Second, various factors that directly affect biological life in the environment are called ecological factors, which are divided into abiotic factors and biological factors. Abiotic factors include light, water, temperature, air and soil. 2. Biological science studies life phenomena and the laws of life activities.
3. If stains appear under the microscope, turn the eyepiece and the stains will move, and the stains will be on the eyepiece; Move the slide specimen, if the stain moves, the stain will be on the slide specimen; Turn the eyepiece and move the sample. If the stain has not moved, it is on the objective lens. 2. When taking out and transporting the microscope, hold the mirror base with one hand and the mirror arm with the other. 3. When turning the coarse focusing screw to lower the objective lens, the eyes must look at the objective lens to prevent the objective lens from damaging the slide specimen. 3. The materials observed by microscope must be thin and transparent. 4. The actual magnification of the object observed under the microscope is: objective magnification x eyepiece magnification.
Fourthly, scientific inquiry is one of the important information channels for people to actively acquire scientific knowledge and know the world, which usually includes asking questions, making assumptions, experimental verification, drawing conclusions, expressing and communicating. Scientific inquiry usually requires controlled experiments. In the controlled experiment, all the factors are the same except the experimental variables. For example, in the experiment to explore where maggots on carrion come from, the variable is whether pork is in direct contact with flies outside, and other factors are the same.
5. Plant cells include seven parts: cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria and chloroplast; Human and animal cells have only cell membrane, cytoplasm, nucleus and mitochondria, but no cell wall, chloroplast and vacuole.
2. Cell membrane can control the substances inside and outside the cell (it is the gatekeeper); Cytoplasm is an important place for life activities; The nucleus contains genetic material and transmits genetic information (Management and Regulation Department); Mitochondria are related to respiration and provide energy for cell life activities (power workshop); There is cell fluid in vacuole; Chloroplast is related to photosynthesis of plants (production workshop).
3. The life activities of organisms are based on various life activities of cells, which are the functional units of the basic structure of life activities.
6. Cell division increases the number of cells; Cell growth increases cell volume. All living things have growth phenomenon, which is the result of cell division and cell differentiation.
2. Cell division is usually a process in which one cell divides into two cells. First, chromosomes appeared, which were divided into two parts in the center of the cell and moved to both ends of the cell, and the cytoplasm was divided into two parts on average.
3. Cell differentiation refers to the process that divided cells change in different directions in morphology, structure and function. Tissue is the result of cell differentiation.
4. Cells with similar morphology and the same structure are United and have certain functions. Such cell groups are called tissues. Animals have epithelial tissue, muscle tissue, connective tissue and nerve tissue. Plants have four kinds of tissues: protective tissue, conductive tissue, basic tissue and meristem.
Seven, the six organs of plants: roots, stems, leaves, flowers, fruits and seeds; Roots, stems and leaves are vegetative organs; Flowers, fruits and seeds are reproductive organs.
2. The structural levels of plants are: cells, tissues, organs and individuals; The structural levels of humans and animals are: cells, tissues, organs, systems and individuals.
Eight, paramecium has only one cell, but it is also a life. Because this cell can independently complete life activities such as nutrition, respiration, excretion, exercise and reproduction. Paramecium eats 43 thousand bacteria every day, which can purify sewage; Paramecium is asexual reproduction through division. Swing by cilia and rotate in the water.
2. Drop two drops of paramecium culture solution on the glass slide, connect them in the middle, add salt at the same time, and all paramecium will swim to the side without salt, because paramecium can escape harmful stimulation; If the beef soup drops aside, all paramecium will concentrate in the beef soup, because paramecium can tend to be beneficial to stimulation.
9. Kidney bean seeds have no endosperm, and nutrients are stored in cotyledons; Corn seeds have endosperm, and nutrients are stored in the endosperm.
2. Seed germination conditions: (1), complete and vigorous embryo; (2), ① Sufficient moisture; ② Sufficient air; ③ Suitable temperature.
3. Seeds include seed coat and embryo. Embryos are all composed of germ, hypocotyl, radicle and cotyledon. Embryo is the larva (new life) of a new plant.
4. After the seeds germinate, the radicle develops into a root; Hypocotyl develops into a part connecting root and stem; The germ develops into stems and leaves; Cotyledons disappear.
Eleven, the root tip is divided into four parts, namely: root cap, which has a protective effect; Meridian belt, strong splitting ability; In the elongation zone, cells are rapidly elongated; Mature area, with root hairs, is the main part of root water absorption and inorganic salts. The growth of roots (roots can grow) depends on cell division in meristem and cell elongation in elongation zone.
2. The roots of plants have the characteristics of growing to the ground, which are rich in fertilizer and water.
12. Young trees can absorb water because the root hair absorbs water when the cell fluid concentration of young root hair is greater than that of soil solution; If too much fertilizer is applied, plants will burn seedlings, because the concentration of soil solution is greater than that of plant cell fluid, and plant root hairs will lose water. 2. The roots of plants not only absorb water, but also absorb inorganic salts dissolved in water.
3, sugar mixed with tomatoes, salt mixed with vegetables, because the concentration of sugar water is greater than the concentration of tomato cell sap, the concentration of salt water is greater than the concentration of vegetable cell sap, so there will be a lot of water on the plate; Withered vegetables are soaked in water, because the cell sap concentration of vegetables is higher than that of green water, and vegetables absorb water and become hard.
Thirteen, nitrogen: leafy; Phosphorus: fruitful; Potassium: The stem is strong. Plants also need inorganic salts containing calcium, zinc and boron.
Fourteen, stems developed from buds; Buds include flower buds (which will develop into flowers later) and branch buds (which will develop into branches and leaves later). (question 2 on page 28 of the experiment)
2. Woody plant stem: (1), the bark has a protective effect on the outside, called phloem inside, and sieve tube inside; (2) The cambium is very thin and has splitting ability, forming phloem outward and xylem inward; (3) The xylem is hard and has strong support, and there are conduits inside; (4) The pith has the function of storing nutrition. 3. The stems of herbaceous plants do not have cambium, so they cannot be thickened year by year. 4. Because the conduit in xylem can transport water and inorganic salts from bottom to top, the stem is inserted into red ink, and only xylem is dyed red; Because the sieve tube in bark phloem can transport organic matter from top to bottom, woody plant stems are stripped of a layer of bark, and the sieve tube is blocked from transporting organic matter, which will produce nodules.
The main parts of flowers are pistils and stamens, because they are related to the formation of fruits and seeds.
2. Ovary includes ovary wall and ovule; There are fertilized eggs in the ovule. Ovary development results; Ovary wall develops into fruit skin; Ovules develop into seeds; A fertilized egg develops into an embryo (an embryo is a new life). 3. Fruit = seed+peel; Seed = seed coat+embryo (page 3 1 in the experiment book)
Sixteen, photosynthesis: raw materials-carbon dioxide+water; Products-organic matter+oxygen; Power: light; Condition: chlorophyll.
2, respiration: absorb oxygen and decompose organic matter; 2. Produce carbon dioxide and water; 3. release energy. 4. Significance: The released energy is the energy that plants need to carry out various life activities.