Answer:
Option-B
Explanation:
Phototropism refers to the movement of plants in response to light. The mechanism of phototropism involves the photoreceptors which respond to a different wavelength of light: the phytochromes to red light, cryptochromes to blue light and the phototropin to the UV light.
Plants integrate the signals obtained from these receptors and then activates the gene which will be involved in the phototropism.
The gene could be the production of the auxin hormone and the PIN proteins which helps in the distribution of the auxin in the plants. Due to the production of this hormone and its distribution in the shoot, the grass tips bend towards the light.
Thus, Option-A is correct.
Answer:
Root hair cells are alive and therefore need energy, which is why root hair cells contain many mitochondria in them. Root hair cells don't contain chloroplasts. Chloroplasts are used by the plant to make food using light energy. Since the roots aren't exposed to any form of light, they have no need for chloroplasts.
Explanation:
Respiration..
the act of respiring; inhalation and exhalation of air; breathing. Biology. the sum total of the physical and chemical processes in an organism by which oxygen is conveyed to tissues and cells, and the oxidation products, carbon dioxide and water, are given off.
