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