MCQ Test Chapter # 6 DNA and Chromosomes

No: of Items: 85

Q:1: The term chromosome was coined by German embryologist

(A) Ernest Hackle (B) Walter Fleming

(C) Schwann (D) Schleiden

Q:2: ___________ are DNA threads which appear inside the nucleus at the time of cell division.

(A) Spindle fibers (B) Centrioles

(C) Asters (D) Chromosomes

Q:3: The chromosomes are composed of

(A) DNA (B) Histone proteins

(C) RNA (D) All A, B and C

Q:4: Walter Fleming, stained some cells with ______________, to see how chromosomes would look under the microscope.

(A) Perkin's dye (B) Iodine Dye

(C) Methyl blue Dye (D) All A, B and C

Q:5: What is diploid number of chromosomes in Mosquito.

(A) 4 (B) 6

(C) 8 (D) 12

Q:6: What is diploid number of chromosomes in Sugar cane.

(A) 20 (B) 40

(C) 80 (D) 60

Q:7: What is diploid number of chromosomes in Frog.

(A) 26 (B) 28

(C) 24 (D) 20

Q:8: What is diploid number of chromosomes in Fern.

(A) 1000 (B) 500

(C) 400 (D) 200

Q:9: Which of the following human cells contains 23 chromosomes

(A) Zygote (B) Normal liver cell

(C) Skin cell of female (D) An ovum

Q:10: Sister chromatids are attached at an area called the

(A) Centrosome (B) Centriole

(C) Centromere (D) All of the choices are correct

Q:11: The chromatids of two different chromosomes are called

(A) Sister chromatids (B) Non-sister chromatids

(C) Chromonemata (D) Kinetochore

Q:12: Whose karyotype is shown in following diagram

(A) Human Male (B) Human female

(C) Person with Down syndrome (D) Female with Turners syndrome

Q:13: DNA threads of chromosomes are termed as

(A) Chromonema (B) Plasmodesmata

(C) Chiasmata (D) Kinetochore

Q:14: Centromere contain a disc shaped protein _______________ to which the spindle fibers are attached.

(A) Chiasmata (B) Pellicle

(C) Kinetochore (D) Perkin's Aniline

Q:15: A pair of morphologically similar chromosomes is known as

(A) Homologous chromosomes (B) Heterologous chromosomes

(C) X and Y male chromosomes (D) Both A, and C

Q:16: _________________________ is a non-sex chromosome.

(A) An autosome (B) Desmosome

(C) Y chromosome (D) Both A and B

Q:17: A ______________________ is the characteristic chromosome complement of a eukaryote species.

(A) Biotype (B) Cytotype

(C) Karyotype (D) All of the choices are correct

Q:18: ­­­­_______________ chromosomes have arms of equal length with the centromere in the middle.

(A) Submetacentric (B) Acrocentric

(C) Telocentric (D) Metacentric

Q:19: _______________ chromosomes have short and long arms of unequal length with the centromere more towards one end.

(A) Submetacentric (B) Telocentric

(C) Metacentric (D) All of the choices are correct

Q:20: ___________________ chromosomes have a centromere very near to one end and have very small short arms.

(A) Acrocentric (B) Telocentric

(C) Metacentric (D) Submetacentric

Q:21: The most abundant chromosomal proteins are called

(A) Scaffold (B) Polymerases

(C) Histones (D) None of these

Q:22: Highly condensed and transcriptionally inactive DNA form

(A) Heterochromatin (B) Euchromatin

(C) Autochromatin (D) Isochromatin

Q:23: Which of the following is NOT a characteristic of DNA?

(A) Composed of nucleotides (B) Complementary

(C) Contains ribose (D) Double-stranded

Q:24: If the strand of DNA from a single chromosome were laid out in a straight line, it would be more than

(A) 4 feet (B) 5feet

(C) 5 meters (D) 7 feet

Q:25: The DNA duplex in a chromosome is coiled around a core of 8 histone proteins every 200 nucleotides , forming a complex called

(A) Nucleosome (B) Supercoil

(C) Spireme (D) Kinetochore

Q:26: “Chromosomes play central role in heredity”, it was first suggested in 1900 by

(A) Karl Correns (B) McCarthy

(C) Messelson (D) Joshua Ryan

Q:27: The chromosomal theory of heredity was first formulated by

(A) Karl Correns (B) McCarthy

(C) Messelson (D) Walter Sutton

Q:28: Which chromosome pair below best illustrates the gene-chromosome theory?

(A) 1 (B) 2

(C) 3 (D) 4

Q:29: The result of Hershey and Chase's T2 experiments showed that the _____ of the virus enters the host where viral replication takes place.

(A) Protein (B) DNA

(C) RNA (D) Both Protein and DNA

Q:30: Hershey and Chase used radioactive _____ to label the DNA core of the bacteriophage.

(A) Phosphorous (B) Nitrogen

(C) Carbon (D) Sulfur

Q:31: In Griffith's experiment

(A) Heat-killed S strain bacteria killed the mice

(B) R strain bacteria killed the mice

(C) A mixture of heat-killed S strain bacteria and R strain bacteria failed to kill the mice

(D) Live S strain bacteria killed the mice

Q:32: What are base-pairing rules for DNA?

(A) A=G, T≡C (B) A=C, T≡G

(C) A=U, C≡G (D) A=T, G≡C

Q:33: A DNA strand having the sequence C-G-A-T-T-G would be complementary to the sequence

(A) C-G-A-T-T-G (B) T-A-G-C-C-T

(C) G-G-T-A-A-G (D) G-C-T-A-A-C

Q:34: In the DNA Double Helix, complementary base pairs are held together by

(A) Peptide bonds (B) Ionic bonds

(C) Hydrogen bonds (D) N-glycosidic bonds

Q:35: The three pyrimidine bases in Nucleic acids are

(A) Thymine, Guanine and Cytosine (B) Adenine, Thymine and Guanine

(C) Cytosine, Thymine and Uracil (D) Adenine, Uracil and Guanine

Q:36: Each unit of a nucleic acid consisting of a sugar, attached phosphate group, and base is a

(A) Nucleolus (B) Nucleotide

(C) Nucleosome (D) Histone

Q:37: In a nucleic acid, the bases are always attached to the _______________ carbon of the sugar.

(A) 5' (B) 4'

(C) 3' (D) 1'

Q:38: The structure of DNA was described __________________.

(A) In the 1850's (B) In 1900

(C) In the 1950's (D) In 1990

Q:39: Thymine (T) and cytosine (C) have pyridimine bases which have a ________ ring.

(A) Single (B) Double

(C) Triple (D) Both A and B

Q:40: Willikin’s X-ray diffraction of DNA showed that

(A) Purines have base with a double ring (B) A equals T

(C) DNA not proteins is the genetic material (D) DNA is a helix

Q:41: The rungs of ladder (DNA) are the ___________________.

(A) Deoxyribose sugars (B) Phosphate groups

(C) Hydrogen-bonded bases (D) Ribose sugars

Q:42: The fact that DNA was responsible for the production of bacterial capsules in Griffith's experiments was discovered by

(A) Avery, MacLeod, and McCarthy (B) Noah Alan and Joshua Ryan

(C) Watson and Crick (D) Messelson and Stahl

Q:43: The diameter of DNA molecule is

(A) 20 A° (B) 50 A°

(C) 100 A° (D) 200 A°

Q:44: Sugar-phosphate backbones make up the _______________ of the ladder (DNA).

(A) Anterior rungs (B) Posterior rungs

(C) Uprights (D) Both uprights and rungs

Q:45: DNA replication is best described as ___________________ .

(A) Completely conservative (B) Semiconservative

(C) A very slow process (D) Error free

Q:46: Replication of DNA requires ____________________.

(A) Unwinding (B) Complementary base pairing

(C) Joining (D) All of the above

Q:47: DNA replication is called Semiconservative because _______________ of the original duplex appears in the duplex formed in replication.

(A) None (B) Most

(C) Half (D) Hardly any

Q:48: DNA replication occurs in the

(A) Nucleus (B) Cytoplasm

(C) Extracellular fluid (D) On the ribosome surface

Q:49: ___________________ is an inherited condition that causes urine to turn black when exposed to air.

(A) Alkaptonuria (B) Phenylketonuria

(C) Diabetes insipidus (D) Diuresis

Q:50: In Human beings the ____________ is whole hereditary information that is encoded in the DNA of 22 pairs of autosome and one pair of sex chromosomes.

(A) Muton (B) Intron

(C) Exon (D) Genome

Q:51: A photographic representation of the chromosomes of a single cell including the number, size and structure of the chromosomes in the nucleus of a cell is termed as

(A) Biotype (B) Karyotype

(C) Cytotype (D) All a, b and c

Q:52: Which two scientists proposed the “one gene-one enzyme” hypothesis?

(A) Watson and Crick (B) Beadle and Tatum

(C) Wilkins and Franklin (D) Hershey and Chase

Q:53: Single large shield shaped cotyledon of monocot seed is called

(A) Coleoptile (B) Coleorhiza

(C) Cotyledon (D) Scutellum

Q:54: Since the X-ray treated mold was able to grow on media enriched with metabolites B, C and D of this metabolic pathway:

A ---1---->B ---2----> C ---3----> D

Where the numbers are enzymes and the letters are metabolites, Beadle and Tatum concluded that the mold lacked enzyme _____________.

(A) 1 (B) 2

(C) 3 (D) None of these

Q:55: Fill in the missing portion of this flow diagram:

DNA's nucleotide sequence --> amino acid sequence --> proteins' polypeptides --> _____ --> an organism's structures.

(A) Steroids (B) Enzymes

(C) Polysaccharides (D) RNA

Q:56: There are about ______________ different types of tRNA.

(A) 20 (B) 40

(C) 60 (D) 64

Q:57: The process of gene expression occurs in

(A) Transcription (B) Translation

(C) Both A and B (D) Transduction

Q:58: What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?

(A) RNA processing (B) Gene expression

(C) Transcription (D) Translation

Q:59: What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of mRNA?

(A) Polypeptide formation (B) Gene expression

(C) Transcription (D) Translation

Q:60: RNA polymerase uses --------- as a template to synthesize ---------

(A) RNA, protein (B) RNA, DNA

(C) DNA, RNA (D) DNA, protein

Q:61: The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence ____________ .

(A) CAG (B) CTG

(C) GAC (D) CUG

Q:62: For 20 different kinds of amino acids there should be

(A) 20 codons (B) 44 codons

(C) 64 codons (D) 40 codons

Q:63: The initiation codon for every gene is

(A) AUG (B) UUU

(C) GCT (D) CGC

Q:64: There are 20 amino acids normally used in protein synthesis. Based on your knowledge of the genetic code, if there were 80 amino acids used in protein synthesis, what would be the minimum size of a single codon?

(A) 3 nucleotides (B) 4 nucleotides

(C) 5 nucleotides (D) 8 nucleotides

Q:65: The genetic code uses sequence of ____________ nitrogenous bases to encode an amino acid.

(A) 2 (B) 3

(C) 4 (D) All A. B and C

Q:66: Codon is present in

(A) mRNA (B) tRNA

(C) rRNA (D) All A. B and C

Q:67: The binding of codon and anticodon is known as

(A) Codation (B) Decodation

(C) Transcription (D) All choices are correct

Q:68: Which of the following is stop codon

(A) UAG (B) UAA

(C) UGA (D) All A. B and C

Q:69: A permanent alteration in the DNA of an organism is called a(n)

(A) Mutation (B) Hereditary marker

(C) Replicon (D) Allele

Q:70: What genetic term describes the situation when a part of chromosome is broken off and lost?

(A) Duplication (B) Inversion

(C) Deletion (D) Nondisjunction

Q:71: An exchange of segments between non-homologous chromosomes is called

(A) Inversion (B) Polyploidy

(C) Translocation (D) Transduction

Q:72: What genetic term describes the situation when a part of chromosome may be present in excess to the normal chromosome?

(A) Duplication (B) Inversion

(C) Deletion (D) Nondisjunction

Q:73: Transcription is initiated by an enzyme

(A) DNA-polymerase (B) RNA-polymerase

(C) Endonuclease (D) Exonuclease

Q:74: X-rays and gamma rays are

(A) Non-ionizing radiations (B) Chemical mutagens

(C) High energy mutagens (D) Both B and C

Q:75: Point mutation involves

(A) Deletion of single nitrogenous base

(B) Duplication of single nitrogenous base

(C) Both A and B

(D) None of these

Q:76: If the sequence of two nucleotides is used, then it will only code for ____________ aminoacids.

(A) 8 (B) 16

(C) 44 (D) 64

Q:77: Sickle cell anemia is caused by a change in the amino acid sequence of the two beta chains in the hemoglobin molecule. How many amino acids have been changed in each beta chain, compared to normal hemoglobin?

(A) 1 (B) 5

(C) 10 (D) Hundreds

Q:78: Phenylketonuria is

(A) An eating disorder

(B) A inherited disease that is treated by diet

(C) A neurotransmitter deficiency disease

(D) Caused by an accident after birth

Q:79: __________________ is a chromosome rearrangement in which a segment of a chromosome is reversed end to end.

(A) Duplication (B) Inversion

(C) Deletion (D) Translocation

Q:80: A scientist puts nucleotide chains of UUUUUU in a test tube under conditions allowing protein synthesis. Soon the test tube is full of polypeptide chains composed of only the amino acid phenylalanine. What does this experiment indicate?

(A) The amino acid phenylalanine is composed of uracil.

(B) UUU codes for the amino acid phenylalanine.

(C) Protein synthesis malfunctions in test tubes.

(D) Most proteins contain only one type of amino acid.

Q:81: In the following diagram process A is known as

(A) Transcription (B) Translation

(C) Transduction (D) All a, b and c are correct

Q:82: In the following diagram process B is known as

(A) Transcription (B) Translation

(C) Transduction (D) All a, b and c are correct

Q:83: RNA molecules that carry amino acids to the growing polypeptide is

(A) messenger RNA (B) ribosomal RNA

(C) transfer RNA (D) small nucleolar RNA

Q:84: It occurs in babies who inherit two mutant genes for the enzyme phenylalanine hydroxylase (PAH). This enzyme normally breaks down molecules of the amino acid phenylalanine that are in excess of the body's needs for protein synthesis

(A) Phenylketonuria (B) Alkaptonuria

(C) Both A and B (D) Sickle cell anemia

Q:85: In sickle cell anemia glutamic acid is replaced by

(A) Threonine (B) Leucine

(C) Histidine (D) Valine

Answer Key:

1.B

2.D

3.D

4.A

5.B

6.C

7. A

8.A

9.D

10.C

11.B

12.B

13.A

14.C

15.A

16.A

17.C

18.D

19.A

20.A

21.C

22.A

23.C

24.D

25.A

26.A

27.D

28.D

29.B

30.A

31.D

32.D

33.D

34.C

35.C

36. B

37. D

38. C

39. A

40. D

41. C

42. A

43. A

44. C

45. B

46. D

47. C

48. A

49. A

50. D

51. B

52. B

53. D

54. A

55. D

56. B

57. C

58. D

59. C

60. C

61. D

62. C

63. A

64. B

65. B

66. A

67. B

68. D

69. A

A 70.

C 71.

C 72.

A 73.

B 74.

C 75.

C 76.

B 77.

A 78.

B 79.

B 80.

B 81.

A 82.

B 83.

C 84.

A 85. D