Genetics PYQs MCQs

Question 1

Correct information flow in eukaryotic cell involving RNA processing is

Accepted Answer

DNA → hnRNA → mRNA → Protein

Answer

DNA → mRNA → Protein

Answer

DNA → Protein → mRNA

Answer

DNA → rRNA → mRNA → Protein

Question 2

Smallest segment of DNA that undergoes mutation is

Accepted Answer

Muton

Answer

Recon

Answer

Cistron

Answer

Gene

Question 3

Which of the following has same genotype and phenotype ratio?

Accepted Answer

Incomplete dominance

Answer

Complete dominance

Answer

Dihybrid cross

Answer

Multiple allelism

Question 4

How many different phenotypes are possible in human ABO blood group system?

Accepted Answer

4

Answer

2

Answer

3

Answer

5

Question 5

Blood group AB, containing both A and B proteins, is an example of

Accepted Answer

Co-dominance

Answer

Incomplete dominance

Answer

Epistasis

Answer

Complete dominance

Question 6

When two genes are very close to each other and tend to inherit together, it is called

Accepted Answer

Complete linkage

Answer

Epistasis

Answer

Crossing over

Answer

Incomplete linkage

Question 7

Sudden heritable change in genetic material that introduces variation is called

Accepted Answer

Mutation

Answer

Polyploidy

Answer

Genetic variation

Answer

Linkage

Question 8

If two pea plants with red flowers of unknown genotype are crossed and 75% red, 25% white flowers are produced, parents are

Accepted Answer

Both heterozygous

Answer

Both homozygous

Answer

Both hemizygous

Answer

One homozygous and another heterozygous

Question 9

Number of gametes that can be obtained from AaBBCc:

Accepted Answer

4

Answer

6

Answer

8

Answer

12

Question 10

A man whose father was colour blind and mother is normal marries a woman who had a colour blind mother and normal father. What percentage of male children of this couple will be colour blind?

Accepted Answer

50%

Answer

25%

Answer

75%

Answer

100%

Question 11

Which of the following doesn't cause variation?

Accepted Answer

Linkage

Answer

Mutation

Answer

Crossing over

Answer

Independent assortment

Question 12

Codon for rRNA is CUA. The anti-codon for tRNA is:

Accepted Answer

GAU

Answer

CUA

Answer

AUC

Answer

GAT

Question 13

If the percentage of A is 30%, what would be the percentage of C?

Accepted Answer

20%

Answer

70%

Answer

50%

Answer

25%

Question 14

Crossing over takes place in:

Accepted Answer

Non-sister chromatids of homologous chromosomes

Answer

Sister chromatids of homologous chromosome

Answer

Sister chromatids of non-homologous chromosomes

Answer

Non-sister chromatids of non-homologous chromosomes

Question 15

Absence of a chromosome from diploid organism:

Accepted Answer

Nullisomy

Answer

Monosomy

Answer

Disomy

Answer

Trisomy

Question 16

Individual having same alleles for a gene is known as:

Accepted Answer

Homozygous

Answer

Heterozygous

Answer

Hemizygous

Answer

Azygous

Question 17

Genetic drift:

Accepted Answer

Occurs in small population

Answer

Occurs in large population

Answer

Occurs in newly formed population

Answer

Occurs in old population

Question 18

DNA is made up of:

Accepted Answer

Nucleoside + phosphate

Answer

Pentose sugar + nitrogen base

Answer

Nucleoside

Answer

Nucleoside + sugar

Question 19

In DNA, if cytosine is 10%, the amount of thymine is:

Accepted Answer

40%

Answer

10%

Answer

20%

Answer

50%

Question 20

Which of the following unwinds DNA molecule?

Accepted Answer

Helicase

Answer

Primase

Answer

Folic acid

Answer

Ligase

Question 21

Cystic fibrosis is:

Accepted Answer

Genetic disorder

Answer

Autoimmune disease

Answer

Communicable disease

Answer

Non-communicable disease

Question 22

A person suffering from sickle cell anemia is:

Accepted Answer

Less prone to malaria

Answer

More prone to typhoid

Answer

More prone to malaria

Answer

Less prone to typhoid

Question 23

The possible blood group of offspring if father has blood group A and mother has blood group B is:

Accepted Answer

A, B, AB, O

Answer

A, AB

Answer

B, AB

Answer

A, B, O

Question 24

A colorblind man marries a normal woman whose father was colorblind. The probability of their son being colorblind is:

Accepted Answer

50%

Answer

25%

Answer

75%

Answer

100%

Question 25

Which of the following has same genotypic and phenotypic ratio?

Accepted Answer

Co-dominance

Answer

Complete dominance

Answer

Epistasis

Answer

Dihybrid cross

Question 26

If the number of chromosomes in Pisum sativum is 2n = 14, then the number of linkage groups is:

Accepted Answer

7

Answer

14

Answer

8

Answer

15

Question 27

All of the following are aneuploidy except:

Accepted Answer

Phenylketonuria

Answer

Turner's syndrome

Answer

Down's syndrome

Answer

Klinefelter's syndrome

Question 28

Chemical causing chromosomal abnormality is called:

Accepted Answer

Mutagen

Answer

Mutation

Answer

Mutant

Answer

Muton

Question 29

If the only person with blood group O-negative in a small population disappears, causing loss of that allele combination from the population, this is an example of:

Accepted Answer

Genetic drift

Answer

Gene pool

Answer

Mutation

Answer

Disaster

Question 30

Study of DNA and RNA is:

Accepted Answer

Molecular biology

Answer

Genetics

Answer

Cytology

Answer

Physiology

Question 31

When radiolabelled C-14 uracil is incorporated into a sample, the molecular component detected is:

Accepted Answer

RNA

Answer

DNA

Answer

Histone

Answer

Nucleotide

Question 32

How many types of gametes are possible from $AaBbDdEE$?

Accepted Answer

8

Answer

2

Answer

16

Answer

4

Question 33

Which cross gives a 1:1 genotypic ratio?

Accepted Answer

Tt × tt

Answer

TT × tt

Answer

Tt × TT

Answer

Tt × Tt

Question 34

If the mother has blood group B with homozygous genotype and the father has blood group A of unknown genotype, possible blood groups of children are:

Accepted Answer

AB and B

Answer

AB and A

Answer

O

Answer

A and B

Question 35

Presence of more than two allelic forms for a single gene is known as:

Accepted Answer

Multiple allelism

Answer

Epistasis

Answer

Pleiotropism

Answer

Blending inheritance

Question 36

Which syndrome is caused by an additional copy of chromosome 18?

Accepted Answer

Edwards syndrome

Answer

Down syndrome

Answer

Patau syndrome

Answer

Klinefelter syndrome

Question 37

Addition of one extra chromosome is called:

Accepted Answer

Trisomy

Answer

Monosomy

Answer

Nullisomy

Answer

Tetrasomy

Question 38

Genetic drift is due to:

Accepted Answer

Random change in allele frequency

Answer

Transfer of alleles from one population to another

Answer

High number of alleles in gene pool

Answer

Gradual change in allele frequency

Question 39

Which is a false statement?

Accepted Answer

tRNA is the largest type of RNA

Answer

mRNA has linear structure with codons

Answer

tRNA contains anticodon

Answer

rRNA helps in protein synthesis

Question 40

Which statement is correct about RNA?

Accepted Answer

One of the bases of DNA is replaced by uracil

Answer

It contains deoxyribose

Answer

It contains adenine paired to thymine

Answer

Its nucleotides contain twice as many phosphate groups as DNA

55Genetics PYQs

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