(2) There are biological factors and abiotic factors that affect biological life. Biological factors refer to other organisms that affect biological life. Abiotic factors include water, sunlight, temperature and soil.
(3) After flowering, angiosperms must be pollinated and fertilized to produce fruits and seeds. In spring, fruit farmers often raise bees in apple orchards to help pollinate.
(4) Photosynthesis mainly takes place in mesophyll cells of leaves. Although fruit farmers began to bag apples, the bagged apples could not see the sun all day, but the organic matter synthesized by photosynthesis of leaves could be transported to the apples through sieve tubes, and the water and inorganic salts absorbed by roots from the soil were transported to the apples through conduits to make them grow.
(5) Seeds are developed from ovules, so the number of seeds depends on the number of ovules. There are many seeds, indicating that there are many ovules in the ovary.
So the answer is: (1) grafting;
(2) Water, sunlight, temperature and soil;
(3) help pollination;
(4) Organic matter synthesized by photosynthesis of leaves can be transported to apples through sieve tubes, and water and inorganic salts absorbed by roots from soil are transported to apples through conduits to make them grow;
(5) Multiple ovules.