Answer: 1D, the virus has no cell structure and is very small. 2C can only be observed under an electron microscope. It is a gymnosperm, and the characteristics of gymnosperm are as follows. 3B of the seed. Peanut shell is the ovary wall, the ovary wall develops into fruit skin, and the ovule develops into seed. 4C, the sieve tube was cut off, which blocked the organic matter transported by the blade to the root. 5B, at night. In this way, the respiration of nails is enhanced, the consumption of organic matter is increased by 0.6c, and the newly harvested seeds should be dried as soon as possible, that is, the respiration is reduced by 0.7c. They are all carried out at the same temperature and humidity, and the germination conditions are the same.

8. The integument develops into seed coat; The polar nucleus develops into _ _ _ endosperm _ _ _ _; The fertilized egg cells develop into embryos. Analysis: This is the phenomenon of double fertilization in angiosperms. The fertilized egg develops into an embryo, the fertilized polar nucleus develops into an endosperm and the integument develops into a seed coat. 4, 1. This virus is very small and must be used.

A, magnifying glass b, low-power microscope c, high-power microscope d, electron microscope

2. Ginkgo biloba is a world-famous "living fossil", which originated in China. Scientists listed it as a gymnosperm, mainly based on

A. the roots, stems and leaves are well developed. B. fertilization does not require water.

C, ovule without ovary wall, seed without pericarp D, ovule with ovary wall and seed without pericarp

3. If there are three seeds in a peanut fruit, then this peanut fruit is made of

A, 1 ovary, 1 ovule, b, 1 ovary, 3 ovules, c, 3 ovaries, 1 ovule, d, 3 ovaries, 3 ovules.

The willow was destroyed, and the base of the stem was peeled off. After a while, the willow tree died. this is because

A, the catheter is cut off, and the root lacks inorganic salts. B, the catheter was cut off, and the leaves lacked inorganic salts.

C. The sieve tube is cut off, and the roots are short of organic matter. D. The sieve tube is cut off, and the blades are short of organic matter.

5. In summer, two pots of plants A and B with the same size and growth status are placed in the same lighting conditions during the day, A is placed in a relatively warm environment at night, and B is placed in a relatively cool environment. After a period of time, it was found that the growth of the two pots was generally as follows

A, A is better than B, B is better than A, C, there is no difference D, so it is impossible to judge.

6. The main reason why newly harvested seeds should be dried as soon as possible is that

A, inhibit photosynthesis b, promote photosynthesis c, inhibit respiration d, and promote transpiration.

7. Divide the seeds with complete and full grains into group A and group B, and sow at about 25℃ respectively. The seeds of group A are fertile.

In moist soil, group B was planted in barren moist soil. The germination of these two groups of seeds is as follows

A, B starts, A starts, C starts, and D starts at the same time, but none of them are sent.

8. _ _ _ _ _ _ develops into a seed coat; The polar nucleus develops into _ _ _ _ _ _ _ _; Egg cells develop into _ _ _ _ _ _ _ _

The answer is: 5: DC BCB 7: CC Question 8, please give the answer to the teacher.