Plant Biology - Hormone Review

Ethylene is the correct answer because it is a hormone that is responsible for ripening fruits, leaf and flower senescence (aging and death), abscission (shedding of leaves and fruits), and the development of root hairs. It also promotes the development of chloroplasts, which are responsible for photosynthesis in plants. Ethylene also regulates the expression of ripening genes, further supporting its role in fruit ripening.

Auxin is the hormone responsible for shoot elongation, apical dominance, lateral root branching in roots, and root hair initiation. It promotes cell elongation in shoots, inhibits the growth of lateral buds to maintain apical dominance, stimulates the formation of lateral roots, and induces the initiation of root hairs. Therefore, auxin is the correct answer for this question.

ABA, or abscisic acid, is the hormone responsible for promoting seed and bud dormancy, suspension of root growth, and stomatal closure. It also inhibits the effects of other hormones. ABA plays a crucial role in regulating plant responses to environmental stresses such as drought and salinity. It helps plants conserve water by closing stomata, reducing transpiration, and promoting dormancy to survive unfavorable conditions. Additionally, ABA interacts with other hormones to maintain hormonal balance in plants.

GA (gibberellic acid) is the hormone responsible for breaking dormancy in buds and seeds, inducing flowering, and promoting stem elongation. It plays a crucial role in plant growth and development by stimulating cell division and elongation. GA also regulates various physiological processes such as seed germination, leaf expansion, and fruit development. Overall, GA promotes plant growth by influencing the production of enzymes and proteins involved in these processes.

Cytokinin is a hormone that promotes cell division, lateral bud growth, and leaf expansion. It is also used artificially to extend the life of cut flowers.

CK (Cytokinin) is a hormone that slows down leaf aging. It promotes cell division and delays the process of leaf senescence. This hormone helps in maintaining the greenness and vitality of leaves by preventing the breakdown of chlorophyll and other essential components.

The pH of the cell wall is 5 and the pH of the cytoplasm is 7. The cell wall is slightly acidic, while the cytoplasm is slightly basic. This difference in pH is important for maintaining the proper functioning of the cell. The acidic environment of the cell wall helps to protect the cell from external threats, while the slightly basic cytoplasm is necessary for various cellular processes to occur.

Auxin is a plant hormone that functions as an anion at pH 7, meaning it carries a negative charge at this pH level. However, at pH 5, auxin is neutral, meaning it does not carry any charge. This change in charge is likely due to the ionization of auxin molecules in different pH environments.