(2) Cotyledons? endosperm
(3) photosynthesis? Chloroplast and mitochondria
(4) Ovary wall
(5) Relative characteristics
(6) artificial pollination
This topic investigated the conditions and process of seed germination, the structure and composition of seeds, the application of photosynthesis principle in production, mitochondria and chloroplasts are two kinds of energy converters in cells, the formation of fruits and seeds, the concepts of biological characteristics and relative characteristics, pollination and fertilization.
(1) The external conditions for seed germination are suitable moisture, sufficient air and suitable temperature; The self-condition of seed germination is that there must be a complete and dynamic embryo and nutrients needed for embryo development. When sowing melon seeds in early spring, because the outside temperature is still relatively low, farmers often cover the ground with plastic films in order to ensure the suitable temperature for seed germination.
(2) The structure of melon seeds and corn seeds includes seed coat and embryo. Embryos of seeds include germ, hypocotyl, radicle and cotyledon. Corn seeds have endosperm and a cotyledon, and nutrients are stored in the endosperm. Melon seeds have no endosperm and two cotyledons, and nutrients are stored in the cotyledons.
(3) The direct function of greenhouse ventilation is to make carbon dioxide in the air enter the greenhouse, increase the concentration of carbon dioxide, promote photosynthesis, and synthesize more organic matter, which is conducive to increasing production.
There are two kinds of energy converters in cells: chloroplasts and mitochondria. Chloroplast is a plastid containing chlorophyll and other pigments in green plant cells, and it is a place for photosynthesis of plant cells. Mitochondria can decompose organic matter in cells into carbon dioxide and water with the participation of oxygen, and at the same time release chemical energy in organic matter for cells to use; Mitochondria exist in animal cells and plant cells and are the main places for cell respiration. Melon leaf cells contain both chloroplasts and mitochondria.
(4) After fertilization, the ovary of the pistil expands slowly, and finally develops into fruit, and the ovules in the ovary develop into seeds, so the edible part of melon develops from the ovary wall of the pistil.
(5) Two kinds of melons, one with green skin and the other with bright white skin, belong to different manifestations of the same trait of the same organism and are relative traits.
(6) Because of the low temperature, insect-borne pollination lacks enough insects to fly out for pollination, thus reducing the chances of pollination and fertilization and affecting the yield of fruits and seeds. In agricultural production, artificial pollination is often used to overcome the defect that pollination cannot be guaranteed due to insufficient conditions and achieve the expected yield. The specific methods of artificial pollination are different for different crops. Generally, pollen is collected from stamens first, and then smeared or sprinkled on the stigma of plant pistils, or the collected pollen is stored in low temperature and dry conditions for later use.