Bio Exam 3
The proteins to which the mitotic spindle attaches on a chromosome are A. kinetochores. B. chromatids. C. histones. D. centromeres. E. nucleosomes.
A. kinetochores.
All sexual life cycles include A. meiosis, gamete formation, and fertilization. B. mitosis, meiosis, and gamete formation. C. mitosis, fertilization, and meiosis. D. mitosis, gamete formation, and fertilization. E. None of the answer choices are correct.
A. meiosis, gamete formation, and fertilization.
In a sexual life cycle, a zygote grows to an adult by A. mitosis. B. fertilization. C. meiosis and fertilization. D. meiosis. E. All of the answer choices are correct.
A. mitosis.
The phase of mitosis in which the chromosomes are aligned along the equator of the cell is A. E, which is telophase. B. C, which is metaphase. C. D, which is anaphase. D. A, which is prophase. E. A, which is prometaphase.
B. C, which is metaphase.
Because cells are very efficient in the processes that they carry out, very little energy is needed for the cell to make proteins. A. True B. False
B. False
In eukaryotes an mRNA molecule can only be translated by one ribosome at a time. A. True B. False
B. False
The complement strands of DNA have the same exact nitrogen base sequence, providing the semiconservative replication needed by cells. A. True B. False
B. False
The component of the DNA nucleotides that varies to produce an organism's genetic information is the deoxyribose. A. True B. False
B. False
The process by which cells use the information of RNA molecules to make proteins is transcription. A. True B. False
B. False
Which mutation in DNA would lead to the change of a single amino acid in a protein? A. a nonsense mutation B. a missense mutation C. a frameshift D. a one base insertion E. a one base deletion
B. a missense mutation
A change in a cell's DNA sequence is A. replication. B. a mutation. C. transcription. D. translation. E. an operon.
B. a mutation.
Using the genetic code shown here, predict what type of mutation has occurred in the hemoglobin sickle cell anemia allele. Normal allele 5'-GGAAUGAAACAGGAACCC-3' Mutant allele 5'-GGAAUGAAACAGGUACCC-3' A. a point mutation, Val to Glu B. a point mutation, Glu to Val C. a frameshift mutation D. addition of a new stop codon
B. a point mutation, Glu to Val
The "twisted ladder" shape of a DNA molecule results from A. cytosine pairing with adenine. B. adenine pairing with thymine. C. adenine pairing with uracil. D. cytosine pairing with thymine. E. thymine pairing with uracil.
B. adenine pairing with thymine.
A three-base sequence (loop) in tRNA that is complementary to a sequence of three bases in mRNA is a(n) A. codon. B. anticodon. C. amino acid attachment site. D. promoter. E. terminator.
B. anticodon.
In a cell dividing by meiosis, DNA is replicated A. during prophase II. B. before meiosis I. C. between meiosis I and again before meiosis II. D. during prophase I.
B. before meiosis I.
How can a single gene encode for more than one protein? A. by mutating their genes B. by removing different combinations of introns C. by using different codons D. by using transgenes E. by transcribing multiple copies of mRNA
B. by removing different combinations of introns
A discrete continuous molecule of DNA, wrapped with its associated proteins, defines the term A. centromere. B. chromosome. C. histone. D. nucleosome. E. genome.
B. chromosome.
In a "silent" mutation the A. mutation is not in DNA. B. codon that mutates does not cause a change in the amino acid specified. C. mutation does not occur in a codon. D. codon that mutates causes a stop codon to occur instead of the placement of an amino acid. E. codon that mutates causes a change in the amino acid specified.
B. codon that mutates does not cause a change in the amino acid specified.
Among enzymes required for DNA replication, ligases are needed to form ________ bonds between to join nucleotides to DNA segments. A. hydrogen B. covalent C. ionic D. weak chemical
B. covalent
While in the biology lab, you observe, in both plant and animal cells, that some single cells are splitting into two daughter cells, in the process of A. binary fission. B. cytokinesis. C. anaphase. D. mitosis. E. metaphase.
B. cytokinesis.
A cell with two full sets of chromosomes would be termed a ________ cell. A. sister B. diploid C. haploid D. somatic E. germ
B. diploid
Before any cell divides into two daughter cells, it must first duplicate its A. array of enzymes. B. entire genome. C. cytoplasmic contents. D. cell membrane structure. E. All of the answer choices are correct
B. entire genome.
A cell with one set of chromosomes would be termed a ________ cell. A. diploid B. haploid C. somatic D. sister E. None of the answer choices are correct.
B. haploid
Complementary DNA strands are held together by A. covalent bonds. B. hydrogen bonds. C. ionic bonds. D. phosphodiester bonds.
B. hydrogen bonds.
The step of translation in which an mRNA, a small ribosomal subunit, and the initiator tRNA are aligned together is A. elongation. B. initiation. C. transcription. D. termination. E. mitosis.
B. initiation.
The enzyme that joins Okazaki fragments is A. DNA polymerase. B. ligase. C. helicase. D. primase. E. ATP synthase.
B. ligase.
In meiosis, chromosomes containing sister chromatids (not homologous chromosomes) align along the center of the cell during A. prophase II. B. metaphase II. C. interphase II. D. prophase I. E. metaphase I.
B. metaphase II.
In an asexual life cycle, cells reproduce by A. meiosis. B. mitosis. C. fertilization. D. meiosis and fertilization. E. All of the answer choices are correct.
B. mitosis.
The twisted ladder shape of DNA is a result of the covalently bonded building blocks called A. monosaccharides. B. nucleotides. C. amino acids. D. phospholipids. E. sterols.
B. nucleotides
The DNA sequence 5'-ATCGTACG-3' will pair with which of the following DNA strands? A. 5'-TAGCTAGC-3' B. 5'-ATGCATGC-3' C. 3'-TAGCATGC-5' D. 3'-ATGCATGC-5' E. 3'-CGTACGTA-5'
C. 3'-TAGCATGC-5'
A human heart cell contains ________ chromatids. A. 23 B. 4 C. 46 D. 2 E. 16
C. 46
The phase of mitosis in which the nuclear envelope breaks into small pieces is A. C, which is telophase. B. C, which is metaphase. C. B, which is prometaphase. D. D, which is anaphase. E. B, which is prophase.
C. B, which is prometaphase.
The molecule that contains the information for making a cell's proteins and copies itself for the next generation of cells is A. NAD. B. RNA. C. DNA. D. ATP synthase. E. FAD.
C. DNA.
The four nitrogen bases that are found in the different nucleotides of DNA are A. uracil, cytosine, guanine, thymine. B. adenine, thymine, cytosine, uracil. C. adenine, thymine, cytosine, guanine. D. uracil, adenine, cytosine, guanine. E. None of the answer choices are correct.
C. adenine, thymine, cytosine, guanine.
In the biology lab, you observe animal cells that resemble this first sign of cytokinesis, the formation of this A. nuclear envelope. B. nucleolus. C. cleavage furrow. D. cell plate. E. cell wall.
C. cleavage furrow.
The COL1A1 gene in humans is responsible for producing collagens in healthy bone and cartilage. A mutation in COL1A1 is known to cause severe Osteogenesis Imperfecta, which is also known as "brittle bone disease," in which bones form irregularly and can break often, with even mild pressure and impacts. The mutation occurs as a "nonsense" mutation, dramatically shortening the proteins, occurring because the A. mutation is not in DNA. B. mutation does not occur in a codon. C. codon that mutates causes a stop codon to occur instead of the placement of an amino acid. D. codon that mutates causes a change in the amino acid specified. E. codon that mutates does not cause a change in the amino acid specified.
C. codon that mutates causes a stop codon to occur instead of the placement of an amino acid.
The DNA subunits that form the "rungs" joining the two sides of the DNA molecule are formed by A. phosphodiester bonds between the deoxyribose sugars. B. covalent bonds between nitrogen base pairs. C. hydrogen bonds between nitrogen base pairs. D. ionic bonds between the phosphate pairs.
C. hydrogen bonds between nitrogen base pairs.
In meiosis, homologous chromosomes align next to one another during A. prophase I. B. metaphase I. C. interphase I. D. prophase II. E. metaphase II.
C. interphase I.
In meiosis, paired homologs align down the center of the cell during A. prophase II. B. anaphase II. C. metaphase I. D. prophase I. E. metaphase II.
C. metaphase I.
If E. coli bacteria are grown in the presence of lactose, then the repressor will A. not bind the operator preventing transcription of the lac operon genes. B. bind the operator allowing transcription of the lac operon genes. C. not bind the operator allowing transcription of the lac operon genes. D. bind the operator preventing transcription of the lac operon genes.
C. not bind the operator allowing transcription of the lac operon genes.
Meiotic cell division replicates a cell's DNA ________ and then divides ________ A. once; once. B. twice; once. C. once; twice. D. twice; twice. E. None of the answer choices are correct.
C. once; twice.
In humans, the sex of a child is determined by the A. number of autosomes in the sperm. B. sex chromosome in the egg. C. sex chromosome in the sperm. D. number of autosomes in the egg. E. number of X chromosomes in the egg.
C. sex chromosome in the sperm.
After replication, in eukaryotes, both the original and its replicated copy chromosome are each called a A. centromere. B. nucleosome. C. sister chromatid. D. chromosome. E. chromatin.
C. sister chromatid.
If a chromosome in one of your bone cells becomes mutated, you will not pass this mutation onto your children because A. germ cells cannot undergo meiosis. B. somatic cells cannot undergo mitosis. C. somatic cells cannot undergo meiosis. D. germ cells cannot undergo mitosis.
C. somatic cells cannot undergo meiosis.
The scientist (scientists) who confirmed DNA was the genetic information by working with bacteria that infect viruses is (are) A. Griffith. B. Chargaff. C. Avery and MacLeod. D. Hershey and Chase. E. Watson and Crick.
D. Hershey and Chase.
The scientist (scientists) who was (were) given credit for first determining the molecule structure of DNA by building a ball-and-stick model is (are) A. Griffith. B. Chargaff. C. Avery and MacLeod. D. Hershey and Chase. E. Watson and Crick.
D. Watson and Crick.
A nucleosome consists of A. a stretch of DNA. B. two or more closely related genes. C. an RNA molecule. D. a stretch of DNA and histones. E. a ribosome and RNA.
D. a stretch of DNA and histones.
In meiosis, the separated sister chromatids move to opposite poles of the cell during A. metaphase I. B. anaphase I. C. telophase I. D. anaphase II. E. metaphase II.
D. anaphase II.
Alternate forms of the same gene A. are homologs. B. are sister chromatids. C. do not exist. D. are alleles. E. do not occur in the same individual.
D. are alleles.
Why don't plant cells form a cleavage furrow during cytokinesis? A. because their cells don't divide after mitosis, but become one larger cell with multiple nuclei B. because they don't have a cell membrane C. because they don't have a nucleus D. because they have a cell wall E. All of the answer choices are correct.
D. because they have a cell wall
How many of the mother's chromosomes are present in the egg before it is fertilized? A. 2 B. 1 C. 4 D. 46 E. 23
E. 23
If a mutation causes the "T" base in the base sequence 5'-AGTCCG-3' to be read as a "G" base, DNA replication of the mutated sequence will read: A. 3'-AGTCCG-5' B. 3'-UCCGGC-5' C. 3'-CTTAAT-5' D. 3'-AGGCCG-5' E. 3'-TCCGGC-5'
E. 3'-TCCGGC-5'
A zygote A. is formed by fertilization. B. has a diploid set of homologous chromosomes. C. has mixed chromosomes from two gametes. D. is a cell produced by meiosis divisions. E. All answer choices are correct, except for being a cell produced by meiosis divisions.
E. All answer choices are correct, except for being a cell produced by meiosis divisions.
Identify the correct comparison between the human X and Y chromosomes. A. Although both are sex chromosomes, they do not share the same genes. B. The X chromosome is larger than the Y chromosome. C. Only the X chromosome is paired with a homologous match in human females. D. Only the Y chromosome is always found without a homologous match. E. All of the answer choices are correct.
E. All of the answer choices are correct
Meiosis is a process that produces ***** A. egg cells. B. sperm cells. C. haploid cells. D. gametes. E. All of the answer choices are correct.
E. All of the answer choices are correct.
Nondisjunction may cause A. Jacobs syndrome. B. Klinefelter syndrome. C. trisomy 21. D. Turner syndrome. E. All of the answer choices are correct.
E. All of the answer choices are correct.
RNA differs from DNA in that A. RNA contains uracil. B. RNA contains ribose. C. RNA can catalyze chemical reactions. D. RNA is usually single stranded. E. All of the answer choices are correct.
E. All of the answer choices are correct.
Why does a replication fork have a leading and lagging strand? A. because DNA polymerase only attaches nucleotides to the 3' end of strands B. because DNA synthesis always goes from 3' to 5' C. because DNA synthesis always goes from 5' to 3' D. because DNA synthesis can grow off of either the 3' or 5' end E. Both answers, with DNA synthesis proceeding from 5' to 3', and DNA polymerase only acting on the 3' end, are correct.
E. Both answers, with DNA synthesis proceeding from 5' to 3', and DNA polymerase only acting on the 3' end, are correct.
The phase of mitosis in which the nuclear envelope reforms is A. C, which is anaphase. B. D, which is metaphase. C. A, which is prometaphase. D. B, which is prophase. E. E, which is telophase.
E. E, which is telophase.
This diagram shows the steps in mitosis, with labels to reference in the questions below. In which of these mitosis phases is the replication of DNA accomplished? A. C, which is telophase. B. E, which is cytokinesis. C. A, which is mitosis. D. A, which is prophase. E. None of these answer options are correct, because replication does not happen during mitosis.
E. None of these answer options are correct, because replication does not happen during mitosis.
The phase of mitosis in which the chromosomes condense and centrosomes move to opposite poles of the cell is A. A, which is prophase. B. E, which is telophase. C. C, which is metaphase. D. D, which is anaphase. E. B, which is prometaphase.
A. A, which is prophase.
The phase of mitosis in which the centromeres split and sister chromatids are pulled to opposite poles of the cell is A. D, which is anaphase. B. E, which is telophase. C. A, which is prometaphase. D. E, which is metaphase. E. B, which is prophase.
A. D, which is anaphase.
A gene is any DNA sequence that is transcribed to any type of RNA. A. True B. False
A. True
A poly A tail helps attach the ribosome to the mRNA molecule and may also determine how long the mRNA is retained within the cell. A. True B. False
A. True
Any change in a cell's DNA sequence is a mutation. A. True B. False
A. True
Because clindamycin and similar antibiotics bind to bacterial ribosomes, they work by inhibiting translation in the bacterial cells. A. True B. False
A. True
In the bacterium E. coli, in the absence of lactose, a repressor protein binds to the operator region of the DNA, preventing the transcription of the genes of the lactose operon. A. True B. False
A. True
The type of RNA that delivers amino acids to the ribosome during protein synthesis is tRNA. A. True B. False
A. True
In meiosis, homologous chromosomes separate during A. anaphase I. B. anaphase II. C. prophase I. D. prophase II. E. metaphase I.
A. anaphase I.
The human chromosomes that do not determine whether an individual is male or female are A. autosomes. B. the X and Y chromosomes. C. called sex chromosomes. D. not found in pairs. E. None of the answer choices are correct.
A. autosomes.
The statement that does not correctly associate an RNA type, and its function, is A. complementary RNA reorders the amino acids to insure their correct sequence. B. ribosomal RNA functions as a catalyst to bind amino acids into proteins. C. transfer RNA functions to carry amino acids to the ribosome. D. messenger RNA is the gene, carrying coding to control the building of proteins.
A. complementary RNA reorders the amino acids to insure their correct sequence.
Which of the following will occur in meiosis but not in mitosis? A. crossing over B. cytokinesis C. DNA replication D. chromosome condensation E. metaphase
A. crossing over
The step of translation in which amino acids are added one at a time to the growing polypeptide is A. elongation. B. initiation. C. transcription. D. mitosis. E. termination.
A. elongation.
In meiosis II, cytokinesis results in the production of A. four haploid daughter cells. B. four diploid daughter cells. C. two diploid daughter cells. D. two haploid daughter cells. E. one daughter cell identical to the parent cell that underwent meiosis.
A. four haploid daughter cells.
What is the major advantage of sexual reproduction over asexual reproduction? A. genetic variability during an ecological disaster B. genetic variability when the environment is stable C. requirement of less energy D. faster reproduction E. simpler form of reproduction
A. genetic variability during an ecological disaster
The enzyme that unwinds and separates the paired DNA strands is A. helicase. B. ATP synthase. C. primase. D. ligase. E. DNA polymerase.
A. helicase.
Chromosomes that look alike and carry the same sequence of genes for the same traits, such as these shown from two parents, are A. homologous chromosomes. B. all the autosomes. C. found in females only. D. found in males only. E. the X and Y chromosome.
A. homologous chromosomes.
The eukaryotic cell will complete the ________ portion of the cell cycle in order to___ A. mitosis; divide the original and replicated chromosomes. B. synthesis; build the two new daughter cells from the original one cell. C. cytokinesis; move the centrioles, centrosomes, and mitotic spindle into position to pull chromosomes apart. D. interphase; build the mitotic spindle and metaphase plate between original and replicate chromosome groups. E. binary fission; divide the original and replicated chromosomes.
A. mitosis; divide the original and replicated chromosomes.
The portion of the cytoskeleton that attaches, pulls, and guides the chromosomes as they are separated equally into two sets is the A. mitotic spindle. B. centromere. C. centrosome. D. Golgi body. E. kinetochore.
A. mitotic spindle.
An embryo fish is in its egg, without fully developed tissues and organs to survive outside the egg. The embryo has a large number of cells undergoing mitosis for the purpose of A. production of new cells that can differentiate and specialize for different functions. B. replication of new DNA copies, so that meiosis will further grow the embryo. C. asexual reproduction, to produce larger numbers of embryos, so that some will survive. D. fertilization of the gametes, so the embryo can continue growing and hatch. E. sexual reproduction of gametes, to produce new offspring.
A. production of new cells that can differentiate and specialize for different functions.
Apoptosis is a name for the process of A. programmed cell death. B. replication. C. the cell cycle. D. mitosis. E. programmed cellular reproduction.
A. programmed cell death.
DNA replication is A. semi-conservative. B. not carried out in prokaryotic cells. C. not carried out by enzymes. D. conservative. E. a one-step process.
A. semi-conservative.
In biology lab, you are observing specimens of muscle cells and nerve cells, as examples of A. somatic cells. B. haploid cells. C. gametes. D. germ cells. E. zygotes.
A. somatic cells.
An example of a haploid cell is a A. sperm cell. B. stem cell. C. skin cell. D. zygote. E. All of the answer choices are correct.
A. sperm cell.
If one strand of a DNA molecule has the base sequence of 5'-ATGTGCC-3' the complementary strand of DNA will read A. 3'-GGCACAT-5' B. 3'-TACACGG-5' C. 3'-ATGTGCC-5' D. 3'-CGTGTAA-5' E. 3'-UACACGG-5'
B. 3'-TACACGG-5'
The DNA sequence 5'-ATCGATCG-3' will pair with which of the following RNA strands? A. 5'-UAGCUAGC-3' B. 3'-UAGCUAGC-5' C. 3'-AUGCAUGC-5' D. 3'-TAGCTAGC-5' E. 5'-TAGCTAGC-3'
B. 3'-UAGCUAGC-5'
If the DNA in a cell consists of 20% A, it will be ________ G. A. 80% B. 30% C. 40% D. 20% E. 10%
B. 30%
The correct sequence for the phases of mitosis, shown in correct sequence in this diagram, is A. interphase - prophase - metaphase - anaphase - telophase. B. prophase - prometaphase - metaphase - anaphase - telophase. C. prophase - metaphase - prometaphase - anaphase - telophase. D. interphase - metaphase - anaphase - prophase - telophase. E. prometaphase - prophase - metaphase - anaphase - telophase.
B. prophase - prometaphase - metaphase - anaphase - telophase.
A person, who has just experienced a painful sunburn, has a large number of cells undergoing mitosis for the purpose of A. replication of new DNA copies, so that meiosis will further grow new skin cells. B. repairing and replacing the damaged cells, in the healing process of the skin. C. modifying new cells that will have different specialties than the original damaged cells. D. asexual reproduction, to produce new skin buds that will fold over and cover the burn.
B. repairing and replacing the damaged cells, in the healing process of the skin.
The process by which DNA is reproduced, with the use of associated enzymes, is A. translation. B. replication. C. transcription. D. catalyzed protein synthesis. E. ligation.
B. replication.
The step of translation in which release factors bind to a stop codon is A. elongation. B. termination. C. initiation. D. transcription. E. mitosis.
B. termination.
If you compared the DNA sequence of a gene with the sequence of the mature mRNA that was transcribed from the gene you would find A. the mRNA is shorter because it does not contain exons. B. the mRNA is shorter because it does not contain introns. C. the mRNA is shorter because each codon of three bases encodes only one amino acid. D. the mRNA is longer because each codon of one amino acid encodes three bases. E. both are the same length
B. the mRNA is shorter because it does not contain introns.
Humans have a gene called PDHA1, which codes for one protein that functions as an enzyme in the cell. It helps energy pathways, by modifying pyruvate molecules into acetyl CoA molecules. Researchers have identified an insertion mutation in the gene, which produces an extra amino acid within the otherwise normal sequence in the protein. In this type of mutation, A. the mutation does not occur in an existing codon. B. the mutation may be caused by an addition of three nucleotides. C. the codon that mutates causes a stop codon to occur instead of the placement of an amino acid. D. the mutation is not in DNA, but in the protein. E. the codon that mutates causes a change in the amino acid specified.
B. the mutation may be caused by an addition of three nucleotides.
Strong evidence of semiconservative replication of DNA comes from the DNA molecule structure, in that A. the hydrogen bonds between paired DNA strands allows conservation of energy, at a lower level than covalent bonds would require. B. the semiconservative replication is explained by the large number of enzymes that are each specialized for each step of replication. C. the DNA molecule is double-stranded, allowing one original strand to be conserved while its replicate forms one strand. D. the DNA molecule has four distinct nitrogen base pairs, requiring minimal chemical bond reactions to replicate their sequence. E. All these properties of DNA and the replication process are part of the evidence and definition of semiconservative replication.
C. the DNA molecule is double-stranded, allowing one original strand to be conserved while its replicate forms one strand.
In the Lac operon, the protein that binds to the operator to prevent transcription is A. lactose. B. the promoter. C. the repressor. D. DNA polymerase. E. RNA polymerase.
C. the repressor.
Mutations are usually rare, because *** A. Okazaki fragments are removed, whenever detected by the ligase enzyme. B. DNA polymerase quickly discards mismatched nucleotide base pairs. C. transcription, after replication, will normally detect and fix mutations. D. ligases serve to conduct "quality control" checks in order to repair mutations. E. Both answer options, regarding the role of the ligase enzyme, are correct.
C. transcription, after replication, will normally detect and fix mutations.
What would be the first codon translated in the mRNA sequence 5'-GGAAUGAAACAGGAACCC-3'? A. CCC B. GAA C. GGA D. AUG E. AAU
D. AUG
Among humans, you can observe that there is variability in shape (size), skin color, and other traits. The variety in a small population results from ________ in sexual reproduction and meiosis. A. crossing over B. random fertilization C. independent assortment D. All of the answer choices are correct.
D. All of the answer choices are correct.
The enzyme that adds nucleotides along the 5' to 3' along a DNA strand, is A. ATP synthase. B. helicase. C. ligase. D. DNA polymerase. E. primase.
D. DNA polymerase.
If E. coli bacteria are grown in the absence of lactose, then the repressor will A. bind the operator allowing transcription of the lac operon genes. B. not bind the operator allowing transcription of the lac operon genes. C. not bind the operator preventing transcription of the lac operon genes. D. bind the operator preventing transcription of the lac operon genes.
D. bind the operator preventing transcription of the lac operon genes.
The 5' and 3' designations used in reference to DNA and RNA sequences are assigned to the A. oxygen atoms contained in the deoxyribose and ribose. B. carbon atoms in the nitrogen base purines and pyrimidines. C. nitrogen atoms in the nitrogen bases. D. carbon atoms of deoxyribose and ribose. E. hydrogen atoms that form hydrogen bonds between the nucleotides.
D. carbon atoms of deoxyribose and ribose.
In biology lab, as you are examining plant root cells, you are having difficulty determining what you are seeing as in the image below. You can still see chromosome strands, as they are in compact bundles. You think this should be telophase, because the chromosomes aren't being actively pulled apart, but when does cytokinesis start? The first sign that cytokinesis has started is the formation of a A. cleavage furrow. B. nucleolus. C. nuclear envelope. D. cell plate. E. spindle fiber.
D. cell plate.
A part of a chromosome, that attaches sister chromatids to each other, defines the term A. chromatin. B. histone. C. nucleosome. D. centromere. E. None of the answer choices are correct.
D. centromere.
The structure that organizes the protein subunits of the mitotic spindle is the A. microfilaments. B. kinetochore. C. cytoskeleton. D. centrosome. E. centromere.
D. centrosome.
A tRNA molecule is "bilingual" because it binds to A. promoters and to amino acids. B. amino acids and to DNA. C. promoters and to terminators. D. codons of mRNA and to amino acids. E. DNA and to mRNA codons.
D. codons of mRNA and to amino acids.
The process that merges the gametes from two parents is A. meiosis. B. conjugation. C. mitosis. D. fertilization. E. parthenogenesis.
D. fertilization.
The abbreviation n indicates that a cell is A. autosomes. B. the X and Y chromosomes. C. diploid. D. haploid. E. somatic cells.
D. haploid.
What type of mutation has occurred in the following? Normal allele 5'-GGAAUGAAACAGGAACCC-3' Mutant allele 5'-GGAAUGAAAUCAGGAACCC-3' A. deletion of two bases B. deletion of one base C. substitution D. insertion of one base E. insertion of two bases
D. insertion of one base
In eukaryotic cells, sequences of mRNA that are removed from an mRNA molecule before being translated are A. proteomes. B. terminators. C. exons. D. introns. E. anticodons.
D. introns.
The process by which homologous chromosomes exchange genetic material A. occurs only during DNA replication. B. occurs only in animals. C. is independent assortment. D. is crossing over. E. is random fertilization.
D. is crossing over.
A desert plant called Kalanchoe can reproduce, either with sexual reproduction through flowers, or asexually by budding off miniature leaf and root clusters from its leaves. When buds are produced, they land on the ground, take root, and grow, genetically identical to the original. If budding is used for several years, a large area may be covered with these descendents from the same original plant. The resulting population of plants will A. be more strongly able to adapt to environmental change, compared to the Kalanchoe that are reproducing sexually. B. adapt to environmental change, by shifting from asexual budding to conjugation, so they can sexually reproduce. C. automatically experience more genetic mutations, so that some of the plants will survive environmental change. D. not be as strongly able to adapt to environmental change, compared to the Kalanchoe that are reproducing sexually. E. None of these
D. not be as strongly able to adapt to environmental change, compared to the Kalanchoe that are reproducing sexually.
The building block of nucleic acids is a(n) A. glycerol molecule. B. amino acid. C. glucose molecule. D. nucleotide. E. None of the answer choices are correct.
D. nucleotide.
Amanatin, a toxin from the death cap poisonous mushroom, inhibits RNA polymerase, so it A. reverses the direction of RNA polymerase action, tearing apart partially formed proteins. B. disables any introns from being produced, to complete the protein structures. C. prevents the initiator tRNA from beginning translation. D. stops initiation, elongation, and termination stages of transcription. E. incorrectly places the release factor protein on mRNA and terminates translation.
D. stops initiation, elongation, and termination stages of transcription.
Keratins are structural proteins in skin, hair, and fingernails. One gene, called KRT10, is located on the 17th paired chromosome in humans. It produces a keratin that strengthens skin cells. Researchers isolated the specific location on the DNA having the nucleotide sequence, accessed during transcription, that encodes for the mRNA strand that will direct translation of the proteins. That specific portion of the DNA is the A. parent strand. B. leading strand. C. codon strand. D. template strand. E. lagging strand.
D. template strand.
If human gametes were diploid A. the embryo would be diploid. B. fertilization could not occur. C. the products of fertilization would have the same number of chromosomes as their parents. D. the products of fertilization would have more chromosomes than their parents. E. the products of fertilization would have fewer chromosomes than their parents.
D. the products of fertilization would have more chromosomes than their parents.
Which proteins initiate transcription in eukaryotes by recognizing sequences within the promoter region of a gene and attracting RNA polymerase? A. inducers B. TATA boxes C. poly A tails D. transcription factors E. repressors
D. transcription factors
The process used by cells to convert the mRNA "message" into a sequence of amino acids is A. transcription. B. amino acid synthesis. C. mitosis. D. translation. E. replication.
D. translation.
In meiosis I, cytokinesis usually occurs after telophase I and produces A. one diploid cell. B. four haploid cells. C. two diploid cells. D. two haploid cells. E. one haploid cell.
D. two haploid cells.
A region of a chromosome contains two strands of DNA, yet only one is used to transcribe a gene because A. the start of transcription is random along the chromosome and doesn't always occur on a gene. B. both strands are transcribed, but only one strand of DNA contains a reading frame. C. RNA polymerase binds to the terminator, stopping transcription on one strand of DNA. D. all genes are found on the same strand of DNA in a chromosome. E. RNA polymerase binds to the promoter, which precedes the gene only on the template strand of DNA.
E. RNA polymerase binds to the promoter, which precedes the gene only on the template strand of DNA.
Why does sexual reproduction produce more genetic variability in a population than asexual reproduction? A. Organisms arising from sexual reproduction can change their genetic material in response to environmental changes. B. Sexually reproducing organisms mutate more rapidly during DNA replication than asexually reproducing organisms. C. Offspring are identical to one parent, when produced through sexual reproduction. D. In sexual reproduction, the parents exchange genetic material of the nuclei, thus increasing their variability. E. Sexually reproducing organisms mix parental genetics in addition to crossing over, random alignment and other modifications.
E. Sexually reproducing organisms mix parental genetics in addition to crossing over, random alignment and other modifications.
The scientist (scientists) who used X-ray diffraction to help reveal the geometric structure of DNA is (are) A. Griffith. B. Watson and Crick. C. Hershey and Chase. D. Chargaff. E. Wilkins and Franklin.
E. Wilkins and Franklin.
In a biology lab exercise, you are asked to examine cells of a growing onion root tip, that has been sectioned to show many cells. In most of the cells, you easily see the circular or oval nucleus as a uniformly filled space in a membrane outline. In a small percentage of cells, you see chromosomes as distinct strands just as cell division begins, and as it progresses, because the chromatin A. increases in length, as replication adds DNA sections to the original. B. becomes less tightly folded, increasing their visible length. C. becomes more tightly folded, increasing their visible length. D. becomes less tightly wound, to facilitate cell division. E. becomes more tightly wound, to protect DNA, and to more easily manage cell division.
E. becomes more tightly wound, to protect DNA, and to more easily manage cell division.
A visiting scientist is introduced to you, and has a current project studying initiation, elongation, and termination. As a result, you know she is studying A. transcription. B. translation. C. replication and translation. D. replication. E. either transcription or translation.
E. either transcription or translation.
The process by which a sperm cell combines with an egg cell is A. germination. B. recombination. C. mitosis. D. replication. E. fertilization.
E. fertilization.
Sister chromatids are A. genetically identical. B. genetically different. C. attached to each other at the centromere. D. genetically different and attached to each other at the centromere. E. genetically identical and attached to each other at the centromere.
E. genetically identical and attached to each other at the centromere.
Keratins are structural proteins in skin, hair, and fingernails. One gene, called KRT10, is located on the 17th paired chromosome in humans. It produces a keratin that strengthens skin cells. Researchers have identified several mutations that can lead to rough, damaged, blistering skin because the keratins are not as strong as normal. Each mutation changes a specific amino acid at a particular location in the protein, and so is an example of a(n) ________ mutation. A. insertion B. duplication C. nonsense D. frameshift E. missense
E. missense
A group of prokaryotic genes that are controlled together is a(n) A. replication fork. B. ribosome. C. proteome. D. chromosome. E. operon.
E. operon.
The enzyme that builds a short complementary piece of RNA at the start of each DNA segment to be replicated is A. ligase. B. ATP synthase. C. helicase. D. DNA polymerase. E. primase.
E. primase.
A DNA sequence that signals a gene's start is a(n) A. terminator. B. codon. C. anticodon. D. amino acid attachment site. E. promoter.
E. promoter.
What type of mutation has occurred in the following? Normal allele 5'-GGAAUGAAACAGGAACCC-3' Mutant allele 5'-GGAAUGAAACAGGUACCC-3' A. deletion of one base B. insertion of one base C. deletion of two bases D. insertion of two bases E. substitution
E. substitution
The scientist (scientists) who discovered that bacteria can transfer genetic information is (are) A. Griffith. B. Watson and Crick. C. Hershey and Chase. D. Chargaff. E. Wilkins and Franklin.
Griffith
