MCQ on Genetics and Plant Breeding (Lecturer in Botany Questions)

11. A mating is expected to produce 50% heterozygotes and homozygotes is

a)BB X Bb

b)BB x Bb

c)both a and b

d) bb xbb

Ans: c)both a and b

12. The codons which collectively code for the same amino acid

a) Synonymous codons or Degenerate codons

b) Initiation codons

c) Termination codons

d)Triplet codons

Ans: a) Synonymous codons or Degenerate codons (Refer: Genetic code)

13. How many  triplet codons can be made from the four nucleotides A, U, G na d C containing one or more uracils?
a)27/64
b)17/64
c)37/64
d)47/64
Ans: c)37/64
Uracil represents 1 among 4 nucleotides, the probability that uracil will be the first letter of the codon is 1/4
The probability that U will not be the first letter is 3/4. 

The probability that no of the three letters of the codon are uracils is (3/4)³

The number of codons containing at least one uracil is 1 - (3/4)^{3
1 - (27/64) = 37/64}

Ans: c)37/64

^{14. Given the antisense DNA codon 3'TAC5', the anticodon that pairs with corresponding mRNA codon could be}
a)3'CAT5'
b)5'AUG3'
c)3'UAC5'
d)none of these

Ans: c)3'UAC5' 

15. The highest number in Ophioglossum reticulatum
a)2n=1260
b) 2n=1206
c) 2n=1026
d) 2n=1620

Ans: a)2n=1260 (Refer : Chromosome number)

16. Sewall Wright effect refers to random fluctuations in the gene frequencies in
a)Small population
b) Large population
c) Ecosystem
d) None of these

Ans: a)Small population

17. What is LD 50?

a) Mutagen kills 50% treated materials

b) Mutagen kills 50% un-treated materials

c) Lose of 50% chemicals

d)Low dose of semi mutagen

Ans: a) Mutagen kills 50% treated materials

18.The central Tuber Crops Research Institute located

a) Trivandrum

b)Kasargode

c)Coimbatore

d)Simla

Ans: a) Trivandrum

19. The method of section of plants from population by their Phenotype

a)Mass Selection

b)Pureline Section

c)Clonal section

d)Both a and b

Ans: a)Mass Selection

20. a nodal organisation in India to coordinate all the activities related to plant collection, introduction, documentation and sustainable management of germplasm

a)NBPGR

b)IARI

c)ICRISAT

d)IBPGR

Ans: a)NBPGR