Tag: chemical coordination in plants

Option D is incorrect as IAA is an auxin that causes apical dominance. It involves withdrawal of root manufactured cytokinins towards apical bud which in turn makes the lateral bud cytokinins deficient. Cytokinins deficiency suppresses growth of lateral buds as cytokinins are the hormones of cell division. Pruning is cutting off the apical portion of branches to induce growth which in turn lowers the amount of auxin synthesized as shoot apex. The lowered auxin synthesis allows translocation of cytokinins to lateral bud stimulating cell division and growth of lateral branches. This makes option C correct. Option A is incorrect as ethylene inhibits lateral buds and causes apical dominance. Option B is incorrect as gibberellins are the hormones of stem elongation of genetic dwarfs and seed germination. 

The cytokinins are plant growth substances which act primarily on cell division and little or no effect on extension growth. The most important function of cytokinins is the promotion of cell division. It is now well established that these are true cell division factors. The varying amount of cytokinins, along with sufficient auxin is required for the growth of callus in the tissue culture experiments. Thus option B is the correct answer.

Cytokinin promotes cell division and cell elongation. Thus they are found in the region where there is rapid cell division like fruits and seeds.

Cytokinins are a class of plant growth substances that promote cell division, or cytokinesis, in plant roots and shoots. They are derivatives of pure adenine. It is a true cell division factor, promotes meristematic tissue regions. It prevents destruction of chlorophyll in leaves.

Cytokinins retard the aging in plants. The effect is called as Richmond-Lang effect. Richmond-Lang effect is retardation of aging due to cytokinins which acts by retarding the rate of destruction of chlorophyll and yellowing of leaves.

Kinetin is present in the coconut water, which is actually a liquid endosperm. Hence, the name coconut milk factor. It actually serves as the nourishment for the growth of embryo in coconut. Coconut water is also used as artificial blood plasma.

Kinetin promotes the synthesis of RNA, proteins, etc., which help in initiation of root, breaking of seed dormancy, etc. In the case of onion root, which underwent kinetin treatment more RNA could be spotted out because of this reason.

Kinetins induce the synthesis of RNA. Kinetin is a type of cytokinin, a class of plant hormone that promotes cell division. It was originally isolated by Miller and Skoog et al. It was given the name kinetin because of its ability to induce cell division. Kinetin is often used in plant tissue culture for inducing formation of callus and to regenerate shoot tissues from callus. Florigen induces flowering.

Cytokinins are a class of plant growth substances that promote cell division or cytokinesis in plant roots and shoots. They are involved primarily in cell growth and differentiation, but also affect apical dominance, axillary bud growth and leaf senescence. Letham first synthesized it from corn milk.

According to Richmond lang effect, cytokinin hormone in plants will cause retardation of chlorophyll and several other proteins. Thus, it helps in reducing the senescence.