MCQs For NCERT Class 12 Biology Chapter 5 Principles of Inheritance and Variation

Please refer to the MCQ Questions for Class 12 Biology Chapter 5 Principles of Inheritance and Variation with Answers. The following Principles of Inheritance and Variation Class 12 Biology MCQ Questions has been designed based on the latest syllabus and examination pattern for Class 12. Our experts have designed MCQ Questions for Class 12 Biology with Answers for all chapters in your NCERT Class 12 Biology book.

Principles of Inheritance and Variation Class 12 MCQ Questions with Answers

See below Principles of Inheritance and Variation Class 12 Biology MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. Which one from those given below is the period for Mendel’s hybridisation experiments?                           
(a) 1840-1850
(b) 1857-1869
(c) 1870-1877
(d) 1856-1863

Question. In his classic experiments on pea plants, Mendel did not use                                 
(a) seed shape
(b) flower position
(c) seed colour
(d) pod length. 

Question. How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?         
(a) Eight
(b) Seven
(c) Five
(d) Six 

Question. Which one of the following traits of garden pea studied by Mendel was a recessive feature?                       
(a) Axial flower position
(b) Green seed colour
(c) Green pod colour
(d) Round seed shape

Question. The genes controlling the seven pea characters studied by Mendel are now known to be located on how many different chromosomes?                                   
(a) Seven
(b) Six
(c) Five
(d) Four

Question. How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits?                         
(a) 4
(b) 2
(c) 14
(d) 8 

Question. Among the following characters, which one was not considered by Mendel in his experiments on pea?   
(a) Trichomes-Glandular or non-glandular
(b) Seed-Green or yellow
(c) Pod-Inflated or constricted
(d) Stem-Tall or dwarf 

Question. The ability of a gene to have multiple phenotypic effects is known as
a) Pleiotropy
b) Co-dominance
c) Incomplete dominance
d) Incomplete dominance

Question. How many different genotypes are possible from a cross between the parents RR and rr
a) Four
b) One
c) Three
d) Two

Question. Match the following organism with the type of sex determination found in them
Column I                 Column II
A) ZW-ZZ type      M) Grasshopper
B) ZO-ZZ               N) Drosophila
C) XX-XO              O) Hen
D) XX-XY              P) Butterfly
a) A- M, B-P, C- O, D-N
b) A-O, B- N, C-M, D- P
c) A-O, B-P, C-M, D-N
d) A- N, B-P, C-M, D- O

Question. “Father of experimental Genetics”
a) Gregor Mendel
b) T.H.Morgan
c) Hugo deVries
d) Carl Correns

Question. Which is the false statement?
a) Sickle cell anemia is a recessive autosomal disorder
b) Phenylketonuria is a recessive allosomal disorder
c) Haemophilia is a recessive sex linked disorder
d) Colour blindness is a recessive allosome linked disorder

Question. If heterozygous round seeded pea plants are self pollinated, the offsprings will be
a) 75% round
b) 50% heterozygous
c) 25% rr
d) All of these

Question. Turner’s syndrome is
a) XO
b) XXY
c) XXX
d) XYY

Question. Mendel developed his basic principles of heredity by
a) Microscopic study of chromosomes and genes
b) Mathematical analysis of the offspring of Pea plant
c) Breeding experiments with Drosophila
d) Anatomical studies of Pea plant

Question. Erythroblastosis foetalis occurs when
a) Mother is Rh negative and father is Rh positive
b) Father is Rh negative and mother is Rh positive
c) Both are Rh positive
d) Both are Rh negative

Question. When two hybrids are crossed, the percentage of recessive is
a) 25%
b) 100%
c) 50%
d) 75%

Question. Which Mendelian cross can produce two genotypes and two phenotypes?
a) Monohybrid cross
b) Monohybrid test cross
c) Incomplete dominance
d) Co-dominance

Question. Which of the following disorder shows Criss cross inheritance?
a) Haemophilia
b) Colour blindness
c) Erythroblastosis foetalis
d) (a) & (b)

Question. The “cri-du-chat” syndrome is caused by change in chromosome structure involving
a) Deletion
b) Duplication
c) Inversion
d) Translocation

Question. Cinderella of Genetics is
a) Pisum sativum
b) Snapdragon
c) Oenothera
d) Drosophila

Question. Eyes that slant upwards with epicanthus is a characteristic of
a) Klinefelter’s syndrome
b) Turner’s syndrome
c) Down’s syndrome
d) Super female

Question. According to Mendelism, which character shows dominance?                               
(a) Terminal position of flower
(b) Green colour in seed coat
(c) Wrinkled seeds
(d) Green pod colour 

Question. Identify the wrong statement with reference to the gene ‘I’ that controls ABO blood groups.                     
(a) The gene (I) has three alleles.
(b) A person will have only two of the three alleles.
(c) When IA and IB are present together, they express same type of sugar.
(d) Allele i does not produce any sugar.

Question. A gene showing co-dominance has                                                 
(a) alleles that are recessive to each other
(b) both alleles independently expressed in the heterozygote
(c) one allele dominant on the other
(d) alleles tightly linked on the same chromosome.

Question. Alleles are                                                           
(a) different molecular forms of a gene
(b) heterozygotes
(c) different phenotype
(d) true breeding homozygotes. 

Question. Multiple alleles are present                                             
(a) at the same locus of the chromosome
(b) on non-sister chromatids
(c) on different chromosomes
(d) at different loci on the same chromosome.

Question. A man with blood group ‘A’ marries a woman with blood group ‘B’. What are all the possible blood groups of their offspring?                                       
(a) A, B, AB and O
(b) O only
(c) A and B only
(d) A, B and AB only

Question. Which idea is depicted by a cross in which the F₁ generation resembles both the parents?                           
(a) Inheritance of one gene
(b) Co-dominance
(c) Incomplete dominance
(d) Complete dominance

Question. F₂ generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1 : 2 : 1. It represents a case of                                         
(a) co-dominance
(b) dihybrid cross
(c) monohybrid cross with complete dominance
(d) monohybrid cross with incomplete dominance.

Question. A test cross is carried out to                                             
(a) determine the genotype of a plant at F₂
(b) predict whether two traits are linked
(c) assess the number of alleles of a gene
(d) determine whether two species or varieties will breed successfully.

Question. First geneticist/father of genetics was                                           
(a) De Vries
(b) Mendel
(c) Darwin
(d) Morgan.

Question. Which contribute to the success of Mendel?                                             
(a) Qualitative analysis of data
(b) Observation of distinct inherited traits
(c) His knowledge of biology
(d) Consideration of one character at one time   

 Question. Test cross in plants or in Drosophila involves crossing                                   
(a) between two genotypes with recessive trait
(b) between two F₁ hybrids
(c) the F₁ hybrid with a double recessive genotype
(d) between two genotypes with dominant trait.

Question. ABO blood groups in humans are controlled by the gene I. It has three alleles – IA, IB and i. Since there are three different alleles, six different genotypes are possible. How many henotypes can occur?                                 
(a) Three
(b) One
(c) Four
(d) Two

Question. ABO blood grouping is controlled by gene I which has three alleles and show co-dominance. There are six genotypes. How many phenotypes in all are possible?                       
(a) Six
(b) Three
(c) Four
(d) Five

Question. A cross in which an organism showing a dominant phenotype is crossed with the recessive parent in order to know its genotype is called                                 
(a) monohybrid cross
(b) back cross
(c) test cross
(d) dihybrid cross.

Question. In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would ou expect in F₁ generation?                       
(a) 9 : 1
(b) 1 : 3
(c) 3 : 1
(d) 50 : 50 

Question. A common test to find the genotype of a hybrid is by                                           
(a) crossing of one F₂ progeny with female parent
(b) studying the sexual behaviour of F₁ progenies
(c) crossing of one F₁ progeny with male parent
(d) crossing of one F₂ progeny with male parent.

Question. 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. 

Question. The genotype of a plant showing the dominant phenotype can be determined by                                     
(a) test cross
(b) dihybrid cross
(c) pedigree analysis
(d) back cross. 

Question. Which one of the following cannot be explained on the basis of Mendel’s law of dominance?                     
(a) The discrete unit controlling a particular character is called a factor.
(b) Out of one pair of factors one is dominant, and the other recessive.
(c) Alleles do not show any blending and both the characters recover as such in F₂ generation.
(d) Factors occur in pairs. 

Question. Phenotype of an organism is the result of                                         
(a) genotype and environment interactions
(b) mutations and linkages
(c) cytoplasmic effects and nutrition
(d) environmental changes and sexual dimorphism

Question. A gene is said to be dominant if                                         
(a) it expresses its effect only in homozygous state
(b) it expresses its effect only in heterozygous condition
(c) it expresses its effect both in homozygous and heterozygous condition
(d) it never expresses its effect in any condition

Question. When dominant and recessive alleles express itself together it is called                                         
(a) co-dominance
(b) dominance
(c) amphidominance
(d) pseudodominance.

Question. In hybridisation, Tt × tt gives rise to the progeny of ratio                                       
(a) 2 : 1
(b) 1 : 2 : 1
(c) 1 : 1
(d) 1 : 2. 

Question. A child’s blood group is ‘O’. The parent’s blood groups cannot be                                           
(a) A and B
(b) A and A
(c) AB and O
(d) B and O. 

Question. An organism with two identical alleles is                                           
(a) dominant
(b) hybrid
(c) heterozygous
(d) homozygous

Question. A man of A-blood group marries a woman of AB blood group. Which type of progeny would indicate that man is heterozygous A?                                           
(a) AB
(b) A
(c) O
(d) B 

Question. Multiple alleles control inheritance of                                               
(a) phenylketonuria
(b) colour blindness
(c) sickle cell anaemia
(d) blood groups. 

Question. The contrasting pairs of factors in Mendelian crosses are called                                                     
(a) multiple alleles
(b) allelomorphs
(c) alloloci
(d) paramorphs. 

Question. Mendel’s last law is                                         
(a) segregation
(b) dominance
(c) independent assortment
(d) polygenic inheritance. 

Question. Blue eye colour is recessive to brown eye colour. A brown eyed man whose mother was blue eyed marries a blue-eyed woman. The children will be                                       
(a) both blue eyed and brown eyed 1 : 1
(b) all brown eyed
(c) all blue eyed
(d) blue eyed and brown eyed 3 : 1.

Question. RR (Red) Antirrhinum is crossed with white (WW) one. Offspring RW are pink. This is an example of         
(a) dominant-recessive
(b) incomplete dominance
(c) hybrid
(d) supplementary genes. 

Question. tt mates with Tt. What will be characteristic of offspring?                                           
(a) 75% recessive
(b) 50% recessive
(c) 25% recessive
(d) All dominant 

Question. A child of O-group has B-group father. The genotype of father will be                                               
(a) IOIO
(b) IBIB
(c) IAIB
(d) IBIO. 

Question. An allele is dominant if it is expressed in                                             
(a) both homozygous and heterozygous states
(b) second generation
(c) heterozygous combination
(d) homozygous combination. 

Question. ABO blood group system is due to                                         
(a) multifactor inheritance
(b) incomplete dominance
(c) multiple allelism
(d) epistasis. 

Question. 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.

Question. Experimental verification of the chromosomal theory of inheritance was done by                                         
(a) Mendel
(b) Sutton
(c) Boveri
(d) Morgan. 

Question. The mechanism that causes a gene to move from one linkage group to another is called                         
(a) inversion
(b) duplication
(c) translocation
(d) crossing-over.

Question. The term “linkage” was coined by                                       
(a) G. Mendel
(b) W. Sutton
(c) T.H. Morgan
(d) T. Boveri. 

Question. The movement of a gene from one linkage group to another is called                                               
(a) translocation
(b) crossing over
(c) inversion
(d) duplication.

Question. Fruit colour in squash is an example of                                                 
(a) recessive epistasis
(b) dominant epistasis
(c) complementary genes
(d) inhibitory genes.

Question. Which of the following statements is not true of two genes that show 50% recombination frequency?       
(a) The gene show independent assortment.
(b) If the genes are present on the same chromosome, they undergo more than one cross-overs in every meiosis.
(c) The genes may be on different chromosomes.
(d) The genes are tightly linked.