MCQGeeks
0 : 0 : 1
CBSE
JEE
NTSE
NEET
English
UK Quiz
Quiz
Driving Test
Practice
Games
NEET
NEET Biology MCQ
Inheritance And Variation Mcq
Quiz 9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Q.1
tion Q3) A ‘new’ variety of rice was patented by a foreign company, though such varieties have been present in India for a long time. This is related to .... [NEET 2018]
0%
a) Lerma Rojo
0%
b) Sharbati Sonora
0%
c) Co-667
0%
d) Basmati
Explanation
The US government granted a patent for Indian Basmati to the company “Rice tech”. The diversity of rice in India is one of the richest in the world, 27 documented varieties of Basmati are grown in India. The government of India challenged. Consequently United States Patent and Trademark Office sent a notice to rice tech for amendments in their claims and the patent was eventually cancelled. Answer:(d)
Q.2
tion Q4) Which of the following characteristics represent ‘Inheritance of blood groups’ in humans ? [NEET 2018] a. Dominance b. Co-dominance c. Multiple allele d. Incomplete dominance e. Polygenic inheritance
0%
a) b, d and e
0%
b) a, b and c
0%
c) b, c and e
0%
d) a, c and e
Explanation
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. Answer:(a)
Q.3
tion Q5) Assertion: Induced mutations are exploited in plant breeding to induce variations. Reason: Mutations are the only reason for variation in living world.
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
0%
b) Both Assertion and Reason are true but Reason is NOT the correct explanation of Assertion.
0%
c) Assertion is true but Reason is false.
0%
d) Both Assertion and Reason are false.
Explanation
Induced mutations are considered as an alternative to naturally occurring variation. Assertion is true. Major causes of variation include mutations, gene flow, and sexual reproduction. Mutation is not the only reason. Reason is false. Answer:(c)
Q.4
tion Q6) From a single ear of corn, a farmer planted 200 kernels which produced 140 tall and 40 short plants. The genotypes of these off springs are most likely.
0%
a) TT ,tt
0%
b) TT , Tt , tt
0%
c) TT ,Tt
0%
d) Tt ,tt
Explanation
Ratio of tall: dwarf is almost 3:1. This occurs when the progeny is of three genotype: (i) Homozygous recessive (tt) (ii) Homozygous dominant (TT) [tall] (iii) Heterozygous (Tt) [tall]. Answer:(b)
Q.5
tion Q7) Which of the following conditions represent a case of co- dominant genes ?
0%
a) A gene expresses itself , suppressing the phenotypic effect of its alleles.
0%
b) genes that are similar in phenotypic effect when present separately, but when together interact to produce a different trait.
0%
c) Alleles, both of which interact to produce effect in homozygous condition
0%
d) Alleles, both of which interact to produce an independent effect in heterozygous condition.
Explanation
Codominance: It is the phenomenon of two alleles lacking dominant recessive relationship and both expressing themselves in the organism. Answer:(d)
Q.6
tion Q8) What does the term recombination describe ?
0%
a) Generation of non- parental gene combination
0%
b) Generation of parental gene combination
0%
c) Generation of internal gene combination
0%
d) All of the above
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:(a)
Q.7
tion Q9) What happens to excessive phenylalanine accumulation in the blood of phenylketonuria patient ?
0%
a) Get deposited on synovial membrane
0%
b) excreted in urine
0%
c) Get deposited in storage organs
0%
d) All of the above
Explanation
Phenylketonuria: The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine. As a result of this phenylalanine is accumulated and converted into phenylpyruvic acid and other derivatives. Accumulation of these in brain results in mental retardation. These are also excreted through urine because of its poor absorption by kidney. Answer:(b)
Q.8
on Q483) Two heterozygous round yellow seeded pea plants are intercrossed. In the progeny, the trait for seed shape will segregate in the ratio:
0%
a) 1 : 1
0%
b) 3 : 1
0%
c) 1 : 1 : 1 : 1
0%
d) 9 : 3 : 3 : 1
Explanation
Two heterozygous plants when intercrossed produces dominant trait progeny and recessive trait progeny. Dominant : recessive = 3 : 1 Answer:(b)
Q.9
ion Q11) Assertion (A) - chromosomes undergo Segregation and independent assortment. Reason (R) - During mitosis, their number is reduced into half.
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
Chromosome segregation occurs at two separate stages during meiosis called anaphase I and anaphase II. Different pairs of chromosomes segregate independently of each other, a process termed “independent assortment of non-homologous chromosomes” In the mitosis two daughter cell formed, they are alike to parent cell in the number and type of chromosome. So due to mitosis, the number of chromosomes in the cell remains the same therefore the division occurred in the parent cell. Answer:(c)
Q.10
ion Q12) Lack of independent assortment of two genes A and B in fruitfly the Drosophilia is due to
0%
a) Repulsion
0%
b) Recombination
0%
c) Linkage
0%
d) Crossing over
Explanation
Morgan carried out several dihybrid crosses in Drosophila to study genes that were sex-linked. The crosses were similar to the dihybrid crosses carried out by Mendel in peas. For example Morgan hybridised yellow-bodied, white-eyed females to brown-bodied, red-eyed males and intercrossed their F1 progeny. He observed that the two genes did not segregate independently of each other and the F2 ratio deviated very significantly from the 9:3:3:1 ratio. Morgan attributed this due to the physical association or linkage of the two genes and coined the term linkage Answer:(c)
Q.11
ion Q13) In humans, an example of sex-linked trait is
0%
a) Curly hair
0%
b) Sickle-cell anaemia
0%
c) Colour-blindness
0%
d) Down's syndrome
Explanation
Colour Blindness : It is a sex-linked recessive disorder due to defect in either red or green cone of eye resulting in failure to discriminate between red and green colour. 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). Down’s Syndrome : The cause of this genetic disorder is the presence of an additional copy of the chromosome number 21 (trisomy of 21) Answer:(c)
Q.12
ion Q14) Among the following which is a test cross?
0%
a) Tt×Tt
0%
b) TT×TT
0%
c) TT×Tt
0%
d) Tt×tt
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 Answer:(d)
Q.13
ion Q15) Identify the incorrect statement regarding experiments on Pisum sativum by Gregor Mendel?
0%
a) He conducted hybridisation experiments on garden peas for seven years (1856-1863) and proposed the laws of inheritance in living organisms.
0%
b) It was for the first time that statical analysis and mathematical logic were applied to problems in biology.
0%
c) Unfortunately his experiments had a small sampling size, which gave less credibility to the data that he collected.
0%
d) He investigated characters in the garden pea plant that were manifested as two opposing traits.
Explanation
From 1856 to 1865, Mendel conducted breeding experiments on garden peas (Pisum sativum) in the garden of his monastery. His breeding materials consisted of pure lines. Unlike his predecessors who worked on large number of characters simultaneously, Mendel worked with one or few pairs of traits at one time. He kept record of every cross and subsequent generations produced through self breeding. Thus he maintained statistical records of all the experiments and analysed them carefully. Different varieties of pure breeding pea had contrasting expression of traits like height, color of flower, position of flower etc. Answer:(c)
Q.14
ion Q16) Monohybrid cross can be defined as
0%
a) Cross between plants differing in one chromosome
0%
b) Cross between plants differing in one character only
0%
c) Cross between plants differing in two traits
0%
d) All of the above
Explanation
When only one allelic pair (one trait/ character) is considered in cross breeding, it is called monohybrid cross. Answer:(b)
Q.15
ion Q17) Which of the following statement is correct?
0%
a) Mendel’s work remained unrecognised till 1920.
0%
b) Mendel’s work suggested that factors were discrete units.
0%
c) Mendel provided physical proof of the existence of factors.
0%
d) He used geographical approaches to solve the problems of biology.
Explanation
Mendel’s work was rediscovered in 1900 by three workers independently. They were Hugo de Vries of Holland, Carl Correns of Germany and Erich von Tschermak of Austria. Mendel’s law of dominance states that characters are controlled by discrete units called factors. Factors occur in pairs. Mendel could not provide physical proof of existence of factor. He kept statistical records of all the experiment and analysed them carefully to formulate clear cut principles or law of heredity. Answer:(b)
Q.16
ion Q18) How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
0%
a) 4
0%
b) 8
0%
c) 16
0%
d) 32
Explanation
No. of gametes = (2)n where n = no. of heterozygous alleles. = (2)3 = 8 Answer:(b)
Q.17
ion Q19) Out of a pair of monozygotic twins, one develops hare lip and the other does not. This can be an example of the genetic phenomenon of:
0%
a) Pleiotropy
0%
b) Incomplete penetrance
0%
c) Variable expressivity
0%
d) Incomplete dominance
Explanation
Penetrance refers to the proportion of people with a particular genetic variant (or gene mutation) who exhibit signs and symptoms of a genetic disorder. If some people with the variant do not develop features of the disorder, the condition is said to have reduced (or incomplete) penetrance. Answer:(b)
Q.18
ion Q20) Which of the following symbols represent consanguineous mating?
0%
0%
0%
0%
Explanation
Consanguineous matings (marriages, if humans are under discussion) are those between related individuals, defined simply as those that share a common ancestor. Male is represented by square. Female is represented by circle. In pedigree charts, consanguineous matings are indicated by double lines between symbols. Answer:(c)
Q.19
ion Q21) Which of the following statements are correct with respect to aneuploidy? (i) Aneuploidy is caused due to failure of segregation of chromatids (ii) Aneuploidy is caused by due to failure of segregation of alleles (iii) Aneuploidy results into loss or gain of chromosomes. (iv) Aneuploidy always results into gain of chromosomes. (v). Down’s syndrome is caused due to aneuploidy in chromosome 21.
0%
a) (i), (iv) and (v)
0%
b) (ii), (iii) and (v)
0%
c) (i), (ii) and (iv)
0%
d) (i), (iii) and (v)
Explanation
Failure of segregation of chromatids during cell division cycle results in the gain or loss of a chromosome(s), called aneuploidy. For example, Down’s syndrome results in the gain of extra copy of chromosome 21. Answer:(d)
Q.20
ion Q22) In dogs, dark coat colour (A) is dominant to albino (a) and short hair (L) is dominant too long hair (l). Determine the probable genotype of the parent who are dark and short and have progenies in the following ratio: Dark and short-89 Dark and long -31 Albino and short- 29 Albino and long-11
0%
a) AaLl
0%
b) AALL
0%
c) AaLL
0%
d) AAll
Explanation
Ratio of the above progenies is almost 9 : 3 : 3 : 1. This ratio is seen in F2 generation of dihybrid cross. F2 generation is obtained by selfing of F1 generation i.e. heterozygous allele. Probable genotype of parent for the above mentioned progenies is AaLl. Answer:(a)
Q.21
ion Q23) Given below is a highly simplified representation of the human sex chromosomes from a karyotype. The gene a and b could be of:
0%
a) Colour blindness and body height.
0%
b) Sickle cell anaemia and Myotonic dystrophy.
0%
c) Haemophilia and red – green colour blindness.
0%
d) Phenyl ketonuria and haemophilia.
Explanation
Haemophilia : This sex linked recessive disease, which shows its transmission from unaffected carrier female to some of the male progeny. Colour Blidness : It is a sex-linked recessive disorder due to defect in either red or green cone of eye resulting in failure to discriminate between red and green colour. This defect is due to mutation in certain genes present in the X chromosome. Answer:(c)
Q.22
ion Q24) Haploids are more suitable for mutation studies than diploids. This is because:
0%
a) Haploids are more abundant in nature than diploids.
0%
b) All mutations, whether dominant or recessive are expressed in haploids.
0%
c) Haploids are reproductively more stable than diploids.
0%
d) Mutagens penetrate in haploids more effectively than diploids.
Explanation
Haploid plants, are always pure because they possess only one set of chromosomes. So, the mutations are expressed very easily in haploid plants as compared to diploid plants. Answer:(b)
Q.23
ion Q25) Assertion: An organism with lethal mutation may not even develop beyond the zygote stage. Reason: All types of gene mutations are lethal.
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
0%
b) Both Assertion and Reason are true but Reason is NOT the correct explanation of Assertion.
0%
c) Assertion is true but Reason is false.
0%
d) Both Assertion and Reason are false.
Explanation
Lethal alleles are alleles that cause the death of the organism that carries them. They are usually a result of mutations in genes that are essential for growth or development. Assertin is true. Mutations can be harmful as well as beneficial. Subvital reduces the chances of survival. Supravital mutations result in the improvement of biological fitness under certain conditions. Reason is false. Answer:(c)
Q.24
ion Q26) A spontaneous mutation results in a couple having only female progeny. When the daughter marries and the children, none of them are males. However, in the third generation there are few male offspring. What is the most likely explanation of this observation?
0%
a) The mutation reverses spontaneously in the third generation.
0%
b) The mutation occurs on the X chromosome and is both recessive and lethal.
0%
c) The mutation occurs on the X chromosome and is both recessive and dominant.
0%
d) The mutation occurs on autosomes and is dominant.
Explanation
From the information, we can derive the conclusion that there is mutation on X chromosomes. This mutation is lethal and recessive. Female has pair of XX chromosomes that why they are carrier of mutation, but male has XY chromosomes and thus mutation on X chromosome does not allow zygote of XY to survive. Answer:(b)
Q.25
ion Q27) If the egg of a female grasshopper is fertilized by A + O sperm, the sex of the progeny is:
0%
a) Super male.
0%
b) Female.
0%
c) Male.
0%
d) Super female.
Explanation
Grasshopper is an example of XO type of sex determination in which the males have only one X-chromosome besides the autosomes, whereas females have a pair of X-chromosomes. AA (female) × AO (male) Gametes A A A AA (female) AA (female) O AO (male) AO (male) Answer:(c)
Q.26
ion Q28) Observe the following genotypes of parents who are allowed to cross: AaBbCcc × AaBbCc. How many different types of phenotypes and genotypes are expressed in the offspring’s?
0%
a) 32 and 64.
0%
b) 8 and 27.
0%
c) 4 and 9.
0%
d) 16 and 32.
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:(b)
Q.27
ion Q29) Which of the following is significance of dominance ?
0%
a) Organisms with dominant genes are more vital
0%
b) Harmful mutations are not expressed due to dominant gene
0%
c) Heterosis is due to dominant gene
0%
d) All the above
Explanation
In DNA, mutations or accidental changes in its code can occur. Mutations can lead to missing or malformed proteins, and that can lead to disease. Most inherited genetic diseases are recessive, which means that a person must inherit two copies of the mutated gene to inherit a disorder. However, in heterozygotes, these recessive mutated alleles do not express themselves in presence of the dominant allele. Thus, harmful mutations are not expressed in presence of dominant gene. Answer:(b)
Q.28
ion Q30) In T. H. Morgan"s Experiment on Drosophilia what will be the result when F1 female flies are crossed with double recessive male files ?
0%
a) 83% parental combinations 17% Recombinations
0%
b) 41.5 % parental combinations 58.5% recombinations
0%
c) 60% parental combinations 40 % recombinations
0%
d) 90 % parental combinations 10% Recombinations
Explanation
83% parental combinations 17% Recombinations Answer:(a)
Q.29
ion Q31) Match the following Column I Column II
Blood groups
Possible Genotypes
A
(a) I
B
I
B
, I
B
i
B
(b) ii
AB
(c) I
A
I
A
, I
A
i
O
(d) I
A
I
B
0%
a) (1 - a) (2 - b) (3 - c) (4 - d)
0%
b) (1 - c) (2 - a) (3 - b) (4 - d)
0%
c) (1 - c) (2 - b) (3 - d) (4 - a)
0%
d) (1 - c) (2 - a) (3 - d) (4 - b)
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
Answer:(d)
Q.30
ion Q32) What do A, B, C represent in the given diagram?
0%
a) Centromere, chromatids chiasma
0%
b) Chromatid, chiasma, centromere
0%
c) Centromere, chiasma, chromatid
0%
d) Chromatid, chiasma centromere
Explanation
Answer:(a)
Q.31
ion Q33) Assertion (A) :- HbA HbS is a carrier of sickle cell anaemia Reason (R) :- Sickle cell anaemia is a recessive character caused by the recessive genes HbS HbS
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
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). The disease is controlled by a single pair of allele, HbA and HbS. Out of the three possible genotypes only homozygous individuals for HbS (HbSHbS) show the diseased phenotype. Heterozygous (HbAHbS) individuals appear apparently unaffected but they are carrier of the disease Answer:(b)
Q.32
ion Q34) The best method to determine whether an individual is homozygous or heterozygous is
0%
a) inbreeding
0%
b) cross-breeding
0%
c) back-crossing
0%
d) self-fertilization
Explanation
Gametes
T
t
t
Tt (tall)
tt (dwarf)
t
Tt (tall)
Tt (dwarf)
A cross of F1 hybrid with either of the two parents is known as back cross. 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 Answer:(c)
Q.33
ion Q35) Albinism in corn plants is best described as
0%
a) lethal
0%
b) sex-linked
0%
c) inbred
0%
d) dominance
Explanation
Albinism is a lethal trait of corn because all the albino plants lack chlorophyll and cannot make their own food by photosynthesis. Therefore, they die as seedlings after their food supply in the seed is exhausted. Under cultivation, the lethal allele for albino has been maintained in a population of corn for decades. Answer:(a)
Q.34
ion Q36) How many meiosis will be required to produce 102 pollen-grains?
0%
a) 25
0%
b) 25.6
0%
c) 26
0%
d) 26.5
Explanation
For the formation of 4 pollen grain= 1 meiotic division is required. So for formation 102 pollen grains will required 25.5 meiotic division. Since half meiosis doesn't occur, 26 meiotic divisions are required. Answer:(c)
Q.35
ion Q37) Which of the following are correct regarding linked genes? I. are located near each other on the same chromosome. II. violate the law of independent assortment III. segregate together during meiosis
0%
a) Only I and II
0%
b) Only I and III
0%
c) Only II and III
0%
d) I, II, III
Explanation
Linked genes are genes that are likely to be inherited together because they are physically close to one another on the same chromosome. Linked genes are exceptions to the law of independent assortment because two genes are located on the same chromosome, but this is generally mitigated when chromosomes cross over. Answer:(d)
Q.36
ion Q38) A pleiotropic gene
0%
a) is expressed only in primitive plants
0%
b) is a gene evolved during Pliocene
0%
c) controls a trait only in combination with another gene
0%
d) controls multiple traits in an individual
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. Since same gene is affecting eye colour as well as depigmentation of body parts, it is an example of pleiotropic gene. Answer:(d)
Q.37
ion Q39) In which mode of inheritance do you expect more maternal influence among the offspring?
0%
a) Autosomal
0%
b) Cytoplasmic
0%
c) Y-linked
0%
d) X-linked
Explanation
The cytoplasmic inheritance is the phenomena of inheritance of maternal characters present in the genetic material in the cytoplasm. It is mainly caused due to the expression of genes present in the extra-chromosomal segments. Mitochondria and chloroplast are the only organelles which are semi-autonomous which have their own DNA. Mitochondrial DNA is known as mt-DNA and the chloroplast is known as ct-DNA. The functional genes of the mitochondria and chloroplast express themselves and allow inheritance of maternal characters. Answer:(b)
Q.38
ion Q40) Our ancestors knew about the inheritance of characters and variations because-
0%
a) They selectively breed plants and animals and selected for organisms that possessed desirable characters.
0%
b) They introduced mutations
0%
c) They performed natural hybridisation
0%
d) All of the above
Explanation
Humans knew from as early as 8000-1000 B.C. that one of the causes of variation was hidden in sexual reproduction. They exploited the variations that were naturally present in the wild populations of plants and animals to selectively breed and select for organisms that possessed desirable characters. Answer:(a)
Q.39
ion Q41) Which of the following about the law of segregation is true?
0%
a) It states that each of two alleles for a given trait segregate into same gametes.
0%
b) It can be explained by the segregation of heterologous chromosomes during meiosis.
0%
c) It can account for the 3:1 ratio seen in the F2 generation of Mendel’s crosses.
0%
d) It is a method that can be used to determine the number of chromosomes in a plant.
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. Answer:(c)
Q.40
ion Q42) Which of the following statements are correct regarding Chromosomal basis of sex determination? (i) The mechanism of sex determination in insects is of XO type. (ii) XX insect is female while XO insect is male. (iii) The X chromosome is called sex chromosome because it was involved in sex determination. (iv) Grasshopper has XY type of sex determination. (v) Man has XX type of sex determination.
0%
a) (iv), (v)
0%
b) (i), (ii), (iii), (iv), (v)
0%
c) (i), (ii), (iii)
0%
d) (i), (iv), (v)
Explanation
In a large number of insects the mechanism of sex determination is of the XO type. Grasshopper is an example of XO type of sex determination in which the males have only one X-chromosome besides the autosomes, whereas females have a pair of X-chromosomes. There is involvement of the X-chromosome in the determination of sex, it was designated to be the sex chromosome. In human, a pair of X-chromosomes are present in the female, whereas the presence of an X and Y chromosome are determinant of the male characteristic. Answer:(c)
Q.41
ion Q43) Myotonic dystrophy is
0%
a) Autosomal recessive trait
0%
b) Autosomal dominant trait
0%
c) X- linked dominant trait
0%
d) X- linked recessive trait
Explanation
Myotonic dystrophy (DM) is a form of muscular dystrophy that affects muscles and many other organs in the body. Myotonic dystrophy (DM) is inherited in an autosomal dominant pattern. This means that one copy of the altered gene in each cell of the body is enough to cause symptoms of the disease. We inherit one copy of each gene from our mother and the other from our father. Answer:(b)
Q.42
ion Q44) In corn plant, the allele for tall plant (T) is dominant to small plant (t) and coloured seed (C) is dominant to (c). In a particular cross, the probability of offspring being tall is ½ and being coloured is ¾, which of the following will produce such progeny?
0%
a) TTCc and ttCc
0%
b) TTCc and TtCc
0%
c) TtCc and ttCc
0%
d) TTCC and ttCC
Explanation
The probability of offspring being tall is ½. This occurs in cross of heterozygous allele and recessive homozygous allele. Genotype of parents for height trait is Tt and tt. The probability of offspring being coloured is ¾. This occurs in cross of heterozygous allele parents. Genotype of parents for colour trait is Cc and Cc. Genotype of parents will be TtCc and ttCc. Answer:(c)
Q.43
ion Q45) Gregor Mendel crossed a true breeding tall plant with true breeding dwarf plant, and raised F2 generation from his F1 hybrid. Mendel observed that out of the total 1064 F2 progenies 787 were tall and 277 were dwarf. How many plants are expected to be in heterozygous condition?
0%
a) 277.
0%
b) 787.
0%
c) 532.
0%
d) 510.
Explanation
The ratio of tall : dwarf is almost 3:1. Out of 3 dominant trait, 1 is homozygous tall and 2 is heterozygous tall. The ratio of homozygous tall : heterozygous tall : homozygous dwarf is 1 : 2 : 1. Therefore out of 1064 progenies, number of heterozygous condition = 2/4× 1064 = 532 Answer:(d)
Q.44
ion Q46) If the number of chromosome in the organisms A, B, C and D after the numerical change is as follows: Organism A – Double Trisomy – Organism B – Simple Nullisomy – Organism C – Double Tetrasomy – Organism D – Simple Monosomy – What will be the ‘2n’ of the same organisms A, B, C and D?
0%
a) 20, 44, 30, 24.
0%
b) 24, 50, 24, 24.
0%
c) 24, 50, 20, 22.
0%
d) 20, 50, 24, 22.
Explanation
A Double trisomy: 2n+1+1 = 26 2n= 24 B Simple nullisomy: 2n-2 = 48 2n = 50 C Double tetrasomy: 2n+2+2 = 28 2n = 24 D Simple monosomy: 2n-1 = 23 2n = 24 Answer:(b)
Q.45
ion Q47) Genes present in the X chromosome of father will be inherited by:
0%
a) 50% of male children and 100% of female children.
0%
b) 50% of male children and 50% of female children.
0%
c) 25% of male children and 75% of female children.
0%
d) 0% of male children and 100% of female children.
Explanation
Gametes
X
Y
X
XX (female)
XY (male)
X
XX (female)
XY (male)
In case the ovum fertilises with a sperm carrying X-chromosome the zygote develops into a female (XX) and the fertilisation of ovum with Y-chromosome carrying sperm results into a male offspring. XX × XY Answer:(d)
Q.46
ion Q48) Assertion: Polygenic inheritance is quantitative. Reason: Mendelism, multiple allelism and epistasis are qualitative.
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
0%
b) Both Assertion and Reason are true but Reason is NOT the correct explanation of Assertion.
0%
c) Assertion is true but Reason is false.
0%
d) Both Assertion and Reason are false.
Explanation
Quantitative inheritance: It is a type of inheritance controlled by more genes in which the dominant alleles have cumulative effect with each dominant allele expressing a part or unit of trait, the full trait being shown only when all the dominant alleles are present. The genes involved are called polygenes. Quantitative inheritance is therefore, also called polygenic inheritance. Qualitative inheritance: It is the type of inheritance in which a single dominant gene influences a complete trait Answer:(b)
Q.47
ion Q49) A gene located an y - chromosome and therefore, transmitted from father to son is known as
0%
a) Supplementary gene
0%
b) Complementary gene
0%
c) Duplicate gene
0%
d) Holandric gene
Explanation
The genes that are carried on the Y chromosome are called holandric genes. Holandric genes can only be passed by males onto their sons; they code for 'maleness' but sometimes cause rare conditions like hypertrichosis pinnae and color blindness. Answer:(d)
Q.48
ion Q50) Out of the following , Find out the reason for occurrence of free martin in cattles ?
0%
a) Both the twins are connected by a common umbilical cord
0%
b) Gonad of the male develop earlier then those of the female
0%
c) Male hormones reach the female embryo and influence the development of male sex in the female embryo
0%
d) All of the above
Explanation
Freemartinism is recognized as one of the most severe forms of sexual abnormality among cattle. This condition causes infertility in the female cattle born twin to a male. When a heifer twin shares the uterus with a bull fetus, they also share the placental membranes connecting the fetuses with the dam. As in cattle, caprine freemartinism is caused by the fusion of fetal membranes in twin gestation and the subsequent vascular anastomosis that allows the passage of cells and hormones from a male fetus to the female fetus . Answer:(d)
Q.49
ion Q51) Inorder to find out the different types of gametes produced by a pea plant having the genotype AaBb it should be crossed to a plant with the genotype ... ....
0%
a) AABB
0%
b) AaBb
0%
c) aabb
0%
d) aaBB
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. Recessive genotype is aabb Answer:(c)
Q.50
ion Q52) ABO blood groups in humans are controlled by the gene I. It has three alleles - IA , IB and i . Since there are 3 different alleles six different genotypes are possible. How many phenotypes Occur?
0%
a) Three
0%
b) One
0%
c) Four
0%
d) Two
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
Answer:(c)
0 h : 0 m : 1 s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Support mcqgeeks.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page