Tag: biology

In the poultry industry, production of hatching egg is more expensive because it requires optimum temperature fo incubation. But the major factor is the weight of the hatching egg and chick weight. Under optimal egg storage and incubation conditions, chick weight is 67-69 per cent of egg weight at setting. Therefore, the more uniform the egg weight, the more uniform the chick weight. Breeder uniformity determines uniformity in the hatching eggs produced; the more uniform the breeder flock, the more uniform the egg weights. Hence, some of the eggs produced by hatchery flocks are not acceptable for incubation and is rejected. So, the production of hatching eggs is more expensive than the production of market eggs.

The indigenous breed of poultry of India is Aseel. It is noted for its pugnacity, high stamina, majestic gait and dogged fighting qualities.

Apical dominance is a phenomenon in which central stem is dominant and lateral stems are suppressed. It is due to plant hormones produced in the tip of the shoot. Auxin hormone is responsible for apical dominance and cytokinin hormone is responsible for breaking the apical dominance. Hence, apical dominance depends on the auxin to cytokinin balance. 

Decapitation involves cutting of apical bud in plants. When the apical bud is removed, the source of auxin is removed. Auxin causes apical dominance. Since the auxin concentration is much lower, the lateral buds can now grow. In fact, their growth will be stimulated by a relatively small drop in auxin concentration. Thus, decapitating a shoot will cause it to branch.

Protease and pectinase are enzymes used in the food industry to clarify fruit juices by breaking down cell wall components. Beer is produced by fermentation, not distillation; methanogens are anaerobic; streptokinase is a clot buster, not a cholesterol-lowering agent.

Auxin exerts profound effects on plants. For example, some plants tend to branch out very little when they grow. Growth in these plants occurs almost exclusively from the apical meristem rather than from axillary buds, which do not develop as long as the terminal bud is present. Such plants are said to exhibit apical dominance, the inhibition of axillary bud growth by the apical meristem. In plants with strong apical dominance, auxin produced in the apical meristem inhibits axillary buds near the apical meristem from developing into actively growing shoots. When the apical meristem is pinched off, the auxin source is removed and axillary buds grow to form branches. Apical dominance is often quickly re-established, however, as one branch begins to inhibit the growth of others.

Auxin is the phytohormone which is responsible for promoting apical dominance in plants. Auxin is usually seen at the growing tips of plants. Thus the auxin present at the tip of plants will be channelized sidewards, lateral meristem; so that the plants will not grow tall but instead becomes bushy in nature.

Auxins promote elongation of stem and coleoptile. It promotes the growth by the elongation of cells in the apical meristem. Growth in the lateral bud is inhibited when the apical bud of a tall plant remains intact. However, the lateral bud grows rapidly on the removal of apical bud. Suppression of growth in the lateral bud by apical bud due to auxin produced by apical bud is termed as apical dominance. IAA is an example of auxin.