The answer to the biology exercise in the second volume of the seventh grade

The seventh grade biology exercise (1) reference answer.

1. 1，A，C 2，D 3，C 4，C 5，A 6，D 7，C 8，B 9，B 10，D 1 1，D 12，B 13，A66。 A 17、B 18、B 19、D 20、C 2 1、B 22、B 23、C 24、A 25、B 26、A 27、D 28、A 29、B

Second,

1, reducing the contingency in the experiment process and ensuring the accuracy of the experiment.

2. Material nuclear and energy information

3. Division and growth

4. Quantity and volume

5. Morphological number of genetic material

6. Uterine placenta and umbilical cord

7, family planning late marriage, late childbirth, fewer children, eugenics.

8. Water, inorganic salts, vitamins, sugar, protein and fat.

9. Vitamin A, Vitamin C and Calcium

10, small intestine and liver

1 1, alveoli

12, big and small

13, moist, clean and warm

14, the combination and separation of iron

15, red blood cells, white blood cells and platelets in plasma

16, artery, capillary, vein

17, pulmonary circulation systemic circulation aorta

18, voluntary blood donation 18~55 transfusion of the same blood.

19, fist in the lower left of the heart and chest.

20. Defense and protection of oxygen and part of carbon dioxide

2 1, blood reflux venous valve atrioventricular valve

Third,

1, omitted

2.( 1) porter: red blood cell repairer: platelet warrior: white blood cell

(2) The porter carries oxygen and a part of carbon dioxide, which is completed by hemoglobin.

(3) Brave soldiers defend our health by surrounding and devouring germs that invade the human body.

3.( 1) Glucose, glycerol and fatty acids

(2) Small intestine

(3)B

4.( 1) Fast

(2) centripetal centrifugation

(3) There is no contradiction, because the optical microscope shows the inverted image, and the blood flow direction seen by the microscope is actually the opposite.

5. Dad: Pig Liver Mom: Pepper Grandpa: Cow Milk Powder Grandma: Spinach.

6. Omission

7.( 1) Diaphragm, trachea, bronchus and lung

(2) Expand inhalation and reduce exhalation.