I did a few biology questions today, and I was a little dizzy. . . Ask the teacher to explain

8. The answer is: D.

If the light intensity is appropriately reduced, point A will be shifted to the right and point B will be shifted to the left;

If the light intensity is appropriately increased, point A will shift to the left and point B to the right.

15. The answer is: B.

Since the cells absorb urea, the concentration of cell fluid should be higher than before the recovery of the plasmo-wall separation.

14. The answer is: a.

The structural level of the living system starts from the cell, and the first, the molecular level, does not belong to the structural level of the living system;

second, at the cellular level;

third, ecosystem level;

fourth, population level;

fifth, community level;

sixth, at the cellular level;

seventh, at the cellular level;

The eighth, at the level of organs.

The correct order is: Combine the options to know A. (The last two of item b are reversed).

1. When the light is weakened, the rate of photosynthesis decreases, that is, the CO2 absorbed by the same CO2 concentration decreases, point A shifts to the right, the CO2 required for saturation decreases, and point B shifts to the left; When the light is enhanced, in the same way, A shifts to the left and B shifts to the right.

2. Urea enters the cell, so that the concentration of cell fluid increases, and the plasma wall is separated and restored (similar to nitrate, glycerol, etc.).

3 7 is an unconditioned reflex.

The reason for automatic recovery is that urea enters the cell fluid, so the concentration of the cell fluid increases after recovery.

The mouth No. 7 is not an organ in the digestive system, the oral cavity is a part of several organs. The teeth, tongue, and salivary glands in the mouth are all separate organs. It is not possible for one organ to contain other organs.

The DNA molecule has two strands and the AGCT follows the principle of base pair complementarity between them (this should be known, right?). For example, if there is 20% G, according to the principle of base pair complementarity, there must be a C corresponding to it, then the DNA molecule also has 20% C, in other words, G and C on a strand account for 40% of the single strand, then the remaining 60% may be A or T.

The question asks how much the maximum value of A on a chain can be accounted for, and if the remaining 60% of a chain is all A, and the remaining 60% of the other chain is all T, the assumption follows the principle of base pair complementarity and is valid, then the maximum value of A on a chain can account for 60% of the chain

(1) The 6 in the figure refers to the pulmonary veins and 7 refers to the aorta.

2) The circulatory pathway through which blood is shot out of 2 and flows through 3 is called the pulmonary circulation; The route by which blood flows from 4 to 1 is called systemic circulation.

3) From m to n, the composition of the blood changes: arterial blood becomes venous blood.

4) Blood flows through the alveoli from venous blood to arterial blood.

5) When someone suffers from enteritis, the doctor takes a intravenous infusion of penicillin** in the upper extremity, and the drug reaches the affected area and passes through the heart twice.

6) In the structure of the heart, the valve between the atria and the ventricles is the atrioventricular valve, and the valve between the ventricles and the arteries is the atrioventricular valve, both of which function to prevent blood from backflowing. The valves of the heart can only open in one direction, which ensures that the direction of blood flow can only be the atrium ventricular artery .

(1) The "dust" in the text refers to spores; "Silk thread" refers to spore filament, or hyphae.

2) This mysterious "dust" and the "silk threads" that grow inside it are parasitic to crickets.

3) The text says: "The wind will carry them to 'sin' again", which means that the mature spores will infect other creatures again. (4) It is the fungus that kills crickets.

"Dust" refers to spores, and "silk threads" refers to hyphae.

"Dust" and "silk thread" are parasitic with crickets.

The wind will carry them to 'sin' again", which means that the mother produces spores, and with the help of wind vectors, it goes to other hosts.

It is the fungus that kills crickets.

(1) Spore hyphae.

2) Parasitic relationship.

3) (Reproduction method) uses wind as a medium to emit spores (germ cells) and infect other organisms again.

4) Fungi (or parasites).

1. Dust refers to bacteria, and decomposers Silk thread refers to mycelium.

2. Parasitism. 3. Find a new host and reproduce.

(1) Spore hyphae.

2. Parasitism 3: This organism uses wind as a medium to spread spores and parasitize other organisms. 4 fungi.

Spores, hyphae.

Parasitic on the body of crickets.

The spores are produced and then the other host fungi are found.

(1) Spore hyphae. 2. Parasitism. (3) The spores drift to a suitable place with the wind, and can re-infect other crickets (organisms); 4 fungi.

A man is a mammal, and he cannot do without air, and space is basically a vacuum. Plants use carbon dioxide to produce oxygen through photosynthesis, while humans and plants use oxygen to produce carbon dioxide through respiration. In addition, the space station is weightless, and the water is suspended in the form of small liquid droplets.

What's more, astronauts only do short stays and don't need to build a simulated micro-ecosystem to test.

Pick B, what do you put the soil in it for?

A person can't live without air, and if it leaks, he can't live.

Read the title: "Pollen of purebred smooth seed coat and yellow cotyledonous peas", purebred sleek and yellow are not necessarily homozygous.

Let the roundness be a and the shrinkage be a

Yellow is a b, and green is a b

then AAB *AAB

When yellow is purebred.

AABB * AABB (accounts for 1 2 chances) derives offspring as AABB

It is sleek and yellow.

When yellow is not purebred.

AABB * AABB (1 2 chance) gives AABB (1 2 chance), i.e. 1 2 * 1 2 = 1 4; It is sleek and yellow.

AABB (1 2 chance) is 1 2 * 1 2 = 1 4;It is sleek and green.

So it's all sleek.

Yellow is 1 2 + 1 4 = 3 4, and green is 1 4

Yellow: Green = 3:1

Set aabb * aabb

The offspring generation is AABB

Among the offspring obtained from inbreeding, the one that can be stably inherited is.

aabb:1/16

aabb:1/16

aabb:1/16

aabb:1/16

The total is 4 16 = 1 4

Obviously b, the soil is not needed, the producer, the decomposer will do.

Do plants need water, soil?

Option d must have mammals, water. So exclude ABC

1 A ribosomes b endoplasmic reticulum c Golgi apparatus is processed, packaged, and transports proteins from endoplasmic reticulum.

2 d Endoplasmic reticulum e cell membrane f Golgi apparatus.

3 The Golgi apparatus first receives the vacuoles from the endoplasmic reticulum and subsequently passes the vacuoles to the cell membrane, so there is no increase in the area of the membrane.

Option A should be 22 autosomes plus XYThere are 24 articles in total.

Option b is correct.

Option C is a chromosomal variation that is more likely to be inherited, not a greater likelihood of a variation Option D is caused by chromosomal variation.