Knowledge points of biology in the second volume of the seventh grade of Jinan Edition (1)
Nutrition in food
1, six nutrients: sugar, fat, protein, vitamins, water and inorganic salts.
Among them: organic matter (sugar, fat, protein, vitamins) and inorganic matter (water, inorganic salt).
2. Three nutrients: sugar, fat and protein.
3. The seventh nutrient: dietary fiber (also called cellulose)
4. Food source: ① sugar (cereals, roots)
② Fat (egg yolk, peanuts, beans and hard fruits)
③ protein (lean meat, eggs and beans)
5. Nutrients: ① Sugar: (starch, maltose, glucose, etc. )
② Fat: (glycerol and fatty acid)
③ protein: (more than 20 kinds of amino acids)
6. Function: ① Sugar: ① Main energy-supplying substance; ② Constitute cell tissue.
② Fat: ① Mainly used to store energy; ② It is also involved in the formation of cell tissue.
③ protein: ① Important substances constituting cell tissues; ② It can also be decomposed to provide energy.
7. Vitamins: (Features: ① small amount, ② various types, ③ great effect, ④ generally unable to be synthesized by human body) Vitamin A: night blindness.
Vitamin B 1: neuritis, beriberi.
Vitamin c: scurvy
Vitamin D: ① Children: rickets; ② Adults: Osteoporosis.
8. Water: ① 60% of body weight? 70% (the largest proportion)
(2) More than 20% water loss is life-threatening.
③ The daily water demand is about 2 liters.
④ Drink plenty of water after hot weather or strenuous exercise.
9. Inorganic salts: (small requirements, many types and great functions)
Calcium: ① Function: Formation of teeth and bones.
② Deficiency: children: rickets, middle-aged and elderly people: osteoporosis.
Iron: ① Function: Participate in the formation of hemoglobin.
② Deficiency: anemia
Iodine: ① Function: Raw material for synthesizing thyroid hormone.
② Deficiency: endemic goiter (commonly known as big neck disease)
Knowledge points of biology in seventh grade of Jinan Edition (2)
Material transport carrier
1, blood: ① Two major components: plasma and blood cells.
2. Plasma: ① Ingredients: water, inorganic salts, protein, glucose, urea, etc.
② The proportion of plasma in blood: 55%;
③ Color and state of plasma: pale yellow liquid;
④ Plasma function: ① Carrying blood cells;
② Transport nutrients and metabolic wastes.
3, blood cells: ① including: red blood cells, white blood cells, platelets;
4, red blood cells: ① the largest number, (the volume is in the middle);
② No nucleus;
3 shape: round cake with concave sides;
④ Rich in hemoglobin: ① a kind of iron protein;
② Characteristics of hemoglobin: ① It is easy to combine with oxygen in places with high oxygen content;
② It is easy to be separated from oxygen in places with low oxygen content.
⑤ Function of red blood cells: The main function is to transport oxygen and part of carbon dioxide.
5. White blood cells: ① The number is the least and the volume is the largest;
② There are nuclei;
(3) can do deformation movement, through the capillary wall into the tissue, swallowing bacteria.
④ Function: Swallow germs and defend against diseases.
6. Platelets: ① the smallest volume, (the number is in the middle);
② No nucleus;
③ Regular shape;
④ Function: It can stop bleeding and accelerate blood coagulation.
7. Blood transfusion and blood type: ①ABO blood type system: A, B, AB and O;
② Blood transfusion principle: Blood transfusion is based on the same type of blood;
④ Blood donation: 200 ml ~ 300 ml blood donation at a time will not affect health.
Knowledge points of biology in the second volume of the seventh grade of Jinan Edition (3)
Organ for transporting substances
1. Blood vessels are divided into three types: arteries, veins and capillaries.
2. Arteries: ① Function: transport the blood in the heart to all parts of the body;
② Distribution: Most of them are distributed in deeper parts of the body;
③ Features: thick wall, large elasticity, relatively small lumen and fast blood flow.
3, vein: ① function: send blood back to the heart from the whole body;
② Some are deeply distributed, while others are shallowly distributed;
③ Features: thin wall, small elasticity, relatively large lumen and slow blood flow.
④ Veins distributed in limbs, with venous valves on the inner surface? Function: prevent blood from flowing backwards.
4. Capillary: ① Material exchange;
② Distribution: large number and wide distribution;
③ Features: Extremely thin wall, thin lumen and slowest blood flow rate.
5. Heart: ① the dynamic organ of blood circulation;
② Size: For example, my fist.
③ The heart is divided into four chambers: ① Left upper: left atrium;
② Lower left: left ventricle; (The heart wall is the thickest)
③ Right upper: right atrium;
④ Lower right: right ventricle.
④ Thickness of heart wall: ① The ventricle is thicker than the atrium.
② The left ventricle is thicker than the right ventricle.
③ The left ventricle is the thickest.
⑤ All ventricles are connected with arteries: ① The left ventricle is connected with aorta;
② Right ventricle with pulmonary artery;
⑥ Atrium is connected with vein: ① The left atrium is connected with pulmonary vein;
② The right atrium is connected with superior and inferior vena cava.
⑦ Valve: ① The valve between atrium and ventricle is called atrioventricular valve;
② The valve between ventricle and artery is called arterial valve;
③ There are venous valves on the inner surface of veins of limbs;
④ The function of the valve: to prevent blood from flowing backwards.
6. Heart rate: ① The number of times the heart beats per minute.
② Average adult heart rate: 75 beats/min;
③ Normal change range: 60? 100 times/minute;