Multiple Choice Questions

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

  • epistatic

  • supplementary

  • hypostatic

  • codominant


A.

epistatic

The phenomenon by which a gene suppresses the phenotypic expression of a non- allelic gene is called epistasis. In F2 generation, the ratio for epistatic gene is 12 : 3. 

The alleles which do not show dominant recessive relationship and are able to express themselves independently when present together are called co- dominant alleles.

Supplementary genes are a pair of non- allelic genes, one of which produces its effect independently in the dominant state while the dominant allele of the second gene is without any independent effect. Although, it is able to modify the effect of the former to produce a new trait.


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Pure line breed refers to

  • heterozygosity only

  • heterozygosity and linkage

  • homozygosity only

  • homozygosity and self assortment


Assertion : Pollution is always caused by human activities.

Reason : Pollution is not different from contamination.

  • 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 : Vegetable oils are fats which are present in plant cells in soluble form.

Reason : Vegetable oils occur only in cells of embryo.

  • 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


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Assertion : Antigen can be easily recognized because it has antigenic determinants.

Reason : The recognition ability is innate.

  • 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 : Chlorofluorocarbons are responsible for ozone depletion.

Reason : Ozone level decreases by as much as 67% every year.

  • 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


Which part of the world has a high density of organism?

  • Deciduous forests

  • Grasslands

  • Tropical rain forests

  • Savannahs


Assertion : The earliest fossil form in the phylogeny of horse is eohippus.

Reason : Eohippus lived during the early pliocene epoch.

  • 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


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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