BIOMOLECULES AND ENZYMES

Detailed explanation-1: -In phototropism a plant bends or grows directionally in response to light. Shoots usually move towards the light; roots usually move away from it. In photoperiodism flowering and other developmental processes are regulated in response to the photoperiod, or day length.

Detailed explanation-2: -Phototropism, or the differential cell elongation exhibited by a plant organ in response to directional blue light, provides the plant with a means to optimize photosynthetic light capture in the aerial portion and water and nutrient acquisition in the roots.

Detailed explanation-3: -The activated phytochrome A changes the activity of genes located in the cell nucleus that govern plant growth and development. Resulting changes in gene expression produce the plant’s developmental responses to light, such as growth, flowering and straining towards the light.

Detailed explanation-4: -Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light contain a hormone called auxin that reacts when phototropism occurs. This causes the plant to have elongated cells on the furthest side from the light.

Detailed explanation-5: -Plants use light to track time, which is known as photoperiodism. They can tell the time of day and time of year by sensing and using various wavelengths of sunlight. Light can also elicit a directional response in plants that allows them to grow toward, or even away from, light; this is known as phototropism.