Tumor Biology
1. The DNA threads which appear inside the nucleus at the time of cell
division
a) Spindle fibers
b) Centrioles
c) Asters
d) Chromosomes
2. Which of the following are essential to the condensation of chromo-
somes as cells enter mitosis?
a) Cohesins
b) Condensins
c) Histones
d) Topoisomerases
3. Chromatin is composed of
a) DNA
b) DNA and proteins
c) DNA, RNA and proteins
d) None
4. Which of the following histones bind to linker DNA?
a) H1
b) H2A
c) H2B
d) H3
5. Which of the following has beads on a string structure?
a) Chromosomes
b) Chromatin
c) Nucleosomes
d) Heterochromatin
6. Which of the following histones shows more sequence similarity
among eukaryotic species?
a) H1
b) H2A
c) H2B
d) H3
Leader Page 1
7. The sister chromatids separate at
a) Prophase
b) Metaphase
c) Telophase
d) Anaphase
8. Cellular DNA is uncondensed throughout
a) Prophase
b) Interphase
c) Telophase
d) Anaphase
9. Changes resulting in abnormal structure of one or more chromosomes
are known as
a) Point mutation
b) gene mutation
c) Chromosomal aberrations
d) Substitution mutations
10. Insertion mutation is also known as
a) Somatic mutation
b) Chromosomal mutation
c) Addition mutation
d) Substitution mutation
11.The type of chromosomal aberration which does not change the num-
ber of genes is
a) Deletion
b) Duplication
c) Inversion
d) Translocation
12. Loss or deletion of a single nucleotide pair cause
a) Insertion mutation
a) Addition mutation
b) Deletion mutation
c) Substitution mutation
Leader Page 2
13.Each gene occupies in a chromosome at a particular
a) Locus
b) Allele
c) Sport
d) Cupid
14.Addition of one or more extra nucleotides into a gene results in
a) Insertion mutation
b) Deletion mutation
c) Substitution mutation
d) Chromosomal mutation
15.The point mutations which bring about phenotypic changes in organ-
ism are
a) Substitution mutation
b) Deletion mutation
c) Addition mutation
d) Insertion mutation
16.Formaldehyde, nitrous acid, mustard gas, X-rays and UV rays are called
a) Mutant
b) Mutagens
c) Sports
d) Cupids
17..Large deletions in chromosomes are usually
a) Beneficial
b) Lethal
c) Harmful
d) useful
18.In which of the following types of mutation, chromosome rotates by
180 ̊
a) duplication
b) translocation
c) inversion
d) deletion
Leader Page 3
19.The carriers of genes are
a) Mitochondria
b) Golgi bodies
c) Chromosomes
d) Lysosomes
20.Mutations which occur in somatic or body cells are
a) Point mutation
b) Gene mutation
c) Lethal mutation
d) Somatic mutation
21.A mutation which brings about structural changes in a DNA molecule is
known as
a) Somatic mutation
b) Spontaneous mutation
c) Point mutation
d) Duplication mutation
22.The mutation that can be induced by certain chemical mutagens is
a) Deletion mutation
b) Addition mutation
c) Substitution mutation
d) Somatic mutation
23.Deletion mutations are reported in some
a) Fungi
b) Yeasts
c) Chlamydomonas
d) All the above
24.Non-heritable mutations are
a) Point mutation
b) Gene mutation
c) Lethal mutation
d) Somatic mutation
Leader Page 4
25.Mutations are artificially induced by some agents called
a) Mutants
b) Mutagens
c) Sports
d) Cupids
26.The mutation which alters the phenotype of an organism is
a) Somatic mutation
b) Deletion mutation
c) Substitution mutation
d) Addition mutation
27.Gene mutations are also known as
a) Spontaneous mutation
b) Point mutation
c) Somatic mutations
d) Duplication mutations
28..If the deletion is an intermediate chromosomal segment it is
a) Intercalary
b) Terminal
c) Insertion
d) Substitution
29.Replacement of a Purine base by another Purine base is called
a) Somatic mutation
b) Addition mutation
c) Deletion mutation
d) Substitution mutation
30.Loss of a segment of a chromosome is called
a) Deletion
b) Addition
c) Insertion
d) Substitution
Leader Page 5
31.The genetically significant mutations are
a) Somatic mutation
b) Addition mutation
c) Substitution mutation
d) Deletion mutation
32.The heritable mutations occurring in gametes are
a) Spontaneous mutation
b) Somatic mutations
c) Chromosomal aberrations
d) Lethal mutations
33..In chromosome, rearrangement of genes occur in
a) Deletion
b) Duplication
c) Inversion
d) Translocation
34..Mutations occurring in reproductive cells are called
a) Spontaneous mutation
b) Germinal mutations
c) Somatic mutations
d) Lethal mutations
35..Local phenotypic changes in the organs are produced by
a) Somatic mutation
b) Gene mutation
c) Point mutation
d) Lethal mutation
36..The genes are arranged in linear order in
a) Chlorophyll
b) Mitochondria
c) Golgi bodies
d) Chromosomes
Leader Page 6
37..Insertion is classified under
a) Gene mutation
b) Chromosomal mutation
c) Genomic mutation
d) Somatic mutation
38. X-chromosome inactivation is known as ______________
a) Dominance
b) Epistasis
c) Dosage compensation
d) Complementation
39. The proposal for the concept of X-chromosome inactivation in female
XX-chromosomes was experimentally shown in ___________
a) Drosophila
b) Mice
c) Human
d) Monkey
40.The maternal X-chromosome is inactivated during Dosage compensa-
tion.
a) True
b) False
41.Female mammals are called genetic mosaics.
a) True
b) False
42.The best genetic mosaicism is observed in which of the following?
a) Tobacco
b) Fruitfly
c) Dragonfly
d) Cat
Leader Page 7
43.Barr body is the ___________
a) Active X chromosome
b) Inactive X chromosome
c) Active Y chromosome
d) Inactive Y chromosome
44.What changes occur in the chromosome to make it inactive?
a) Methylation
b) Glycosylation
c) Acetylation
d) Phosphorylation
45.The X-chromosome once inactivated remains inactive throughout the
life in all the cells of the body.
a) True
b) False
46.All genes on the inactivated X chromosome are transcriptionally silent.
a) True
b) False
47.The functional product of the Xist gene is ___________
a) mRNA
b) rRNA
c) RNA devoid of ORF
d) Protein
Leader Page 8
