1, here are some simple unit 7, chapter 1, biological reproduction and development 1. Plant propagation 1. Sexual reproduction: a reproductive mode in which fertilized eggs develop into new individuals. For example, seed propagation (reproduction of offspring from seeds in fruits through flowering, pollination and fruiting). ) (Egg cells in ovules combine with sperm in pollen to form fertilized eggs → embryos → seeds) 2. Asexual reproduction: new individuals are directly produced by the mother and do not need the combination of bisexual germ cells. Such as cutting, grafting, layering and tissue culture. 3. The key of grafting: the scion is closely combined with the cambium of the rootstock to ensure survival. 2. The reproduction and development of insects is 1. Complete metamorphosis: In the process of developing from fertilized eggs into new individuals, the structure and life habits of larvae and adults are very different. This development process is called metamorphosis: eggs → larvae → pupae → adults. For example: silkworms, bees, butterflies, moths, flies and mosquitoes. 2. Incomplete metamorphosis: egg → nymph → adult. Examples: locust, cicada, cricket, mole cricket, mantis. Reproduction and development of amphibians 1. Abnormal development: egg → tadpole → young frog → adult frog 2. Features: Oviposition, in vitro fertilization. Four. Breeding and development of birds 1. Process: nesting, courtship, mating, spawning, hatching and brooding. 2. Features: Fertilization in the egg. 3. Structure of bird eggs: yolk is an egg cell. The blastoderm contains the nucleus. Eggshell and shell membrane-protection, egg white-nutrition and protection, egg yolk-nutrition. The blastoderm is where the embryo develops. Chapter II Inheritance and Variation of Organisms? Heredity: refers to the similarity between parents and children. ? Variation: refers to the difference between offspring and parents. 1. Genetic control of biological characteristics 1 Biological characteristics: morphological and structural characteristics, physiological characteristics and behavior patterns. 2 Relative characteristics: different manifestations of the same trait of the same organism. 3. Genes control biological characteristics. For example: transgenic super mice and mice. Organisms inherit genes rather than traits. Second, gene transmission between parents and children 1. Gene: DNA fragment on chromosome that controls biological characteristics. 2.DNA: It is the main genetic material of double helix structure. 3. Chromosome: A substance in the nucleus that can be dyed dark by alkaline dyes. 4. Genes are transmitted through sperm or egg cells. Sperm and egg cells are the "bridge" of gene transmission between parents and children. ? The morphology and number of chromosomes in each biological cell are determined. ? Chromosomes exist in pairs in biological cells, and genes also exist in pairs, which are located on paired chromosomes respectively. ? In cell division that forms sperm or egg cells, chromosomes are reduced by half. Three. Dominant and recessive genes 1. Relative characters are dominant and recessive. The first generation hybrids are dominant. 2. Recessive trait genome becomes: dd dominant trait genome is called DD or Dd3 .. China's marriage law stipulates that marriage is prohibited between lineal blood relatives and collateral blood relatives within three generations. 4. If a family has inherited diseases or carried pathogenic genes, its offspring are more likely to carry pathogenic genes. If the related offspring remarry and have children, the chances of suffering from this disease will increase. Number four. The human sex inheritance is 1. There are 23 pairs of chromosomes in each normal person's somatic cells. (male: 44+XY female: 44+XX) 2. Among them, 22 pairs of men and women are the same, and one pair of men and women is different, which is called sex chromosome. The male is XY, and the female is XX.3. Variation is first determined by the difference of genetic material basis, and secondly related to the environment. So there are genetic variation and non-genetic variation. 2. Examples of human applying the principle of genetic variation to cultivate new varieties: artificial selection, cross breeding and space breeding (gene mutation) Chapter III Evolution of organisms 1. The origin of life on earth is 1. Most scholars believe that this process is carried out on the primitive earth, from inorganic substances in the primitive atmosphere to organic substances and then to primitive life. 2. Primitive earth conditions: high temperature, high pressure, ultraviolet rays, thunder and lightning, primitive ocean and lack of oxygen. 3. protein and nucleic acid are important substances in life. 2. The course of biological evolution 1. Comparative method: according to certain standards, compare interrelated things to determine their similarities and differences. 2. Fossils: the remains, relics or traces of life of organisms buried in the stratum for various reasons and formed after tens of thousands of years of complex changes. For example, archaeopteryx fossils (ancient reptiles → ancient birds) submit answer 3. The general trend of biological evolution: simple to complex, low to high, aquatic to terrestrial, reasons for biological evolution 1. Simulating the formation process of protective color: one aspect of animals' adaptation to the environment is the result of natural selection II. Natural selection: organisms compete for survival, the fittest survive, and the unsuitable are eliminated. 3. Process: excessive reproduction, survival competition, genetic variation, survival of the fittest. 4. Significance: Organisms constantly evolve through heredity, variation and natural selection.