Biology in the second year of junior high school, ask for the lth question of the major, and the bio

Hello: Dirty laundry contains organic matter where mold grows and multiplies.

Solution: Dirty clothes are easy to mold, indicating that there is mold breeding on clothes, the biggest difference between washed clothes and dirty clothes is whether the organic matter contained in the clothes is removed Organic matter provides nutrients for the growth of mold, which shows that dirty clothes are easy to mold, which is the reason why mold uses organic matter to grow and reproduce

Causes of food spoilage:

Food spoilage is due to microorganisms such as bacteria and fungi in food, or microorganisms such as bacteria and fungi in the air, which come into contact with food and attach to it to use organic matter in food, growth and a large number of reproduction During the period, a lot of growth metabolites will be produced, producing a variety of tastes, human acid, odor, etc. Therefore, food spoilage is caused by the growth and mass reproduction of microorganisms such as bacteria and fungi

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Protocol Procedure:

1. After peeling the fruits separately, put them into the juicer to squeeze the juice.

2. Use a graduated cylinder to measure the same amount of sweet pear juice and sour pear juice in small beakers A and B.

3. Use a dropper to measure an appropriate amount of potassium percalrate solution and drop it into a and B beakers, and stir well with a glass rod to observe the time when the purple red color fades.

4. If the sweet pear juice fades purple red for a long time, the sweet pear juice contains more vitamin C, and vice versa, the pear juice contains more vitamin C.

The increase in the BC segment in 1c is due to the fact that the organic matter does not increase when the seeds germinate first, and the organic matter does not increase until the leaves are grown.

2c Urine is formed after the original urine passes through the renal tubules, most of the water is reabsorbed, and the concentration of urea should increase.

C BC segment seed germination absorbs water, but organic matter does not increase.

2.c When the original urine passes through the renal tubules, the reabsorption of water through the renal tubules is reduced, so the urea concentration should be increased.

c Seeds need to consume organic matter to provide energy in the early stage of germination The total amount of organic matter decreases c After the original urine passes through the renal tubules, the water in the urine is reabsorbed, and the urea concentration should increase.

I think the answer to the first question should be C. Because the seed germination of the BC segment absorbs more water, the fresh weight will increase. Seed germination requires the consumption of organic matter, which should be reduced, not increased. So the C answer is incorrect. Therefore, C should be chosen.

For the second question, you should choose C. Because Figure C reflects the change of urea after the original urine passes through the renal tubules. The renal tubules reabsorb most of the water in the original urine, some of the inorganic salts, and all of the glucose and send them back to the bloodstream.

The concentration of urea in the urine remaining in the tubules should increase, not decrease. So the C answer is inaccurate. Therefore, C should be chosen.

(1) A seeds cannot photosynthesize before germination, produce organic matter, and can only consume the original energy in the seeds, so the seed mass of the OA segment decreases.

2) c After the original urine passes through the renal tubules, the urea concentration will decrease within a certain range and will not drop to zero.

(1) Person B has 22 pairs of autosomes, 1 pair of very chromosomes, two autosomes are the same, and the two very chromosomes are inconsistent, so as long as 22 + 2 = 24 are measured.

Lizards, on the other hand, are cold-blooded animals, and when the temperature decreases, the enzyme activity on the body decreases, and the oxygen consumption decreases.

Question 1 is A. There are 23 pairs of chromosomes in human cells, i.e., 46 lines. (Except for germ cells, there are only 23.) ）

Question 2 is selected b. Birds are homeotherms, and when the outside temperature is lower, birds need to expend more energy to maintain a constant body temperature, so oxygen consumption increases. Lizards are ectotherms, and when the outside temperature is low, they can sustain their lives by suppressing their own energy consumption, which is what we often call hibernation, when oxygen consumption is reduced.

a。46 articles.

b。Birds increase, lizards decrease.

Middle School: c. Biologically, the basic unit of species is the species. That is, a species is a living organism.

Similar morphological structure and physiological function are not necessarily the same species, just like flowers, different flowers have the same basic structure and the same function (reproduction).

2.The same distribution is not necessarily the same species, such as tens of thousands of species of tropical fish.

High School Theory: A species is a living thing.

Species are the basic units of taxonomy.

The existence of the same species and subspecies that are reproductively isolated from other similar groups is called reproductive isolation in interspecific isolation, that is, there are no homologous chromosomes.

And occupy a certain ecological niche in nature.

d is wrong species can be considered to be a species of genus and species of the phylum family, then a obviously treats the species as an individual wrong, b species must first form a genus and cannot directly form a family, c a creature is not a species, obviously correct, for d, a group of organisms with similar morphological structure and physiological function performance, and the ecological distribution is basically the same may be different species, because the said shi performance is similar For example, two subspecies may have this kind of acquaintance, but the metabolism is different and it can still be divided into different species, Plus a bunch of the word is very inaccurate.

Species are the basic units of taxonomy. A species is a natural group formed by the same organisms that reproduce with each other, are reproductively isolated from each other and occupy a certain ecological niche in nature.

D is problematic. For example, silkworms and earthwormsThe morphological structure and physiological function are similar, and the ecological distribution is basically the same, but they are not the same species.

C false. Skeletal muscles are made up of the muscles, abdomen, and tendons. The thicker part of the middle of the skeletal muscle is called the muscle abdomen, and the milky white part with the thinner ends is called the tendon.

The composition of skeletal muscle does not include blood vessels and nerve bridges, but only neurovascular distribution within skeletal muscle.

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