Sep 113 mins read

The summary of Xueba, very comprehensive and practical knowledge points for middle school entrance examinations


1. The concept of the biosphere: The biosphere refers to the field of life activities on the earth and the whole of its living environment. The biosphere is a common home on the earth.

2. The environmental factors affecting biological life are divided into two types: 1. Non -biological factors such as light, temperature, water, air and other non -biological factors. 2. Biological factors.

3. The impact of biological factors on biological: Biological factors refer to other creatures that affect a certain biological life. Each organism in nature is affected by many other creatures around. The relationship between creatures and creatures is: predation relationship, competition, cooperative relationship, etc.

4. Each creature has a form structure and lifestyle that is compatible with its living environment. The adaptability of creatures is common.

4. Biomedical ingredients: producers (mainly refer to green plants) consumers (mainly animal) decomposition (mainly refer to microorganisms such as bacteria and fungi)

5. Non -biological components: sunlight, air, water, etc.

6. Various creatures that constitute an ecosystem are mutually influenced, interactive, and interdependent.

7. The substances and energy in the ecosystem are flowing along the food chain and food network. Toxic substances can accumulate along the food chain.

8. The ecosystem has a certain self -regulating ability, so that the number and proportion of various creatures in the ecosystem have remained relatively stable, but this regulation ability is limited. In the limit, the ecosystem will be subject to this limit. destroy.

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9. Make onion scales, leaf epithelial cell temporary fashion tablets:

1. Wipe the slide with a clean gauze.

2. Put the slide on the experiment and use a dropper to drop a drop (clear water) in the center of the glass.

3. Use a small piece to tear a small piece of bright film from the onion scales (inside) -inner epidermis. Immerse the torn inner epidermis in the water droplets on the slice of the glass, and flatten it with a mule.

4. Use the gardenia to clamp the cover glass to make it one side (first contact the water droplets on the glass piece), and then (slowly) to put it down and cover it on the materials to be observed. And affect observation).

5. Drop a drop of dilute iodine (the side of the cover of the glass).

6. Use water absorption paper to be attracted from the other side of the lid, so that the dyeing fluid infiltrates all of the specimen.

First, the structure of plant cells.

1. Cells are mainly composed of cell walls, cell membranes, cytoplasm, and nucleus. The cell contains liquid bubbles and chloroplasts

2. The role of cell wall: to play a role in protecting and supporting cells.

3. Sweet watermelon is mainly because the cell liquid of watermelon contains a lot of sugar.

4. The various structures of plant cells have their own functions. They coordinate and cooperate to complete the life activities of cells.

2. 1. Plant cells and animal cells have the same structure and differences in structure:

The same point is: both cell membrane, cytoplasm, nuclear, etc. are the basic units of the structure and function of the organism.

The difference is that plant cells have cell walls, animal cells do not have cell walls; plant cells have liquid bubbles, animal cells do not have liquid bubbles; plant cells have chloroplasts, and animal cells have no chloroplasts.

2. The cell membrane can enable the useful substances to enter the cells, block other substances outside the cell, and at the same time excrete the waste produced in the cells outside the cell.

Third, the substance that stores genetic information in the nucleus is -DNA

1. The carrier of genetic information is an organic matter called DNA. DNA exists in the nucleus.

2. Each clip of DNA has specific genetic information. These fragments are called genes.

Fourth, chromosomes are composed of two substances: DNA and protein.

1. In the process of development, some cells have different functions, and they have gradually changed in form and structure. This process is called cell differentiation.

2 、Four basic organizations of the human body:

Epitrobial tissue: composed of epithelial cells, with protection, secretion and other functions.

Muscle tissue: composed of muscle cells, with contraction and diastolic function.

Nervous tissue: It is composed of nerve cells, which can produce and conduct excitement.

Connective organizations: support, connection, protection, nutrition and other functions.

3. Eight major systems of the human body: exercise system, digestive system, respiratory system, circulation system, urinary system, nervous system, endocrine system, reproductive system.

Fifth, the plant is divided and differentiated by the fertilized eggs, forming tissue and organs, and eventually forming plants.

1. Six major organs: roots, stems, leaves, flowers, fruits, seeds

2. Organization: Conchistic organizations, protection organizations, nutritional organizations, and guidance organizations.

The structure of the seeds includes the seeds and embryos, and the seeds of the seeds protect the tender embryos; (embryo) are the larvae of the new plant, including (germ, embryo, embryo root, and citrus). Vegetable bean seeds (two sons), no embryo; corn seeds (one peel), (with embryonic).

The cotyledon and embryo are rich in (nutrients). Seed plants are higher than moss and ferns, and it is an important reason to produce (seeds).

Seed plants include (bare plants and quilt plants). (Pine, fir, Plaid, Ginkgo, and Su Tie) Seeds are naked, and the peel that does not protect its peel outside is a bareon plant. Other common green flowering plant seeds have peeling quilts outside, forming fruits, all of which are quilt plants.

4. Obstical conditions required for seed germination (suitable temperature, certain water and sufficient air). Itself conditions (the seeds or the seeds that are bite in insects in dryness cannot germinate) (seeds with too long storage time, and embryos are dead). (Seeds that are dormant) cannot germinate.

5. When the seed germination, first (absorb water). (Nutrition) (nutrients) in the cotrin or embryo (nutrients) to (embryo root, germ, embryo axis). Subsequently, (embryo root) developed, breaking the seed skin, and forming a root. (Embryo axis) elongation, germ development (stems and leaves).

6. There are also in the buds (conidia). When the buds are developed, the cells of the conid tissue are divided and differentiated to form new branches. It is composed of delicate stems, leaves, and buds. The (buds) on the branches can develop into new branches.

7. The nutrients required for plant growth include (water, inorganic salts, and organic matter) roots absorb (water and inorganic salts) from the soil; green leaves through (photosynthesis) to create organic matter. The most required growth of plants is inorganic salts containing (nitrogen, phosphorus, potassium).

8. The main part of a flower is (stamens and pistils), stamens are composed of (flower medicine and flower shredded), and the flower medicine has pollen; the pistil is composed of (stigma, flower columns, and sub -room), and there are embryo in the sub -room.

9. A flower passes (powder and insemination) to the result. The process of pollen from flower medicine to the pistil stigma is called flour.

10. After the pollen falls on the stigma, grows (pollen tube) under the stimulation of the mucus on the stigma. The pollen tube passes through (flower pillar), enters (sub -room), and reaches (embryo). The (sperm) in the pollen tube is combined with (egg cells) in the beads to form (fertilized eggs). Called fertilization.

11. After the fertilization is completed, the rest of the part is withered, and only the sub -houses continue to develop. The sub -wall of the sub -room is developed, the beads develop into seeds, and the fertilized eggs develop into embryos. Corn and sunflower seeds are often caused by (insufficient powder). Artificial auxiliary pollination and production can be performed.

12. (Pole) is the "portal" of plants (transpiration) and "windows" (gas exchange). It is an empty cavity surrounded by a pair of half -moon -shaped cells- (defending cells). Open during the day and close at night.

13. The energy provided by the use of green plants (light) is synthesized in (chloroplasts) such as (starch) and other organic matter, and (light energy) is converted into (chemical energy) and stored in (organic matter). This process is (photosynthesis). Photosynthesis also produces (oxygen).

six, Nutrition in food

1 、 protein: The basic substance that constitutes human cells, providing energy for the physiological activities of the human body;

carbohydrate: The most important energy supply substance of the human body is also the composition of the cell;

Fat: Energy supply substances, the unit quality releases the most energy; but under normal circumstances, fat is used as spare energy substances, and stores in the body;

Vitamin: Do not participate in constituting human cells and do not provide energy. The content is small.

Vitamin A: Promote the normal development of the human body, enhance resistance, and maintain the normal vision of people.

When lack, the skin is rough, night blindness

Vitamin B1: Maintain the normal physiological function of the human body's normal metabolism and the nervous system. When lack, neuritis, beriberi disease

Vitamin C: Maintain normal metabolism, maintain the normal physiological effects of bones, muscles and blood vessels, and enhance resistance. When lack, scurvy, resistance decreases

Vitamin D: Promote calcium, phosphorus absorption and bone development.

When lacking, the disease (such as chicken breasts, X -shaped or O -shaped legs, etc.), osteoporosis

water:It accounts for about 60%to 70%of the weight. The main components of the cells are inseparable from the various physiological activities of the human body.

Inorganic salt:Important materials that constitute human tissues, such as calcium, phosphorus (constitute bones and teeth), iron (constitute hemoglobin)

2. Digestion and absorption

(1) The composition of the digestive system

Gastrointestinal: Oral pharyngeal esophageal gastrointestinal, large intestine, large intestine, anal

The digestive system digests food and absorb nutrients, etc.

Digestive glands: salivary glands, gastric glands, liver, pancreas, intestinal glands

Small digestive solution, the liver is the largest digestive glands in the human body, bile secretion, and participating in fat digestion

(3) Digestion of food: The food decomposition of food into an ingredient that can be absorbed in the digestive tract.

Physical digestion: The chewing of the teeth, the mixing of the tongue, and the peristalsis of the stomach and intestines, mix the food, mix, and mix with the digestive solution.

Chemical digestion: Through the role of various digestive enzymes, various ingredients in food are decomposed into nutrients that can be absorbed.

Salmonic amylase starch digestion (small intestine):

Starch (oral cavity) → maltose (small intestine) → glucose

Digestion of protein (stomach, small intestine): protein → amino acid

Bile (liver) does not contain digestive enzymes and can break down fat

Digestive (small intestine): fatty fat particles glycerin+fatty acids

Sugar -initial digestion in the oral cavity -eventually decomposed as glucose is absorbed

Protein -initial digestion in the stomach -eventually decomposed into amino acids to be absorbed

Fat -the small intestine is initially digested -eventually decomposed into glycerin and fatty acids to be absorbed

3. The absorption of nutrients: The process of entering the circulatory system through the wall of nutrients through the wall of the digestive tract.

The absorption of nutrients in each section of the digestive tract:

Stomach: a small amount of water, alcohol (non -nutrition)

Small intestine: (main absorption venues) glucose, amino acids, glycerin, fatty acids, most water, inorganic salts and vitamins, most of the fat lymphic lymphic vessels (blood circulation of lymphatic vessels) from small intestinal velvet; Blood vessels enter the blood circulation.

Large intestine: a small amount of water, inorganic salts and some vitamins

Seven, 1. The respiratory tract of the respiratory tract: the nasal throat bronchial bronchial

Gas entering and leaving the lung channel, clean, humid, warm and inhaled gas

2. When the intercostal muscles and diaphragm contraction, the chest volume is expanded, the lungs are expanded, and the pressure of gas in the lungs is reduced, so the gas is inhaled and the inhalation is completed. When the intercostal muscle and diaphragm relaxation, the chest volume is reduced, the lungs are shrunk, and the pressure of gas in the lungs increases, so the gas is discharged and exhaled. Inhalation and exhalation are achieved through breathing.

Eight, 1,plasma: Transport blood cells, transport the material and waste produced in the body and the body in the body.

blood cells: Blood cells include red blood cells, white blood cells and platelets. After the blood layered, the red blood cells are in the lower layer, red, white blood cells and platelets at the junction of two layers, very thin and white.

Red blood cell: The largest number of blood cells, round cakes on both sides, no nucleus, hemoglobin, hemoglobin can carry oxygen.

leukocyte: There is a nucleus, which is larger than red blood cells. It can pass through the capillary wall, surround, and devour bacteria.

Platelet: The smallest blood cells, no nucleus, irregular shape, can release substances related to blood coagulation.

Hemoglobin: Red blood cells contain a red iron -containing protein.

anemia:The number of red blood cells in the blood is too small, or the content of hemoglobin in red blood cells is too small.

serum: After blood coagulation, a small amount of yellow transparent liquid appears around the blood clot.

Blood function:① transport oxygen; ② transportation nutrients; ③ transportation of carbon dioxide and other waste; ④ swallowing pathogen; ⑤ regulate body temperature.

2. The type and characteristics of blood vessels

3. The structure of the heart

Vein blood arteries blood

Path: 1) Skin: Down water, inorganic salt, and urea in the form of sweat

2) Respiratory system: discharge carbon dioxide and water in the form of gas

3) Urinary system: discharge water, inorganic salt, and urea in the form of urine

5. Basic structure and function of the nervous system

6. The structure and function of the kidney unit

Genomo: It is made of dozens of capillaries separated by the scotial arteries, and the other end is collected into a small artery

Nymph sac: The blind end of the renal tubules is mostly depressed. The capsule wall is divided into two layers in the inner and outer layer. The inner layer is close to the glomerular ball.

Tunnel: The cyst cavity between the two floors inside and outside of the renal small sac is connected to the renal tube

(2) Visual formation:

Outlets are conducted along the optic nerve

The imaging of external light on the retina produces nerve impulsive visual center (forming vision)

(3) Sanitary care of the eye:

Myopia: Due to the long front and rear diameter of the eyeball, or too large the crystal composition, the image image falls in front of the retina, and correction: wear a concave lens

O remosteritious: Due to the short front and rear diameter of the eyeball, or the crystal composition is too small, the image image falls on the rear correction of the retina: wearing a convex lens

1) Structural cell body

Progressive shaft: one, long and less branch

Truth: Divided, short and tree -like branches

The axis set is a bundle, an outsourced connecting tissue film

(2) Function: Feel excitement, generate excitement, and conduct excitement (excitement is transmitted in the form of nervous impulse)

(3) The hormone secretion hormone is called thyroid hormone, which has promoted metabolism and accelerated substances

Decomposition, promote growth and development, and improve the excitement of the nervous system. Thyroid machine

Energy: excessive secretion hormone, adults increased significantly, weight loss. Thyroid

Insufficient: Small hormones, small symptoms in childhood.

9. Pyntial body: secrete growth hormone, etc., regulate human growth and development. ⑴ Insufficient growth hormone secretion; dwarf. ⑵ Excessive growth hormone secretion: A. Childhood: Giant disease. B. Adult: Ending hypertrophy.

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