The high school biology master advances, and the high school biology master comes quickly

Semi-preserved replication is the two strands of newly formed DNA, one of which is newly synthesized and the other is the original parent strand.

The meaning of semi-reservation means that when the two complementary paired DNA strands on the original parent strand are replicated, they are uncoiled and become the mother strand of replication, and the nucleotide strand is synthesized through the principle of four base complementary pairing, and the newly synthesized nucleotide strand contains both a DNA strand of the parent strand and a copied nucleotide strand. Isn't the newly synthesized and pre-spin DNA the same? You have forgotten the principle of four complementary base pairings.

It retains half of the parent chain, half of it is new, half of it is old, and it's theoretically exactly the same as the parent chain.

1.The answer is d

Option C, the more water a plant has, the more vigorous its metabolism will be, and the faster the organic matter will be consumed, which is not conducive to the preservation of vegetables.

Option D is correct, the concentration of CO2 increases, which can inhibit aerobic respiration and reduce the consumption of organic matter.

2.This sentence is not true, first of all, mitochondria are the site of 2 or 3 steps of aerobic respiration, which provides a large amount of ATP required for life activities, while the first step of aerobic respiration is carried out in the cytoplasmic matrix, which also releases a small amount of energy, while chloroplast is the place where ATP is converted into stable chemical energy, and does not provide energy. Aerobic respiration, anaerobic respiration, anaerobic respiration is carried out in the cytoplasmic matrix, and ATP is released in the cytoplasmic matrix, which has nothing to do with mitochondria.

Therefore, the ATP consumed in the cytoplasm is not true with mitochondria and chloroplasts.

3.Carbon dioxide is not toxic, you may say that CO2 reacts with water to form carbonic acid and will cause human poisoning, but carbonic acid is unstable and easy to decompose, so it is not harmful to the human body.

When people are severely hypoxic, they carry out anaerobic respiration to produce lactic acid, and if they are ignored for a long time, they will cause acidification of the constitution, which may cause serious diseases.

4.Lactic acid bacteria are anaerobic organisms that react slowly under aerobic conditions, so the less oxygen, the faster the reaction rate, that is, the fastest reaction rate in a 100ml bottle.

Under aerobic conditions, yeast only increases the number of bacteria and does not produce alcohol, so in a 400ml beaker, a part of organic matter must be consumed to increase the number of bacteria. However, the amount of milk and starch solution is sufficient relative to lactic acid bacteria and yeast, so the organic matter consumed in this part is negligible, so the more bacteria (i.e., the more oxygen), the faster the reaction rate, so the fastest reaction rate in the 400ml flask is C

The first question, the cellar is closed, the air is very uncirculated, can be approximated as the oxygen content is constant, put a lot of cabbage in the cellar, cabbage respiration, consume oxygen and exhale carbon dioxide, so the oxygen content decreases sharply, and the carbon dioxide content increases, so that the respiration is weakened, and the material consumption of cabbage will be reduced, so that it can be kept fresh for a longer time.

Third, because carbon dioxide cannot exist in the human body in a gaseous state, it will dissolve in water to form lactic acid (molecular formula C3H6O3).

The other two won't, it's been too long since I graduated, and they've been returned to the teacher, but the fourth question should be closely related to the two chemical reaction equations, that is, the trim number, and the specific ones need to be solved.

1.Under hypoxic conditions, it can reduce the respiration of plants and achieve the effect of long-term storageWrong, the cytoplasmic matrix releases small amounts of ATP3 during the first phase of aerobic respiration

When hypoxia, the degree of anaerobic respiration increases and lactic acid is generated, resulting in lactic acidosis. There is no CO2 poisoning claim.

4.Lactic acid bacteria produce lactic acid by anaerobic respiration, and yeast produces alcohol by anaerobic respiration

1 It is true that the temperature is right It proves that cellular respiration is normal and will not be inhibited Then when you come out in ten days and half a month, there is no difference from being outside, and the water problem Does breathing consume water? So the moisture has nothing to do with respiration, the temperature is right, the stomata will open, so the water evaporates, and besides, the temperature of the cellar is lowered, and it can't be suitable... So I think d should add another temperature reduction...

Decreased cell activity Decreased enzyme activity

2.Definitely not ... Chloroplasts are self-produced and self-consumed by ATP. . . In addition, in the first stage of cellular respiration, a small amount of energy is produced in the cells.

3.Patients with severe hypoxia are anaerobic respiration, you can write it yourself Glucose is C6H12O6 Lactic acid is C3H6O3 Do not write the equation according to biology Write according to chemistry Write directly from glucose to lactate It is equivalent to 1 molecule of glucose directly to 2 molecules of lactate There is no carbon dioxide production at all!

4 Yeast is facultatively anaerobic so it can be aerobic or anaerobic and its anaerobic respiration product is alcohol! Lactic acid bacteria must produce lactic acid, and then the concentration of the solution is the same as the number of bacteria, and the difference is the amount of oxygen. And lactic acid is produced by anaerobic respiration, and in terms of volume, there must be the least amount of air and the least oxygen in 100 milliliters, and lactic acid bacteria can survive more and produce lactic acid, and yeast will use oxygen to multiply first, and you say that one yeast produces more or thousands of yeasts, so this is how winemaking works

You're too stupid to pick 1 d because otherwise the oxidation reaction will rot, 2 is not right.

Because the last gametes formed are two identical. The two different pairs are developed from the homologous chromosomes of the primary spermatocytes, respectively.

Question 1a. Since the composition of genes is a, a, b, b then the total number of genes of his gametes does not change.

Question 2b. Because the sum of gametes is the same as the parental genes.

If you don't understand it, just ask your questions. Hope it helps.

Egg cells, pollen Normal cells 2

The germ belongs to normal cells.

So, the germ is 6 times more developed and the pollen is 3 times more developed.

In vitro culture and other cell engineering methods should be used.

It must be pure, because it all comes from this haplotype genome. But it doesn't have to be diploid. It's entirely possible to replicate more. The amount and timing of colchicine need to be controlled.

1.Pollen has 3 sets of chromosomes like egg cells, and germ cells have 6 sets of chromosomes. So pollen develops into haploid and germ cells develop into 2ploid.

2 All need to be cultured in vitro, colchicine to double chromosomes and other technologies.

3 First of all, it must be homozygous, and as for how ploidized it is, it depends on the amount of colchicine, so the answer should be d.

First of all, if the essence of the enzyme is RNA, it can be ruled out that the final test result is all nucleic acid.

Then, the enzyme is broken down into amino acids, and it may be that nucleic acids are a class of enzymes, but this kind of enzyme can only be RNA in nature, and DNA cannot appear, so B is wrong.

C and D are both enzyme catalysis and may be present.

The above is just my personal opinion, I haven't been exposed to high school biology for a long time, and I'm embarrassed if it's wrong.

Because regardless of whether the enzyme catalyzes the decomposition of nucleic acids into smaller segments of DNA or nucleotides, enzymes generally do not break down into amino acids on their own, so no amino acids appear, but nucleic acids (which are not broken down), smaller segments of DNA, or nucleotides may appear, depending on the function of the enzyme.