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NEET Biology MCQ
Inheritance And Variation Mcq
Quiz 1
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Q.1
The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called ... [ NEET 2021]
0%
a) Net square
0%
b) Bullet square
0%
c) Punch square
0%
d) Punnett square
Explanation
Different combinations of gametes are theoretically represented in a square tabular form known as ‘Punnett Square’. Reference NCERT 12th Biology text book, Page 93, summary Answer : (d)
Q.2
In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased? : ...[NEET 2021]
0%
a) This experiment does not follow the Principle of Dominance.
0%
b) Pink colour in F1 is due to incomplete dominance.
0%
c) Ratio of F2 is 1/4 (Red) : 2/4 (Pink) :1/4(White)
0%
d) Law of Segregation does not apply in this experiment
Explanation
Gamate
Hb
A
Hb
S
Hb
A
Hb
A
Hb
A
Normal
Hb
A
Hb
S
Carrier
Hb
S
Hb
A
Hb
S
Carrier
Hb
S
Hb
S
diseased
Sickle cell anaemia is an autosome linked recessive trait. Homozygous HbS HbS shows diseased phenotype. Hetrozygous HbA HbS are carrier. Female and male both are heterozygous i.e. carrier of disease. Female HbA HbS × Male HbA HbS Progeny that will be diseased = ¼ = 25% Answer : (d)
Q.3
Experimental verification of the chromosomal theory of inheritance was done by ... [ NEET 2020]
0%
a) Boveri
0%
b) Morgan
0%
c) Mendel
0%
d) Sutton
Explanation
Experimental verification of the chromosomal theory of inheritance by Thomas Hunt Morgan and his colleagues, led to discovering the basis for the variation that sexual reproduction produced. Morgan worked with the tiny fruit flies, Drosophila melanogaster Answer : (d)
Q.4
In Antirrhinum (Snapdragon), a red flower was crossed with a white flower and in F1 generation pink flowers were obtained. When pink flowers were selfed, the F2 generation showed white, red and pink flowers. Choose the incorrect statement from the following : ...[NEET 2019]
0%
a) This experiment does not follow the Principle of Dominance.
0%
b) Pink colour in F1 is due to incomplete dominance.
0%
c) Ratio of F2 is 1/4 (Red) : 2/4 (Pink) :1/4(White)
0%
d) Law of Segregation does not apply in this experiment
Explanation
Genes for flower colour in snapdragon shows incomplete dominance which is an exception of Mendel's first principle i.e. Law of dominance. Whereas Law of segregation is universally applicable. When an organism makes gametes, each gamete receives just one gene copy, which is selected randomly. This is known as the law of segregation. Answer : (d)
Q.5
What is the genetic disorder in which an individual has an overall masculine development gynaecomastia, and is sterile ? [NEET 2019]
0%
a) Turner's syndrome
0%
b) Klinefelter's syndrome
0%
c) Edward syndrome
0%
d) Down's syndrome
Explanation
Klinefelter syndrome (47,XXY) results from an additional X chromosome on an XY background; therefore, this condition affects only males. The vast majority of men with Klinefelter syndrome are infertile and can't father a child the usual way. Answer : (b)
Q.6
Select the correct match : [NEET 2018]
0%
a) T.H. Morgan – Transduction
0%
b) F2 × Recessive parent – Dihybrid cross
0%
c) Ribozyme – Nucleic acid
0%
d) G. Mendel – Transformation
Explanation
Answer : (c)
Q.7
Select the correct match ... [NEET 2021]
0%
a) Sickle cell anaemia – Autosomal recessive trait, chromosome-11
0%
b) Thalassemia – X linked
0%
c) Haemophilia – Y linked
0%
d) Phenylketonuria – Autosomal dominant trait
Explanation
Sickle-cell anaemia : This is an autosome linked recessive trait that can be transmitted from parents to the offspring when both the partners are carrier for the gene (or heterozygous). Sickle cell disease is caused by a mutation in the hemoglobin-Beta gene found on chromosome 11. Thalassemia : This is also an autosome-linked recessive blood disease transmitted from parents to the offspring when both the partners are unaffected carrier for the gene (or heterozygous).. Phenylketonuria : This inborn error of metabolism is also inherited as the autosomal recessive trait. Haemophilia : This sex linked recessive disease, which shows its transmission from unaffected carrier female to some of the male progeny has been widely studied. Answer : (a)
Q.8
How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits? [ NEET 2020]
0%
a) 14
0%
b) 8
0%
c) 4
0%
d) 2
Explanation
Answer : (a)
Q.9
Genotype of hybrid is known by crossing ... ... [ CBSE 2007]
0%
a) F2 progeny with female parent
0%
b) F1 × F1
0%
c) Crossing F1 with recessive parent
0%
d) F2 with recessive parent
Explanation
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. Answer : (c)
Q.10
The number of phenotypes in ABO blood group is ... ... [ CBSE 2010 ]
0%
a) 1
0%
b) 4
0%
c) 6
0%
d) 8
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
The four basic ABO phenotypes are O, A, B, and AB. Answer : (b)
Q.11
When a cluster of genes show linkage behaviour, they ... .. [ CBSE 2003 ]
0%
a) Do not show chromosome map
0%
b) Induce cell division
0%
c) Do not show independent assortment
0%
d) Show recombination during meiosis
Explanation
Answer : (c)
Q.12
Word genetics comes from ... .. [ Manipur 2006 ]
0%
a) Gene
0%
b) Genesis
0%
c) Genome
0%
d) Genomics
Explanation
Word genetics comes from the word gene. The term was coined and used for the first time by W. Bateson(1905). Answer : (a)
Q.13
A dwarf pea plant with wrinkled seeds (ttrr) produces seeds of type ... ... [ Odisha 2009]
0%
a) 2
0%
b) 4
0%
c) 1
0%
d) 9
Explanation
Since pea plant is homozygous, it will produces only one type of gamete i.e., tr. Answer : (c)
Q.14
In guinea pig, black short hair (BBSS) is dominant over white hair (bbss). In the dihybrid cross, F2 genotype BBSS, BbSS, BBSs and BbSs appear in the ratio of ... .. [ EAMCET 2008 ]
0%
a) 9:3:3:1
0%
b) 4:2:1:2
0%
c) 1:2:1:4
0%
d) 1:2:2:4
Explanation
Gametes of F2
BS
Bs
bS
bs
BS
BBSS
BBSs
BbSS
BbSs
Bs
BBSs
BBss
BbSs
Bbss
bS
BbSS
BbSs
bbSS
bbSs
bs
BbSs
Bbss
bbSs
bbss
BBSS : BbSS : BBSs : BbSs 1 : 2 : 2: 4 Answer : (d)
Q.15
Which is connected with multiple phenotypes? [ CPMT 1999 ]
0%
a) Epistasis
0%
b) Pleiotropy
0%
c) Polygenic inheritance
0%
d) Mutations
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 : (b)
Q.16
A baby of blood group A cannot belong to parents of blood group ... .. [ EAMCET 2005 ]
0%
a) Husband O, wife AB
0%
b) Husband A, wife B
0%
c) Husband B, wife O
0%
d) Husband AB, wife A
Explanation
Baby has blood group A. It means the genotype is either IAIA or IAIO. One of the allele comes from mother and another from father. So both the parents should have any of the following blood group. 1) Both the parents have blood group A. 2) Husband O, wife AB vice-versa 3) Husband A, wife B or vice-versa 4) Husband AB, wife A or vice-versa. Answer : (c)
Q.17
In garden Pea, yellow colour of cotyledons is dominant over green and round shape of seed is dominant over wrinkled. When a plant with yellow and round seeds is crossed with a plant having yellow and wrinkled seeds, the progeny showed segregation for all the four characters. the probability of obtaining green round seeds in the progeny of this cross is ... ... [ EAMCET 2009]
0%
a) 1/8
0%
b) 1/16
0%
c) 1/4
0%
d) 3/16
Explanation
Round yellow : Round green : Wrinkled yellow : Wrinkled green 9 : 3 : 3 : 1 Round green = 3/16 Answer : (d)
Q.18
pure line is connected with development of ... .. [ AIIMS 2002])
0%
a) homozygosity
0%
b) heterozygosity
0%
c) homozygosity and self assortment
0%
d) heterozygosity and linkage
Explanation
Pure line varieties are raised by selection of individual plants from a traditional variety or some other mixed population and thus, they are homozygous, i.e., true breeding and homogeneous as they are genetically similar. A pure line produces a single type of gametes and parental combinations in the progeny. Pure line breed refers to a group of identical individuals that always produce offspring of the same phenotype when intercrossed. This occurs only when they are homozygous. Thus, the correct answer is option a. Answer : (a)
Q.19
How many types of gametes are required for F2 generation of a monohybrid cross? [ Bih PMT 1995 ]
0%
a) 2
0%
b) 4
0%
c) 16
0%
d) 8
Explanation
No. of traits (n)
Experiment
Types of gametes (2n)
No. of offsprings (gametes)
2
No. of phenotype (2
n
)
No. of genotype (3
n
)
Phenotypic ratio
Genotypic ratio
1
Monohybrid cross
2
4
2
3
3:1
1:2:1
2
Dihybrid cross
4
16
4
9
9:3:3:1
2:4:2:1:2:1:1:2:1
3
Trihybrid cross
8
64
8
27
(3:1)
3
(1:2:1)
3
Answer : (a)
Q.20
A yellow seeded true breeding Pea plant is crossed with green seeded true breeding plant. F1 plants were yellow seeded showing that allele for yellow colour is .... ... [ MPPMT 1993 ]
0%
a) Heterozygous
0%
b) Dominant
0%
c) Lethal
0%
d) Epistasis
Explanation
A true breeding is a kind of breeding wherein the parents would produce offspring that would carry the same phenotype. This means that the parents are homozygous for every trait. Since only one trait i.e yellow colour is expressed in F1 generation, it means yellow colour seed is a dominant allele. Answer : (b)
Q.21
In Cucurbita, W is epistatic over Y and y gene normally responsible for yellow and green colour fruits. It produces white flowers. What is the ratio of fruits in the progeny of cross WwYy × wwYy? .... .. [ AMU 1999 ]
0%
a) 9 white : 7 yellow : 0 green
0%
b) 3 white : 4 yellow : 1 green
0%
c) 4 white : 3 yellow : 1 green
0%
d) 2 white : 1 yellow : 1 green
Explanation
Gametes
WY
Wy
wY
wy
wY
WwYY (white)
WwYy (white)
wwYY (yellow)
wwYy (yellow)
wy
WwYy (white)
Wwyy (white)
wwYy (yellow)
wwyy (green)
Fruit colour of Cucurbita is governed by gene which produces yellow colour in dominant state (Y) and green colour in recessive state (yy). There is non-pigment forming epistatic gene which in dominant state (W) produces white colour while in recessive state it allows the yellow and green colour expression. WwYy (white fruit) × wwYy (yellow fruit ) White : yellow : green = 4 : 3 : 1 Answer : (c)
Q.22
Possible blood group of children born to parents having A and AB groups are ... ... [ BHU 2007 ]
0%
a) O, A
0%
b) A, B, AB
0%
c) O, A, B
0%
d) O, A, B, AB
Explanation
I
A
I
O
I
A
I
A
I
A
(A blood group)
I
A
I
O
(A blood group)
I
B
I
A
I
B
(AB blood group)
I
B
I
O
(B blood group)
Parent having blood group A has genotype IAIA or IAIO. Parent having blood group AB has genotype IAIB. Answer : (b)
Q.23
Tt × tt is ... .. [ Har PMT 2001 ]
0%
a) Test cross
0%
b) Back cross
0%
c) Hybridization
0%
d) Reciprocal cross
Explanation
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. Answer : (a)
Q.24
Segregation of Mendelian factors ( no linkage, no crossing over ) occurs during ... .. [ CBSE 1992 ]
0%
a) Anaphase I
0%
b) Anaphase II
0%
c) Diplotene
0%
d) Metaphase I
Explanation
During Anaphase of meiosis I, the two chromosome pairs can align at the metaphase plate independently of each other. Answer : (a)
Q.25
Select the correct statement from the one given below with respect to dihybrid cross ... . [ CBSE 2010 ]
0%
a) Genes far apart on the same chromosome show very few recombination
0%
b) Genes loosely linked in the same chromosome show similar recombination as the tightly linked ones
0%
c) Tightly linked genes on the same chromosome show very few recombination
0%
d) Tightly linked genes on the same chromosome show higher recombination
Explanation
term recombination means the generation of non-parental gene combinations. Morgan and his group also found that even when genes were grouped on the same chromosome, some genes were very tightly linked and showed very low recombination, while others were loosely linked and showed higher recombination. Answer : (c)
Q.26
A cross involving parents differing only in one trait is ... .. [ AMU 2000 ]
0%
a) Haploid
0%
b) Diploid
0%
c) Monohybrid
0%
d) Dihybrid
Explanation
The cross in which only alternate forms of a single character are taken into consideration is called monohybrid cross. Answer : (c)
Q.27
Mendel was successful in discovering the principles of inheritance as .... ... [ JKCMEE 2011 ]
0%
a) He took Pea plants for his experiments
0%
b) He was a mathematician
0%
c) He did not encounter linkage
0%
d) He had an in depth knowledge on hybridization
Explanation
Mendel was lucky in choosing characters which showed complete independent assortment. He only took those traits for his studies which did not show linkage, interaction or incomplete dominance. Answer : (c)
Q.28
The allele which is unable to express its effect in the presence of another is called ... ... [ CBSE 1991 ]
0%
a) Codominant
0%
b) Supplementary
0%
c) Complementary
0%
d) Recessive
Explanation
Recessive allele is factor of an allele pair which is unable to express its effect in the presence of its contrasting factor in heterozygote. Example t in Tt. Answer : (d)
Q.29
Monohybrid cross produced both tall and dwarf Pea plants in the ratio of 3:Their genotypes would be ... .. [ Wardha 2003 ]
0%
a) TT × Tt
0%
b) Tt ˜ Tt
0%
c) Tt × tt
0%
d) TT × tt
Explanation
Tall : Dwarf 3 : 1 Answer : (b)
Q.30
Alleles are ... .. [ CPMT 2002 ]
0%
a) Alternate forms of gene
0%
b) Pairs of sex chromosomes
0%
c) Homologous chromosomes
0%
d) None of the above
Explanation
A pair of contrasting characters is called allelomorph or allele. The term allele was given by W.Bateson for alternative forms of same gene. Answer : (a)
Q.31
Two allelic genes are located on . .... [ AMU 2011]
0%
a) Two homologous chromosomes
0%
b) Two non-homologous chromosomes
0%
c) Any two chromosomes
0%
d) The same chromosome
Explanation
In homozygous condition, organisms have two similar genes or alleles for a particular character in a homologous pair of chromosomes. Answer : (a)
Q.32
A cross between AA and aa will produce an F1 progeny.. ... [ CPMT 2004]
0%
a) Genotypically aa, phenotypically A
0%
b) Genotypically AA, phenotypically a
0%
c) Genotypically Aa, phenotypically A
0%
d) Genotypically Aa, phenotypically a
Explanation
All the progeny of F1 generation has genotype Aa. A is dominant and a is recessive, thus F1 generation has external characters i.e., phenotype of dominant allele. Phenotype of F1 generation is A. Answer : (c)
Q.33
Which variations are temporary and are not connected with last or next generation ... ... [ CPMT 2008]
0%
a) Hereditary variations
0%
b) Environmental variation
0%
c) Discontinuous variations
0%
d) Continuous variations
Explanation
Environmental variations are those variations which are merely due to environment. These variations are temporary and have nothing to do with the next generation. Continuous variation refers to the type of genetic variation, which shows an unbroken range of phenotypes of a particular character in the population while discontinuous variation refers to the type of genetic variation, which shows to or more separate forms of a character in the population. Answer : (b)
Q.34
A human male produces diallelic sperms in equal proportion AB, Ab, aB and ab. The genotype of the person would be .... .. [ CBSE 2007 ]
0%
a) Aa Bb
0%
b)Aa BB
0%
c) AA Bb
0%
d) AA BB
Explanation
A pair of contrasting trait is called allele. From the given data, one can identify that there two pair of allele A and A, B and b. Answer : (a)
Q.35
Number of gamete types formed by AaBbCc individual/ heterozygous for three gene loci is ... ... [ DPMT 2001 ]
0%
a) 2
0%
b) 4
0%
c) 8
0%
d) 16
Explanation
No. of traits (n)
Experiment
Types of gametes (2
n
)
No. of offsprings (gametes)
2
No. of phenotype (2
n
)
No. of genotype (3
n
)
Phenotypic ratio
Genotypic ratio
3
Trihybrid cross
8
64
8
27
(3:1)
3
(1:2:1)
3
Answer : (c)
Q.36
Mendel's experimental material was ... ... [ JKCMEE 200 7]
0%
a) Drosophila melanogaster
0%
b) Homo sapiens
0%
c) pisum sativum
0%
d) Antirrhinum majus
Explanation
Mendel conducted experiments on garden peas (Pisum sativum) and formulated the laws which explain the manner of inheritance of characters. Answer : (c)
Q.37
Number of genotypes produced when individuals of genotype 'YyRrTt; are crossed with each other ... ... [ Wardha 2000 ]
0%
a) 4
0%
b) 45
0%
c) 28
0%
d) 27
Explanation
No. of traits (n)
Experiment
Types of gametes (2n)
No. of offsprings (gametes)
2
No. of phenotype (2
n
)
No. of genotype (3
n
)
Phenotypic ratio
Genotypic ratio
1
Monohybrid cross
2
4
2
3
3:1
1:2:1
2
Dihybrid cross
4
16
4
9
9:3:3:1
2:4:2:1:2:1:1:2:1
3
Trihybrid cross
8
64
8
27
(3:1)
3
(1:2:1)
3
individuals of genotype 'YyRrTt, means that no. of traits is 3. it's a formula just get it.... genotype=3n; phenotypes=2n for YyRrTt....so just count n=3 thus 33 = 27 gnotypes and 23 = 8 phenotypes ... now if it is YYRrTt then n=2 Answer : (d)
Q.38
In a cross 45 tall and 14 dwarf plants were obtained. genotype of parents was ... .. [ BHU 1993 ]
0%
a) TT × TT
0%
b) TT × Tt
0%
c) Tt × Tt
0%
d) TT × tt
Explanation
Tall : Dwarf = 45 : 14 that is approximately 3 : 1. This happens when both the parents are identical and allele is heterozygous. Parents are Tt and Tt Answer : (c)
Q.39
The graphical representation to calculate the probability of all possible genotypes of offspring in a genetic cross is called ... .. [ kerala 2010]
0%
b) Punnett square
0%
a) Pedigree analysis
0%
c) Chromosome map
0%
d) Genotypic ratio
Explanation
The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach in 1905. The diagram is used by biologists to determine the probability of an offspring having a particular genotype. Answer : (b)
Q.40
Multiple phenotype is seen in ... ... [ Odisha 2011]
0%
a) Dominance relationship
0%
b) Particulate inheritance
0%
c) Monogenic inheritance
0%
d) Polygenic inheritance
Explanation
Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits. Such a gene that exhibits multiple phenotypic expression is called a pleiotropic gene. Polygenic inheritance occurs when one characteristic is controlled by two or more genes Answer : (d)
Q.41
A cross between pure tall Pea plant with green pods and dwarf Pea plant with yellow pods will produce short F2 plants out of 16 ... .. [ CBSE 1994 ]
0%
a) 9
0%
b) 3
0%
c) 4
0%
d) 1
Explanation
Gametes
TG
Tg
tG
tg
TG
TTGG (tall,green)
TTGg (tall, green)
TtGG (tall,green)
TtGg (tall, green)
Tg
TTGg (tall, green)
TTgg (tall, yellow)
TtGg (tall, green)
Ttgg (tall, yellow)
tG
TtGG (tall, green)
TtGg (tall, green)
ttGG (dwarf, green)
ttGG (dwarf, green)
tg
TtGg (tall, green)
Ttgg (tall, yellow)
ttGG (dwarf, green)
ttGG (dwarf, green)
F2 generation Dwarf F2 plants = 4 Answer : (c)
Q.42
Mendel could not find recombination and crossing over as ... .. [ AIIMS 2000 ]
0%
a) Traits he chose were either present on different chromosomes or were far apart
0%
b) Traits chosen by him were not influenced by genes
0%
c) He did not have a high power microscope
0%
d) He selected only pure types
Explanation
Mendel studied traits which were on different pairs of homologous chromosomes. That is why he concluded that gene pairs segregate independently of one another. Mendel’s gene pairs did not show linkage. Answer : (a)
Q.43
Two cross between the same pair of genotypes / phenotypes in which the sources of gametes are reversed in one cross are called ... .. [ CBSE 2003 ]
0%
a) Test cross
0%
b) Reverse cross
0%
c) Dihybrid cross
0%
d) Reciprocal cross
Explanation
Reciprocal cross: A set of two reciprocal crosses means that the same two parents are used in two experiments in such a way that if in one experiment, ‘A’ is used as female parent and ‘B’ is used as male parents, in other experiments ‘A’ will be used as male parents and ‘B’ will be used as female parents. Thus the reciprocal crosses involve two crosses concerning the same characteristic, but with reverse sexes. Answer : (d)
Q.44
Out of two alleles of the same gene, one finds morphological expression. the phenomenon is ... .. [ AMU 1999 ]
0%
a) Epistasis
0%
b) Codominance
0%
c) Dominance
0%
d) Incomplete dominance
Explanation
In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome.. Dominant allele is one of the factor of an allele pair which can express itself whether present in homozygous or heterozygous state. Answer : (c)
Q.45
A man with blood group B and woman with blood group O, will have children with blood group ... .. [ KCET 2012 ]
0%
a) B or O
0%
b) AB, A, B or O
0%
c) AB or O
0%
d) A or O
Explanation
I
B
I
O
I
O
I
B
I
O
(B blood group)
I
O
I
O
(O blood group)
I
O
I
B
I
O
(B blood group)
I
O
I
O
(O blood group)
Man having blood group A has genotype IBIBI or IBIO. Mother having blood group O has genotype IOIO. Answer : (a)
Q.46
Blood group of mother is A. that of son is b. What is blood group of father ... .. [ Wardha 2011]
0%
a) B
0%
b) A
0%
c) O
0%
d) None of the above
Explanation
I
A
I
O
I
A
I
A
I
A
(A blood group)
I
A
I
O
(A blood group)
I
B
I
A
I
B
(AB blood group)
I
B
I
O
(B blood group)
Mother may have genotype IAIA or IAIO. Son may have genotype IBIO or IBIB. It means Genotype IB is from father. This implies father may B or AB. Most correct option is option A. Answer : (a)
Q.47
Pure tall plant is crossed to dwarf plant F1 generation consists of only tall plants while F2 generation has both tall and dwarf in ratio of 3:the phenomenon is due to ... ... [ BHU 2005 ]
0%
a) Dominance
0%
b) Codominance
0%
c) Incomplete dominance
0%
d) Heredity
Explanation
(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). 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 : (a)
Q.48
A man with blood group 'A' marries a woman with blood group 'B'. Their child has a blood group 'O'. What are genotypes of the parent?
0%
a) IAIA, IBIB
0%
b) IA i, IBi
0%
c) IAi, IBIB
0%
d) IAIB, IAIB
Explanation
I
A
I
O
I
B
I
A
I
B
(AB blood group)
I
B
I
O
(B blood group)
I
O
I
A
I
O
(A blood group)
I
O
I
O
(O blood group)
Parent having blood group A has genotype IAIA or IAIO. Parent having blood group BB has genotype IBIO. Parents have genotype as IAIO and IBIO. Answer : (b)
Q.49
Marriage between close relatives should be avoided because it induces more ... ... [ MPPMT 1990 ]
0%
a) Recessive alleles to come together
0%
b) Mutations
0%
c) Multiple births
0%
d) Blood group abnormalities
Explanation
Gametes
AB
Ab
aB
AaBB
AaBb
ab
AaBb
Aabb
Marriage between related individuals are risky. It is because the recessive alleles in the gene pool will accumulate. If the recessive allele, which reaches the female individual is heterozygous, female is called as carrier. Then the gene gets transferred to further generations, and in male child the defective gene will be expresses to cause disease AABb × aaBb → AaBB : AaBb : Aabb : aabb = 1 : 2 : 1 : 0 Answer : (a)
Q.50
In F2 generation quantitative inheritance of 1:4:6:4:1 is obtained instead of ... ... [ DPMT 2008 ]
0%
a) 9:3:3:1
0%
b) 8:6:4:1
0%
c) 7:4:1:4
0%
d) 6:6:4:7
Explanation
No. of traits (n)
Experiment
Types of gametes (2
n
)
No. of offsprings (gametes)
2
No. of phenotype (2
n
)
No. of genotype (3
n
)
Phenotypic ratio
Genotypic ratio
2
Dihybrid cross
4
16
4
9
9:3:3:1
2:4:2:1:2:1:1:2:1
Answer : (a)
0 h : 0 m : 1 s
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