Epistasis refers to the phenomenon in which one gene hides the effect of the other. In other word, it does not allow the other gene to express itself. This is counterpart of dominance. While dominance works at inter allelic but intragenic level, Epistasis works at inter generic level. Epistasis is of following types: ·
Due to a recessive allele: A hides the effect of B, ·
Due to a dominant allele: A hides the effect of B.
This may be in one direction only meaning that either A hides the effect of B or vice versa.

Correct Option: A

Epistasis refers to the phenomenon in which one gene hides the effect of the other. In other word, it does not allow the other gene to express itself. This is counterpart of dominance. While dominance works at inter allelic but intragenic level, Epistasis works at inter generic level. Epistasis is of following types: ·
Due to a recessive allele: A hides the effect of B, ·
Due to a dominant allele: A hides the effect of B.
This may be in one direction only meaning that either A hides the effect of B or vice versa.

Numerous investigators have shown that nitrate nitrogen accumulates in higher plants and fungi which are deficient in molybdenum. In molybdenum-deficient plants grown in the presence of nitrate, molybdenum is required for the synthesis of nitrate reductase. Molybdenum deficiency results in the decrease of free amino acids in the plants in comparison to normal plants.

Correct Option: D

Numerous investigators have shown that nitrate nitrogen accumulates in higher plants and fungi which are deficient in molybdenum. In molybdenum-deficient plants grown in the presence of nitrate, molybdenum is required for the synthesis of nitrate reductase. Molybdenum deficiency results in the decrease of free amino acids in the plants in comparison to normal plants.

Grass ecosystems are an early stage of succession in regions where the mature ecosystems are forests. However, grass ecosystems are climax ecosystems in grassland regions, where there is not enough rainfall to support a forest. Due to limiting factors such as water scarcity and forest fire, a grassland ecosystem changes to a desert ecosystem. The ecological succession of grassland is desert. It is, however, notable that the soil of grassland ecosystem is rich in nutrients and organic matters and provides the largest biomass.

Correct Option: D

Grass ecosystems are an early stage of succession in regions where the mature ecosystems are forests. However, grass ecosystems are climax ecosystems in grassland regions, where there is not enough rainfall to support a forest. Due to limiting factors such as water scarcity and forest fire, a grassland ecosystem changes to a desert ecosystem. The ecological succession of grassland is desert. It is, however, notable that the soil of grassland ecosystem is rich in nutrients and organic matters and provides the largest biomass.

The compounds that resist biodegradation and thereby persist in the environment are called recalcitrant. The recalcitrant xenobiotic compounds can be grouped into the following six types:
(i) halocarbons;
(ii) polychlorinated biphenyls;
(iii) synthetic polymers;
(iv) alkylbenzyl sulphonates;
(v) oil mixture and
(vi) others.

Correct Option: D

The compounds that resist biodegradation and thereby persist in the environment are called recalcitrant. The recalcitrant xenobiotic compounds can be grouped into the following six types:
(i) halocarbons;
(ii) polychlorinated biphenyls;
(iii) synthetic polymers;
(iv) alkylbenzyl sulphonates;
(v) oil mixture and
(vi) others.

X-rays are used to detect and photograph defects of internal structure of a body such as metals, machine parts, cracks in wood, defects in diamonds and other precious stones, etc. They can reveal inhomogeneities—such as inclusions, lattice defects, etc in gems and stones.

Correct Option: C

X-rays are used to detect and photograph defects of internal structure of a body such as metals, machine parts, cracks in wood, defects in diamonds and other precious stones, etc. They can reveal inhomogeneities—such as inclusions, lattice defects, etc in gems and stones.