The distance between two genes in a chromosome is measured in cross-over units which represent

• ratio of crossing over between them

• percentage of crossing over between them

• number of crossing over between them

• none of these.

Gene which suppresses other gene's activity but does not lie on the same locus is called as

• epistatic

• supplementary

• hypostatic

• codominant

Assertion : A gamete may carry either of the traits but not both.

Reason : This is Mendel's second law or law of independent assortment.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Haemophilia is a recessive sex linked disease.

Reason : Haemophilia occurs due to mutation of a structural gene on chromosome 15.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion: A geneticist crossed two plants, he got 50% tall and 50% dwarf progenies.

Reason: It follows Mendelian law as one of the parent plant might be heterozygous.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion: Blood group 'O' have anti-A & antiB antibodies.

Reason: It does not have any antigens.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion: Persons suffering from haemophilia fail to produce blood clotting factor VIII.

Reason: Prothrombin producing platelets in such persons are found in very low concentration.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Pure line breed refers to

• heterozygosity only

• heterozygosity and linkage

• homozygosity only

• homozygosity and self assortment

If a homozygous red-flowered plant is crossed with a homozygous white-flowered plant, the offsprings will be

• half- white flowered

• half- red flowered

• all white flowered

• all red flowered

XO-chromosomal abnormality in human beings causes

• Turner's syndrome

• Down's syndrome

• Klinefelter's syndrome

• None of these