NCERT MCQ CLASS-12 CHAPTER-5 | BIOLOGY NCERT MCQ | PRICIPLES OF INHERITANCE AND VARIATION | EDUGROWN

In This Post we are  providing Chapter-5 Principles of Inheritance and Variation  NCERT MCQ for Class 12 Biology which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON PRINCIPLES OF INHERITANCE AND VARIATION

Question 1.
If a genetic disease is transferred from a phenotypically normal but carrier female to only some of the male progeny, the disease is
(a) autosomal dominant
(b) autosomal recessive
(c) sex-linked dominant
(d) sex-linked recessive.
Answer:
(d) sex-linked recessive.

Question 2.
In sickle cell anemia glutamic acid is replaced by valine. Which one of the following triplets codes for valine ?
(a) GGG
(b) A AG
(c) G A A
(d) GUG
Answer:
(d) GUG

Question 3.
Person having genotype IA IB would show the blood group as AB. This is because of
(a) pleiotropy
(b) co-dominance
(c) segregation
(d) incomplete dominance.
Answer:
(b) co-dominance

Question 4.
ZZ/ZW type of sex determination is seen in
(a) platypus
(b) snails
(c) cockroach
(d) peacock
Answer:
(d) peacock

Question 5.
A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents ?
(a) TT and Tt
(b) Tt and Tt
(c) TT and TT
(d) Tt and It
Answer:
(b) Tt and Tt

Question 6.
In a dihybrid cross, if you get 9 : 3 : 3 : 1 ratio it denotes that
(a) the alleles of two genes are interacting with each other
(b) it is a multigenic inheritance
(c) it is a case of multiple allelism
(d) the alleles of two genes are segregating independently.
Answer:
(d) the alleles of two genes are segregating independently

Question 7.
Which of the following will not result in variations among siblings ?
(a) Independent assortment of genes
(b) Crossing over
(c) Linkage
(d) Mutation
Answer:
(c) Linkage

Question 8.
Mendel’s Law of independent assortment holds good for genes situated on the
(a) non-homologous chromosomes
(b) homologous chromosomes
(c) extra nuclear genetic element
(d) same chromosome.
Answer:
(b) homologous chromosomes

Question 9.
Occasionally, a single gene may express more than one effect. The phenomenon is called
(a) multiple allelism
(b) mosaicism
(c) pleiotropy
(d) polygeny.
Answer:
(c) pleiotropy

Question 10.
In the F2 generation of a Mendelian dihybrid cross the number of phenotypes and genotypes are
(a) phenotypes – 4; genotypes – 16
(b) phenotypes – 9; genotypes – 4
(c) phenotypes – 4; genotypes – 8
(d) phenotypes – 4; genotypes – 9.
Answer:
(d) phenotypes – 4; genotypes – 9.

Question 11.
The color based contrasting traits in seven contrasting pairs, studied by Mendel in pea plant were
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(c) 3

Question 12.
_________ pairs of contrasting traits were studied by Mendel in pea plant.
(a) 6
(b) 7
(c) 8
(d) 10
Answer:
(b) 7

Question 13.
Which of the following characters was not chosen by Mendel ?
(a) Pod shape
(b) Pod color
(c) Location of flower
(d) Location of pod
Answer:
(d) Location of pod

Question 14.
Genes which code for a pair of contrasting traits are known as
(a) dominant genes
(b) alleles
(c) linked genes
(d) none of these
Answer:
(b) alleles

Question 15.
A recessive allele is expressed in
(a) heterozygous condition only
(b) homozygous condition only
(c) F3 generation
(d) both homozygous and heterozygous conditions.
Answer:
(b) homozygous condition only