Answer:
1. reducing soil erosion,
2.Controlling runoff water
Explanation:
Contour farming mitigates the impacts of floods, storms and landslides on the crops by reducing soil erosion up to 50 percent, controlling runoff water, increasing moisture infiltration and retention and thus enhancing soil quality and composition
P700 is photosystem I. It includes chlorophyll a 670, 680, 695, 700, Chlorophyll b, carotenoids. The active reaction center of photosystem is p700, as it absorbs light of a wavelength longer than 680nm.
P680 or the photosystem II has the following pigments: chlorophyll b, 660, 670, 680, 695, 700, phycobilins, and xanthophylls. The active reaction center, in this case, is p680 of chlorophyll a, as it absorbs the light having a wavelength shorter than 680nm.
The answer is osteoporosis
Osteoporosis is a condition when the bone(osteo) density is decreased, makes them look like having pore or spongy. It is found frequently in the elder woman that has been menopause for a few years.
Estrogen has a role in bone remodeling which causes a protective effect on woman before menopause.