Biology MCQ
#5 Biology Class XII- Principles of Inheritance and Variation (NEET, MHTCET) MCQ
1) Which one of the following is an example of polygenic inheritance?
(a) Skin colour in humans.(b) Flower colour in Mirabilis jalapa.(c) Production of male honey bee.(d) Pod hsape in garden pea.
Answer
(a) Skin colour in humans.
2) In Mendel’s experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY × rryy?
(a) Round seeds with yellow cotyledons, and wrinkled seeds with yellow cotyledons.(b) Only round seeds with green cotyledons.(c) Only wrinkled seeds with yellow cotyledons.(d) Only wrinkled seeds with green cotyledons.
Answer
(a) Round seeds with yellow cotyledons, and wrinkled seeds with yellow cotyledons.
3) Test cross involves
(a) crossing between two genotypes with dominant trait(b) crossing between two genotypes with recessive trait(c) crossing between two F1 hybrids(d) crossing the F1 hybrid with a double recessive genotype.
Answer
(d) crossing the F1 hybrid with a double recessive genotype.
4) If a colour blind woman marries a normal visioned man, their sons will be
(a) all colour blind(b) all normal visioned(c) one-half colour blind and one-half normal(d) three-fourths colour blind and one-fourth normal
Answer
(a) all colour blind
5) Inheritance of skin colour in humans is an example on
(a) point mutation(b) polygenic inheritance(c) codominance(d) chromosomal aberration.
Answer
(b) polygenic inheritance
6) Study the pedigree chart given below. What does it show?
(a) Inheritance of a condition like phenylketonuria as an autosomal recessive trait.(b) The pedigree chart is wrong as this is not possible.(c) Inheritance of a recessive sex-linked disease like haemophilia.(d) Inheritance of a sex-linked inborn error of metabolism like phenylketonuria.
Answer
(a) Inheritance of a condition like phenylketonuria as an autosomal recessive trait.
7) All genes located on the same chromosome [NCERT Exemplar]
(a) form different groups depending upon their relative distance(b) form one linkage group(c) will not from any linkage groups(d) form interactive groups that affect the phenotype
Answer
(b) form one linkage group
8) Conditions of a karyotype 2n + 1, 2n – 1 and 2n + 2, 2n – 2 are called [NCERT Exemplar]
(a) aneuploidy(b) polyploidy(c) allopolyploidy(d) monosomy
Answer
(a) aneuploidy
9) Distance between the genes and percentage of recombination shows [NCERT Exemplar]
(a) a direct relationship(b) an inverse relationship(c) a parallel relationship(d) no relationship
Answer
(a) a direct relationship
10) If a genetic disease is transferred from a phenotypically normal but carrier female to only some of the male progeny, the disease is [NCERT Exemplar]
(a) autosomal dominant(b) autosomal recessive(c) sex-linked dominant(d) sex-linked recessive
Answer
(d) sex-linked recessive
11) If a plant heterozygous for tallness is selfed, the F2 generation has both tall and dwarf plants. It proves the principle of
(a) dominance(b) segregation(c) independent assortment(d) incomplete dominance
Answer
(b) segregation
12) In sickle cell anaemia glutamic acid is replaced by valine. Which one of the following triplets codes for valine? [NCERT Exemplar]
(a) G G G(b) A A G(c) G A A(d) G U G
Answer
(d) G U G
13) Person having genotype IA IB would show the blood group as AB. This is because of [NCERT Exemplar]
(a) pleiotropy(b) co-dominance(c) segregation(d) incomplete dominance
Answer
(b) co-dominance
14) Z Z/ZW type of sex determination is seen in [NCERT Exemplar]
(a) platypus(b) snails(c) cockroach(d) peacock
Answer
(d) peacock
15) A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the parents? [NCERT Exemplar]
(a) TT and Tt(b) Tt and Tt(c) TT and TT(d) Tt and tt
Answer
(b) Tt and Tt
16) In a dihybrid cross, if you get 9:3:3:1 ratio it denotes that [NCERT Exemplar]
(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.
17) 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
18) What will never be father’s blood group if the mother has blood group B and child blood group O?
(a) A(b) B(c) AB(d) O
Answer
(c) AB
19) Mendel’s Law of independent assortment holds good for genes situated on the [NCERT Exemplar]
(a) non-homologous chromosomes(b) homologous chromosomes(c) extra nuclear genetic element(d) same chromosome
Answer
(b) homologous chromosomes
20) Occasionally, a single gene may express more than one effect. The phenomenon is called [NCERT Exemplar]
(a) multiple allelism(b) mosaicism(c) pleiotropy(d) polygeny
Answer
(c) pleiotropy
21) In a certain taxon of insects some have 17 chromosomes and the others have 18 chromosomes. The 17 and 18 chromosome bearing organisms are [NCERT Exemplar]
(a) males and females, respectively(b) females and males, respectively(c) all males(d) all females
Answer
(a) males and females, respectively
22) The inheritance pattern of a gene over generations among humans is studied by the pedigree analysis. Character studied in the pedigree analysis is equivalent to [NCERT Exemplar]
(a) quantitative trait(b) Mendelian trait(c) polygenic trait(d) maternal trait
Answer
(b) Mendelian trait
23) It is said that Mendel proposed that the factor controlling any character is discrete and independent. His proposition was based on the [NCERT Exemplar]
(a) results of F3 generation of a cross.(b) observations that the offspring of a cross made between the plants having two contrasting characters shows only one character without any blending.(c) self pollination of F1 offsprings.(d) cross pollination of F1 generation with recessive parent.
Answer
(b) observations that the offspring of a cross made between the plants having two contrasting characters shows only one character without any blending.
24) Which of the following represents a pair of contrasting characters?
(a) Allele (or allelomorphs)(b) Phenotype(c) Homozygous(d) Heterozygous
Answer
(a) Allele (or allelomorphs)
25) Two genes ‘A’ and ‘B’ are linked. In a dihybrid cross involving these two genes, the F1 heterozygote is crossed with homozygous recessive parental type (aa bb). What would be the ratio of offspring in the next generation? [NCERT Exemplar]
(a) 1 : 1 : 1: 1(b) 9 : 3 : 3 : 1(c) 3 : 1(d) 1 : 1
Answer
(d) 1 : 1
26) In the F2 generation of a Mendelian dihybrid cross the number of phenotypes and genotypes are [NCERT Exemplar]
(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
 MCQ){kind=link}