Several junior high school organisms are solved. Two junior high school biology questions

1.The relationship between the position of the tree trunk from the inside to the outside is xylem-cambium-phloem, that is, the cambium layer forms xylem inward to produce growth rings and outward to produce bark.

2.Marked by the beginning, the organic acids secreted by lichens turn the stone into soil.

3.It's really just a concept, the main thing is that the concentration of the canopy evaporates and then the concentration gradient causes the water to overcome gravity and go up, or the sum of the intermolecular forces in a certain direction caused by the concentration gradient between all cells during the so-called tensile force (but hello creative...). Never thought about it, eh).

C. Inhale:

Enlarged lungs and thoracic enlargement.

Respiratory muscle contraction.

Diaphragm declines. The air pressure in the lungs is small and traces in the cavity and the outside atmospheric pressure.

The gas enters the lungs.

The interstitium between the alveoli contains a rich network of capillaries, which is the place for gas exchange between the blood and the gas in the alveoli of Huilao.

b Lactic acid bacteria are anaerobic bacteria that need to be sealed and will die in the air.

Yeast facultative anaerobes can survive aerobic conditions, but the metabolites of aerobic respiration are completely decomposed into CO2 and H2O, and no longer produce C2H5OH (alcohol).

Spore reproduction is the method of reproduction of fungi and lactic acid bacteria are bacteria

b Both yogurt and wine are made in the absence of oxygen.

Description: Yogurt manufacturing is the use of lactobacilli fermentation in an anaerobic environment; Wine production uses glycophilic yeast for anaerobic fermentation, which converts the glucose into alcohol, but a part of the oxygen is required in the early stages of fermentation!

The upstairs are all nice.

As for why human blood is dark red after clotting, it is actually not just the color of cells or cell death. During wound scarring, blood cells release some clotting factors and fibrinogen, which cause the blood that comes into contact with the air (i.e., the wound site) to become viscous, increasing the viscosity of the blood and eventually leading to scarring.

In addition, due to the differences between human blood and genetic diseases, the color of blood and scars flowing from different individuals or different parts of the same body are very different.

Because the blood cells are at the bottom of the test tube, the bottom of the test tube is not in contact with the air and is in a state of hypoxia, and hemoglobin is characterized by the fact that it is easy to separate from oxygen in places with low oxygen concentration, so it is dark red.

I'm late, the one on it is good. As for your second question - the outside of the pig blood clot is bright red because it can come into contact with the air and always keep the blood cells fresh, and the cells inside the blood clot cannot contact the air and will die before the outside, so it is dark red.

It's amazing. I don't dare. You can think so deeply about junior high school biology questions!

1. B2, the dominant factor should be temperature, but it is also related to the length of sunshine.

3. There should be biological relationship between plants and animals, the number of animals will increase with the increase of the number of plants, but will not increase without limit, will decrease with the decrease of the number of plants, under the premise that the ecological balance is not destroyed, the number between the two to achieve a dynamic balance.

Temperature. 3.The number of animals is less than the number of plants.

1. The movement of the earthworm copied with its.

It is related to the bristles and has little to do with the shape of the body (elongated, stubby).

2. The function of the airbag is not single: it can adjust the specific gravity of the body (also related to flight), can help dissipate heat, can reduce the friction of internal organs, and is related to double breathing.

Supplements: 1: Body surface.

2: Provide energy for life activities.

3: Maintain the homeostasis of the organism. (i.e., to provide a suitable environment for life activities).

The longitudinal muscle layer of some body segments is contracted, and the annular muscle layer is dilated, and this segment of body segment becomes thicker and shorter, and it grows.

The bristles that stretch out on the wall of the body are protruding and inserting into the surrounding soil; At this time, the annular muscle layer of the previous somite contractes, the longitudinal muscle layer relaxes, the body segment becomes thinner and longer, the bristles retract, and the surrounding soil is freed from contact, so that the body is pushed forward by the support of the bristles of the latter segment. In this way, the contraction waves of the muscles are gradually transmitted from front to back along the longitudinal axis of the body. Causes earthworm movement.

The air bag assists in double breathing, reduces the friction between the muscles and internal organs in the body, and dissipates heat through breathing.

1.When stubby, bai

When the muscles contract and are elongated, the muscles relax.

zhi2.Function.

1. Stores air, double breathing, and provides oxygen for the flight as needed;

Function 2 helps to fly, and reduces the friction of internal organs.

Function 3: Heat dissipation as soon as possible after flying.

Supplement 1**。

2.It provides oxygen for all physiological activities of living organisms and converts sugars into energy3Able to adapt to different environments, so that the range of activities is greatly expanded.

In earthworms, the longitudinal muscle layer of some somites shrinks and the annular muscle layer relaxes, so the somites become thicker and shorter, and the bristles that are born on the body wall and stretch out obliquely and protrude into the surrounding soil. At this time, the annular muscle layer of the previous somre is contracted, and the air bag assists in completing double breathing, reducing the friction between the muscles and internal organs in the body