The first four chapters of Biology in Compulsory 3 focus on summarizing and summarizing the key know

All things are foreseen, and those who are not prepared are wasted. Learning biology requires attention to methods and skills, and more importantly, it is necessary to learn to summarize and organize knowledge points. The following is the knowledge points of Chapter 5 of Biology Compulsory 3 that I have compiled for you, I hope it will be helpful to you!

Chapter 5: Ecosystems and Their Stability.

2. The function of the ecosystem: the material cycle and energy flow, which is composed of biological communities and inorganic environments.

4. Characteristics of energy flow: one-way flow, decreasing step by step. Efficiency of energy transfer between two adjacent trophic levels: 10% 20%.

5. Study the meaning of energy flow:

1) It can help people plan and design artificial ecosystems scientifically, so that energy can be used most effectively.

2) It can help people rationally adjust the energy flow relationship in the ecosystem.

6. Similarities and differences between energy flow and material circulation

Differences: In the material cycle (which is global and circular), substances are recycled; As energy flows through trophic levels, it decreases and flows in one direction, rather than in a cyclic manner.

Connection: (1) The two are at the same time, interdependent and inseparable.

2) The fixation, storage, transfer, and release of energy are inseparable from the synthesis and decomposition of matter.

3) Matter acts as a carrier of energy, so that energy flows along the food chain (net); Energy acts as a power force that enables matter to constantly circulate back and forth between the biome and the inorganic environment.

7. Types of information in the ecosystem: physical information, chemical information, behavioral information (peacock opening, bee dancing, courtship).

8. The role of information transfer in the ecosystem:

1) The normal progress of life activities is inseparable from the transmission of information; The reproduction of biological populations is also inseparable.

Transfer of information.

2) Information can also regulate the interspecific relationships of organisms to maintain the stability of ecosystems.

Application of information transfer in agricultural production:

1) Increase the production of agricultural and livestock products.

2) Control of pest animals.

9. Stability of the ecosystem: The ability of the ecosystem to maintain or restore the relative stability of its own structure and function. Ecosystems have the ability to self-regulate, but this self-regulation capacity is limited.

Resistance stability: Ecosystems resist external disturbances and keep their structure intact.

In general, the more components in the ecosystem, the more complex the food web, the stronger its self-regulation ability, the higher the stability of resistance, and the worse the stability of resilience.

11. Ways to improve the stability of ecosystems:

1) The degree of disturbance to the ecosystem should be controlled, and the use of the ecosystem should be moderate, and should not exceed the self-regulating capacity of the ecosystem.

The three compulsory knowledge points of biology are as follows:1. Homeostasis: The normal body makes various organs and systems coordinate their activities through regulation to jointly maintain a relatively stable state of the internal environment.

The stability of the internal environment is a necessary condition for the body to carry out normal life activities.

2. Hormone regulation: regulated by chemicals secreted by endocrine organs (or cells).

3. The life activities of animals are often regulated by nerves and body fluids at the same time, but neuromodulation is still in a dominant position.

4. Negative feedback regulation is ubiquitous in ecosystems, and it is the basis of the self-regulation ability of ecosystems.

5. Applying a certain concentration of auxin solution to the stigma of the pistil without pollination can obtain fruitless fruits.

The three compulsory knowledge points of biology are as follows:

1. The composition and content of interstitial fluid and lymph are similar to those of plasma, but not identical, the main difference is that plasma contains more protein, while interstitial fluid and lymph contain less protein.

2. The homeostasis of the internal environment refers to the fact that the composition and physical and chemical properties of the internal environment are in dynamic equilibrium.

3. Measurement methods of population density: sample method (plants and animals with weak locomotor ability), marker recapture method (animals with strong locomotion ability).

4. Most of the auxin is concentrated in the parts with vigorous growth, such as: germ sheath, apical meristem of buds and roots, developing fruits and seeds, etc.

5. The dual role of auxin is related to concentration and organs. For example, roots are more sensitive than buds, and buds are more sensitive than stems. Low concentrations promote growth, and high concentrations inhibit growth.