Biology 191 Test 3 Review

Place the following in order, starting with the smallest (#1) and ending with the largest (#4). nucleotide codon chromosome gene

1 (nucleotide) 2 (codon) 4 (chromosome) 3 (gene)

Cystic fibrosis is an inherited disease that affects breathing and digestion. It is caused by a single recessive allele. Two parents without cystic fibrosis have a child who has cystic fibrosis. What is the probability that their third child will be a boy with cystic fibrosis? 1/16 1/8 1/4 3/8 3/16

1/8

In snapdragons, there is one allele that produces red flowers and another allele that produces white flowers. Neither allele is dominant and heterozygous individuals have pink flowers. A plant breeder decides to cross a white flowered snapdragon with a pink flowered snapdragon. What is the expected phenotypic ratio among the offspring? 1:1 2:1 3:1 1:2:1

1:1

Arrange the following in the proper order in which they occur during signal amplification. 1. Activation of protein kinase 2. Activation of G protein 3. Activation of adenylyl cyclase 1, 2, 3 2, 1, 3 2, 3, 1 3, 2, 1 3, 1, 2

2,3,1

he complimentary messenger RNA strand that would be synthesized from the DNA base sequence of 5' CTGAC 3' would be... 3' GACTG 5' 5' UGACU 3' 3' AGTUG 5' 3' GACUG 5' 5' GACGU 3'

3' GACUG 5'

In pea plants, the allele for round seeds is dominant to the allele for wrinkled seeds. At another gene locus, the allele for yellow seeds is dominant to the allele for green seeds. These two allele pairs assort independently. If a plant breeder crosses two plants that are both heterozygous at both gene loci, what proportion of the offspring will produce round, green seeds? 1/16 3/16 1/4 3/4 9/16

3/16

Which of the following DNA sequences is complementary to 5' TAGAC 3'? 5' TAGAC 3' 5' ATCTG 3' 5' GTCTA 3' 5' CAGAT 3' none of these choices are correct

5' GTCTA 3'

Translation is terminated when a stop codon is presented at the ________ site. A P E either A or P either A or E

A

Which of the following statements about signal amplification is TRUE? A single cell surface receptor can activate only one G protein. A single cell surface receptor can activate only two G proteins. A single cell surface receptor can activate many G proteins. It takes two cell surface receptors to activate a single G protein. It takes many surface receptors to activate a single G protein.

A single cell surface receptor can activate many G proteins.

n eukaryotes, how can a single gene code for several different proteins? A single pre-mRNA can be spliced to form different mature mRNAs by including different sets of exons Eukaryotes have 3 different RNA polymerases and if they all transcribe the same gene, each polymerase will produce a different mRNA molecule The genetic code is degenerate, so a single codon may code for several different amino acids By transcribing different segments of a single gene, RNA polymerase II can produce different mRNA molecules By translating different segments of a single mRNA molecule, ribosomes can produce different proteins

A single pre-mRNA can be spliced to form different mature mRNAs by including different sets of exons

The protein Sonic Hedgehog (SHH) plays a role in specifying the identity of digits (such as fingers and toes) in mammals. Several digits arise directly from cells that both express and respond to secreted SHH. What type of signaling would this be considered? Direct contact Paracrine Endocrine Synaptic Autocrine

Autocrine

Thinking about the structure of DNA, why is it more likely for a mutation to occur that replaces a Guanine with Adenine rather than either Cytosine or Thymine? Because Guanine commonly pairs with Adenine. Because Guanine and Adenine can both pair with Thymine. Because Guanine and Adenine are both pyrimidines and have a single ring structure. Because Guanine and Adenine are both purines and have a double ring structure.

Because Guanine and Adenine are both purines and have a double ring structure.

Avery, Macleod, and McCarty determined that the substance responsible for changing live, nonvirulent bacteria into live, virulent bacteria was______________

DNA

_______________ acts on the lagging strand to remove RNA primers and replace them with DNA

DNA Pol I

__________________ does not appear to play a role in replication but is involved in DNA repair.

DNA Pol II

_______________ is the main replication enzyme; it is responsible for the bulk of DNA synthesis

DNA Pol III

How do DNA polymerase I and DNA Polymerase III differ? DNA Polymerase I synthesizes DNA only on the leading strand and DNA Polymerase III synthesize DNA only on the lagging strand. DNA Polymerase III synthesizes DNA only on the leading strand and DNA Polymerase I synthesize DNA only on the lagging strand. DNA Polymerase III synthesizes the majority of the DNA, while DNA Polymerase I synthesizes DNA in the regions where the RNA primers were laid down on the lagging strand. DNA Polymerase III synthesizes the majority of the DNA, while DNA Polymerase I synthesizes DNA in the regions where proofreading has found mismatched bases to occur. DNA Polymerase III is the primary DNA polymerase in eukaryotes, while DNA polymerase I is the primary DNA polymerase in prokaryotes.

DNA Polymerase III synthesizes the majority of the DNA, while DNA Polymerase I synthesizes DNA in the regions where the RNA primers were laid down on the lagging strand.

DNA is used as a template to make a complementary strand of DNA.

DNA Replication

Enzymes required to replicate DNA

DNA primase DNA gyrase DNa polymerases DNA ligase DNA helicase

Why is the lagging strand synthesized in a discontinuous fashion? The lagging strand is complementary to the leading strand DNA synthesis must occur in a 5' to 3' direction, which imposes spatial constraints on the synthesis of the lagging strand The DNA polymerase enzyme that synthesizes the lagging strand can only synthesize short sequences of DNA before it falls off the template The template of the lagging strand is discontinuous All of these are reasons why the lagging strand is synthesized in a discontinuous fashion

DNA synthesis must occur in a 5' to 3' direction, which imposes spatial constraints on the synthesis of the lagging strand

One cell sends second messengers to another cell through gap junctions. What type of signaling would this be considered? Direct contact Paracrine Endocrine Synaptic Autocrine

Direct Contact

The developmental defects associated with three copies of chromosome 21 are referred to as____________________________

Down syndrome

Addison's disease is a disorder that results from a reduction in production of glucocorticoids and mineralocorticoids. Individuals with Addison's disease suffer from a variety of systemic symptoms including: muscle weakness, fever, issues with the gastrointestinal tract, and increased tanning. Considering this information, what type of signaling do you think that glucocorticoids and mineralocorticoids stimulate? Direct contact Paracrine Endocrine Synaptic Autocrine

Endocrine

The binding of epinephrine to its receptor activates a(n) A protein. D protein. G protein. K protein. M protein.

G protein

Introns are generally considered 'free to mutate,' meaning that if a mutation occurs within the intron, it will not effect the functional protein. What is an exception to this axiom? If there is a mutation in a snurp, the intron won't be spliced If there is a mutation in the 3' or 5' splice site, the snurp won't recognize it, and it will not be removed from the mRNA. If there is a mutation within the region of the lariat, the lariat won't be removed from the mRNA If there is a mutation in the exon, it will effect the functional protein All of these are true

If there is a mutation in the 3' or 5' splice site, the snurp won't recognize it, and it will not be removed from the mRNA.

How can phosphorylation affect protein function? Select all choices that apply. It can activate some enzymes. It can inhibit some enzymes. It can provide a site or location on some proteins for other proteins to bind. It acts as a coactivator for some proteins. It serves as a ligand to activate some receptors.

It can activate some enzymes. It can inhibit some enzymes. It can provide a site or location on some proteins for other proteins to bind.

The developmental defects associated with two X chromosomes and one Y chromosome are referred to as___________________

Kleinfelter syndrome

________________ is translated by the ribosomes and contains the code that specifies the sequence of amino acids in a polypeptide chain.

Messenger RNA

_______________acts to cleave target mRNAs to inhibit the translation of target mRNAs present in the cytoplasm of eukaryotes

Micro RNA

Not directly required for DNA replication

Nucleoside monophosphates Ribose

Building blocks needed to assemble a new DNA molecule

Nucleoside triphosphates

In response to injury, cell fragments called platelets get activated to induce clotting. Activated platelets release factors that can in turn bind to specific membrane receptors on nearby cells. What type of signaling would this be considered? Direct contact Paracrine Endocrine Synaptic Autocrine

Paracrine

Serves as a template for a new DNA molecule.

Parental DNA strands.

CCR5 is a cell surface receptor protein of white blood cells that attracts them to specific tissue and organs to elicit an immune response. It is also the receptor to which R5 strains of HIV bind to and enter T cells. Between 5-14% of people from Northern European descent possess an allele known as CCR5-Δ32. In this allele, a 32 base pair section of the gene has been deleted. What phenotype do people carrying the CCR5-Δ32 allele exhibit? People with CCR5-Δ32 will die before birth. People with CCR5-Δ32 will have impaired immune function. They will be particularly susceptible to infection by HIV. People with CCR5-Δ32 will have impaired immune function, but they will exhibit resistance to infection by HIV. People with CCR5-Δ32 will have improved immune function, but they will be particularly susceptible to infection by HIV. People with CCR5-Δ32 will have improved immune function, and they will exhibit particular resistance to infection by HIV.

People with CCR5-Δ32 will have impaired immune function, but they will exhibit resistance to infection by HIV.

Before addition of DNA nucleotides can take place on the lagging strand, which of the following must occur? DNA polymerase III adds deoxyribonucleotides. DNA polymerase I removes some material and replaces it with DNA. OH bonds must be broken between the two strands of DNA. DNA ligase forms a phosphodiester bond between the 3' OH of the growing strand and the 5' phosphate in front of it. Primase constructs a short RNA primer.

Primase constructs a short RNA primer.

Which of the following statements is TRUE? Once helicase has initially opened up the DNA double helix, it dissociates from the molecule allowing single stranded binding proteins and DNA polymerase to bind Primase, an RNA polymerase, is capable of synthesizing RNA without attaching the incoming nucleotide to a pre-existing, free, 3' hydroxyl group DNA polymerase is capable of synthesizing DNA without attaching the incoming nucleotide to a pre-existing, free, 3' hydroxyl group DNA polymerase incorporates new nucleotides into the growing DNA molecule by forming hydrogen bonds between complementary nucleotides on opposite strands of the double helix. Only the lagging strand requires the enzyme primase

Primase, an RNA polymerase, is capable of synthesizing RNA without attaching the incoming nucleotide to a pre-existing, free, 3' hydroxyl group

Why is RNA synthesis called 'transcription' and protein synthesis called 'translation?' RNA synthesis happens in the nucleus and protein synthesis happens in the cytoplsam. RNA synthesis makes an exact copy of the DNA molecule and protein synthesis makes a complementary copy of the RNA. RNA synthesis makes a complementary copy of the DNA using nucleic acid and protein synthesis requires the information in the RNA to be changed into a different type of molecule. RNA synthesis makes a complementary copy of the entire DNA molecule and protein synthesis only uses a short piece of the RNA molecule. Because that's one someone named them a long time ago.

RNA synthesis makes a complementary copy of the DNA using nucleic acid and protein synthesis requires the information in the RNA to be changed into a different type of molecule.

Sickle cell disease is an autosomal _______________ disorder affecting red blood cells.

Recessive

RNA is used as a template to make a complementary strand of DNA.

Reverse Transcription

______________combines with protein to form the ribosomal subunits.

Ribosomal RNA

_______________comnines with protein to form particles that help ribosomes attach top the endoplasmic reticulum in eukaryotes.

SRP RNA

______________________ plays a key role in the splicing reaction that removes introns from eukaryotic pre-mRNA

Small nuclear RNA

DNA is used as a template to make a complementary strand of RNA.

Transcription

________________transports amino acids to the ribosomes for use in protein synthesis.

Transfer RNA

RNA is used as a template to make a polypeptide.

Translation

The developmental defects associated with a singl X chromosome and no Y chromosome are referred to as __________________

Turner syndrome

Nondisjunction of the Y chromosome can produce fertile __________________ males

XYY

The second messenger cAMP is synthesized by the enzyme adenylyl cyclase. cAMP phoshodiesterase. ATPase. ligase. phosphorylase.

adenylyl cyclase

A diploid individual contains two alternative forms, or ______________, for each gene.

alleles

The phenotype of an organism is determined by which___________their chromosomes possess for a specific trait.

alleles

Having one or more extra or missing chromosomes is called _________________

aneuploidy

An example of a second messenger is epinephrine. ATP. cAMP. G-protein. adenylyl cyclase.

cAMP

A nucleotide deletion in DNA replication causes one amino acid of the protein to be incorrect causes all of the amino acids of the protein to be incorrect causes the amino acids inserted after the deletion to be incorrect causes the amino acids inserted before the deletion to be incorrect has no effect on the resulting protein

causes the amino acids inserted after the deletion to be incorrect

In synaptic signaling, neurotransmitters are released into a space that is referred to as a: chemical synapse. neuron junction. paracrine space. gap junction. plasmodesmata.

chemical synapse

Genes are located on _______________ each chromosome contains one allele for each gene at a site called the gene's __________

chromosomes, locus

When the phenotype of heterozygotes shows some aspects of both homozygotes, this is called______________________

codominance

Which characteristic of DNA allows each strand of the molecule to act as a template that specifies the exact sequence of nucleotides in the other strand? complementarity of the bases complementarity of the pentose sugars the 2 strands are antiparallel the 2 strands are twisted into a double helix the 2 strands are held together by hydrogen bonds between the nitrogenous bases

complementarity of the bases

The abnormal shape of blood cells in sickle cell _____________________ their ability to pass along capillaries resulting in poor circulation and joint pain.

decreases

Segments of a chromosome that are lost are called______________

deletions

If one plant cell sends a signal to another plant cell by passing a small molecule to that cell through the plasmodesmata, this would be referred to as ______________________ signaling

direct contact

Segments of a chromosome that are repeated are called__________________

duplications

According to Mendel's Principle of Independent Assortment each individual has two alleles controlling a given trait. dominant alleles assort independently of recessive alleles. the two alleles at each gene locus segregate during gamete formation. each pair of alleles segregates independently of the other allele pairs. the two alleles controlling a given trait remain discrete - they neither blend with nor alter each other.

each pair of alleles segregates independently of the other allele pairs.

After a big meal, in those individuals who do not have Type I diabetes, the pancreas secretes insulin which circulates through the body and binds to receptors on various cell types to signal to those cells that the body is in the "fed state." This is an example of ______________________________________

endocrine signaling

Genetic counselors can also examine ___________________ activity and _________________ markers to determine the presence of a genetic condition

enzyme, genetic

When alleles at one gene locus can interfere with the expression of alleles at another gene locus, this is called____________________

epistasis

Epinephrine has to cross the cell membrane to bind to its receptor in the cytoplasm. True False

false

Parents transmit information about traits to their offspring in units called________________

genes

Because of possible genetic disorders, many potential parents seek out _____________________ before conceiving children

genetic counseling

This set of alleles is referred to as organism's________________

genotype

The particular alleles that an individual has are the individual's______________, whereas the appearance of an individual is called its _____________________.

genotype, phenotype.

The enzyme that unwinds a segment of the DNA molecule is... DNA polymerase. DNA ligase. RNA primase. DNA polymerase III. helicase.

helicase

The mutated gene in sickle cell produces _______________ with a signle amino acid change from its normal form

hemoglobin

If the two alleles are the same, the individual is said to be______________, if the two alleles are different, the individual is said to be_____________________.

homozygous, heterozygous

In some pairs of alleles, ________________ dominance is exhibited when the heterozygote has an intermediate phenotype

incomplete

When the phenotype of heterozygotes is intermediate between the homozygotes, this is called____________________________

incomplete dominance

Genetic disorders may be _____________________ through abnormal chromosomes or gene mutations in egg or sperm cells

inherited

In the pink heterozygotes, the expression of the alleles is _________________ between that of either homozygote

intermediate

Segments of chromosome that are broken in 2 places, reversed, and then put back together are called__________________

inversions

Which of the following best describes the pattern of inheritance for mitochondrial DNA? most of it comes from the mother, but some is usually inherited from the father as well most of it comes from the father, but some is usually inherited from the mother as well it is usually inherited entirely from the father it is usually inherited entirely from the mother it is usually inherited equally from the mother and the father

it is usually inherited entirely from the mother

Nicotine is a molecule that is chemically similar to acetylcholine and binds to the same receptors. What affect will nicotine have on the cell shown in the animation? it will open sodium channels It will close sodium channels It will kill the cell It will excite the cell It will depress the cell

it will open sodium channels

If a woman has already conceived, tests such as chomosomal ____________________ can be performed on fetal cells in order to determine if the child will be born unaffected

karyotyping

A child has a disease that is causing severe growth delays and rapid aging. His cells are assayed, and it is noticed that there is a severe decrease in DNA synthesis compared to normal cells. When DNA from his cells was gently heated to separate the double helix, numerous, small, single-stranded fragments of about 1000 base pairs were found. Which enzyme is likely to be defective in this child? helicase DNA polymerase ligase topoisomerase primase

ligase

A trait is most likely to exhibit continuous variation if it is controlled by two gene loci with epistasis. many gene loci, each with several possible alleles. a single pleiotropic gene locus with three possible alleles. a single gene locus with two codominant alleles. many gene loci, each with a single possible allele.

many gene loci, each with several possible alleles.

Chromosomes carry genes from parent to offspring and are distributed to gametes during____________, each receives one copy of each chromosome and therefore one allele for each_______

meiosis, gene

Humans that are missing autosome are called ___________________

monosomics

When a single gene locus has more than two possible alleles, this is called__________________________

multiple alleles

During meiosis, the process of __________________ produces gametes, therefore offspring, that have extra or missing chromosomes.

nondisjunction

The nucleic acid sequence in mRNA is determined by the order of amino acids in the protein nucleotide sequence in DNA nucleotide sequence in t-RNA all of these choices are correct.

nucleotide sequence in DNA

During an allergic response, histamines are released by mast cells. These histamines bind to receptors on cells in the local environment only. This is an example of ______________________________

paracrine signaling

Hershey and Chase used radioactively labeled protein and DNA to demonstrate that the genetic material of________________ is DNA

phages

The term_____________refers to the outwards expression of a trait, either physically, microscopically, or metabolically.

phenotype

The enzyme alpha-kinase adds ________ to proteins. acetates benzoats carbonates phosphates hydroxyls

phosphates

In Japanese four-o'clocks, flowers can be red or white, and the incomplete dominant from a mating of the two exhibits the color_________________

pink

When a single gene locus affects more than one trait, this is called ________________.

pleitropy

When a single trait is affected by more than one gene locus, this is called_____________________________

polygenic inheritance

Translation is the synthesis of mRNA from DNA. mRNA from proteins. proteins from DNA proteins from mRNA proteins from tRNA

proteins from mRNA

Mendel observed that alleles can be dominant or ________________, and the __________________ allele typically masks the expression of the other allele.

recessive, dominant

If two chromosomes are broken and they exchange non-homologous segments, this is called a _____________ translocation

reciprocal

A genetic counselor uses genetic information about a family to predict the ______________ a couple has of conceiving a child affected by a genetic disorder

risk

NA replication is said to be dispersive. semi-conservative. conservative. liberal. inconclusive.

semi-conservative

Female gametes with no sex chromosomes are produced when two X chromosomes fail to _______________________ during meiosis

separate

The physical basis for the segregation of alleles when gametes are formed is crossing over during prophase I. separation of sister chromatids during anaphase I followed by separation of homologous chromosomes during anaphase II. the formation of chiasmata during the first meiotic division. separation of the two strands of DNA during DNA replication. separation of homologous chromosomes during anaphase I followed by separation of sister chromatids during anaphase II.

separation of homologous chromosomes during anaphase I followed by separation of sister chromatids during anaphase II.

Humans who have gained or lost_____________________________ may reach maturity, but with somewhat abnormal features

sex chromosome

The alteration in hemoglobin from sickle cell causes red blood cells to take on a ____________ shape

sickle

Sickle cell is due to a ________________ base change in a gene

single

The offspring of the pink flowers can be red, white, or pink, making it clear there is a ____________ pair of alleles involved

single

The snRNPs are also called smurfs. snurps. snores. snippets. splits.

snurps.

Neurons secrete neurotransmitters that bind to target cells in the local environment and induce a response. While this is an example of paracrine signaling, it is more specifically referred to as_____________________________________

synaptic signaling

If a duplication occurs directly next to the original segment, it is termed a ____________ duplication

tandem

Genomic imprinting leads to non-Mendelian inheritance because in genomic imprinting the allele pairs controlling a trait do not assort independently. the expression of an allele varies depending on which parent it was inherited from. the alleles at one gene locus hide or prevent the expression of alleles at a second gene locus. the expression of an allele varies depending on whether the individual is homozygous or heterozygous. the expression of an allele varies depending on whether the individual is male or female.

the expression of an allele varies depending on which parent it was inherited from.

The physical basis for the independent assortment of alleles when gametes are formed is the random combination of gametes during fertilization. the independent replication of chromosomes during interphase. the independent formation of chiasmata during the first meiotic division. the independent alignment of homologous pairs during metaphase I. the independent alignment of sister chromatids during metaphase I.

the independent alignment of homologous pairs during metaphase I.

If a frameshift mutation causes a stop codon to be inserted into the DNA sequence the resulting protein will not be affected the phenotype will change but not the genotype the resulting protein will be too short and non-functional the resulting protein will be too long and non-functional

the resulting protein will be too short and non-functional

Morgan's experiments with red and white eye color in the fruit fly Drosophila provided evidence that alleles are located on chromosomes because the results of his crosses could be explained if he assumed that the alleles controlling eye color are located on the X chromosome. the results of his crosses could be explained if he assumed that the alleles controlling eye color are located on the Y chromosome. the results of his crosses could be explained if he assumed that the allele for white eyes is located on the X chromosome and the allele for red eyes is located on the Y chromosome. when he exposed the chromosomes of Drosophila to radiation, he sometimes produced mutants with white eye color. the results of his crosses indicated that the alleles that control eye color and the alleles that control several other traits do not assort independently.

the results of his crosses could be explained if he assumed that the alleles controlling eye color are located on the X chromosome.

When the acetylcholine binds to the receptor sites a ligand is formed. the sodium channels open. the sodium channels remain closed. sodium ions diffuse through and enter the cell. sodium ions diffuse through and leave the cell.

the sodium channels open

When the acetylcholine receptor sites are not occupied a ligand is formed. the sodium channels open. the sodium channels remain closed. sodium ions diffuse through and enter the cell. sodium ions diffuse through and leave the cell.

the sodium channels remain close

Which of the following occurs as the ribosom... Which of the following occurs as the ribosome shifts down the mRNA by a distance of three nucleotides? the tRNA that was in the A site moves into the E site the tRNA that was in the P site moves into the A site the tRNA that was in the E site moves into the P site the tRNA that was in the E site moves into the A site the tRNA that was in the P site moves into the E site

the tRNA that was in the P site moves into the E site

According to Mendel's Principle of Segregation each individual has two separate alleles controlling each trait. heterozygous individuals have one dominant allele and one recessive allele. the two alleles at each gene locus separate during gamete formation. each allele pair separates independently of all other allele pairs.

the two alleles at each gene locus separate during gamete formation.

The structure that causes the synthesis of RNA to cease is known as the promoter region sigma factor transcription terminator polymerase template

transcription terminator

Based on his experiments with the bacterium S. pneumoniae, Griffith concluded that the genetic information of virulence was transferred from dead, virulent cells to live, nonvirulent cells, a process called ______________________

transformation.

Segments of a chromosome that break off and attach to another chromosome are called_____________________

translocations

When an XX gamete combines with an X gamete, a _________________________ female results

triple X

Humans that have one extra autosome, in addition to the normal diploid number, are called_______________________

trisomics

For diploid organisms, each cell contains______alleles for each trait, one allele on a chromosome from the mother and the other on a chromosome from the father

two