1) Example of biological adaptation to the environment: Camels in the desert have little urine. The underground roots of Alhagi are much longer than the aboveground parts. Seals in cold seas, thick subcutaneous fat on the chest, flag trees, etc.
2) Biological impact on the environment: Earthworms move in the soil, which can loosen the soil, and their feces increase the fertility of the soil; Sand plants such as windbreak and sand fixation belong to the biological influence environment.
7. Concept and composition of ecosystem
Concept: The unified whole formed by biology and environment in a certain area is called ecosystem.
Composition: including biological part and abiotic part. The biological part includes producers, consumers and decomposers. Abiotic parts include sunlight, water, air, temperature, etc.
8, food chain and food web:
The relationship between producers and consumers is mainly the relationship between eating and being eaten, thus forming a food chain. There are often many food chains in an ecosystem, which often cross each other to form a food web.
Second unit
9. Names and functions of various parts of the optical microscope:
Mirror holder-stabilize the mirror body. Column—Supports the component above the column. Mirror arm-the part that supports the mirror. Stage-the place where the slide specimen is placed. There is a light hole in the middle and two flat clips on both sides. Lens barrel-the eyepiece is installed at the upper end and the converter is installed at the lower end. Converter-a turntable with an objective lens. Coarse focus screw-when rotating, the lens barrel can be greatly raised and lowered. Fine-tuning the focus screw-when rotating, the lifting range of the lens barrel is small, which can make the image clearer. Eyepiece and objective lens-the eyepiece is the lens for eyes to observe; An objective lens is a lens close to an object. Shader-there are round holes of different sizes on it, called aperture. The light intensity can be adjusted for light holes with different apertures. Reflector-one side is a flat mirror (used in strong light) and the other side is a concave mirror (used in low light). Rotating the reflector can make the light reflect upward through the light hole. The magnification of the object image is the magnification of the eyepiece multiplied by the magnification of the objective lens.
10, and observe the loading situation with a microscope.
① The object seen from the eyepiece is an inverted image. Example: If you see a "D" in the field of vision of a microscope, then "P" is written on transparent paper. ② Eyepiece magnification ╳ objective magnification = microscope magnification
1 1, the basic structure and function of cells
① Cell membrane-② cytoplasm-cytoplasm contains many fine structures related to various life activities. The cytoplasm of living cells is fluid, and ③ the nucleus plays an important role in biological inheritance. 12, the difference between plant cells and animal cells
In addition to cell membrane, cytoplasm and nucleus, plant cells generally have cell walls, chloroplasts and vacuoles.
13, Preparation and Observation of Onion Epidermal Cell Slices
Manufacturing steps: (1) First, drop a drop of water in the center of a clean glass slide. (2) Break the onion scales outward, and tear off a small piece of transparent film from the inner surface of the scales with tweezers. (3) Put the torn film into the water drop in the center of the glass slide and flatten it gently with a dissecting needle. (4) Clamp the edge of one side of a cover glass with tweezers, first touch the other side with water drops, then gently flatten it and cover it on the film. Be careful not to leave bubbles under the cover glass. (5) After dyeing with iodine solution. (6) Slice the prepared onion epidermal cells and observe them under a low-power microscope.