A detailed investigation of the control mechanisms of this protein in both organisms would include a comparison of which of the following?

pleiotropic

A single allele that controls more than one character is said to be __________.

Plasmid

A small ring of independently replicating DNA separate from the main chromosome(s). Are found in prokaryotes and yeast.

Terminator

A special sequence of nucleotides in DNA that marks the end of a gene. It signals RNA polymerase to release the newly made RNA molecule, which then departs from the gene

a nucleic acid probe

A specific DNA sequence within a mass of DNA can be readily detected using ______________.

Promoter

A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing RNA.

Codon

A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code.

Incomplete Dominance

A type of inheritance in which the phenotype of a heterozygote (Aa) is intermediate between the phenotypes of the two types of homozygotes (AA and aa).

Complete Dominance

A type of inheritance in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.

Alternative RNA Splicing

A type of regulation at the RNA-processing level in which multiple mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns.

Transfer RNA (tRNA)

A type of ribonucleic acid that functions as an interpreter in translation. Each molecule has a specific anticodon, picks up a specific amino acid, and conveys the amino acid to the appropriate codon on mRNA.

Trait

A variant of a character found within a population, such as purple or white flowers in pea plants

manufactured proteins to be short and defective

A virus infects a cell and randomly inserts many short segments of DNA containing a stop codon throughout the organism's chromosomes. This will probably cause _____.

Bacteriophage

A virus that infects bacteria

50% of sons and 50% of daughters

A woman who is a carrier of hemophilia marries a man affected with hemophilia. What percentage of their sons and daughters is expected to have hemophilia?

Purines

Adenine and Guanine Larger, double ring structures

signal molecule

Adrenaline is a "fight-or-flight" hormone and is released when danger threatens or in an emergency. It binds to a protein receptor, which causes a number of reactions to occur inside the cell. Enzymes are produced that perform a number of functions, including release of sugar into the bloodstream. What function does adrenaline play in this pathway?

Mitosis

After fertilization, the resulting human zygote begins to divide by __________.

Post-Transcriptional Control

Alternative RNA splicing Stability of mRNA molecule

Transcription of the same gene can lead to the production of different mRNAs and therefore different proteins.

Alternative RNA splicing has revealed inaccuracies in the one gene-one polypeptide hypothesis. Why?

Trisomy for the other autosomal chromosomes is often lethal, and the affected embryos are miscarried.

Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. Of the remaining 19 autosomes, many trisomies have not been seen in newborns. Why not?

Recessive Allele

An allele that has no noticeable effect on the phenotype of a gene when the individual is heterozygous for that gene.

a set of triplet bases on a tRNA that is complementary to a codon triplet on mRNA

An anticodon is __________.

a restriction enzyme

An enzyme that "cuts" DNA at a specific sequence of nucleotide bases is called __________.

Somatic Cell

An example of a cell that is 2n is a __________.

Carrier

An individual who is heterozygous for a recessive disorder. Therefore they do not show it, but they can pass the recessive allele to someone else

Intron

An internal, noncoding region of a gene that does not become part of the final messenger RNA molecule and is therefore not expressed.

Human Genome Project

An international collaborative effort to map and sequence the DNA of the entire human genome. Revealed most of the human genome does not consist of genes Repetitive DNA (includes transposable elements)= 44% Repetitive DNA (does not include transposable elements)= 15% Introns and regulatory sequences= 24% Unique noncoding DNA= 15% Exons= 1.5%

Genetic Map

An ordered list of the genetic loci along a particular chromosome.

Cell Cycle

An ordered sequence of events (including interphase and the mitotic phase) that extends from the time a eukaryotic cell is first formed from a dividing parent cell until its own division into two cells.

Transgenic Animals

Animals that contain genes transferred from other animals, usually from a different species (Recombinant DNA) Obtain information on gene function and regulation Production of pharmaceutical proteins and organ tissue for humans Identification of new drug targets

1.5%

Approximately what percentage of the human genome actually encodes proteins or functional RNA molecules?

can produce great variation among the offspring

Asexual and sexual reproduction differ in that sexual reproduction _____.

small interfering RNA (siRNA)

Associates with one or more proteins in a complex that can degrade or prevent translation of an mRNA with a complementary sequence Can be artificially created

1/4

Assume that in cattle a spotted coat is dominant to an even coat, short horns are dominant to long horns, and the traits for coat type and horn length assort independently. In a cross between cattle that are each heterozygous for both traits, what proportion of their offspring are expected to have long horns?

Haploid and the sister chromatids are joined

At the conclusion of meiosis I, the daughter cells are _____.

Two haploid cells

At the end of telophase I of meiosis, as cytokinesis occurs, there are __________.

start codon on the mRNA molecule

At the start of translation, where does the initiator tRNA bind?

work backward from mRNA to make a version of the gene without introns

Bacteria lack RNA-splicing machinery, which means they are unable to splice out introns from eukaryotic genes. To engineer a bacterium to produce a eukaryotic protein, it is necessary to synthesize a gene without introns. If you know the nucleotide sequence, you can _____.

recent human evolution

Because it is passed essentially intact from father to son, Y chromosome research has been particularly useful in improving our understanding of __________.

Somatic Cell

Body cell (non-sex cell) Has 46 chromosomes When undergoing mitosis, has 23 pairs of duplicated chromosomes

CRISPR

Can modify a gene Clustered Regularly Interspaced Short Palindromic Repeats Founded by Doudna and Charpentier

G1

Cells will usually divide if they receive the proper signal at a checkpoint in the __________ phase of the cell cycle.

Mutation

Change in the genetic material of a cell Can occur in the DNA or RNA of a virus

identical copies of each other if they are part of the same chromosome

Chromatids are _____.

M Checkpoint Conditions

Chromosomes connected to spindle

Autosomes

Chromosomes other than sex chromosomes 44 of them

Recombinant Chromosomes

Chromosomes that carry DNA from two different parents

formed a cell plate

Consider the photograph shown below. You can determine this is a plant cell rather than an animal cell because it has __________.

the exchange of homologous portions of nonsister chromatids

Crossing over is _____.

allows the exchange of different versions of genes between homologous chromosomes

Crossing over is important because it __________.

Prophase I

Crossing over occurs during _____.

the harmful allele "hides" inside heterozygous individuals and one-fourth of the offspring of two heterozygotes should be afflicted

Cystic fibrosis is inherited in an autosomal recessive pattern. Males who have cystic fibrosis are usually sterile. Furthermore, the disease is often lethal before the age of reproduction. Even though people with the disease rarely reproduce, cases continue to arise because __________.

Cleavage

Cytokinesis in animal cells and in some protists, characterized by pinching in of the plasma membrane In animal development, the succession of rapid cell divisions without cell growth that converts the animal zygote into a ball of cells.

Cell Plate

Cytokinesis in plant cells A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis

Pyrimidines

Cytosine, Thymine, and Uracil Single ring structures

G2 Checkpoint Conditions

DNA copied correctly Cell size

gene expression

DNA microarrays are useful tools for studying _____.

the presence of various-sized fragments of DNA

DNA profiles used as evidence in a murder trial look similar to supermarket bar codes. The pattern of bars in a DNA profile shows _____.

compares the DNA banding patterns of small segments of the genome

DNA profiling is a forensic procedure being utilized to identify individuals. This technique _____.

the S phase of interphase

DNA replication occurs in _____.

cDNA

DNA synthesized using an RNA template is called _____.

each parental strand serves as a template for the synthesis of a complementary strand

During DNA replication, __________.

sister chromatids separate and migrate toward opposite poles

During anaphase II, __________.

genetically identical offspring

During asexual reproduction, yeast cells can produce _____.

It ensures that each daughter cell receives one copy of the chromosome.

During binary fission, each copy of the duplicating chromosome moves to opposite ends of the cell. What does this achieve?

They organize the microtubules.

During cell division, what role do centrosomes play?

Crossing over creates new combinations of genes present on a single chromosome.

During meiosis I, homologous chromosomes form a tetrad and crossing over occurs. What is the outcome of crossing over?

Nondisjunction

During meiosis, homologous chromosomes sometimes "stick together" and do not separate properly. This phenomenon is known as _____.

they attach to a dynamic, precisely regulated mitotic spindle

During mitosis, the chromosomes move because _____.

serves as the template for the creation of two complete sets of DNA

During replication, the original "parent" DNA __________.

applying heat that breaks the hydrogen bonds connecting the DNA strands

During the Polymerase Chain Reaction, the two strands of DNA are separated by __________.

Post-Translational Control

Enzyme Inhibition

RNA Polymerase

Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

Phenotype

Expressed traits of an organism

Trisomy 21

Extra copy of chromosome 21 Down Syndrome

Cell Fusion

For the yeast Saccharomyces cerevisiae, cells of different mating types secrete factors that bind to specific receptor proteins on the cell surface of cells of the opposite mating type. This initiates a signal transduction pathway that eventually results in __________.

Even though the S strain had been heat-killed, it genetically changed the R strain.

Frederick Griffith was one of the leading scientists looking at the genetic role of DNA. He was working on two strains of Streptococcus pneumoniae: The rough strain (R) did not cause pneumonia, but the smooth strain (S) did. When Griffith heat-killed the S strain and gave both the heat-killed S strain and the R strain to mice, the mice developed pneumonia and died. What happened in this experiment that caused the mice to develop pneumonia?

F plasmid (100 kb)

Gel electrophoresis separates DNA molecules on the basis of size. Which of the following DNA molecules would move the slowest?

breakdown of RNA

Gene expression can also be controlled after the mRNA molecule has left the nucleus. These mechanisms may include the __________.

Linked Genes

Genes located near each other on the same chromosome that tend to be inherited together. May not follow Mendel's law of independent assortment

can occur naturally

Genetic mutations __________.

These microbes have been designed so that conditions outside the laboratory would be unfavorable to their survival.

Genetically modified organisms include microbes used in biotechnology that possess enzymes promoting antibiotic resistance. This could be a problem given the rise of antibiotic-resistant organisms. However, these engineered microorganisms do not pose a risk to public health. What do you think prevents them from spreading antibiotic resistance to pathogens outside the laboratory?

beta-carotene

Golden rice has been genetically engineered. Golden rice differs from other rice varieties because it contains genes that will produce _____.

Interphase

Growing stage The period in the eukaryotic cell cycle when the cell is not actually dividing The majority of time spent in the cell cycle (90%) Duplicates its chromosomes G1 phase (first gap), S phase (synthesis of DNA), and G2 phase (second gap)

G1 Checkpoint Conditions

Growth factors? Cell size "Health"/nutrient supply?

Zygote

Has one set of homologous chromosomes from each parent, therefore making it a diploid

Heterozygous

Having two different alleles for a particular gene

Homozygous

Having two identical alleles for a particular gene

the female must possess the hemophilia allele on both X chromosomes

Hemophilia appears rarely in females. This is because __________.

T2 viruses consist only of proteins and DNA and only the DNA was injected into the host cells

Hershey and Chase's experiment allowed them to discern whether DNA or proteins contain genetic information because __________.

100%

High levels of LDL cholesterol in the bloodstream can be the result of familial hypercholesterolemia, an inherited condition that displays incomplete dominance. In a family with a severely affected father and an unaffected mother, what percentage of their children are expected to have higher than normal blood cholesterol?

Epigenetic Control

Histone Modification Chromatin Structure

It starts at a certain nucleotide sequence called a promoter

How does RNA polymerase know where to start transcribing a gene into mRNA?

22

How many pairs of autosomes do humans have?

Microorganisms were genetically engineered to produce hepatitis B proteins.

How was the hepatitis B vaccine produced?

harvested from cadavers

Human growth hormone is a secreted protein that stimulates growth and cell reproduction. In the 1960s it was discovered that this was an effective treatment for a form of dwarfism. However, before it was genetically engineered, it was _____.

An inversion

If a fragment of a chromosome breaks off and then reattaches to the original chromosome at the same place but in the reverse direction, the resulting chromosomal abnormality is called _____.

0.5

If one parent is blood type AB and the other is type O, what fraction of their offspring is expected to have blood type A?

would have deviated from the 9:3:3:1 phenotypic ratio that is predicted by the law of independent assortment

If the two characteristics that Mendel looked at in his dihybrid cross of smooth yellow peas with wrinkled green peas had been controlled by genes that were located close together on the same chromosome, then the F2 generation __________.

Perform a cross between two true-breeding individuals and observe the trait or traits expressed by the F1 individuals.

Imagine a particular character (such as flower color) that is determined by a single gene. If this gene is present in two forms, how can you tell which allele is dominant and which is recessive?

Cross the long-finned fish with short-finned fish; if the offspring are all long-finned, the long-finned parent is homozygous. Submit

Imagine that long fins in zebrafish is a dominant trait. A breeder wants to set up a breeding program beginning with homozygous dominant long-finned fish. If she obtains a handful of the long-finned fish, how can she tell which, if any, of these are homozygous for the trait?

They should be informed that if they have a child, the child will not have Tay-Sachs disease but will have a 50% chance of being a carrier of the Tay-Sachs allele.

Imagine you're counseling a couple who have undergone carrier screening for Tay-Sachs disease. The man is a carrier, and the woman does not carry the Tay-Sachs allele. How should you advise them?

9/64

In Labrador retrievers, a common breed of dog, black coat is dominant to chocolate, normal vision is dominant to progressive retinal atrophy (PRA), and normal hip joint is dominant to hip dysplasia. All these genes assort independently. Two dogs that are heterozygous for alleles of all three genes are crossed. Using rules of probability (not a Punnett square), what is the chance that the first pup born to these dogs will be chocolate, have normal vision, and have normal hip joints?

In the Nucleus

In a eukaryotic cell, transcription takes place _____.

homologous chromosomes move toward opposite poles

In anaphase I, __________.

distribution of a copy of the single parental chromosome to each daughter cell

In bacterial cells, binary fission involves __________.

Intercross the F1 and see if the F2 contains three size classes (consistent with the incomplete dominance model) or if there is a range of sizes (consistent with the polygenic model).

In breeding pure-breeding large and small strains of mice, you cross individuals of each strain and note that their offspring are intermediate in size. Two models (explanations) to account for this result are (1) that body size in these strains is due to one gene with alleles that show incomplete dominance and (2) that body size is a polygenic trait. How could you distinguish between these models?

The coloration and shape genes are linked on the same chromosome.

In corn, blue kernels are produced by a dominant allele of a coloration gene, and white kernels are produced in individuals homozygous for a recessive allele of the same coloration gene. Another gene has two alleles for shape, with smooth kernels being dominant to wrinkled. A plant heterozygous for both genes is testcrossed (crossed to a homozygous recessive white, wrinkled strain). The testcross offspring consist of the following types: 1,447 blue smooth; 1,436 white wrinkled; 150 blue wrinkled; 145 white smooth. Explain the inheritance of the coloration and shape traits.

a specific nucleotide sequence in DNA that signals the RNA polymerase to stop

In eukaryotic cells, a terminator in mRNA synthesis is _____.

a series of relay molecules, of which the last activates a transcription factor

In eukaryotic cells, signal transduction pathways involve __________.

includes the addition of a cap and tail, which protect the mRNA molecule from enzymatic attack, and the removal of introns

In eukaryotic cells, the RNA is processed before it leaves the nucleus. This processing __________.

2^23

In humans, the haploid number of chromosomes is 23. Independent assortment has the possibility of producing __________ different gametes.

Stop Codon

In mRNA, one of three triplets (UAG, UAA, UGA) that signal gene translation to stop

are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes

In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.

cuts double-stranded DNA

In the CRISPR-Cas9 system, the Cas9 protein __________.

Cancer cells continuously secrete growth factors into the cell culture medium.

In the laboratory, cancer cells fail to show density-dependent inhibition of growth in cell culture. What is one explanation that could account for this?

RNA polymerase links nucleotides to form mRNA.

In transcription, __________.

it's possible that they cannot produce a child with sickle-cell disease, but blood tests on them both will be required to make sure

John and Jane are planning a family, but each has a brother who has sickle-cell disease, so they are concerned that their children may develop sickle-cell disease. Neither John nor Jane nor their respective parents have the disease. They consult a genetic counselor who tells them that __________.

are on the same chromosome

Linked genes are inherited together. This is because linked genes _____.

mice

Many useful products, mainly for medical purposes, are produced by cloning human genes into other organisms, which then mass-produce these compounds. Which of the following organisms has NOT been used to mass-produce pharmaceutical compounds used to treat human diseases?

Crossing Over

Meiosis differs from mitosis in that _____ only occurs in meiosis.

independent assortment of alleles of one gene relative to the alleles of any other gene

Mendel's principle of independent assortment applies to the __________.

unblendable heritable factors that were contributed by each parent and never altered by mixing

Mendel's view of the mechanism of heredity was radically different from the prevailing view of the time because he saw heredity working through __________.

DNA Technology

Methods used to study and/or manipulate DNA, including recombinant DNA technology

Translation

MicroRNA (miRNA) controls __________.

Centrosomes

Microtubule-organizing centers that help to form and organize the mitotic spindle during mitosis

two diploid cells : four haploid cells

Mitosis and cytokinesis result in the formation of __________; meiosis and cytokinesis result in the formation of __________.

200 trillion

Number of cells in your body

Hybrids

Offspring of crosses between parents with different traits

Anticodon

On a tRNA molecule, a specific sequence of three nucleotides that is complementary to a codon triplet on mRNA.

Start Codon

On mRNA, the specific three-nucleotide sequence (AUG) to which an initiator tRNA molecule binds, starting translation of genetic information.

Sister Chromatid

One of the two identical parts of a duplicated chromosome in a eukaryotic cell.

red eyes; white eyes

One version of a gene may encode __________, whereas a different version of the same gene may encode __________.

homologous chromosomes

Pair of chromosomes that are the same size, same appearance and same genes. Matched pair in a diploid cell

P Generation

Parental generation, the first two individuals that mate in a genetic cross

Heredity

Passing of traits from parents to offspring

1/16

Pea flowers may be purple (P) or white (p). Pea seeds may be round (R) or wrinkled (r). What proportion of the offspring from the cross PpRr × PpRr are expected to have white flowers and wrinkled seeds?

Farmers can reduce chemical use

Plants are being engineered to produce their own insecticides; therefore, __________.

A normal watermelon has 22 chromosomes but seedless watermelons have 33 chromosomes

Polyploidy is involved in which of the following examples?

after a mating, genes of the two parents are mixed in the offspring and lose their individual identities

Previously, it was thought that the blending hypothesis explained inheritance. The blending hypothesis maintained that __________.

gel electrophoresis

Procedure used to separate and analyze DNA fragments (macromolecules) by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel

Prokaryotic DNA molecules much smaller than eukaryotic DNA molecules

Prokaryotic organisms have a single origin of replication, whereas eukaryotic organisms have many origins where replication occurs simultaneously. Which of the following is the most probable reason for this observation?

Cell Identity

Proteins that are expressed in the cell

True-breeding

Referring to organisms for which sexual reproduction produces offspring with inherited traits identical to those of the parents; the organisms are homozygous for the characteristics under consideration.

Duplication

Repetition of part of a chromosome resulting from fusion with a fragment from a homologous chromosome; can result from an error in meiosis or from mutagenesis.

signal transduction systems

Researchers have used yeast mating systems as model systems to study _____.

a restriction enzyme; DNA ligase

Scientists who wish to clone genes of interest into bacterial plasmids utilize __________, which cuts the target and vector DNA at specific sites. Then __________ is used to form covalent bonds between the resulting fragments to complete the recombinant DNA molecule.

The seedlings should differ from each other, depending on their genetic constitution.

Seeds from a single sexually reproducing plant are harvested and later planted under identical conditions. What results should be expected?

50% red, 50% pink

Snapdragons show incomplete dominance in their flowers. A pink snapdragon is crossed with a red snapdragon. What color(s) are the offspring?

Translational Control

Speed of Translational miRNAs

a female with Tay-Sachs

Tay-Sachs disease runs in Rebecca's family. On a family pedigree, she saw a shaded circle. This represented _____.

destroy foreign DNA

The "normal" function of restriction enzymes in cells is to __________.

The pairing up of homologous chromosomes and crossing over only occur during meiosis.

The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?

holds the growing polypeptide chain

The P site of a ribosome __________.

"maleness" and a few other characteristics

The Y chromosomes of mammals contain genes that code for _____.

Polygenic Inheritance

The additive effect of two or more gene loci on a single phenotypic characteristic.

Dominant Allele

The allele that determines the phenotype of a gene when the individual is heterozygous for that gene.

sugar-phosphate backbone

The alternating chain of sugar and phosphate to which the DNA and RNA nitrogenous bases are attached

Genes segregate; chromosomes come in pairs.

The chromosome theory of inheritance is based upon which of the following sets of observations?

Chromatin

The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, it exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope

bioinformatics

The computer-assisted analysis of genomic data is an application of the field of __________.

Pleiotropy

The control of more than one phenotypic character by a single gene

Asexual Reproduction

The creation of genetically identical offspring by a single parent, without the participation of sperm and egg. Creates a clone Functions in reproduction

Sexual Reproduction

The creation of genetically unique offspring by the fusion of two haploid sex cells (gametes), forming a diploid zygote. Does not create clones

result in hybrid plants

The cross-fertilization of two different, but true-breeding, varieties of pea plants will _____.

rice

The current estimate for the number of genes in the human genome is about 20,500. Which of the following organisms has approximately twice as many genes as humans?

Fertilization

The diploid phase of the human life cycle begins with _____.

Genetic Engineering

The direct manipulation of genes for practical purposes.

Meiosis

The division of a single diploid cell into 4 haploid daughter nuclei Produce haploid gametes in the reproductive organs of the parents Goes through two different stages 4 daughter cells (genetically unique) Ploidy cut in half Fertilization → ploidy preserved Germ cells → gametes

Mitosis

The division of a single nucleus into two genetically identical nuclei 2 daughter cells (genetically identical to parent) Ploidy preserved Somatic cells

Cytokinesis

The division of the cytoplasm to form two separate daughter cells Usually occurs in conjunction with telophase of mitosis

Reciprocal Translocation

The exchange of parts between nonhomologous chromosomes is called _____.

Crossing Over

The exchange of segments between non-sister chromatids of homologous chromosomes during synapsis in prophase I of meiosis; also, the exchange of segments between DNA molecules in prokaryotes.

Telophase

The fifth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell. This usually occurs together with cytokinesis.

methionine

The first amino acid inserted into a new polypeptide chain in eukaryotic cells is always __________.

adenine, guanine, cytosine, thymine

The four bases contained in DNA are _____.

Anaphase

The fourth stage of mitosis, beginning when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell.

Complementary single-stranded ends

The fragments produced by most restriction enzymes have __________.

four cells with a haploid number of chromosomes

The function of meiosis is to make __________.

Genotype

The genetic makeup of an oranism

The vast majority of our genome is noncoding, with nearly half of it (44%) derived from "jumping genes" inserted into our genome.

The human genome is approximately 30 times larger than that of the nematode C. elegans, yet both species contain a similar number of genes. What accounts for this difference?

map all the human genes and determine the nucleotide sequence of the entire human genome

The individuals working on the Human Genome Project (HGP) were attempting to _____.

the order of the nucleotides in the molecule

The information carried by a DNA molecule is in _____.

Messenger RNA (mRNA)

The kind of RNA that encodes amino acid sequences In eukaryotic cells, it must depart from the nucleus into the cytoplasm to perform translation In prokaryotic cells, transcription and translation occur in the same place

sites at which microtubules attach to chromosomes

The kinetochores are __________.

Biotechnology

The manipulation of living organisms or their components to produce useful products.

F2 Generation

The offspring of two F1 generation individuals

F1 Generation

The offspring of two parental individuals

Exon

The part of a gene that becomes part of the final messenger RNA and is therefore expressed.

Signal Transduction Pathway

The process by which a signal on a cell's surface is converted into a specific cellular response.

Nucleic Acid Hybridization

The process of base pairing between a gene and a complementary sequence on another nucleic acid molecule.

pharm

The production of genetically identical animals that are carrying recombinant human genes for pharmaceutical purposes, for example using goats to produce antithrombin, is called a __________.

DNA Cloning

The production of many identical copies of a DNA sequence

Centromere

The region of a duplicated chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. Divides at the onset of anaphase during mitosis and anaphase II during meiosis

Introns

The regions of noncoding DNA that separate the coding regions within a gene are called __________.

RNA Splicing

The removal of introns and joining of exons in eukaryotic RNA, forming an mRNA molecule with a continuous coding sequence; occurs before mRNA leaves the nucleus.

Cell Division

The reproduction of a cell through duplication of the genome and division of the cytoplasm Functions in development, growth, and repair

studies when and where proteins are produced in an organism and how the proteins interact

The science of proteomics __________.

Genetics

The scientific study of heredity

Prometaphase

The second stage of mitosis, during which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids.

Genetic Code

The set of rules that dictates the amino acid translations of each mRNA nucleotide triplet.

Anaphase

The stage of mitosis during which the chromosomes move toward separate poles of the cell is _____.

Genomics

The study of complete sets of genes and their interactions A larger genome does not correlate with complexity

Translation

The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of language from nucleotides to amino acids.

Transcription

The synthesis of an RNA molecule from a DNA template

Prokaryotes

The term binary fission is best applied to _____.

Metaphase

The third stage of mitosis, during which all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle.

transfer RNA, ribosomes, AUG codons

The translation process requires all of the following: __________.

hydrogen bonds between nucleotide bases

The two strands of a DNA molecule are joined to each other through _____.

frameshift

The type of mutation represented below is a(n) __________. The big red fly had one eye (wild type) The fbi gre dfl yha don eey (mutant)

Ribosomal RNA (rRNA)

The type of ribonucleic acid that, together with proteins, makes up ribosomes; the most abundant type of RNA in most cells.

Mutant

The version of a character that occurs less frequently in nature than the wild-type.

1/64

Three characteristics assort independently in one species of insect: Red eyes (R) are dominant to black eyes (r). Blue wings (B) are dominant to white wings (b). Green bodies (G) are dominant to yellow bodies (g). A cross is made between two heterozygous insects (RrBbGg). What is the probability that the offspring will be homozygous dominant for all three characteristics?

short tandem repeat DNA profile

To identify an individual involved in a crime, criminologists analyze DNA from a suspect's blood and compare the __________ to samples found at the crime scene.

Transcriptional Control

Transcription factors Enhancers Repressors Most gene regulation occurs here

Only one copy of the X chromosome is functional within any given cell, regardless of the total number of X chromosomes.

Trisomy for most autosomes is fatal, yet trisomy or even tetrasomy (four copies) of the X chromosome is not. What is the explanation for this difference?

identical ... variable

Two identical twins are raised in different environments. They possess _____ genotypes and _____ phenotypes.

IAi x IAIB

Two individuals decide to have children. The expected blood group genotypes are 50% of blood type A, and 25% each of blood types AB and B. What genotypes are the parents?

DNA polymerase

Two new strands of DNA molecules grow as bases are added by the enzyme _____.

Semiconservative Model

Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.

100%

Vitamin D - resistant rickets is an X-linked dominant bone disorder. A man with this form of rickets marries a normal woman. What proportion of the couple's daughters is expected to have vitamin D - resistant rickets?

It adds a functioning version of the defective gene to the cells of an individual.

What does the process of gene therapy involve?

an alternative version of a gene

What is an allele?

It can make a large amount of DNA from a tiny amount.

What is the function of the polymerase chain reaction (PCR)?

It allows for the separation of fragments of DNA.

What is the purpose of gel electrophoresis?

four haploid cells

What is the typical result when a diploid cell undergoes meiosis?

The mitotic spindle would not form.

What would be the immediate consequence of destroying a cell's centrosomes?

Deletion

When a chromosomal fragment becomes detached

Translocation

When a chromosomal fragment joins a non-homologous chromosome

Inversion

When a chromosomal fragment reattaches to the original chromosome but in reverse orientation

offspring identical to the parent

When applied to Mendel's experiments, the term true-breeding means a self-fertilization of two plants that produces __________.

U ... A

When messenger RNA (mRNA) is being transcribed, the RNA base _____ always pairs with the base _____ in DNA.

Recombinant DNA

When scientists combine pieces of DNA from two different sources (often different species)

Mitotic Phase

When the cell physically divides About 10% of the cell cycle Divided into mitosis and cytokinesis Creates two genetically identical daughter cells, each with a single nucleus, surrounding cytoplasm stocked with organelles, and a plasma membrane

its cells each have one set of chromosomes

When we say that an organism is haploid, we mean that _____.

in the ratio 1:1 homozygotes to heterozygotes

When you cross two heterozygotes (Aa), the offspring will most likely be __________.

Polymerase Chain Reaction (PCR)

Where a specific segment of a DNA molecule can be targeted and quickly amplified (copied in quantity) in the laboratory Allows a DNA profile to be constructed

Numerous short DNA fragments are rapidly and simultaneously sequenced.

Which of the following accurately describes "next generation sequencing" technology?

randomly cut DNA fragments are sequenced, and the sequences assembled via mapping software

Which of the following accurately describes a step in the shotgun cloning technique?

Neanderthals productively interbred with Homo sapiens populations that had left Africa.

Which of the following accurately describes the relationship between modern humans (Homo sapiens) and Neanderthals?

a nitrogenous base, a sugar, and a phosphate group

Which of the following describes a complete nucleotide?

Gene cloning occurs when a bacterium carrying a recombinant plasmid reproduces, thus allowing for the production of multiple copies of the recombinant plasmid.

Which of the following describes gene cloning?

producing insulin in a laboratory

Which of the following is NOT a use of DNA profiling?

The genetic code is ambiguous.

Which of the following is NOT true about the genetic code?

Synapsis occurs

Which of the following is a key difference between meiosis and mitosis?

an additional hydroxyl group

Which of the following is found in RNA but not in DNA?

Each tRNA binds a particular amino acid.

Which of the following is true of tRNAs?

DNA polymerase elongates the daughter strand, adding new nucleotides to the 3' end of the molecule. The molecule grows 5' to 3' but the template strand is therefore read 3' to 5'.

Which of the following occurs during DNA replication?

Two daughter nuclei, one at each pole of the cell, are generated.

Which of the following occurs during mitosis?

Translation

Which of the following processes takes place in the cytoplasm of eukaryotic cells?

prophase, prometaphase, metaphase, anaphase, telophase

Which of the following shows mitosis in the correct chronological order?

Each amino acid in a polypeptide is coded for by three bases in the DNA.

Which of the following statements about the genetic code is correct?

combining genes from different sources

Which of the following statements best defines recombinant DNA technology?

DNA is synthesized in the S phase of interphase.

Which of the following statements correctly describes the timing of DNA synthesis?

The strands run in opposite directions.

Which of the following statements is true about double-stranded DNA?

X-ray crystallography

Which of the following techniques were most helpful to Watson and Crick in determining the structure of DNA?

A rat with rabbit hemoglobin genes

Which of the following would be considered a transgenic organism?

Beadle and Tatum

Who formulated the one gene-one enzyme hypothesis?

Extra copies of the other somatic chromosomes are probably fatal

Why are individuals with an extra chromosome 21, which causes Down syndrome, more numerous than individuals with an extra chromosome 3 or chromosome 16?

The sequences are identical.

Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?

Homeotic Gene

a master control gene that determines the identity of a body structure of a developing organism, presumably by controlling the developmental fate of groups of cells

MicroRNA (miRNA)

a small, single-stranded RNA molecule, generated from a double-stranded RNA precursor; this associates with one or more proteins in a complex that can degrade or prevent translation of an mRNA with a complementary sequence

Alleles

alternative versions of a gene

Karyotype

an ordered display of the pairs of chromosomes from a cell

anaphase I

at what point in meiosis do the chromosomes segregate from one another?

Prophase

first stage of mitosis, during which the cell's chromatin condenses into chromosomes Nucleus is still intact

Sex-linked Gene

gene located on a sex chromosome Mostly located on the X chromosome

Ploidy

number of sets of chromosomes in a cell

Cleavage Furrow

the first sign of cytokinesis during cell division in an animal cell; a shallow groove in the cell surface near the old metaphase plate

Fertilization

the fusion of the nucleus of a haploid sperm cell and the nucleus of a haploid egg cell, forming a diploid zygote

Locus

the particular site where a gene is found on a chromosome

Wild-Type

the phenotype for a character most commonly observed in natural populations