MCQs for Biology Class 12 with Answers Chapter 5 Principles of Inheritance and Variation

Students of class 12 Biology should refer to MCQ Questions Class 12 Biology Principles of Inheritance and Variation with answers provided here which is an important chapter in Class 12 Biology NCERT textbook. These MCQ for Class 12 Biology with Answers have been prepared based on the latest CBSE and NCERT syllabus and examination guidelines for Class 12 Biology. The following MCQs can help you to practice and get better marks in the upcoming class 12 Biology examination

Chapter 5 Principles of Inheritance and Variation MCQ with Answers Class 12 Biology

MCQ Questions Class 12 Biology Principles of Inheritance and Variation provided below have been prepared by expert teachers of grade 12. These objective questions with solutions are expected to come in the upcoming Standard 12 examinations. Learn the below provided MCQ questions to get better marks in examinations.

Question. How many genotype of human blood group are possible in population due to thee alleles
(a) 4
(b) 3
(c) 6
(d) None of these

Answer

C

Question. Blood group is a good example of
(a) Incomplete dominance
(b) Multiple allelism
(c) Four alleles
(d) Reciprocal cross

Answer

B

Question. In a dihybrid cross gametes will have
(a) Two alleles of the same character
(b) One allele only
(c) Four alleles of two characters
(d) Two alleles of two different characters

Answer

D

Question. What is the genotype ratio of dihybrid cross (RRYY × rryy)?
(a) 1 : 2 : 2 : 4 : 1 : 2 : 1 : 2 : 1
(b) 1 : 1 : 1 : 1
(c) 1 : 2 : 1
(d) 9 : 7

Answer

A

Question. In dihybrid cross (RRYY × rryy) the pure dominant species in genotype will be
(a) Two offspring
(b) 9 offspring
(c) 12 offspring
(d) None of the above

Answer

D

Question. For law of independent assortment cross used was
(a) Monohybrid cross
(b) Trihybrid cross
(c) Recombination
(d) Dihybrid cross

Answer

D

Question. How many types of gametes can be formed by a plant with AaBb genotype?
(a) Two
(b) One
(c) Four
(d) Six

Answer

C

Question. Mendel’s work was not recognized because
(a) Communication was not easy at that time
(b) Concept of genes as unit of inheritance was not well established
(c) Chemical nature of genes was not provided by Mendel
(d) All of these

Answer

D

Question. Knowledge about which process helped in better understanding of Mendel’s law in 1900
(a) Cell elongation
(b) Cell division
(c) Cell adhesion
(d) All the above

Answer

B

Question. Movement of chromosome is in parallel to the movement of genes this was observed by
(a) T.H.Morgan
(b) W.Sutton
(c) G.J.Mendel
(d) Hugo de vries

Answer

B

Question. What is not true about germ cells produced during meiosis?
(a) They are haploid
(b) Chromosome segregate dependently on each pair of chromosomes during meiosis
(c) They are four in numbers
(d) During the prosses of meiosis gametes are produced

Answer

B

Question. Chromosomal Theory of inheritance was verified by
(a) Von Tshermak
(b) T.H. Morgan
(c) G.J. Mendel
(d) Carl Correns

Answe

B

Question. Advantages of having D. melanogaster in morgan’s experiment
A. Short life cycle
B. Single mating produces many offspring
C. Sex can be distinguished easily
D. Hereditary variations can be seen by low power
Choose the correct option.
(a) only A, B and D are true
(b) only B, C and D are true
(c) only A,B and C are true
(d) all are true

Answer

D

Question. Morgan performed which type of cross for verification of chromosomal theory of inheritance
(a) Monohybrid cross
(b) Dihybrid cross
(c) Test cross
(d) Trihybrid cross

Answer

B

Question. The deviation in phenotypic ratio in Morgan’s dihybrid cross was attributed to
(a) Aneuploidy
(b) Disease in experimental fruit fly
(c) Mutation
(d) Linkage

Answer

D

Question. 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

Question. Mendel’s rules do not correctly predict patterns of inheritance for tightly linked genes or the inheritance of alleles that show incomplete dominance or epistasis. Does this mean that his hypothesis are incorrect ?
(a) Yes, because they are relevant to only a small number of organisms and traits.
(b) Yes, because not all data support his hypothesis.
(c) No, because he was not aware of meiosis or the chromosome theory of inheritance.
(d) No, it just means that his hypothesis are limited to certain conditions.

Answer

D

Question. 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

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.

Answer

D

Question. Conditions of a karyotype 2n + 1, 2n – 1 and 2n + 2, 2n – 2 are called
(a) aneuploidy
(b) polyploidy
(c) allopolyploidy
(d) monosomy

Answer

A

Question. Distance between the genes and percentage of recombination shows
(a) a direct relationship
(b) an inverse relationship
(c) a parallel relationship
(d) no relationship

Answer

A

Question. 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

Question. In a certain taxon of insects some have 17 chromosomes and the others have 18 chromosomes.
The 17 and 18 chromosome bearing organisms are
(a) males and females, respectively
(b) females and males, respectively
(c) all males (d) all females

Answer

A

Question. In sickle cell anaemia glutamic acid is replaced by valine. Which one of the following triplets codes for valine?
(a) G G G
(b) A A G
(c) G A A
(d) G U G

Answer

D

Question. Multiple alleles are present
(a) at different loci in the same chromosome.
(b) in different chromosomes.
(c) at the same locus in one type of chromosomes.
(d) None of the above

Answer

C

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

Answer

D

Question. 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 tt

Answer

B

Question. 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

Question. In sickle-cell anaemia, shape of RBCs under oxygen tension becomes
(a) biconcave disc like
(b) elongated and curved
(c) circular
(d) spherical

Answer

B

Question. 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

Question. 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
(a) quantitative trait
(b) Mendelian trait
(c) polygenic trait
(d) maternal trait

Answer

B

Question. The F2 generation offspring in a plant showing incomplete dominance, exhibit
(a) variable genotypic and phenotypic ratios.
(b) a genotypic ratio of 1 : 1.
(c) a phenotypic ratio of 3 : 1.
(d) similar phenotypic and genotypic ratios of 1 : 2 : 1.

Answer

D

Question. Which of the following represents a pair of contrasting characters?
(a) Allele (or allelomorphs)
(b) Phenotype
(c) Homozygous
(d) Heterozygous

Answer

A

Question. 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

Question. How would you test a pea plant whether it is a pure or hybrid for tallness ?
(a) Cross the pea plant with another tall pea plant of unknown genotype.
(b) Cross the pea plant with a pure tall pea plant.
(c) Cross the pea plant with a homozygous dwarf pea.
(d) Cross the pea plant with any pea plant.

Answer

C

Question. Inheritance of skin colour in humans is an example on
(a) point mutation
(b) polygenic inheritance
(c) codominance
(d) chromosomal aberration

Answer

B

Question. 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?
(a) 1 : 1 : 1: 1
(b) 9 : 3 : 3 : 1
(c) 3 : 1
(d) 1 : 1

Answer

D

Question. 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

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

Answer

C

Question. Mental retardation in man associated with sex chromosomal abnormality is usually due to
(a) increase in size of X-chromosome.
(b) increase in size of Y-chromosome.
(c) increase in number of Y-chromosome.
(d) increase in number of X-chromosome.

Answer

D

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

Answer

B

Question. Regarding ABO blood group, if one parent is homozygous and other is heterozygous, what are the chances that their child will have ‘O’ blood group?
(a) 25%
(b) 50%
(c) 75%
(d) Zero

Answer

B

Question. The monohybrid genotypic ratio 1 : 2 : 1 in F2 generation indicates
(a) segregation
(b) independent assortment
(c) dominance
(d) incomplete dominance

Answer

A

Question. Punnett square is used to know the
(a) outcome of a cross
(b) probable result of a cross
(c) types of gametes
(d) result of meiosis

Answer

B

Question. The crossing of F1 to homozygous recessive parent is called
(a) back cross
(b) test cross
(c) F1 cross
(d) all of these

Answer

B

Question. The distance between the genes is measured by
(a) angstrom
(b) map unit
(c) Dobson unit
(d) millimetre

Answer

B

Question. All genes located on the same chromosome
(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

Question. Linkage reduces the frequency of
(a) hybrids.
(b) all parental types.
(c) homozygous recessive parents.
(d) heterozygous recessive parents

Answer

A

Question. 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

Question. In a dihybrid cross, F2 phenotypic ratio is 13 : 3. It is case of
(a) complementary genes
(b) epistatic genes
(c) multigenic inheritance
(d) incomplete dominance

Answer

B

Question. Sickle cell anaemia is
(a) caused by substitution of valine by glutamic acid in the beta globin chain of haemoglobin.
(b) caused by a change in a single base pair of DNA.
(c ) characterized by elongated sickle like RBCs with a nucleus.

Answer

B

Question. Extra chromosome ‘X’ is present in which one of the following cases?
(a) Down syndrome
(b) Klinefelter syndrome
(c) Turner syndrome
(d) Bleeder’s disease

Answer

B

Question. The F2 generation of a cross produced identical phenotypic and genotypic ratio. It is not an expected Mendelian result, and can be attributed to
(a) independent assortment
(b) linkage
(c) incomplete dominance
(d) none of the above

Answer

C

Question. The person with Turner’s syndrome has
(a) 45 autosomes and X sex chromosome
(b) 44 autosomes and XYY sex chromosomes
(c) 45 autosomes and XYY sex chromosomes
(d) 44 autosomes and X sex chromosome

Answer

D

Question. 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

Question. In XO type of sex determination
(a) females produce two different types of gametes.
(b) males produce two different types of gametes.
(c) females produce gametes with Y chromosomes.
(d) males produce single type of gametes

Answer

B

Question. 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

Question. Which one of the following conditions correctly describes the manner of determining the sex in the given example?
(a) Homozygous sex chromosomes (ZZ) determine female sex in birds.
(b) XO type of sex chromosomes determine male sex in grasshopper.
(c) XO condition in human as found in Turner’s syndrome, determines female sex.
(d) Homozygous sex chromosomes (XX) produce male in Drosophila.

Answer

B

Question. Which of the following is incorrect regarding ZW-ZZ type of sex determination?
(a) It occcurs in birds and some reptiles
(b) Females are homogametic and males are heterogametic
(c) 1 : 1 sex ratio is produced in the offsprings
(d) All of these

Answer

B

Question. 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

Question. 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

Question. Which of the following statements are the correct?
(i) Failure of segregation of chromatids during cell division results in aneuploidy.
(ii) Chromosomal disorders are mainly determined by alteration or mutation in a single gene.
(iii) Thalasemia and cystic fibrosis are Mendelian disorders.
(iv) Sickle cell anemia is an X-linked trait.
(v) Haemophilia is an autosome linked recessive disease.
(a) (i) and (iii)
(b) (i), (iii) and (iv)
(c) (iii) and (iv)
(d) (ii) and (iii)

Answer

A

Question. In a normal couple, half the sons are haemophilic while half the daughters are carriers. The gene responsible for it is located on
(a) X-chromosome of father.
(b) Y-chromosome of father.
(c) one X-chromosome of mother.
(d) both the X-chromosomes of mother.

Answer

C

Question. Down’s syndrome is caused by an extra copy of chromosome number 21. What precentage of offspring produced by an affected mother and a normal father?
(a) 50%
(b) 25%
(c) 100%
(d) 75%

Answer

A

Question. It is said that Mendel proposed that the factor controlling any character is discrete and independent. His proposition was based on the
(a) results of F3 generation of a cross.
(b) observations that the off spring 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

Question. Two organisms that are true-breeding for a certain genetic characteristic are mated and their offspring were analysed.
Which of the following statements about this situation is correct?
(a) Both parents are homozygotes.
(b) The offspring are either all homozygotes or all heterozygotes.
(c) The offspring represent the F1 generation and the gametes produced by the offspring will carry only one allele for this gene.
(d) All of the above

Answer

D

Question. Which one is an example for chromosomal mutation
(a) Sickle cell anemia
(b) Muscular dystrophy
(c) Phenylketoneuria
(d) Klinefelter’s syndrome

Answer

D

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

Answer

A

Question. Child has blood group “O” and his father is “B” type. Then genotype of the father should be    
(a) IBIB
(b) IBIO
(c) IAIB
(d) IOIO

Answer

B

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

Answer

C

Question. A holandric gene cause hypertrichosis.When a man with hypertrichosis marries a normal women, what percentage of their daughters would be expected to have hypertrichosis?       
(a) 50%
(b) 25%
(c) 75%
(d) 0%

Answer

D

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

Answer

B

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

Answer

A

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

Answer

C

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

Answer

B

Question. Round seed is dominant over wrinkled seeds in Pea. If homozygous, round seeded Pea plants are crossed with wrinkled seeded plants, the offsprings will be         
(a) All round
(b) All wrinkled
(b) 75% round and 25% wrinkled
(d) 50% round and 50% wrinkled

Answer

B

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

Answer

B

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

Answer

A

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

Answer

D

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

Answer

D

Question. A phenomenon of a single gene regulating several phenotypes is called     
(a) Multiple allelism
(b) Pleiotropy
(c) Incomplete dominance
(d) Co-dominance

Answer

B

MCQs-for-Biology-Class-12-with-Answers-Chapter-5-Principles-of-Inheritance-and-Variation.jpg

We hope the above multiple choice questions for Class 12 Biology for Chapter 5 Principles of Inheritance and Variation provided above with answers based on the latest syllabus and examination guidelines issued by CBSE, NCERT and KVS are really useful for you. Principles of Inheritance and Variation is an important chapter in Class 12 as it provides very strong understanding about this topic. Students should go through the answers provided for the MCQs after they have themselves solved the questions. All MCQs have been provided with four options for the students to solve. These questions are really useful for benefit of class 12 students. Please go through these and let us know if you have any feedback in the comments section.

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