BIOL 1009 Midterm II Sample Exam
d
The following figure illustrates various stages of either mitosis or meiosis. Which diagram represents prophase I of meiosis? a. VI b. II c. I d. IV
"Independent assortment" refers to Select one: a. different tetrads orient and segregate independently of each other during meiosis. b. the process of mitosis is independent of the process of meiosis. c. in an F1 cross, gametes combine independently to form the F2 progeny. d. homologous chromosome pairs separate during mitosis.
a
A man has extra digits (six fingers on each hand and six toes on each foot). His wife and their daughter have a normal number of digits. Having extra digits is a dominant trait. The couple's second child has extra digits. What is the probability that their next (third) child will have extra digits? Select one: a. 1/2 b. 1/4 c. 1/8 d. 3/4
a
A man who carries an allele of an X-linked gene will pass it on to _____. Select one: a. all of his daughters b. all of his sons c. half of his sons d. half of his daughters
a
An example of a hydrogen bond is the bond between: Select one: a. the H of one water molecule and the O of another water molecule b. C and H in methane (CH4) c. Mg+ and Cl- in MgCl2 d. the two hydrogen atoms in a molecule of hydrogen gas (H2)
a
Complete the following sentence: A ______ is a sequence of DNA nucleotides that occurs at a particular _______ on a chromosome. Select one: a. gene; locus b. centromere; homolog c. gene; chromatid d. gamete; centromere e. locus; chromatid
a
Duplication of a cell's genome occurs during: Select one: a. The S phase of the cell cycle. b. Prophase of mitosis. c. Cytokinesis. d. All phases of the cell cycle. e. Embryonic development only, not in adult individuals.
a
During the first meiotic division (meiosis I), a. homologous chromosomes separate. b. four haploid daughter cells are produced. c. sister chromatids separate. d. two diploid daughter cells are produced.
a
In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short? Select one: a. 0 b. 1/2 c. 1/6 d. 1/4
a
In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the explanations correctly describes one of these processes and supports the claim that heritable information is passed from one generation to another? Select one: a. In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes. b. Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population. c. Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell. d. During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced.
a
In plants and animals, genes are transmitted to offspring by specialized cells called: Select one: a. gametes b. somatic cells c. autosomes d. zygotes
a
Metaphase is characterized by _____. Select one: a. Aligning of chromosomes at a plane that is equidistant between the spindle's two poles. b. Splitting of the centromeres. c. Cytokinesis. d. Separation of sister chromatids. e. Both a and d occur during metaphase.
a
Phenylketonuria is an inherited disease caused by a recessive autosomal allele. If a woman and her husband are both carriers, what is the probability that their first child will be a phenotypically normal girl? Select one: a. 3/8 b. 1/2 c. 1/4 d. 3/4
a
Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant characteristic. The flower color trait in radishes is an example of which of the following? Select one: a. incomplete dominance b. sex linkage c. codominance d. a multiple allelic system
a
The ends of linear chromosomes are known as Select one: a. telomeres b. DNA replication origins c. centromeres d. endomeres
a
The observation that only one of an individual's two alleles at each locus ends up in each gamete is also called: Select one: a. the law of segregation b. homozygosity c. the law of independent assortment d. heterozygosity
a
The primary reason why cytokinesis in plants happens differently from cytokinesis in animals is: Select one: a. Plant cells have cell walls, whereas animal cells do not. b. Plant cells have chloroplasts, whereas animal cells do not. c. Plant cells are much larger than animal cells. d. Animal cells divide more often than plant cells. e. Plant cells have a Golgi apparatus, whereas animal cells do not.
a
The reactions of the Calvin cycle are Select one: a. endergonic, and thus require a source of free energy to occur b. exergonic, and thus require a source of free energy to occur c. endergonic, and thus may proceed spontaneously without a source of free energy d. exergonic, and thus may proceed spontaneously without a source of free energy
a
What is the best description of a carbonyl group? Select one: a. A carbon atom joined to an oxygen by a double covalent bond b. An oxygen joined to a carbon by a single covalent bond c. A nitrogen and two hydrogens joined to a carbon by covalent bonds d. A carbon joined to a hydroxyl group by a single covalent bond
a
What is the function of topoisomerase? Select one: a. relieving tight twisting in the DNA ahead of the replication fork b. unwinding of the double helix c. adding methyl groups to bases of DNA d. elongating new DNA at a replication fork by adding nucleotides to the existing chain
a
What kind of chemical bond is found between paired bases of the DNA double helix? Select one: a. Hydrogen b. Phosphate c. Ionic d. Covalent
a
When during meiosis do synaptonemal complexes form or are still present? Select one: a. Prophase I only b. Metaphase I and Metaphase II only c. Prophase I and Telophase I only d. Prophase I and Telophase II only
a
When during meiosis do tetrads of chromosomes aligned at the equator of the spindle? Select one: a. Metaphase I b. Metaphase II c. Prophase I d. Prophase II
a
When two atoms are equally electronegative, they will interact to form Select one: a. nonpolar covalent bonds b. ionic bonds c. polar covalent bonds d. ions
a
Which kind of metabolic poison would most directly interfere with glycolysis? Select one: a. an agent that closely mimics the structure of glucose but is not metabolized b. an agent that reacts with oxygen and depletes its concentration in the cell c. an agent that reacts with NADH and oxidizes it to NAD+ d. an agent that binds to pyruvate and inactivates it
a
Which of the following are external signals that INHIBIT normal cell division? I. Crowding by many other cells. II. The presence of damaged cells nearby. III. The absence of a surface or substrate to which the cell can attach. IV. The presence of growth factors such as PDGF. a. I and III. b. I and IV. c. III only. d. I, II, and III. e. III and IV.
a
Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? Select one: a. Golgi-derived vesicles b. cyclin-dependent kinases c. kinetochores d. actin and myosin
a
Which of the following describes the sequence of events that occurs during DNA replication of a double-stranded DNA molecule? Select one: a. separation of the DNA strands at DNA replication origins, unwinding of the DNA double helix, synthesis of RNA primers, synthesis of DNA, ligation of DNA fragments b. separation of the DNA strands at DNA replication origins, synthesis of RNA primers, synthesis of DNA, ligation of DNA fragments, unwinding of DNA c. separation of the DNA strands at DNA replication origins, unwinding of the DNA double helix, synthesis of RNA primers, ligation of RNA fragments, synthesis of DNA d. separation of the DNA strands at DNA replication origins, unwinding of the DNA double helix, synthesis of DNA, synthesis of RNA primers, ligation of DNA fragments
a
Which of the following does not occur during mitosis? Select one: a. replication of the DNA b. separation of sister chromatids c. spindle formation d. condensation of the chromosomes
a
Which of the following does not occur in prokaryotic gene expression, but does in eukaryotic gene expression? Select one: a. A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end. b. mRNA, tRNA, and rRNA are transcribed. c. RNA polymerase binds to the promoter. d. Transcription can begin as soon as translation has begun even a little.
a
Which of the following is a statement of the first law of thermodynamics? Select one: a. Energy cannot be created or destroyed b. The entropy of the universe is constant. c. The entropy of the universe is decreasing d. The entropy of the universe is increasing.
a
Which of the following statements is not true? Sister chromatids Select one: a. segregate from each other during meiosis I. b. segregate from each other during each mitotic anaphase. c. arise by replication during interphase. d. usually contain identical versions of the same genetic information.
a
Which of these is NOT an outcome of mitotic cell division? Select one: a. Production of haploid gametes. b. Reproduction of an entire organism. c. Growth of an embryo. d. Replacement of worn-out or damaged body cells.
a
f a diploid cell has 16 chromosomes, how many pairs of homologous chromosomes does this cell have? Select one: a. 8 b. 16 c. 4 d. 32
a
"Independent assortment" refers to Select one: a. in an F1 cross, gametes combine independently to form the F2 progeny. b. different tetrads orient and segregate independently of each other during meiosis. c. the process of mitosis is independent of the process of meiosis. d. homologous chromosome pairs separate during mitosis.
b
A particular triplet of bases in the coding strand of a gene is AAA. If an mRNA is made from this gene, the anticodon on the tRNA that will bind the codon on the mRNA is Select one: a. UUA. b. UUU. c. TTT. d. AAA.
b
A young man has Down syndrome (trisomy-21), a consequence of non-disjunction of chromosomes during the first meiotic division. This genetic disease could have been caused by him receiving Select one: a. three copies of chromosome 21 from his father. b. two copies of chromosome 21 from his father. c. one X chromosome and one chromosome 21 from his father. d. three copies of chromosome 21 from his mother.
b
Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are both of normal pigmentation, but both have one parent who is albino (without melanin pigmentation). What is the probability that their first child will be an albino? Select one: a. 3/4 b. 1/4 c. 0 d. 1/2
b
Crossing over normally takes place during which of the following processes? Select one: a. Meiosis II b. Prophase I c. Interphase d. Meiosis I and meiosis II
b
Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. The relationship between genes S and N is an example of _____. Select one: a. pleiotropy b. epistasis c. complete dominance d. incomplete dominance
b
Generation of proton gradients across membranes occurs during Select one: a. neither photosynthesis nor cellular respiration. b. both photosynthesis and cellular respiration. c. cellular respiration. d. photosynthesis.
b
Given the genotypes of the following parents, AABBCc X AabbCc, and assuming simple dominance and independent assortment, what proportion of the progeny will be expected to have the same phenotype as the second parent (AabbCc)? Select one: a. 3/16 b. 0 c. 1/4 d. 3/8
b
Gray seed color in peas is dominant to white. Assume that Mendel conducted a series of experiments where plants with gray seeds were crossed among themselves, and the following progeny were produced: 302 gray and 98 white. (a) What is the most probable genotype of each parent? (b) Based on your answer in (a) above, what genotypic and phenotypic ratios are expected in these progeny? (Assume the following symbols: G = gray and g = white.) Select one: a. (a) gg × Gg; (b) genotypic = 1:2, phenotypic = 3:1 b. (a) Gg × Gg; (b) genotypic = 1:2:1, phenotypic = 3:1 c. (a) GG × Gg; (b) genotypic = 1:2:1, phenotypic = 2:1 d. (a) GG × gg; (b) genotypic = 3:1, phenotypic = 1:2:1
b
How does the sexual life cycle increase the genetic variation in a species? Select one: a. by increasing gene stability b. by allowing crossing over c. by conserving chromosomal gene order d. by decreasing mutation frequency
b
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)? Select one: a. 8 b. 16 c. 32 d. 4
b
If two molecules are mirror images of each other, the two molecules may be Select one: a. cis isomers b. Enantiomers c. trans isomers d. Structural isomers
b
In Guinea pigs, black hair (B) is dominant over white (b), rough coat texture (R) is dominant over smooth (r), and short hair (H) is dominant over long hair heart. Assume independent assortment (i.e., these genes are unlinked). A true-breeding black Guinea pig with short hair and rough coat is crossed with a white one that has long hair and smooth coat. The offspring (F1) are all black with short hair and rough coats. Two of these F1 offspring are crossed, producing an F2 generation. What is the expected proportion (fraction) of these F2 individuals that are black with long hair and rough coats? Select one: a. 3/16 b. 9/64 c. 1/16 d. 3/32
b
In Mendel's pea plant experiments, the round seed trait (RR) is completely dominant over the wrinkled seed trait (rr). If the alleles for the height character were incompletely dominant, such that TT are tall, Tt are intermediate and tt are short, what would be the proportion (fraction) of offspring of the cross RrTt x RrTt that have round seed and intermediate height? Assume independent assortment (unlinked). Select one: a. 3/4 b. 3/8 c. 1/4 d. 1/2
b
In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white (rr) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white? Select one: a. red × white b. roan × roan c. red × roan d. white × roan
b
In the cross AaBbCc × AaBbCc, what is the probability of producing the genotype AABBCC? Assume complete dominance and independent assortment. Select one: a. 1/8 b. 1/64 c. 1/32 d. 1/16
b
The DNA molecule is able to carry a vast amount of hereditary information in which of the following? Select one: a. phosphate-sugar backbones b. sequence of bases c. complementary pairing of bases d. side groups of nitrogenous bases
b
The active site of an enzyme is the region that Select one: a. is inhibited by the presence of a coenzyme or cofactor b. is involved in the catalytic reaction of the enzyme c. binds the products of the catalytic reaction d. binds allosteric regulators of the enzyme
b
The first gap in the cell cycle (G1) corresponds to _____. Select one: a. A "resting phase" for cells that do not replicate. b. A time of intense metabolic activity and growth. c. The phase in which DNA is being replicated. d. The beginning of mitosis. e. The phase between DNA replication and the M phase.
b
The first gap in the cell cycle (G1) corresponds to _____. Select one: a. A "resting phase" for cells that do not replicate. b. A time of intense metabolic activity and growth. c. The phase in which DNA is being replicated. d. The beginning of mitosis. e. The phase between DNA replication and the M phase.
b
The first gap in the cell cycle (G1) corresponds to _____. Select one: a. A "resting phase" for cells that do not replicate. b. A time of intense metabolic activity and growth. c. The phase in which DNA is being replicated. d. The beginning of mitosis. e. The phase between DNA replication and the M phase.
b
The reactions of the Calvin cycle are Select one: a. exergonic, and thus may proceed spontaneously without a source of free energy b. endergonic, and thus require a source of free energy to occur c. endergonic, and thus may proceed spontaneously without a source of free energy d. exergonic, and thus require a source of free energy to occur
b
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely Select one: a. an animal cell in the S phase of the cell cycle. b. a plant cell in the process of cytokinesis. c. a plant cell in metaphase. d. an animal cell in the process of cytokinesis.
b
Transcription initiation in eukaryotes requires which of the following in addition to RNA polymerase? Select one: a. start and stop codons b. several transcription factors c. ribosomes and tRNA d. the protein product of the promoter
b
What is the function of topoisomerase? Select one: a. relieving tight twisting in the DNA ahead of the replication fork b. adding methyl groups to bases of DNA c. unwinding of the double helix d. elongating new DNA at a replication fork by adding nucleotides to the existing chain
b
What would be the sequence of the DNA molecule made using the following DNA strand as a template? 5' TCTGAA 3' Select one: a. 5' AGACUU 3' b. 5' TTCAGA 3' c. 5' UUCAGA 3' d. 5'AGACTT 3'
b
Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? Select one: a. cyclin-dependent kinases b. Golgi-derived vesicles c. kinetochores d. actin and myosin
b
Which of the following best describes enthalpy (H)? Select one: a. the condition of a cell that is not able to react b. in biological systems, enthalpy is equivalent to total energy c. the total kinetic energy of a system d. the system's entropy
b
Which of the following describes the ability of a single allele to have multiple phenotypic effects? Select one: a. codominance b. pleiotropy c. incomplete dominance d. multiple alleles
b
Which of the following is an example of polygenic inheritance? Select one: a. Huntington's disease in humans b. skin pigmentation in humans c. pink flowers in snapdragons d. the ABO blood group in humans
b
Which of the following modifies polypeptides that will be secreted? Select one: a. lysosome b. Golgi apparatus c. mitochondrion d. vacuole
b
Which of the following provides an example of epistasis? Select one: a. An individual corn snake that is homozygous recessive at two loci (aabb) will be an albino. b. In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing, regardless of the individual's genotype at other loci affecting fur color. c. In Drosophila (fruit flies), white eyes can be due either to an X-linked gene or to a combination of other genes. d. In cacti, there are several genes affecting the shape of a plant's spines.
b
Which of the following sequences correctly represents the flow of electrons during photosynthesis? Select one: a. H2O → photosystem I → photosystem II b. H2O → NADPH → Calvin cycle c. NADPH → chlorophyll → Calvin cycle d. NADPH → electron transport chain → O2
b
Which of the following statements is FALSE? Select one: a. Sugars are the monomers from which polysaccharides are formed. b. Fatty acids are the monomers from which lipid molecules are formed. c. Amino acids are the monomers from which proteins are formed. d. Nucleotides are the monomers from which nucleic acids are formed.
b
Which of the following will happen to the chromosomes in your somatic cells as you become older? Select one: a. All of these answers are correct. b. Your chromosomes will become shorter. c. Your DNA will accumulate segments of RNA that are left over from the work of primase. d. The frequency of mutations will become smaller as DNA repair enzymes do their job.
b
Which term includes all the other terms on the list? Select one: a. monosaccharide b. carbohydrate c. polysaccharide d. starch
b
Three genes are tightly linked. An individual with genotype AADDgg is crossed with an individual with genotype aaddGG. In the absence of crossing over, what gametes could an F1 offspring of the above cross (AaDdGg) produce? Select one: a. ADG b. adG c. adg d. aDg
b (WHAT)
A man who carries an allele of an X-linked gene will pass it on to _____. Select one: a. all of his sons b. half of his daughters c. all of his daughters d. half of his sons
c
A new DNA strand elongates only in the 5' to 3' direction because Select one: a. the polarity of the DNA molecule prevents addition of nucleotides at the 3' end. b. DNA polymerase begins adding nucleotides at the 5' end of the template. c. DNA polymerase can only add nucleotides to the free 3' end. d. Okazaki fragments prevent elongation in the 3' to 5' direction.
c
A nonreciprocal crossover causes which of the following products? Select one: a. deletion only b. duplication only c. deletion and duplication d. nondisjunction
c
A recessive allele is one that: Select one: a. produces a smaller or weaker version of a trait than a dominant allele. b. is less common within a population than a dominant allele. c. is not expressed when in the presence of a dominant allele at the same locus. d. is less likely to be passed on than a dominant allele.
c
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows complete dominance over Rh negative and is designated by the alleles R and r, respectively. Which of the following is a possible genotype for the father? Select one: a. IBIB Rr b. not possible to determine c. IBi Rr d. IBi RR
c
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows complete dominance over Rh negative and is designated by the alleles R and r, respectively. Which of the following is a possible partial genotype for the son? Select one: a. IAIB b. IBIB c. IBi d. ii
c
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows complete dominance over Rh negative and is designated by the alleles R and r, respectively. Which of the following is a possible partial genotype for the son? Select one: a. ii b. IAIB c. IBi d. IBIB
c
Alleles are Select one: a. different genes on the same chromosome. b. expressed only when homozygous. c. alternative forms of the same gene. d. particular locations on the chromosome.
c
Alternative forms of a gene occurring on homologous chromosomes are called _______. Select one: a. chiasmata b. traits c. alleles d. loci
c
During the first meiotic division (meiosis I), Select one: a. sister chromatids separate. b. four haploid daughter cells are produced. c. homologous chromosomes separate. d. two diploid daughter cells are produced.
c
Homologous chromosomes _____. Select one: a. Align on the metaphase plate in meiosis II. b. Are identical. c. Carry information for the same traits. d. Carry the same alleles.
c
Homologous chromosomes _____. a. Align on the metaphase plate in meiosis II. b. Are identical. c. Carry information for the same traits. d. Carry the same alleles.
c
If a diploid cell has 16 chromosomes, how many pairs of homologous chromosomes does this cell have? Select one: a. 16 b. 32 c. 8 d. 4
c
If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis? Select one: a. Half of the gametes will be n + 1, and half will be n - 1. b. All the gametes will be diploid. c. 1/4 of the gametes will be n + 1, 1/4 will be n - 1, and 1/2 will be n. d. Two of the four gametes will be haploid, and two will be diploid.
c
If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis? Select one: a. Half of the gametes will be n + 1, and half will be n - 1. b. All the gametes will be diploid. c. 1/4 of the gametes will be n + 1, 1/4 will be n - 1, and 1/2 will be n. d. Two of the four gametes will be haploid, and two will be diploid.
c
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male? Select one: a. tortoiseshell females; orange males b. black females; orange males c. tortoiseshell females; black males d. orange females; black males
c
In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short? Select one: a. 1/6 b. 1/2 c. 0 d. 1/4
c
Mitochondria are sites where Select one: a. some of the reactions required to complete the breakdown of lipids, resulting in formation of CO2 and H2O, occur b. some of the reactions required to complete the breakdown of sugars, resulting in formation of CO2 and H2O, occur c. all of these answers are correct d. ATP molecules are formed.
c
Starting with one molecule of glucose, the energy-containing products of glycolysis are Select one: a. 2 FADH2, 2 pyruvate, and 4 ATP. b. 2 NAD+, 2 pyruvate, and 2 ATP. c. 2 NADH, 2 pyruvate, and 2 ATP. d. 6 CO2, 2 ATP, and 2 pyruvate.
c
Tallness (T) in snapdragons is dominant to dwarfness (t), while red (R) flower color is dominant to white (r). The heterozygous condition results in pink (Rr) flower color. A dwarf, red snapdragon is crossed with a plant homozygous for tallness and white flowers. What are the genotype and phenotype of the F1 individuals? Select one: a. ttrr—dwarf and white b. TtRr—tall and red c. TtRr—tall and pink d. ttRr—dwarf and pink
c
The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following? Select one: a. None of the traits obeyed the law of segregation. b. All of the genes controlling the traits were located on the same chromosome. c. All of the genes controlling the traits behaved as if they were on different chromosomes. d. The diploid number of chromosomes in the pea plants was 7.
c
The following functional group is known as -SH Select one: a. a hydrogen sulfide group b. all of these answers are correct c. a sulfhydryl group d. a sulfate group
c
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction Select one: a. gains electrons. b. decreases electrons in solution. c. loses electrons. d. increases electrons in solution.
c
The three most important cell cycle checkpoints occur during: Select one: a. The S phase, metaphase of mitosis, and the G1 phase. b. The G1 phase, the G2 phase, and prophase of mitosis. c. The G1 phase, the G2 phase, and metaphase of mitosis d. Prophase of mitosis, telophase of mitosis, and the G1 phase e. The S phase, metaphase of mitosis, and the G2 phase.
c
Unsaturated fats Select one: a. contain at least one branched fatty acid molecule b. dissolve more readily in water c. contain at least one covalent double bond joining two carbon atoms (i.e. C=C) d. are solid at room temperature
c
When during meiosis do tetrads of chromosomes aligned at the equator of the spindle? Select one: a. Prophase II b. Metaphase II c. Metaphase I d. Prophase I
c
Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction? Select one: a. DNA ligase b. primase c. DNA polymerase III d. helicase
c
Which of the following correctly shows the flow of information in a cell? Select one: a. RNA to DNA to protein b. RNA to protein to DNA c. DNA to RNA to protein d. DNA to protein to RNA
c
Which of the following is true of a species that has a chromosome number of 2N = 24? Select one: a. The species has 24 different types of chromosomes. b. There are 24 homologous pairs of chromosomes. c. A gamete from this species has 12 chromosomes. d. The species is diploid with 48 chromosomes.
c
Which of the following statements about nucleic acids is FALSE? Select one: a. DNA acts as the template for formation of RNA b. The nucleotides that form RNA molecules contain ribose c. The nucleotides that form DNA molecules contain ribose d. RNA acts as the template for formation of proteins
c
Which of the following statements is correct about diffusion? Select one: a. It requires an expenditure of energy by the cell. b. It is an active process in which molecules move from a region of lower concentration to one of higher concentration. c. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. d. It requires integral proteins in the cell membrane.
c
Which of the following structures act to fasten together neighboring animal cells into sheets of tissue? Select one: a. extracellular matrix b. gap junctions c. desmosomes d. tight junctions
c
Which of the following types of molecules are the major structural components of the cell membrane? Select one: a. phospholipids and cellulose b. glycoproteins and cholesterol c. phospholipids and proteins d. nucleic acids and proteins
c
Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? Select one: a. No genes interacted to produce the parental phenotype. b. The traits blended together during fertilization. c. One allele was completely dominant over another. d. Each allele affected phenotypic expression.
c
A group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone? Select one: a. a compound with the same number of carbon atoms as the hormone b. a compound with the same number of orbital electrons as the hormone c. a compound with the same molecular mass (measured in daltons) as the hormone d. a compound with the same three-dimensional shape as part of the hormone
d
A particular triplet of bases in the coding strand of a gene is AAA. If an mRNA is made from this gene, the anticodon on the tRNA that will bind the codon on the mRNA is Select one: a. TTT. b. AAA. c. UUA. d. UUU.
d
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? Select one: a. Hh b. tt c. HhTt d. HT
d
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows complete dominance over Rh negative and is designated by the alleles R and r, respectively. Which of the following is a possible partial genotype for the son? Select one: a. ii b. IBIB c. IAIB d. IBi
d
A young man has Down syndrome (trisomy-21), a consequence of non-disjunction of chromosomes during the first meiotic division. This genetic disease could have been caused by him receiving Select one: a. three copies of chromosome 21 from his mother. b. three copies of chromosome 21 from his father. c. one X chromosome and one chromosome 21 from his father. d. two copies of chromosome 21 from his father.
d
Allosteric enzyme regulation is usually associated with Select one: a. lack of cooperativity. b. the need for cofactors. c. competitive inhibition. d. an enzyme with more than one subunit.
d
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). The genes for the two traits are non-linked. What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails? Select one: a. 3/16 b. 3/8 c. 1/16 d. 1/2
d
Chromatids are separated from each other. Select one: a. The statement is true for mitosis and meiosis I. b. The statement is true for meiosis II only. c. The statement is true for mitosis only. d. The statement is true for mitosis and meiosis II.
d
Homologous chromosomes _____. Select one: a. Are identical. b. Align on the metaphase plate in meiosis II. c. Carry the same alleles. d. Carry information for the same traits.
d
Homologous pairs of chromosomes align opposite of each other at the equator of a cell during _____. Select one: a. Meiosis Metaphase II b. Mitosis Metaphase c. Meiosis Anaphase I d. Meiosis Metaphase I
d
How can one increase the rate of a chemical reaction? Select one: a. Increase the entropy of the reactants. b. Cool the reactants. c. Increase the activation energy needed. d. Add a catalyst
d
If atom "A" is more electronegative than atom "B", then Select one: a. atom "A" will have a negative charge of -1 b. atom "A" will remove electrons from atom "B" c. atom "A" has fewer electrons than atom "B" d. atom "A" will attract electrons more strongly than atom "B"
d
In Guinea pigs, black hair (B) is dominant over white (b), rough coat texture (R) is dominant over smooth (r), and short hair (H) is dominant over long hair heart. Assume independent assortment (i.e., these genes are unlinked). A true-breeding black Guinea pig with short hair and rough coat is crossed with a white one that has long hair and smooth coat. The offspring (F1) are all black with short hair and rough coats. Two of these F1 offspring are crossed, producing an F2 generation. What is the expected proportion (fraction) of these F2 individuals that are black with long hair and rough coats? Select one: a. 3/16 b. 1/16 c. 3/32 d. 9/64
d
In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules? Select one: a. A = C b. A = G and C = T c. G + C = T + A d. A + G = C + T
d
In mitochondria, the electron transport chain pumps protons from the matrix into the intermembrane space, whereas in chloroplasts, the electron transport chain pumps protons from Select one: a. the stroma to the photosystem II. b. the matrix to the stroma. c. the thylakoid space to the stroma. d. the stroma to the thylakoid space.
d
Mitochondria are sites where Select one: a. some of the reactions required to complete the breakdown of sugars, resulting in formation of CO2 and H2O, occur b. some of the reactions required to complete the breakdown of lipids, resulting in formation of CO2 and H2O, occur c. ATP molecules are formed. d. all of these answers are correct
d
Nucleotides in a single DNA strand are joined together by Select one: a. a covalent bond between the nitrogenous base of one nucleotide and the nitrogenous base of the next nucleotide b. hydrogen bonds between the phosphate group of one nucleotide and the sugar group of the next nucleotide c. hydrogen bonds between the nitrogenous base of one nucleotide and the nitrogenous base of the next nucleotide d. a covalent bond between the phosphate group of one nucleotide and the sugar group of the next nucleotide
d
Polygenic (or quantitative) traits Select one: a. are controlled by multiple alleles at only a single gene locus. b. are very rare in humans. c. often show only two different phenotypes. d. are controlled by alleles at several to many different gene loci.
d
Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant characteristic. The flower color trait in radishes is an example of which of the following? Select one: a. codominance b. sex linkage c. a multiple allelic system d. incomplete dominance
d
Reduction of oxygen to form water occurs during Select one: a. photorespiration only. b. both photosynthesis and cellular respiration. c. photosynthesis only d. cellular respiration only.
d
Some substances such as oil and gasoline will not dissolve in water because Select one: a. oil and gasoline are organic compounds. b. their electrons are so stable that they do not exchange atoms with water molecules. c. their molecules are so large. d. their molecules have no charges or partial charges to which water molecules can interact.
d
The M-phase checkpoint ensures that all chromosomes are attached to the mitotic spindle. If this does not happen, cells would most likely be arrested in _____. Select one: a. Telophase b. Prophase c. Interphase d. Metaphase e. Anaphase
d
The ends of linear chromosomes are known as Select one: a. endomeres b. centromeres c. DNA replication origins d. telomeres
d
The genetic code consists of sequences of three consecutive Select one: a. transfer RNA molecules, each of which has a specific amino acid attached. b. amino acids, each sequence specifying a codon. c. genes, each sequence specifying a particular protein. d. nucleotides, each sequence specifying a particular amino acid.
d
The joining of nucleotides in the polymerization of DNA requires energy from Select one: a. DNA polymerase. b. the hydrolysis of the terminal phosphate group of ATP. c. the phosphate groups of the sugar-phosphate backbone. d. the hydrolysis of the pyrophosphate removed from the nucleoside triphosphate during elongation.
d
The mathematical expression for the change in the free energy of a system is ∆G = ∆H - T∆S. Which of the following is (are) TRUE? Select one: a. T is the temperature in degrees Celsius. b. ∆H is the change in free energy. c. ∆G is the change in enthalpy. d. ∆S is the change in entropy
d
The order of chemical bonds from strongest to weakest is Select one: a. ionic bonds in the formation of salt crystals, covalent bonds, hydrogen bonds, van der Waals interactions b. hydrogen bonds, covalent bonds, ionic bonds in the formation of salt crystals, van der Waals interactions c. covalent bonds, hydrogen bonds, ionic bonds in the formation of salt crystals, van der Waals interactions, d. covalent bonds, ionic bonds in the formation of salt crystals, hydrogen bonds, van der Waals interactions
d
What would be an expected consequence of changing one amino acid for a different amino acid in a particular protein? Select one: a. The primary structure would be changed. b. The tertiary structure might be changed. c. The biological activity of this protein might be altered. d. All of the above are possible.
d
What would be the sequence of the mRNA molecule made using the following DNA strand as a template? 3' AATTCGC 5' Select one: a. 5' TTAAGCG 3' b. 5' GCGAATT 3' c. 3' UUAAGCG 5' d. 5' UUAAGCG 3'
d
What would be the sequence of the mRNA molecule made using the following DNA strand as a template? 3' GAGGCTT 5' Select one: a. 5' CTCCGAA 3' b. 3' CUCCGAA 5' c. 5' AAGCCTC 3' d. 5' CUCCGAA 3'
d
What would be the sequence of the mRNA molecule made using the following DNA strand as a template? 3' TCTGAA 5' Select one: a. 5' TTCAGA 3' b. 5'AGACTT 3' c. 3' AGACUU 5' d. 5' AGACUU 3'
d
When an electron is moved further from the nucleus Select one: a. its potential energy may change, depending on how the electron was moved b. it loses potential energy c. its potential energy is unchanged d. it gains potential energy
d
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? Select one: a. It is used to generate ADP from nucleotide precursors. b. It is used to store energy as more ATP. c. It is used to power yet more cellular work. d. It is lost to the environment.
d
When homologous chromosomes crossover, what occurs? Select one: a. Two sister chromatids exchange identical pieces of DNA. b. Two chromatids get tangled, resulting in one re-sequencing its DNA. c. Each of the four DNA strands of a tetrad is broken and the pieces are mixed. d. Specific proteins break two non-sister chromatids and re-join them with their homologs.
d
Which of the enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments? Select one: a. primase b. DNA polymerase III c. ligase d. DNA polymerase I
d
Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? Select one: a. kinetochores b. cyclin-dependent kinases c. actin and myosin d. Golgi-derived vesicles
d
Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? Select one: a. by cotransport of glucose and hydrogen b. by increasing the percentage of cholesterol molecules in the membrane c. by decreasing the number of hydrophobic proteins in the membrane d. by increasing the percentage of unsaturated phospholipids in the membrane
d
Which of the following statements about pre-mRNAs (primary mRNAs) is correct? Select one: a. Primary mRNAs may contain both exons and introns b. Introns are removed from primary mRNAs by splicing c. PolyA tails are added to primary mRNAs d. all of these answers are correct
d
Which of the following statements is TRUE of linkage? Select one: a. Linked genes are found on different chromosomes. b. All of the traits that Mendel studied—seed color, pod shape, flower color, and others—are due to genes linked on the same chromosome. c. Genes that are on the same chromatid are never separated by recombination. d. The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.
d
Which of the following structures act to fasten together neighboring animal cells into sheets of tissue? Select one: a. tight junctions b. extracellular matrix c. gap junctions d. desmosomes
d
Which of these is NOT an outcome of mitotic cell division? a. Reproduction of an entire organism. b. Growth of an embryo. c. Replacement of worn-out or damaged body cells. d. Production of haploid gametes. e. All of these are outcomes of mitosis.
d
Which of these is NOT an outcome of mitotic cell division? Select one: a. Reproduction of an entire organism. b. Growth of an embryo. c. Replacement of worn-out or damaged body cells. d. Production of haploid gametes. e. All of these are outcomes of mitosis.
d
Will the chromosomes you pass onto your children be shorter than your chromosomes? Select one: a. Yes, because DNA polymerase is not able to fully replicate the ends of chromosomes. b. Yes, because DNA repair enzymes do not function properly in germline cells (the cells that produce egg or sperm cells). c. No, because DNA repair enzymes will fill in any missing gaps at the ends of your chromosomes. d. Hopefully not, because telomerase will restore the telomeres in your germline cells (the cells that produce egg or sperm cells) to approximately their original length.
d
n eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the explanations correctly describes one of these processes and supports the claim that heritable information is passed from one generation to another? Select one: a. Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell. b. Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population. c. During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced. d. In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.
d
If a cell has a diploid number of 12, it will contain ______ sister chromatids at the start of mitosis and _______ unduplicated chromosomes afterwards. Select one: a. 12, 6 b. 12, 12 c. 24, 24 d. 6, 12 e. 24, 12
e
If a cell has a diploid number of 12, it will contain ______ sister chromatids at the start of mitosis and _______ unduplicated chromosomes afterwards. Select one: a. 12, 6 b. 12, 12 c. 24, 24 d. 6, 12 e. 24, 12
e
