Principles of Inheritance and Variation Chapter-Wise Test 11

Correct answer Carries: 4.

Wrong Answer Carries: -1.

Which of the following is an incorrect statement about linked genes?

Linked genes are inherited together.
They are located on the same chromosome.
They always follow the Law of Independent Assortment.
Crossing over can separate linked genes.
3

Linked genes do not follow the Law of Independent Assortment as they are inherited together unless crossing over occurs.

Which of the following is a correct statement about incomplete dominance?

One allele completely masks the effect of the other.
Heterozygous individuals exhibit a blend of both parental traits.
Both alleles are expressed equally in heterozygous individuals.
Incomplete dominance follows Mendel’s Law of Segregation.
2

Incomplete dominance results in an intermediate phenotype, as seen in pink flowers from red and white parents.

What is the probability of a son inheriting an X-linked recessive disorder if his mother is a carrier?

0%
25%
50%
100%
3

A son has a 50% chance of inheriting an X-linked recessive disorder from a carrier mother, as he receives one X chromosome from his mother.

What is the chromosomal composition of a male with Klinefelter’s syndrome?

45, XO
47, XXY
46, XY
47, XYY
2

Klinefelter’s syndrome is characterized by an extra X chromosome, resulting in a 47, XXY karyotype.

Which scientist conducted experiments on Drosophila and established the concept of linkage and recombination?

Gregor Mendel
Thomas Hunt Morgan
Walter Sutton
Alfred Sturtevant
2

Thomas Hunt Morgan worked on Drosophila and discovered linkage and recombination.

Which of the following correctly describes a test cross?

A cross between two dominant individuals.
A cross between an individual of unknown genotype and a homozygous recessive individual.
A cross between two heterozygous individuals.
A cross between two recessive individuals.
2

A test cross helps determine an organism’s genotype by crossing it with a homozygous recessive individual.

Which blood group is an example of both co-dominance and multiple allelism?

A
B
AB
O
3

Blood group AB is an example of co-dominance (both A and B are expressed) and multiple allelism (three alleles: IA, IB, and i).

Which type of genetic disorder is caused by the presence of an extra chromosome 21?

Turner’s syndrome
Klinefelter’s syndrome
Down’s syndrome
Edward’s syndrome
3

Down’s syndrome is caused by trisomy of chromosome 21, leading to developmental and cognitive impairments.

Which chromosomal disorder is caused by trisomy of chromosome 13?

Down’s syndrome
Edward’s syndrome
Patau syndrome
Turner’s syndrome
3

Patau syndrome is caused by trisomy of chromosome 13, leading to severe developmental abnormalities.

What is the phenotypic ratio observed in the F2 generation of a monohybrid cross?

1:2:1
9:3:3:1
3:1
4:0
3

In a monohybrid cross, Mendel observed a phenotypic ratio of 3:1 in the F2 generation.

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