Fundamentals of Molecular Biology and Genetics, Exams of Nursing

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BIOLOGY II PRACTICE EXAM 2 MOCK 81 Questions with

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1. The building block of nucleic acids is a(n) A. None of the answer choices are correct. B. glycerol molecule. C. nucleotide. D. amino acid. - CORRECT ANSWER C. nucleotide.
2. Complementary DNA strands are held together by A. ionic bonds. B. hydrogen bonds. C. covalent bonds. D. phosphodiester bonds. - CORRECT ANSWER B. hydrogen bonds.
3. The enzyme that unwinds and separates the paired DNA strands is A. ATP synthase. B. ligase. C. helicase. D. primase. - CORRECT ANSWER C. helicase.
4. The enzyme that joins Okazaki fragments is A. helicase. B. ligase. C. DNA polymerase. D. primase. - CORRECT ANSWER B. ligase.
5. The enzyme that builds a short complementary piece of RNA at the start of each DNA segment to be replicated is A. ATP synthase. B. DNA polymerase. C. helicase. D. primase. - CORRECT ANSWER D. primase.

6. The enzyme that adds nucleotides along the 5' to 3' along a DNA strand, is A. ATP synthase. B. DNA polymerase. C. ligase. D. primase. - CORRECT ANSWER B. DNA polymerase.
7. Apoptosis is a name for the process of A. mitosis. B. programmed cell death. C. replication. D. programmed cellular reproduction. - CORRECT ANSWER B. programmed cell death.
8. Before any cell divides into two daughter cells, it must first duplicate its A. cytoplasmic contents. B. array of enzymes. C. All of the answer choices are correct. D. entire genome. - CORRECT ANSWER D. entire genome.
9. A nucleosome consists of A. an RNA molecule. B. a stretch of DNA and histones. C. two or more closely related genes. D. a stretch of DNA. - CORRECT ANSWER B. a stretch of DNA and histones.
10. The process by which a sperm cell combines with an egg cell is A. recombination. B. fertilization. C. germination. D. replication. - CORRECT ANSWER B. fertilization.
11. Meiosis is a process used for A. growth of an organism. B. repair of damaged cells. C. production of stem cells. D. production of gametes. - CORRECT ANSWER D. production of gametes.

12. The two main stages of the eukaryote cell cycle, in which the cell spends most of its time and metabolic energy, are A. mitosis and meiosis. B. interphase and mitosis. C. interphase and binary fission. D. mitosis and cytokinesis. - CORRECT ANSWER B. interphase and mitosis.
13. 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. metaphase. C. cytokinesis. D. mitosis. - CORRECT ANSWER C. cytokinesis.
14. The correct sequence for the phases of the cell cycle, starting with a newly divided cell, is A. interphase - binary fission - cytokinesis. B. cytokinesis - replication - interphase - mitosis. C. replication - binary fission - cytokinesis. D. interphase - mitosis - cytokinesis. - CORRECT ANSWER D. interphase - mitosis - cytokinesis.
15. The correct sequence for the phases of mitosis, shown in correct sequence in this diagram, is A. prophase - metaphase - prometaphase - anaphase - telophase. B. interphase - metaphase - anaphase - prophase - telophase. C. interphase - prophase - metaphase - anaphase - telophase. D. prophase - prometaphase - metaphase - anaphase - telophase. - CORRECT ANSWER D. prophase - prometaphase - metaphase - anaphase - telophase.
16. The phase of mitosis in which the centromeres split and sister chromatids are pulled to opposite poles of the cell is A. prometaphase. B. anaphase. C. telophase. D. prophase. - CORRECT ANSWER B. anaphase.

17. The phase of mitosis in which the chromosomes condense and centrosomes move to opposite poles of the cell is A. anaphase. B. prometaphase. C. metaphase. D. prophase. - CORRECT ANSWER D. prophase.
18. The phase of mitosis in which the nuclear envelope reforms is A. prometaphase. B. prophase. C. telophase. D. metaphase. - CORRECT ANSWER C. telophase.
19. The phase of mitosis in which the chromosomes are aligned along the equator of the cell is A. metaphase. B. telophase. C. prophase. D. prometaphase. - CORRECT ANSWER A. metaphase.
20. If one strand of a DNA molecule has the base sequence of 5'-ATGTGCC-3' the complementary strand of DNA will read A. 3'-CGTGTAA-5' B. 3'-ATGTGCC-5' C. 3'-TACACGG-5' D. 3'-UACACGG-5' - CORRECT ANSWER
21. 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'-TCCGGC-5' B. 3'-AGGCCG-5' C. 3'-UCCGGC-5' D. 3'-AGTCCG-5' - CORRECT ANSWER
22. In order for a cell to become cancerous, oncogenes must be ___, or tumor suppressors are ___. A. inactivated; activated

B. activated; activated C. inactivated; inactivated D. activated; inactivated - CORRECT ANSWER D. activated; inactivated

23. In the biology lab, you are shown petri dishes of cheek cell cultures. One set of cells is thin, with individual cells arranged in a single, orderly layer. The other culture shows irregular crowding of cells. The crowding cells are likely cancer cells, showing an absence of A. angiogenesis. B. contact inhibition. C. telomerases. D. oncogenes. - CORRECT ANSWER B. contact inhibition.
24. Sexual reproduction is important to the survival of a species in a changing environment because A. sexual reproduction produces genetically identical individuals. B. sexual reproduction produces genetically variable individuals in the population. C. sexual reproduction requires only one individual to survive and produce germ cells. D. sexual reproduction requires less overall energy expenditure than asexual reproduction. - CORRECT ANSWER B. sexual reproduction produces genetically variable individuals in the population.
25. The human chromosomes that do not determine whether an individual is male or female are A. the X and Y chromosomes. B. called sex chromosomes. C. autosomes. D. not found in pairs. - CORRECT ANSWER C. autosomes.
26. The chromosomal combination for a human male is A. XXX. B. XY. C. XO. D. XX. - CORRECT ANSWER B. XY.
27. The chromosomal combination for a human female is

A. XX.

B. XY.

C. XYY.

D. None of the answer choices are correct. - CORRECT ANSWER A. XX.

28. The process by which homologous chromosomes exchange genetic material A. is independent assortment. B. is random fertilization. C. occurs only during DNA replication. D. is crossing over. - CORRECT ANSWER D. is crossing over.
29. Nondisjunction may cause A. trisomy 21. B. Turner syndrome. C. Klinefelter syndrome D. All of the answer choices are correct. - CORRECT ANSWER D. All of the answer choices are correct.
30. How many of the mother's chromosomes are present in the egg before it is fertilized? A. 4 B. 23 C. 46 D. 1 - CORRECT ANSWER B. 23
31. The movement of a section of DNA from a chromosome to a non-homologous chromosome is an example of A. translocation during meiosis. B. random alignment during mitosis. C. crossing over during meiosis. D. nondisjunction during meiosis. - CORRECT ANSWER A. translocation during meiosis.
32. Which of the following statements is correct about epigenetic mechanisms? a. They occur early in life b. Methylation is an epigenetic mechanism that is associated with methylation of cytosine that is situated next to a guanine

c. Modifications of histones can turn ON or OFF gene expression depending on the type of modifications that occur along the histone tail d. All of the above are correct - CORRECT ANSWER d. All of the above are correct

33. Which of the following diseases are due to a translocation of a piece of a chromosome from one location to another? a. Acute Myelogenous leukemia b. Down Syndrome c. Cri du chat d. Fragile X syndrome - CORRECT ANSWER a. Acute Myelogenous leukemia
34. A three-base sequence (loop) in tRNA that is complementary to a sequence of three bases in mRNA is a(n) a) amino acid attachment site. b) promoter. c) terminator. d) Anticodon - CORRECT ANSWER d) Anticodon
35. The step of translation in which amino acids are added one at a time to the growing polypeptide is a) elongation. b) termination. c) transcription. d) Initiation - CORRECT ANSWER a) elongation.
36. Which one of the following plays a role in transcription? a. DNA helicase b. DNAprimase c. RNA polymerase d. DNA polymerase - CORRECT ANSWER c. RNA polymerase
37. Poly A tail and mRNA cap are added during a. Replication b. Translation c. mRNA processing d. Transcription - CORRECT ANSWER c. mRNA processing

38. The codon is a sequence of nucleotide that belongs to a. DNA b. mRNA c. rRNA d. tRNA - CORRECT ANSWER b. mRNA
39. Which one of the following is not a stop codon? a. AUG b. UAG c. UGA d. UAA - CORRECT ANSWER a. AUG
40. Which of the following statements is correct? a. Translation is efficient since many ribosomes attach to mRNA leading to the formation of one polypeptide b. Translation is efficient since many ribosomes attach to mRNA leading to the formation of many polypeptides c. Transcription is efficient since many ribosomes attach to mRNA leading to the formation of one polypeptide d. Transcription is efficient since many ribosomes attach to mRNA leading to the formation of many polypeptides - CORRECT ANSWER b. Translation is efficient since many ribosomes attach to mRNA leading to the formation of many polypeptides
41. Which of the following statements is/are correct? a. Frameshift mutations affect multiple codons b. Insertion of one nucleotide changes every codon after the insertion c. Substitution of one nucleotide by another can lead to the formation of a different amino acid d. All of the above are correct - CORRECT ANSWER d. All of the above are correct
42. Sickle cell anemia is a disorder that results from a a. Frameshift mutation b. Insertion c. Deletion d. Substitution - CORRECT ANSWER d. Substitution

43. What type of mutation has occurred in the following? Normal allele 5'- GGAAUGAAACAGGAACCC-3' Mutant allele 5' GGAAUGAAAUCAGGAACCC-3' a) substitution b) deletion of one base c) insertion of one base d) insertion of two bases - CORRECT ANSWER c) insertion of one base
44. The 5' and 3' designations used in reference to DNA and RNA sequences are assigned to the a) carbon atoms of deoxyribose and ribose. b) oxygen atoms contained in the deoxyribose and ribose. c) hydrogen atoms that form hydrogen bonds between the nucleotides. d) carbon atoms in the nitrogen base purines and pyrimidines - CORRECT ANSWER a) carbon atoms of deoxyribose and ribose.
45. The DNA sequence 5'-ATCGATCG-3' will pair with which of the following RNA strands? a) 3'-TAGCTAGC-5' b) 3'-AUGCAUGC-5' c) 5'-UAGCUAGC-3' d) 3'-UAGCUAGC-5' - CORRECT ANSWER d) 3'-UAGCUAGC-5'
46. If the DNA in a cell consists of 20% A, it will be ___ G. a) 80% b) 40% c) 20% d) 30% - CORRECT ANSWER d) 30% In terms of some of the classical experiments that examined DNA structure, which of the following isINCORRECTLY paired? A) Chargaff -- DNA bases B) Franklin -- 3D shape of DNA C) Hershey and Chase -- DNA is the genetic material D) Griffith -- DNA is composed of complementary strands - CORRECT ANSWER B) Franklin -- 3D shape of DNA Which of the following correctly lists structures in order from smallest to largest?

A) genome, nucleotide, gene, chromosome B) nucleotide, gene, chromosome, genome C) chromosome, genome, nucleotide, gene D) gene, chromosome, genome, nucleotide - CORRECT ANSWER B) nucleotide, gene, chromosome, genome The process of translation occurs in the ____ and the outcome is ____. A) cytoplasm; a protein B) cytoplasm; a nucleotide C) nucleus; RNA D) nucleus; a protein - CORRECT ANSWER A) cytoplasm; a protein Which of the following is FALSE about RNA? A) it is single stranded B) it has four nucleotide bases C) it has a ribose sugar D) RNA nucleotide base T pairs with A on DNA E) RNA nucleotide C pairs with G on DNA - CORRECT ANSWER D) RNA nucleotide base T pairs with A on DNA What is the end result of a DNA strand with the sequence ATTCGA transcribed and translated? A) TAAGCT B) UAACGU C) a protein D) AUUCGA E) rRNA - CORRECT ANSWER C) a protein What is the role of mRNA? A) encodes a sequence of amino acids B) combines with proteins to form a ribosome C) carries amino acids D) catalyzes protein synthesis - CORRECT ANSWER A) encodes a sequence of amino acids What alterations occur before mRNA leaves the nucleus for translation? A) a 5' cap is added

B) a poly-A tail is added C) introns are removed D) All of the above are correct. - CORRECT ANSWER D) All of the above are correct. Sickle cell anemia is caused by what type of mutation? A) frameshift mutation B) expanding repeat mutation C) substitution mutation D) nonsense mutation - CORRECT ANSWER C) substitution mutation If a strand of DNA is composed of 35% of the base adenine (A), it must also contain ____. A) 35% cytosine (C) B) 65% thymine (T) C) ribose sugar molecules D) 15% guanine (G) E) ATP - CORRECT ANSWER D) 15% guanine (G) The order of nucleotide bases on two sides of a DNA double-helix is ____. A) identical B) similar C) complementary D) unrelated - CORRECT ANSWER C) complementary The full complement of genetic material for an animal is called its ____ and is organized into different____. Each strand of DNA in turn contains many specific ____. A) genome; chromosomes; genes B) nucleotide; genomes; proteins C) chromosome; nucleotides; RNA D) gene; nucleotide bases; chromosomes - CORRECT ANSWER A) genome; chromosomes; genes What differs between DNA and RNA? A) DNA is double stranded vs. RNA is single stranded B) DNA contains nucleotide base T vs. RNA contains nucleotide base U

C) DNA contains deoxyribose sugar vs. RNA contains ribose sugar D) All of the above are correct. - CORRECT ANSWER D) All of the above are correct. What enzyme copies DNA into RNA? A) RNA polymerase B) transcription factors C) DNA polymerase D) terminator - CORRECT ANSWER A) RNA polymerase How do cells regulate gene expression? A) operons of genes, promoter, and operator B) transcription factors C) different combinations of exons from the same mRNA sequence D) All of the above are correct - CORRECT ANSWER D) All of the above are correct What types of mutations are NOT passed to future generations? A) mutations to chromosomes of eggs B) mutations to chromosomes of sperm C) somatic mutations D) germline mutations - CORRECT ANSWER C) somatic mutations An unfertilized egg from a Venezuelan gecko has 16 chromosomes. Thus, the entire ____consists of 32 chromosomes. A) DNA B) genome C) chromatin D) nucleosomes - CORRECT ANSWER B) genome Which of the following reproduce asexually? A) bacteria B) some protists C) archaea D) single-celled organisms E) All of the above are correct. - CORRECT ANSWER E) All of the above are correct.

A mutation in the tumor suppressor gene p53 prevents the protein from functioning normally. What is most likely to occur as a result of this mutation? A) growth and replication of damaged cells B) apoptosis C) normal cells will undergo additional mutation D) growth of cells with repaired DNA4 - CORRECT ANSWER A) growth and replication of damaged cells After a visit to a specialist, Dan was diagnosed with liver cancer. Six months later additional tumors were found in his stomach and small intestine. This is an example of____. A) oncogenes B) contact inhibition C) benign tumors D) metastasis - CORRECT ANSWER D) metastasis A gene that codes for a receptor for a growth factor is mutated. A normally functioning receptor binds with a growth factor and then sends a signal into the cell. However, the abnormal receptor sends a constant signal into the cell whether or not it binds with the growth factor. The gene that codes for the abnormal receptor is ____. A) an oncogene B) a tumor C) benign D) a tumor suppressor gene E) metastatic - CORRECT ANSWER A) an oncogene Webbing of digits (fingers) in humans, or syndactyly, typically occurs during the sixth to eighth weeks of embryonic life. One of every 2000-2500 births have syndactyly and it is more common among Caucasian males. Syndactyly is caused by the failure of what process? A) cell division B) mitosis C) cytokinesis D) apoptosis - CORRECT ANSWER A) cell division

An unfertilized egg from a Venezuelan gecko has 16 chromosomes. Each chromosome consists of chromatin, which is a collection of histone ___ and ____. A) DNA; genome B) proteins; RNA C) proteins; DNA D) RNA; genome - CORRECT ANSWER C) proteins; DNA Which of the following cell cycle stages is INCORRECTLY matched with its process? A) S phase -- DNA replication B) G1 phase -- cell growth C) mitosis -- cell division D) G0 phase -- non-dividing - CORRECT ANSWER C) mitosis -- cell division Homologous chromosomes ____. A)are identical B)are sex chromosomes C)are found in diploid cells D)carry identical genes - CORRECT ANSWER D)carry identical genes An insect has a total number of 16 chromosomes. Thus, its diploid number is ____and the haploid number is ____. A)16; 8 B)8; 16 C)16; 32 D)32; 163 - CORRECT ANSWER A)16; 8 Which of the following is a homologous pair? A)two chromosomes with the same alleles in the same sequence B)two chromosomes with identical alleles C)two chromosomes with the same alleles and different genes D)two chromosomes with the same sequence of genes - CORRECT ANSWER D)two chromosomes with the same sequence of genes Which of the following is TRUE about gametes? A)undergo meiosis B)formed by mitosis C)always have 23 chromosomes

D)fuse to form a diploid zygote - CORRECT ANSWER D)fuse to form a diploid zygote Crossing over occurs _____. A)in the developing zygote B)in gametes prior to fertilization C)during prophase II D)during prophase I - CORRECT ANSWER D)during prophase I The process resulting in an incorrect number of chromosomes is called ____. A)trisomy B)monozygosity C)nondisjunction D)autosomy - CORRECT ANSWER C)nondisjunction Which of the following leads to increased genetic diversity? A) sexual reproduction B) asexual reproduction C) conjugation D) All of the above are correct. E) both (a) and (c) - CORRECT ANSWER A) sexual reproduction During meiosis, a male elk produces ____ sperm from specialized ____ cells in his testes. A) diploid; germ B) identical; haploid C) diploid; haploid D) haploid; germ E) haploid; haploid - CORRECT ANSWER D) haploid; germ ____ divide during meiosis I, while ____ divide in meiosis II. A) Sister chromatids; homologous pairs B) Chromosomes; cytoplasm C) Homologous pairs; sister chromatids D) Autosomes; sex chromosomes - CORRECT ANSWER C) Homologous pairs; sister chromatids

Somatic cells in a goldfish have 92 chromosomes. An egg produced by a female will be____ and have ____ chromosomes. A) haploid; 46 B) diploid; 46 C) a gamete; 92 D) a germ cell; 92 E) diploid; 92 - CORRECT ANSWER A) haploid; 46 What process(es) result(s) in genetic variability? A) mitosis B) DNA replication C) random alignment in meiosis I D) crossing over E) both (c) and (d) - CORRECT ANSWER E) both (c) and (d) Typically, organisms with a missing chromosome are unable to survive. However, humans can survive without ____. A) a sex chromosome B) an autosome C) chromosome 21 D) chromosome 1 - CORRECT ANSWER B) an autosome