If a colorblind woman marries a normal visioned man, their sons will be:

One half normal and one half colorblind

Three fourth colour blind and one fourth normal

A testcross is done to find out

The genotype of an individual by examining the phenotypes of its offsprings from a particular mating

The genotype of an individual for testing for its DNA content

To identify the genotype of recessive parent

Whether two species can interbreed

Identify the incorrect statement from the following.

When Morgan crossed wild type Drosophila for eye colour and body colour with mutated form like white eye and yellow body the recombination was more

When genes are tightly packed on the chromosomes, recombinations are almost nil

Incomplete dominance expression is also noticed in garden pea

Multiple alleles for a character in a population found on the same locus on homologous chromosomes

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Statement-1: Phenylketonuria is a recessive hereditary disease caused by the body’s failure to oxidize amino acid phenylalanine to tyrosine, because of deficiency of an enzyme.

Statement-2: It results in the presence of phenylalanine and its acid derivative in urine.

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Important Questions on Principles of Inheritance and Variation

HARD

NEET

IMPORTANT

Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 85

A husband and wife have normal vision, although both of their fathers are red-green colour blind, which is inherited as an x-linked recessive trait.

What is the probability that their first child will be?

i. A normal son.

ii. A carrier daughter.

iii. A colour-blind son.

iv. A colour-blind daughter.

EASY

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IMPORTANT

Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 86

Sickle cell anaemia is caused by

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Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 87

If two pea plants having red (dominant) coloured flowers with unknown genotypes are crossed,

75 %

of the flowers are red and

25 %

are white. The
genotypic constitution of the parents having red coloured flowers will be :-

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Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 89

If enough crosses are made between male flies of the genotype 'Aa' and the female flies of the genotype 'aa' to produce about 1000 offsprings. Which one of the following is the most likely distribution of genotypes in the offsprings?

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Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 90

In a monohybrid cross, 120 plants are obtained. What is the ratio of homozygous and heterozygous?

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IMPORTANT

Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 91

Match the terms in Column-I with their description in Column-II and choose the correct option:

Column – I	Column – II
(a) Dominance	(i) Many genes govern a single character
(b) Codominance	(ii) In a heterozygous organism, only one allele expresses itself
(c) Pleiotropy	(iii) In a heterozygous organism, both alleles express themselves fully
(d) Polygenic inheritance	(iv) A single gene influences many characters

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Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 92

Theoretically a normal phenotype is expressed when a particular substrate transforms into a product. However, in which of the following conditions the phenotype may be affected?

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IMPORTANT

Biology Crash Course NEET>Chapter 27 - Principles of Inheritance and Variation>Level 2>Q 93

If selfing occurs in the plant having genotype RrYy, then ratio of given genotype will be :- RRYY, RrYY, RRYy, RrYy

Statement-1: Phenylketonuria is a recessive hereditary disease caused by the body’s failure to oxidize amino acid phenylalanine to tyrosine, because of deficiency of an enzyme. Statement-2: It results in the presence of phenylalanine and its acid derivative in urine.

Important Questions on Principles of Inheritance and Variation

Learn and Prepare for any exam you want !

Statement-1: Phenylketonuria is a recessive hereditary disease caused by the body’s failure to oxidize amino acid phenylalanine to tyrosine, because of deficiency of an enzyme.

Statement-2: It results in the presence of phenylalanine and its acid derivative in urine.