Bio002 Final Review

11) What is the reason that closely linked genes are typically inherited together? A) They are located close together on the same chromosome. B) The number of genes in a cell is greater than the number of chromosomes. C) Alleles are paired together during meiosis. D) Genes align that way during metaphase I of meiosis.

Answer: A

13) In a plant, the reactions that produce molecular oxygen (O2) take place in _____. A) the light reactions alone B) the Calvin cycle alone C) the light reactions and the Calvin cycle D) neither the light reactions nor the Calvin cycle

Answer: A

14) Where does the Calvin cycle take place? A) stroma of the chloroplast B) thylakoid membrane C) interior of the thylakoid (thylakoid space) D) outer membrane of the chloroplast

Answer: A

19) Which of the following statements is true of linkage? A) The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them. B) Linked genes are found exclusively on sex chromosomes C) All of the traits that Mendel studied—seed color, pod shape, flower color, and others—are due to genes linked on the same chromosome. D) Linked genes are found on different chromosomes.

Answer: A

21) DNA is synthesized through a process known as _____. A) semiconservative replication B) conservative replication C) translation D) transcription

Answer: A

3) What is meant by the description "antiparallel" regarding the strands that make up DNA? A) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. B) The twisting nature of DNA creates nonparallel strands. C) Base pairings create unequal spacing between the two DNA strands. D) One strand contains only purines and the other contains only pyrimidines.

Answer: A

36) The reason for using Taq DNA polymerase for PCR is that _____. A) it is heat stable and can withstand the heating step of PCR B) only minute amounts are needed for each cycle of PCR C) it binds more readily than other polymerases to the primers D) it has a primase activity

Answer: A

4) The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that _____. A) the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose B) the nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups C) ATP contains three high-energy bonds; the nucleoside triphosphates have two D) ATP is found only in human cells; the nucleoside triphosphates are found in all animal and plant cells

Answer: A

40) A G protein-coupled receptor with GTP bound to it _____. A) is in its active state B) is in its inactive form C) signals a protein to maintain its shape and conformation D) directly affects gene expression

Answer: A

6) How might a single base substitution in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene, and why? A) Only a single amino acid could change, because the reading frame is unaffected. B) The amino acid sequence would be substantially altered, because the reading frame would change with a single base substitution. C) All amino acids following the substitution would be affected, because the reading frame would be shifted. D) It is not possible for a single base substitution to affect protein structure, because each codon is three bases long.

Answer: A

8) What is a major difference between mitosis and meiosis I in a diploid organism? A) Sister chromatids separate in mitosis, while homologous chromosomes separate in meiosis I. B) Sister chromatids separate in mitosis, while homologous chromosomes separate in meiosis II. C) DNA replication takes place prior to mitosis, but not before meiosis I. D) Only meiosis I results in daughter cells that contain identical genetic information.

Answer: A

1) Which of the following sequences correctly represents the flow of electrons during photosynthesis? A) NADPH → O2 → C O2 B) H2O → NADPH → Calvin cycle C) NADPH → chlorophyll → Calvin cycle D) NADPH → electron transport chain → O2

Answer: B

12) In mitochondria, chemiosmosis moves protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis moves protons from the _____. A) matrix to the stroma B) stroma to the thylakoid space C) intermembrane space to the matrix D) thylakoid space to the stroma

Answer: B

17) When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result? A) The gene involved is on the Y chromosome. B) The gene involved is on the X chromosome. C) The gene involved is on an autosome, but only in males. D) Other male-specific factors influence eye color in flies.

Answer: B

2) Which of the following is the meaning of the chromosome theory of inheritance as expressed in the early twentieth century? A) Individuals inherit particular chromosomes attached to genes. B) Mendelian genes are at specific loci on the chromosome and their inheritance is explained by meiosis. C) No more than a single pair of chromosomes can be found in a healthy normal cell. D) Mitosis generates two daughter cells identical to each other and the parental cell.

Answer: B

23) According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins A) microRNA B) rRNA C) mRNA D) tRNA

Answer: C

24) DNA contains the template needed to copy itself, but it has no catalytic activity in cells. What catalyzes the formation of phosphodiester bonds between adjacent nucleotides in the DNA polymer being formed? A) ribozymes B) DNA polymerase C) kinase D) RNA polymerase

Answer: B

26) In eukaryotic cells, RNAs containing exons and introns are most likely to be found: A) in the cytosol. B) in the nucleus. C) associated with the rough endoplasmic reticulum. D) in the Golgi apparatus.

Answer: B

27) In the process of transcription, _____. A) DNA is replicated B) RNA is synthesized C) proteins are synthesized D) mRNA attaches to ribosomes

Answer: B

30) Pairs of homologous chromosomes are aligned at the equator of the spindle. A) Prophase I B) Metaphase I C) Telophase I D) Metaphase II

Answer: B

34) Which of the following does NOT occur during the Calvin cycle? A) oxidation of NADPH B) release of oxygen C) regeneration of the CO2 acceptor D) consumption of ATP

Answer: B

39) In eukaryotic cells, the place where ribosomal RNA synthesis and ribosome subunit assembly occur is the: A) rough endoplasmic reticulum (ER) B) nucleolus C) Golgi D) smooth ER

Answer: B

5) What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants? A) There is considerable genetic variation in garden peas. B) Traits are inherited in discrete units and are not the results of "blending." C) Recessive genes occur more frequently in the F1 generation than do dominant ones. D) Genes are composed of DNA.

Answer: B

10) Mendel's second law of independent assortment has its basis in which of the following events of meiosis I? A) synapsis of homologous chromosomes B) crossing over C) independent alignment of two tetrads in the equator plane at the metaphase D) separation of cells at telophase

Answer: C

15) In the process of carbon fixation, RuBP attaches a CO2 to produce a six-carbon molecule, which is then split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P), what more needs to happen to complete the Calvin cycle? A) addition of a pair of electrons from NADPH B) regeneration of ATP from ADP C) regeneration of RuBP D) regeneration of NADP+

Answer: C

16) In an analysis of the nucleotide composition of DNA, which of the following will be found? A) T = G B) A = C and G = T C) A + C = G + T D) G + C = T + A

Answer: C

22) Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an F2 generation. The results were as follows: 6022 yellow and 2001 green (8023 total). The allele for green seeds has what relationship to the allele for yellow seeds? A) dominant B) linked C) recessive D) unlinked

Answer: C

29) Which of the following occurs in prokaryotes but not in eukaryotes? A) RNA polymerase binds to the promoter B) translation in the absence of a ribosome C) concurrent transcription and translation D) mRNA and tRNA are transcribed

Answer: C

33) What would occur if the repressor of a repressible operon is mutated so that it cannot bind the operator? A) irreversible binding of the repressor to the operator B) complete inhibition of transcription of the operon's genes C) continuous transcription of the operon's genes D) reduced transcription of the operon's genes

Answer: C

7) Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the _____. A) binding of ribosomes to mRNA B) binding of the anticodon to small subunit of the ribosome C) binding of the anticodon to the codon and the attachment of amino acids to tRNAs D) attachment of amino acids to rRNAs

Answer: C

38) Which of the following does not occur in mitosis? A) Chromosomes align at the metaphase plate. B) The spindle apparatus attaches to chromosomes. C) Crossing over between homologous chromosomes D) The nuclear envelope breaks down.

Answer: C.

18) Recombination between linked genes comes about for what reason? A) Nonrecombinant chromosomes break and then rejoin with one another. B) Independent assortment sometimes fails. C) Linked genes travel together at anaphase. D) Crossovers between these genes result in chromosomal exchange.

Answer: D

20) A new DNA strand elongates only in the 5' to 3' direction because _____. A) replication must progress toward the replication fork B) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end C) DNA polymerase begins adding nucleotides at the 5' end of the template D) DNA polymerase can add nucleotides only to the free 3' end

Answer: D

25) Hershey and Chase used a DNA-based virus for their work. What would the results have been if they had used an RNA virus? A) With an RNA virus radioactive protein would have been in the final pellet. B) With an RNA virus the protein shell would have been radioactive in both samples. C) With an RNA virus neither sample would have had a radioactive pellet. D) With an RNA virus radioactive RNA would have been in the final pellet.

Answer: D

28) The genetic code is "degenerate" means that A) A single codon can specify the addition of more than one amino acid. B) Some transfer RNAs (tRNAs) can become attached to different amino acids. C) The genetic code is universal (the same for all organisms). D) More than one codon can specify the addition of the same amino acid.

Answer: D

31) Centromeres of sister chromatids disjoin and chromatids separate. A) Anaphase I B) Telophase I C) Prophase II D) Anaphase II

Answer: D

32) Which of the following is a protein produced by a regulatory gene to control a bacterial operon? A) RNA polymerase B) DNA polymerase C) promoter D) repressor

Answer: D

35) In photosynthesis, which process is most directly driven by light energy? A) creation of a pH gradient by pumping protons across the thylakoid membrane B) carbon fixation in the stroma C) reduction of NADP+ molecules D) removal of electrons from chlorophyll molecules

Answer: D

37) Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? A) No genes interacted to produce the parental phenotype. B) Each allele affected phenotypic expression. C) The traits blended together during fertilization. D) One allele was dominant.

Answer: D

9) Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? A) prophase I of meiosis B) anaphase II of meiosis C) metaphase II of meiosis D) anaphase I of meiosis

Answer: D