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NEET Biology MCQ
Inheritance And Variation Mcq
Quiz 13
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Q.1
on Q204) what is called pleiotropism ?
0%
a) Phenomenon of multiple effect of a simple gene
0%
b) Phenomenon of multiple effect of multiple genes
0%
c) Phenomenon of multiple effect of multiple alleles
0%
d) all of the above
Explanation
The ability of a gene to have multiple phenotypic effect because it influences a number of characters simultaneously is known as pleiotropy. The gene having a multiple phenotypic effect because of its ability to control expression of a number of characters is called pleiotropic gene. Answer:(a)
Q.2
on Q205) In Bonellia all larva are genetically and cytologically similar. In this worm mole individuals live inthe uterus of female. If a particular larva settle near proboscis of an adult female, it becomes a male individuals. Larva develops free in water it becomes.
0%
a) Male individuals
0%
b) Female individuals
0%
c) Inter Sex
0%
d) Super female
Explanation
Marine worm Bornellia develops into 3 cm long female if its larva settles down in an isolated place. It grows into small (0.3 cm) parasitic male if it comes closer to an already established female. The male enters the body of the female and stays there as a parasite. Answer:(b)
Q.3
on Q206) Klinefelter's syndrome is developed when the chromosome in male is
0%
a) XXY
0%
b) XXXY
0%
c) XXYY
0%
d) All of these
Explanation
Answer:(d)
Q.4
on Q207) A colour-blind man marries the daughter of a colour-blind person. In their progeny
0%
a) none of her daughters are colour-blind
0%
b) all her sons are colour-blind
0%
c) all her daughters are colour-blind
0%
d) half of her sons are colour-blind
Explanation
Answer:(d)
Q.5
on Q208) Which of the following is a recessive trait for a character chosen by Mendel in garden pea?
0%
a) Violet flower colour
0%
b) Yellow pod colour
0%
c) Axial flower position
0%
d) tall stem height
Explanation
Traits
Dominant
Recessive
Plant height
Tall (1.2 – 2.0m)(T)
Dwarf (0.25 – 0.5m) (t)
Flower position
Axillary (A)
Terminal (a)
Pod colour
Green (G) or (Y)
Yellow (g) or (y)
Pod shape
Full or inflated (I) or (C)
Constricted (i) or (c)
Flower colour
Violet (V) or (W)
White (v) or (w)
Seed shape
Round (R) or (W)
Wrinkled (r) or (w)
Seed colour
Yellow (Y) or (G)
Green (y) or (g)
Answer:(b)
Q.6
on Q209) A couple has a daughter. What is the probability that their next child will be a daughter?
0%
a) 0 %
0%
b) 25 %
0%
c) 50 %
0%
d) 100 %
Explanation
Cross between XX and XY chromosomes produces 50% daughter carrying XX chromosomes and 50% son carrying XY chromosomes. Answer:(c)
Q.7
on Q210) A female whose father was colour-blind marries and normal male whose father was also colour-blind. What is the probability that their daughter will be colour-blind?
0%
a) 0 %
0%
b) 25 %
0%
c) 50 %
0%
d) 75 %
Explanation
Answer:(a)
Q.8
on Q211) If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is
0%
a) 0
0%
b) 0.5
0%
c) 0.75
0%
d) 1
Explanation
Answer:(a)
Q.9
on Q212) The incorrect statement with regard to haemophilia is
0%
a) it is a sex-linked disease
0%
b) it is a recessive disease
0%
c) it is a dominant disease
0%
d) a single protein involved in the clotting of blood effected
Explanation
Answer:(c)
Q.10
on Q213) 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 phenotypes can occur?
0%
a) Three
0%
b) One
0%
c) Four
0%
d) Two
Explanation
Answer:(c)
Q.11
on Q214) Which one of the following is the most suitable, medium for culture of Drosophila melanogaster?
0%
a) Moist bread
0%
b) Agar agar
0%
c) Ripe banana
0%
d) Cow dung
Explanation
Answer:(c)
Q.12
on Q215) Which of the following chromosomal disorders is the commonest in the new borns?
0%
a) Edward's syndrome
0%
b) Patio’s syndrome
0%
c) Down's syndrome
0%
d) None of these.
Explanation
Answer:(b)
Q.13
on Q216) The ratio in a dihybrid test cross between two individuals is given by
0%
a) 2:1
0%
b) 1:2:1
0%
c) 3:1
0%
d) 1:1:1:1
Explanation
The ratio of dihybrid test crosss between two individuals is 1 : 1 : 1 : 1. Answer:(d)
Q.14
on Q217) Which of the following is true for a recessive disease in family A and B?
0%
a) In family A, both the parents are homozygous recessive.
0%
b) In family B, both the parents are homozygous dominant
0%
c) In family B, both the parents are heterozygous recessive.
0%
d) In family A, both the parents are heterozygous recessive.
Explanation
Answer:(d)
Q.15
on Q218) A pea plant parent having violet-coloured flowers with unknown genotype was crossed with a plant having white-coloured flowers. In the progeny, 50% were white. The genotypic constitution of the parent having violet-coloured flowers was
0%
a) homozygous
0%
b) merozygous
0%
c) heterozygous
0%
d) Hemizygous
Explanation
50% of progeny expresses recessive trait. This occurs when heterozygous parent is crossed with recessive homozygous parent. Genotype of violet coloured flowers is heterozygous (Vv). Answer:(c)
Q.16
on Q219) For how many years Gregor Mendel conducted hybridisation experiments on garden peas?
0%
a) 5
0%
b) 7
0%
c) 14
0%
d) 34
Explanation
Gregor Mendel, conducted hybridisation experiments on garden peas for seven years (1856-1863) and proposed the laws of inheritance in living organisms Answer:(b)
Q.17
on Q220) What is the cause of variation?
0%
a) Asexual reproduction
0%
b) Amitosis
0%
c) Mitosis
0%
d) Meiosis
Explanation
Answer:(d)
Q.18
on Q221) Mendel’s principle of segregation means that the germ cells always receive:
0%
a) One pair of alleles.
0%
b) One quarter of the alleles.
0%
c) One of the paired alleles.
0%
d) Any pair of alleles.
Explanation
Law of Segregation is based on the fact that the alleles do not show any blending and that both the characters are recovered as such in the F2 generation though one of these is not seen at the F1 stage. Though the parents contain two alleles during gamete formation, the factors or alleles of a pair segregate from each other such that a gamete receives only one of the two factors. Of course, a homozygous parent produces all gametes that are similar while a heterozygous one produces two kinds of gametes each having one allele with equal proportion. Answer:(c)
Q.19
on Q222) Which among the following is an inborn error in metabolism?
0%
a) Phenylketonuria.
0%
b) Sickle cell anaemia.
0%
c) Down’s syndrome.
0%
d) Thalassemia.
Explanation
Answer:(a)
Q.20
on Q223) In a true breeding tall or dwarf pea variety the possible set of allelic pair(s) of genes for height are
0%
a) TT, Tt, tt
0%
b) TT, tt
0%
c) TT
0%
d) tt
Explanation
True breeding plant are homozygous plants. There are two traits homozygous tall (TT) and homozygous dwarf (tt). Answer:(b)
Q.21
on Q241) Phenotypic ratio 3:1 proves
0%
a) Dominance
0%
b) Segregation
0%
c) Crossing over
0%
d) Independent Assortment
Explanation
The law of dominance is used to explain the expression of only one of the parental characters in a monohybrid cross in the F1 and the expression of both in the F2 . It also explains the proportion of 3:1 obtained at the F2 . Answer:(b)
Q.22
on Q224) ABO blood grouping provides an example of (i) co-dominance (ii) Multiple allelism (iii) Incomplete dominance
0%
a) i and iii
0%
b) i and ii
0%
c) ii and iii
0%
d) i, ii and iii
Explanation
Blood type (phenotype)
Genotype
Antigen
Antibodies
A
I
A
I
A
or I
A
I
O
A
b
B
I
B
I
B
or I
B
I
0
B
a
AB
I
A
I
B
Both A and B
Neither a nor b
O
I
O
I
O
Neither A nor B
Both a and b
Inheritance of ABO blood group is an example of dominance, codominance and multiple allele. Co-dominance because In ABO both allele expresses themselves in the organism. Multiple alleles because blood group is determined by combination of three alleles IA, IB and IO or i. Dominance because blood group is determined by antigen types. And IA and IB is codominant over recessive i. Answer:(b)
Q.23
on Q225) What does Blending inheritance refers to?
0%
a) Mixed characters in an offspring
0%
b) Dominant character
0%
c) Recessive character
0%
d) Dominant & recessive character
Explanation
Blending inheritance is an obsolete theory in biology from the 19th century. The theory is that the progeny inherits any characteristic as the average of the parents' values of that characteristic. As an example of this, a crossing of a red flower variety with a white variety of the same species would yield pink-flowered offspring. Answer:(a)
Q.24
on Q226) What will be the ratio of homozygous dominant, homozygous recessive and pure heterozygous traits in F2 generation in pea plant is
0%
a) 1: 1: 8
0%
b) 2: 3: 2
0%
c) 1: 1: 2
0%
d) 2: 2: 6
Explanation
When pure breeding plant with dominant trait and plant with recessive trait is crossed F1 generation is heterozygous expressing dominant trait. When F1 generation is self-crossed, F2 generation. The progeny are Homozygous dominant : Homozygous recessive : heterozygous = 1 : 1 : 2 Answer:(c)
Q.25
on Q227) In a cross between AABB X aabb, the ratio of F2 genotypes between AABB, AaBB, Aabb and aabb would be:
0%
a) 9 : 3 : 3 : 1
0%
b) 2 : 1 : 1 : 2
0%
c) 1 : 2 : 2 : 1
0%
d) 7 : 5 : 3 : 1
Explanation
Gametes
AB
Ab
aB
ab
AB
AABB
AABb
AaBB
AaBb
Ab
AABb
AAbb
AaBb
Aabb
aB
AaBB
AaBb
aaBB
aaBb
ab
AaBb
Aabb
aaBb
aabb
AABB × aabb produces F1 generation AaBb. F1 generation when self-pollinated, produces F2 generation. AaBb × AaBb → AABB : AaBB : Aabb : aabb = 1 : 2 : 2 : 1 Answer:(c)
Q.26
on Q228) Two pure lines of corn have mean cob lengths of 9 and 3 inches respectively. The polygenes involved in this trait all exhibit additive gene action. Crossing these two lines is expected to produce a progeny with mean cob length [in inches] of:
0%
a) 12.0
0%
b) 7.5
0%
c) 6.0
0%
d) 2.75
Explanation
Additive genetic effects occur when two or more genes source a single contribution to the final phenotype. Since both the alleles contribute, the phenotype of hybrid will be intermediate trait. Length of the cob will be average of 9 and 3 inches. The expected length of progeny will be 6 inches. Answer:(c)
Q.27
on Q229) Sickle cell anaemia is a classic example of
0%
a) Point mutation
0%
b) silent mutation
0%
c) Frame shift mutation
0%
d) non sense mutation
Explanation
Answer:(a)
Q.28
on Q230) If a haemophilic female who marries a normal male gives birth to a male child, then what are the chances of boy being normal? (a hypothetical situation but it won’t happen practically)
0%
a) 0%
0%
b) 50 %
0%
c) 25%
0%
d) 75%
Explanation
Answer:(a)
Q.29
on Q231) Sickle cell anaemia is caused by
0%
a) Substitution of valine by glutamic acid at 6th position in the polypeptide.
0%
b) Substitution of valine by glycine at 4th position in the polypeptide.
0%
c) Substitution of glutamic acid by valine at 4th position in the polypeptide.
0%
d) Substitution of glutamic acid by valine at 6th position in the polypeptide.
Explanation
Answer:(d)
Q.30
on Q232) What is the characteristic feature of haplodiploid sex determination?
0%
a) Males produce sperms by mitosis
0%
b) Number of sets of chromosomes present in progenies will decide their sex
0%
c) Workers will have diploid set of chromosomes.
0%
d) Drones will have haploid set of chromosome.
Explanation
The sex determination in honey bee is based on the number of sets of chromosomes an individual receives. An offspring formed from the union of a sperm and an egg develops as a female (queen or worker), and an unfertilised egg develops as a male (drone) by means of parthenogenesis. This means that the males have half the number of chromosomes than that of a female. The females are diploid having 32 chromosomes and males are haploid, i.e., having 16 chromosomes. This is called as haplodiploid sex-determination system and has special characteristic features such as the males produce sperms by mitosis they do not have father and thus cannot have sons, but have a grandfather and can have grandsons Answer:(a)
Q.31
on Q233) if two brown eyed people marry each other and each one had one blue eyed parent. What is the proportion of eye colour in their offspring?
0%
a) 3:1
0%
b) 1:4
0%
c) 1:2
0%
d) 2:2
Explanation
Gametes
B
t
B
BB (brown)
Bb (brown)
b
Bb (brown)
bb (blue)
Brown eyes is dominant over blue eyes. Both the individuals have blue eyed parent, thus both the individuals genotype for brown eyes is heterozygous Bb. Bb (brown) × Bb (brown) Brown eyes : blue eyes = 3 : 1 Answer:(a)
Q.32
on Q234) Fruit fly is excellent model of genetics because of: (i) Small life cycle (two weeks). (ii) Can be fed on simple synthetic medium. (iii) Single mating produces large number of progeny. (iv) Clear differentiation of sexes. (v) Many heredity variations can be seen with low power microscopes. Choose the correct options:
0%
a) (i), (ii) and (iii).
0%
b) (iii), (iv) and (v).
0%
c) (i), (iv) and (v).
0%
d) All of these.
Explanation
Answer:(d)
Q.33
on Q235) “Independent pairs segregate independent of each other”: This statement is applicable to the segregation of:
0%
a) Alleles of genes.
0%
b) Chromosome pairs.
0%
c) Alleles of gene and chromosome pairs.
0%
d) Not true regarding both alleles of genes and chromosome pairs.
Explanation
The law of independent assortment states that ‘when two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters’. This applies alleles of gene Answer:(b)
Q.34
on Q236) If Mendel had studied 7 traits using a plant with 12 chromosomes instead of 14, he would have
0%
a) Discovered incomplete dominance
0%
b) Not discovered the law of independent assortment
0%
c) Discovered sex linkage
0%
d) Mapped the chromosomes
Explanation
Answer:(b)
Q.35
on Q237) Match the human genetic disorders with the causative abnormal chromosomes.
List I
List II
A. Sickle cell anaemia
Sex linked (X chromosome)
B. Colour blindness
Autosomal chromosome 7
C. Phenylketonuria
Autosomal chromosome 11
D. Cystic fibrosis
Autosomal chromosome 4
E. Huntington's disease
Autosomal chromosome 12
0%
a) A- 3, B- 5, C- 1, D- 2, E- 4.
0%
b) A- 5, B- 1, C- 2, D- 3, E- 5
0%
c) A- 4, B- 1, C- 5, D- 2, E- 3
0%
d) A- 3, B- 1, C- 5, D- 2, E- 4
Explanation
Answer:(d)
Q.36
on Q238) In a plant, gene X is responsible for flower colour, Y for plant height and Z for fruit shape. Recombination frequency of tall plant with white flower is 15% and tall plant with wrinkled fruit is 27% and white flower with wrinkled fruit is 12%. Then how is the arrangement of these genes on the chromosome?
0%
a) XYZ.
0%
b) XZY.
0%
c) YXZ.
0%
d) YZX.
Explanation
Answer:(c)
Q.37
on Q239) If an organism having the chromosome number 2n = 36; the number of chromosome in triploidy, trisomy, monosomy, Tetrasomy, Nullisomy will be:
0%
a) 54, 37, 35, 38, 34.
0%
b) 36, 37, 35, 38, 34.
0%
c) 54, 37, 34, 39, 36.
0%
d) 36, 37, 34, 39, 36.
Explanation
The inheritance of flower colour in the dog flower (snapdragon or Antirrhinum sp.), Mirabilis jalapa (four o’clock flower) is a good example to understand incomplete dominance. Answer:(a)
Q.38
on Q240) The chromosome arrangement in diploid cell is AABBCCDD. It has undergone numerical change in such a way that AABCCCCDD, it can be numerically represented as:
0%
a) 2n + 1 + 2.
0%
b) 2n – 1 + 2.
0%
c) 2n + 2 – 1.
0%
d) 2n – 1 + 1.
Explanation
Answer:(b)
Q.39
on Q242) In a plant, gene "T" is responsible for tallness and its recessive allele "t" for dwarfness and "R" is reponsible for red colour flower and its recessive allele "r" of white flower colour. A tall and red flowered plant with genotype TtRr crossed with dwarf and red flowered ttRr. What is the percentage of dwarf - white flowered offspring of above cross ?
0%
a) 50%
0%
b) 6.25%
0%
c) 12.5 %
0%
d) 50 %
Explanation
Gametes
TR
Tr
tR
tr
tR
TtRR (tall, red flower)
TtRr (tall, red flower)
ttRR (dwarf, red flower)
ttRr (dwarf, red flower)
tr
TtRr (tall, red flower)
Ttrr (tall, white flower)
ttRr (dwarf, red flower)
ttrr (dwarf, white flower)
TtRr (tall, red flower) × ttRr (dwarf, red flower) Dwarf, white flowered offspring = 1/8 = 12.5% Answer:(c)
Q.40
on Q243) Segregation of genes take place during which phase of cell division ?
0%
a) Metaphase
0%
b) Anaphase
0%
c) prophase
0%
d) Embryo formation
Explanation
Answer:(b)
Q.41
on Q244) In humans , height shows a lot of variation . It is an example of
0%
a) Multiple alleles
0%
b) Pleiotropic inheritance
0%
c) polygenic inheritance
0%
d) False allelic inheritance
Explanation
Skin colour, human height and eye colour show polygenic inheritance Answer:(c)
Q.42
on Q245) In a plant, red fruit (R) dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTT genotype is crossed with a plant that is rrtt. Then
0%
a) 25% will be tall with red fruit
0%
b) 50% will be tall with red fruit
0%
c) 75% will be tall with red fruit
0%
d) All of the offspring will be tall with red fruits
Explanation
This is an example of dihybrid cross. When homozygous dominant of two genes (RRTT) is crossed with homozygous recessive (rrtt), progeny expresses dominant traits with heterozygous genotype RrTt. Red fruit and tallness is dominant trait. Thus all the offsprings will be tall with red fruits. Answer:(d)
Q.43
on Q246) State the mutant gene Which converts the male flowers into female flowers In Maize plant
0%
a) TA TA
0%
b) ta ta
0%
c) TA Ta
0%
d) Both (A) & (C)
Explanation
In sex chromosomes are absent. It possess separate genes for development of tassel (male inflorescence) and cob (female inflorescence). If the plant is homozygous for gene ta, that is ta ta and there is mutation in the same gene, it will convert the male flower into female flower. Answer:(b)
Q.44
on Q247) "Large thick and Swollen tongue and droping lips"----- are the symptoms of which genetical disorder
0%
a) Autosomal aneuploidy
0%
b) Trisomy of 21st chromosome
0%
c) Down’s syndrome
0%
d) Total number of chromosomes become 47
Explanation
Answer:(c)
Q.45
on Q248) What does the diagram represent ?
0%
a) synapsis Zygotene
0%
b) crossing over, Diplotene
0%
c) Tetrad, Pachytene
0%
d) Terminalization, Diakinesis
Explanation
Answer:(b)
Q.46
on Q249) Asserton (A) :- Alkaptonuria is not an inborn error in metabolism Reason (R) It is caused by crossing over.
0%
a) If both (A) and (R) are true and (R) is the correct explanation of (A)
0%
b) If both (A) and (R) are true but (R) is not the correct explanation of (A)
0%
c) If (A) is true but (R) is false
0%
d) If both (A) and (R) are false.
Explanation
Answer:(d)
Q.47
on Q250) A woman with normal vision, but whose father was colourblind, marries a colourblind man. Suppose that the fourth child of this couple was a boy. This boy
0%
a) May be colourblind or may be of normal vision
0%
b) Must be colourblind
0%
c) Must have normal colour vision
0%
d) Will be partially colourblind since he is heterozygous for the colourblind mutant allele.
Explanation
Answer:(a)
Q.48
on Q251) What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
0%
a) There is considerable genetic variation in garden peas.
0%
b) Traits are inherited in discrete units, and are not the results of ʺblending.ʺ
0%
c) Genes are composed of DNA.
0%
d) An organism that is homozygous for many recessive traits is at a disadvantage.
Explanation
Law of Dominance (i) Characters are controlled by discrete units called factors. (ii) Factors occur in pairs. (iii) In a dissimilar pair of factors one member of the pair dominates (dominant) the other (recessive). This law is based on the fact that the alleles do not show any blending and that both the characters are recovered as such in the F2 generation though one of these is not seen at the F1 stage Answer:(b)
Q.49
on Q252) Test cross involves .... ...
0%
a) Crossing between two genotypes with dominant trait
0%
b) Crossing between two genotypes with recessive trait
0%
c) Crossing between two F1 hybrids
0%
d) Crossing the F1 hybrid with a double recessive genotype
Explanation
Gametes
T
t
t
Tt (tall)
tt (dwarf)
t
Tt (tall)
tt (dwarf)
Crossing of F1 individual having dominant phenotype with its homozygous recessive parents is called test cross. The test cross is used to determine whether the individuals exhibiting dominant characters are homozygous or heterozygous. Tt × tt Tall : dwarf = 1 : 1 Answer:(d)
Q.50
on Q253) A human male produces sperms with the genotypes AB , Ab , aB , ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?
0%
a) AaBB
0%
b) AABb
0%
c) AABB
0%
d) AaBb
Explanation
Parents contain two alleles during gamete formation, the factors or alleles of a pair segregate from each other such that a gamete receives only one of the two factors. From the genotype of all four sperms, we can conclude that genotype of the person is AaBb. Answer:(d)
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