NEET Biology Principles of Inheritance and Variation MCQs Set A

Question: Mark the odd one (w.r.t. true breeding line)

• a) Shows expression for few generations only
• b) Shows the stable trait inheritance
• c) Undergone continuous self-pollination
• d) None of these

Answer: Shows expression for few generations only

Question: Which of the following is not a dominant trait in edible pea?

• a) Green seed colour
• b) Green pod
• c) Inflated pod
• d) Axial flower

Answer: Green seed colour

Question: The phenotype of an individual may be affected if the modified allele produces

(a) No enzyme at all
(b) The normal/less efficient enzyme
(c) A non-functional enzyme

• a) (a) and (c) are correct
• b) (b) and (c) are correct
• c) Only (c) is correct
• d) Only (a) is correct

Answer: (a) and (c) are correct

Question: What will be possible blood group in children from the parents with B and AB blood groups?

• a) A, B, AB
• b) B, O
• c) A, B, AB & O
• d) A, O

Answer: A, B, AB

Question: In garden pea, starch is synthesised effectively in

• a) Homozygous round seeded plants
• b) Pure and hybrid round seeded plants
• c) Heterozygous round seeded plants
• d) Wrinkled seeded plants

Answer: Homozygous round seeded plants

Question: F₁ progeny of Mendelian dihybrid cross produces

• a) Four genotypes of gametes
• b) Two types of eggs
• c) Four types of pollens only
• d) Two types of pollen grains

Answer: Four genotypes of gametes

Question:

• a) 3 : 1 ratio
• b) 10 : 6 ratio
• c) 3 : 3 ratio
• d) 9 : 1 ratio

Answer: 3 : 1 ratio

Question: Mendel published his work on inheritance of characters in 1865 but it remained unrecognised till 1900 because

(a) He could not provide any physical proof for the existence of factors
(b) His concept of factors as stable, discrete units that controlled the expression of traits did not find acceptance from the contemporaries
(c) Mendel's approach of using mathematics to explain biological phenomena was totally old
(d) Communication was not easy (as it is now)

• a) (a), (b) & (d) are correct
• b) (a), (b) & (c) are correct
• c) (c) & (d) are correct
• d) Only (a) is correct

Answer: (a), (b) & (d) are correct

Question: Which of the following statement for chromosomal theory of inheritance is incorrect?

• a) Pairing and separation of a pair of chromosomes would lead to the segregation of a factor they carried
• b) Behaviour of chromosomes is parallel to the behaviour of genes
• c) The two alleles of a gene pair are located on homologous sites on homologous chromosomes
• d) Chromosomes as well as genes occur in pairs

Answer: Pairing and separation of a pair of chromosomes would lead to the segregation of a factor they carried

Question: Experimental verification of the chromosomal theory of inheritance was given by

• a) T.H. Morgan
• b) Tschermak
• c) Correns
• d) Sutton and Boveri

Answer: T.H. Morgan

Question: Fruit flies are one of the best materials for genetic studies because of all, except

• a) Presence of few externally visible and identifiable contrasting traits
• b) Production of a large number of progeny in each mating
• c) Short life span
• d) Ability to grow on simple synthetic medium in the laboratory

Answer: Presence of few externally visible and identifiable contrasting traits

Question: Generation of non-parental gene combinations is termed as

• a) Recombination
• b) Aneuploidy
• c) Polyploidy
• d) Linkage

Answer: Recombination

Question: Initial clue about the genetic/chromosomal mechanism of sex-determination can be traced back to some of the experiments carried out in

• a) Insects
• b) Plants
• c) Birds
• d) Human beings

Answer: Insects

Question: In which of the sex determination both male and female have same number of chromosomes?

• a) XY type
• b) ZO type
• c) XO type
• d) None of these

Answer: XY type

Question: Two different types of gametes in terms of the sex chromosomes, are produced by

• a) Female birds
• b) Male butterfly
• c) Female fruit fly
• d) Male human and female Drosophila

Answer: Female birds

Question: Individuals having homomorphic sex chromosomes produce

• a) One type of gametes
• b) Two type of gametes
• c) Only one gamete in complete life span
• d) No gametes

Answer: One type of gametes

Question: Which of the following phenomena leads to variation in DNA?

• a) Mutation, recombination
• b) Linkage, mutation
• c) Recombination, linkage
• d) Aneuploidy, linkage

Answer: Mutation, recombination

Question: Sickle cell-anaemia disorder arises due to

• a) Substitution in a single base of DNA
• b) Duplication in a base pair of RNA
• c) Duplication of a segment of DNA
• d) Deletion of a segment of DNA

Answer: Substitution in a single base of DNA

Question: In pedigree analysis, symbol given for sex unspecified is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Cystic fibrosis, Myotonic dystrophy and Thalassemia are

• a) Mendelian disorders
• b) Chromosomal disorders
• c) Autosomal dominant disorders
• d) Autosomal recessive disorders

Answer: Mendelian disorders

Question: Which of the following trait shows transmission from carrier female to male progeny?

• a) X-linked recessive
• b) Y-linked recessive
• c) X-linked dominant
• d) Autosomal dominant

Answer: X-linked recessive

Question: Phenylketonuria is an inborn error of metabolism that is inherited as

• a) Autosomal recessive trait
• b)  X-linked recessive trait
• c) Sex-linked dominant trait
• d) Autosomal dominant trait

Answer: Autosomal recessive trait

Question: Which of the following abnormalities is due to autosomal dominant mutation?

• a) Myotonic dystrophy
• b) Haemophilia
• c) Thalassemia
• d) Colour blindness

Answer: Myotonic dystrophy

Question: Absence or excess or abnormal arrangement of one or more chromosomes results in

• a) Chromosomal disorders
• b) Gene mutation
• c) Point mutation
• d) Mendelian disorders

Answer: Chromosomal disorders

Question:  Mark the odd one w.r.t. syndrome which occur due to failure of segregation of homologous pair of chromosomes during cell division cycle.

• a) Thalassemia
• b) Turner's syndrome
• c) Down's syndrome
• d) Klinefelter's syndrome

Answer: Thalassemia

Question: Heterozygous round and yellow seeded pea plants were selfed and total 800 seeds are collected. What is the total number of seeds with first dominant and second recessive traits?

• a) 150
• b) 200
• c) 300
• d) 950

Answer: 150

Question:

• a) Down's syndrome
• b) Myotonic dystrophy
• c) Cystic fibrosis
• d) Turner's syndrome

Answer: Down's syndrome

Question: Mark the correct match

• a) Klinefelter's syndrome - 44 + XXY
• b) Turner's syndrome - 45 + XO
• c) Phenylketonuria - 44 + XYY
• d) Thalassemia - 44 + YO

Answer: Klinefelter's syndrome - 44 + XXY

Question: Physical, psychomotor and mental development is retarted in an individual affected with

• a) Down's syndrome
• b) Sickle cell-anaemia
• c) Turner's syndrome
• d) Colour blindness

Answer:  Down's syndrome

Question: In which of the following disorder's affected individual's possess 47 chromosomes?

• a) Both
• b) Klinefelter's syndrome
• c) Down's syndrome
• d) None of these

Answer: Both

More Questions..............................

Question: The affected individuals are short statured in disorders like

• a) Down's syndrome, Turner's syndrome
• b) Turner's syndrome, Klinefelter's syndrome
• c) Turner's syndrome, phenylketonuria
• d) Klinefelter's syndrome, Down's syndrome

Answer: Down's syndrome, Turner's syndrome

Question: In which of the following disorder gynaecomastia symptom is seen in individuals?

• a) Klinefelter's syndrome
• b) Phenylketonuria
• c) Turner's syndrome
• d) Down's syndrome

Answer: Klinefelter's syndrome

Question: Mark the correct option (w.r.t. monosomy)

• a) Turner's syndrome
• b) Haemophilia
• c) Down's syndrome
• d) Klinefelter's syndrome

Answer: Turner's syndrome

Question: Allosomic trisomy condition is seen in

• a) Klinefelter's syndrome
• b) Down's syndrome
• c) Haemophilia
• d) Klinefelter's syndrome

Answer:  Klinefelter's syndrome

Question: Allosomic trisomy condition is seen in

• a) Klinefelter's syndrome
• b) Down's syndrome
• c) Turner's syndrome
• d) None of these

Answer: Klinefelter's syndrome

Question: Which of the following disorder is seen in human female only?

• a) Turner's syndrome
• b) Down's syndrome
• c) Klinefelter's syndrome
• d) Haemophilia

Answer: Turner's syndrome

Question: When a pink flowered Antirrhinum plant is test crossed, then phenotypic ratio in resulting progenies is

• a) 1 Pink : 1 White
• b) 2 Pink : 1 White
• c) 3 Red : 1 White
• d) 1 Red : 1 White

Answer:  1 Pink : 1 White

Question: Heterozygous tall and violet flowered pea plants were selfed and total 512 seeds are collected. What will be total number of seeds for both heterozygous traits?

• a) 128
• b) 256
• c) 384
• d) 64

Answer: 128

Question: Mark the odd one (w.r.t. F₂ generation of Mendelian dihybrid cross)

• a) Frequency of ttRr genotype = 25%
• b) Frequency of ttrr genotype = 6.25%
• c) Frequency of TtRR genotype = 12.5%
• d) Frequency of TTRR genotype = 6.25%

Answer: Frequency of ttRr genotype = 25%

Question:

• a) (a) & (b) only
• b) (b) & (c) only
• c) (b) & (d) only
• d) (c) & (d) only

Answer: (a) & (b) only

Question:  ___(A)___ used the frequency of recombination between gene pairs on the ___(B)___ as a measure of the distance between genes and mapped their position on the chromosome.

• a)

  

  

• b)

  

  

• c)

  

  

• d) None of these

Answer:

Question: While solving the problem of sex determination in large number of insects, it was observed that

• a) Some of the sperms bear the X-chromosome
• b) All eggs lack sex chromosome
• c) All eggs as well as sperms bear the X-chromosome
• d) Some of the eggs bear the X-chromosome

Answer: Some of the sperms bear the X-chromosome

Question: Loss or gain of a segment of DNA results in

• a) Chromosomal aberration
• b) Point mutation
• c) Frame-shift muation
• d) Polyploidy

Answer: Chromosomal aberration

Question:  Which one of the following is a physical factor that induce mutation?

• a) UV-rays
• b) Base analogue
• c) Acridines
• d) HNO₂

Answer:  UV-rays

Question:

• a) It can be recessive or dominant both
• b) Codominant
• c) Recessive
• d) Dominant

Answer: It can be recessive or dominant both

Question: In which of the following disorder a single protein that is a part of the cascade of proteins involved in blood clotting is affected?

• a) Haemophilia
• b) Phenylketonuria
• c) Sickle-cell anaemia
• d) Thalassemia

Answer: Haemophilia

Question: Mark the correct statement (w.r.t. sickle cell-anaemia)

• a) Heterozygous individuals exhibit sickle-cell trait
• b) Homozygous individuals for HbS are apparently unaffected
• c) Heterozygous individuals are affected as well as carrier
• d) Homozygous individuals for Hb^A show the diseased phenotype

Answer:  Heterozygous individuals exhibit sickle-cell trait

Question: The defect sickle-cell anaemia is caused by the ______ of glutamic acid by valine at the 6th position of the ______ globin chain of the haemoglobin molecule.

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A Y-linked gene is responsible for hypertrichosis (long hair on ears). When an affected man marries a normal woman, what percentage of their daughters would be expected to have hairy ears?

• a) 0%
• b) 25%
• c) 50%
• d) 100%

Answer: 0%

Question: A normal woman, whose father had colour blindness, married a normal man. What is the chance of occurrence of colour blindness in the progeny?

• a) 25%
• b) 50%
• c) 100%
• d) 75%

Answer: 25%

Question: Mr. Stevan is suffering from haemophilia and cystic fibrosis. His father is hetrozygous for cystic fibrosis. The probability of Stevan's sperm having recessive X-linked as well as autosomal allele is

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Select incorrect one (w.r.t. reciprocal cross)

• a) It is made to eliminate the effect of nuclear traits
• b) To know whether the alleles are present on sex chromosomes or autosomes
• c) Two individuals with contrast genotypes are involved
• d) Results are not changed for autosomal traits

Answer: It is made to eliminate the effect of nuclear traits

Question: The chromosome maps are not accurate maps because

• a) Crossing over frequency is higher than recombination frequency
• b) One crossing over interferes and increases the frequency of nearby crossing over
• c) Crossing over frequency decreases towards the ends of chromosome
• d) Heterochromation increases crossing over

Answer: Crossing over frequency is higher than recombination frequency

Question: In Lathyrus odoratus, hybrid blue flowered and long pollen plant is test crossed with homozygous recessive red flowered and round pollen plant then how many parental types are obtained when genes are present in cis stage in parents?

• a) 87.4%
• b) 12.6%
• c) 43.7%
• d) 50%

Answer:  87.4%

Question: Find out the frequency of AabbCcDdee if parents are AabbCCddEe and AabbccDdee

• a) 12.5%
• b) 0.78%
• c) 25%
• d) 50%

Answer: 12.5%

Question: In incomplete dominance

• a) Two dominant alleles are needed to express the complete dominant trait
• b) Phenotypic and genotypic ratio are different
• c) Dominant trait is completely expressed in F₁ generation
• d) F₁ individuals have the equal traits of both parents

Answer: Two dominant alleles are needed to express the complete dominant trait

Question: Progeny with blood group ‘O’ can not be obtained in cross

• a) O×AB
• b) B×B
• c) A×B
• d) A×A

Answer: O×AB

Question: If a agouti mice (CcAa) is crossed with albino mice (ccAA), then how many albino mice are produced in resulting progeny?

• a) 2
• b) 3
• c) 9
• d) 4

Answer:  2

Question:

• a) a(iii), b(iv), c(ii), d(i)
• b) a(i), b(ii), c(iv), d(iii)
• c) a(ii), b(iii), c(iv), d(i)
• d) a(iv), b(iii), c(ii), d(i)

Answer: a(iii), b(iv), c(ii), d(i)

Question: Epistasis and dominance are respectively

• a) Non-allelic, Interallelic
• b) Intragenic, Intergenic
• c) Non-allelic, Extra-allelic
• d) Intergenic, Non-allelic

Answer:  Non-allelic, Interallelic

Question: Which of the following combination seems to have some linkage in character selected by Mendel?

• a) Plant height and pod shape
• b) Flower colour and flower position
• c) Stem height and pod colour
• d) Seed shape and seed colour

Answer: Plant height and pod shape

Question: A diploid organism is heterozygous for five loci and homozygous for 2 loci, how many types of gametes can be produced?

• a) 32
• b) 128
• c) 4
• d) 14

Answer: 32

Question: Lesch Nyhan disease is an X-linked recessive disorder that causes neurological damage in human beings. A survey of 500 mates from a caucasion population revealed that 20 were effected with this disorder. What is the frequency of the normal allele in this population?

• a) 0.8
• b) 0.096
• c) 96
• d) 9.6

Answer: 0.8

Question: How many types of zygotic combinations are possible between a cross Aa BB Cc Dd × AA bb Cc DD?

• a) 16
• b) 64
• c) 128
• d)  32

Answer:  16

Question: In a complimentary gene interaction calculate the number of phenotype and genotype produced in a cross AaBb × aaBB

• a) 2 phenotypes, 4 genotypes
• b) 2 phenotypes, 2 genotypes
• c) 1 phenotype, 2genotypes
• d) 4 phenotypes, 4 genotypes

Answer: 2 phenotypes, 4 genotypes

Question:

• a) (A), (B) & (D)
• b) All of these
• c) (B) & (C)
• d) (A) & (B)

Answer: (A), (B) & (D)

Question: In phenylketonuria

• a) Accumulation of phenylalanine in body
• b) Break down of phenylalanine is rapid
• c) TSD gene situated on chromosome 15 undergoes mutation
• d) Chromosomal constitution of patient changes

Answer: Accumulation of phenylalanine in body

Question:

• a) 2
• b) 4
• c) 1
• d) 8

Answer: 2

Question: If interference is complete or cent percent then the frequency of observed double crossover will be

• a) Zero
• b) Greater than expected frequency
• c) Equal to expected frequency
• d) Lesser than expected frequency

Answer: Zero

Question: In F₂ generation of a Mendelian dihybrid cross (TTRR × ttrr)

• a) More than one option is correct
• b) Recombinant plants are obtained in 1 : 1 frequency
• c) Ratio of parental and non-parental plants is 1 : 15
• d) Tall plants and violet flowered plants are obtained in 1 : 1 frequency

Answer: More than one option is correct