MCQS FOR PRACTICE (INHERITANCE AND VARIATION)

MCQS FOR PRACTICE

CHAPTER 3- INHERITANCE AND VARIATION 

1) Genome represents

a) Haploid chromosomes set

b) Complete chromosome set

c) Diploid chromosome set

d) All the genes present in the population

2) Chromosomes were first seen by

a) Hofmeister b) Strasburger

c) Flemming d) Waldeyer

3) The word chromosome was coined by

a) Benda b) Waldeyer

c) Robert Hooke d) T.H.Morgan

4) An octamer of a 4 histones complexed with DNA forms

a) Endosome b) Nucleosome

c) Mesosome d) Centromere

5) Nucleosome core is made of

a) H1, H2A, H2B and H3

b) H1, H2A, H2B, H4

c) H1, H2A, H2B, H3 and H4

d) H2A, H2B, H3 and H4

6) Haploids are able to express both recessive and dominant alleles/mutations because there are

a) Many alleles for each gene

b) Two alleles for each gene

c) Only one allele for each gene in the individual

d) Only one allele in a gene

7) Allosomes are the name of

a) Sex chromosomes

b) Swellings on the chromosomes

c) Chromosomes other than the ones which determine sex

d) Nucleolus organizing regions of chromosomes

8) In humans, the sex chromosome complement is

a) XX–XY b) XX–XO

c) ZO–ZZ d) ZW–ZZ

9) A family of five daughters only in expecting sixth issue. The chance of its beings a son is

a) Zero b) 25% c) 50% d) 100%

10) In human beings 45 chromosomes/single X/XO abnormality causes

a) Down's syndrome

b) Klinfelter's syndrome

c) Turner's syndrome

d) Edward's syndrome

11) Down's syndrome/mongolism is due to

a) Extra sex chromosome

b) Extra 21st chromosome

c) Extra Y-chromosome

d) Deficient sex chromosome

12) Webbed neck is characteristic of

a) XXX                     b) YY

c) XXY                     d) XO

13) Daughter of a colour blind father and normal mother marries a colour blind person. Colour blindness in the family shall be

a) 50% sons and 50% daughters

b) All sons and daughters

c) All daughters

d) All sons

14) Chromosome number of Down's syndrome/mongolism is

a) 46             b) 47             c) 45             d) 23

15) Sex of a child is due to

a) Size of ovum

b) Health of father

c) Sex chromosome of father/sperm

d) Sex chromosome of mother/ovum.

16) Diploid chromosome number in humans is

a) 46             b) 44             c) 48             d) 42

17) Genes for colour blindness in humans are carried by

a) Mother                         b) Father

c) Both                         d) Abnormal sex

18) Hemophilic man marries a carrier woman. Percentage of daughters becoming hemophiliac shall be

a) 0%                 b) 50%             c) 75%         d) 100%

19) Colour blindness is due to one

a) Recessive allele in females

b) Dominant allele in females

c) Dominant allele in males

d) Recessive allele in males

20) Ovum producing Klinfelter’s syndrome shall have chromosome number

a) 21                 b) 22             c) 23             d) 24

21) Both husband and wife have normal vision though their fathers were colour blind. The probability of their daughter becoming colour blind is

a) 0%                 b) 25%             c) 50%         d)75%

22) Which one is a hereditary disease/Mendelian disorder?

a) Cataract b) Leprosy

c) Blindness d) Phenylketonuria

23) Sex determined in human beings

a) By ovum

b) At time of fertilization

c) 40 days after fertilization

d) Seventh to eight week when genitals differentiate in foetus

24) Hemophilia is more common in males because it is a

a) Recessive character carried by Y-chromosomes

b) Dominant character carried by Y-chromosome

c) Dominant trait carried by X-chromosome

d) Recessive trait carried by X-chromosome

25) Women rarely experience sex-linked defects because they must be

a) Homozygous b) Carrier

c) Heterozygous d) Develop immunity

26) which of the following will be colour blind?

a) XY         b) XCXC         c) XCX         d) XX

27) In humans, sex is determined by

a) Y-chromosome 

b) X-chromosome

c) A and X-chromosomes

d) A and Y-chromosomes

28) Which one of the following is responsible for mental abnormalities in humans?

a) XXX and XY b) XX and XXX

c) XO and XXX d) XX and XO

29) The phenomenon of exchange of segments between non sister chromatids/paternal and maternal chromosomes is called

a) Linkage                 b) Recombination

c) Crossing over         d) Segregation

30) Linkage was discovered by

a) Blakeslee 

b) Sutton

c) Muller 

d) Bateson and Punnet

31) Crossing over produces

a) Recombination of linked genes

b) Synapsis of linked genes

c) Expression of recessive genes

d) Linkage of dominant genes

32) A colour blind girl is rare because she will be born only when

a) Her mother and maternal grandfather were colour blind

b) Her father and maternal grandfather were colour blind

c) Her mother is colour blind and father has normal vision

d) Parents have normal vision but grandparents were colour blind

33) Bateson used the terms coupling and repulsion for linkage and crossing over. Name the correct parental or coupling type along with its cross over or repulsion.

a) Coupling AABB, aabb; Repulsion AABB, AAbb.

b) Coupling AAbb, aaBB; Repulsion AaBb, aabb

c) Coupling aaBB, aabb; Repulsion AABB, aaBB.

d) Coupling AABB, aabb; Repulsion AAbb, aaBB

34) A single recessive allele which can express its effect should occur on

a) Any autosome

b) Any chromosome

c) X-chromosome of female

d) X-chromosome of male

35) Mongolism, Patau's syndrome and Edward's syndrome are due to

a) Allosomal abnormalities

b) Autosomal abnormalities

c) Both A and B

d) None of these

36) Down's syndrome is due to

a) Crossing over

b) Linkage

c) Sex-linked inheritance

d) Nondisjunction of chromosomes

37) A colour blind mother and normal father would have

a) Colour blind sons and normal/carrier daughters

b) Colour blind sons and daughters

c) All colour blind

d) All normal