It can be seen that the integument develops into a seed coat, so the shell of peanut develops from the ovary wall, and the seed and seed coat of kidney bean develop from the ovule.
B. Planting plants in desert areas can prevent wind and fix sand, while planting plants in sand-blown areas can prevent wind and fix sand, which belongs to the biological impact on the environment. Therefore, this statement is wrong.
C. Algae plants are simple in structure and have no differentiation of roots, stems and leaves. The cells of algae plants contain chloroplasts. The life of algae plants needs suitable temperature. In spring, the temperature is suitable for the growth of algae, which will make algae multiply and make the water green. It can be seen that the poem in the title should describe algae plants; So, C is correct.
D. the conditions of seed germination are divided into self-condition and external condition. The external conditions are suitable temperature, suitable humidity and sufficient air. Early spring sowing often affects seed germination because of low temperature. Plastic film is often used to cover the ground to raise the ground temperature and promote early and uniform seedling emergence. Therefore, after sowing in early spring, plastic film is often used to cover the ground to promote early emergence. The main reason is that moisturizing and heat preservation is beneficial to seed germination. This statement is wrong.
So choose: C.