High School Biology Everyone helps, high school biology does a favor

Item A: Organisms have evolved over a long period of time to form today's characteristics, and in long-term evolution, through the survival of the fittest, most of the features that have been retained are adapted to the surrounding environment. If a gene mutation occurs, it will change the characteristics that are suitable for the environment and become unsuitable for the environment, so it is said that gene mutations have more harm than benefit.

Item A is incorrect. Item B: Genetic recombination is the recombination of the original genes, which can only produce new genotypes, but not new genes. Item B error.

C: Gene mutations can occur in somatic cells as well as in germ cells. Gene mutations that occur in somatic cells cannot be passed on to offspring, whereas gene mutations that occur in germ cells can be passed on to offspring. Item C is wrong.

Item D: Genetic recombination can only occur in organisms that undergo sexual reproduction, and at the same time, the genetic material has been altered, which is a heritable variation. Therefore, item D is correct.

A mistake is that it will do more harm than good.

B Error Gene mutations produce new genes.

c I don't think so.

I advocate D

a.One of the five characteristics of genetic mutations is that most genetic mutations are harmful to living organisms.

b.False Recombination refers to the recombination of genes that control different traits in the process of sexual reproduction.

c.Wrong, not all of them, if the mutation results in a recessive trait, then it can't be passed on to future generations.

d.Pair of the concept in the book: genetic recombination refers to the recombination of genes that control different traits in the process of sexual reproduction, and it says that it is sexual, and it says that it is okay, that is, there is sex, and there is something that can be inherited.

For the sake of cellular senescence.

Studies have shown that the nucleus, cytoplasm and cell membrane of senescent cells have obvious changes: the intracellular water decreases, the volume becomes smaller, and the metabolism slows down; decreased activity of intracellular enzymes; Pigments accumulate within the cells; The rate of intracellular respiration slows down, the size of the nucleus increases, the number of mitochondria decreases, and the volume increases; The permeability function of the cell membrane is changed, which reduces the function of material transport.

Young children and adolescents are in the period of growth and development, and their metabolism is vigorous, and at this time, there needs a large amount of water in the cells to metabolize water. As we age, the intensity of metabolism decreases, and the content of metabolic water decreases significantly, so it is water that decreases significantly in the cells.

Red blood cells that are mature and do not contain DNA are red blood cells.

Red blood cells have no organelles, i.e., no chondria.

Perform anaerobic breathing.

Therefore, the oxygen concentration has nothing to do with ATP production and K+ entry rate. Choose A

When the cell aerobic respiration provides ATP but is anaerobic, the cell will carry out anaerobic respiration to produce a small amount of ATP, so that K+ can enter the cell even in the anaerobic state, excluding B and D

As oxygen increases, ATP production increases, and K+ entry accelerates, eliminating a cause of carrier proteins. O2 is finite, and eventually the velocity tends to be balanced.

A mature cell of mammals cannot undergo aerobic respiration without mitochondria, so anaerobic respiration produces ATP, which has nothing to do with oxygen.

Because that cell is a mature red blood cell, it doesn't have mitochondria, it doesn't have oxygen or not, it can't do aerobic respiration.

O2 is free diffusion into the cell, and the concentration ladder is related, cellular respiration needs to consume energy, that is, ATP, and the substance enters the cell needs to be transported through the carrier, which has its own specific carrier to be transported through recognition.

As can be seen from the question, the grandfather is xby, the grandmother is xbxb, so the aunt is 1 2xbxb or 1 2xbxb; Uncle is xby; The aunt's daughter is xbxb(1 2+1 2*1 2=3 4) or xbxb(1 4) and she is xby, so the probability of their offspring being xby is: 1 4*1 4=1 16

Pick D. According to the previous algorithm, 1mol of glucose decomposes to produce 38mol of oxylatp, which consumes 6mol of oxygen. 4mol of glucose sugar was accumulated, indicating the release of 24mol of oxygen. So 152 molatp can be generated.

This question is older.

According to the new theory, 1mol of glucose decomposes to produce 32mol of oxylatp, which consumes 6mol of oxygen.

1.Are plasmids and nucleoids the same substance? If not, what is wrong with "bacterial DNA replication only occurs in nucleoidal mimetry"?

A: Plasmids and nucleoids are not the same substance, nucleoids are large DNA in bacterial cells, while plasmids are medium-sized circular DNA. Therefore, the DNA production of bacteria is not only the replication of nucleoids, but also the replication of plasmids.

2.How is it wrong to "culture phages containing radioisotope 35S and radioisotope 32p, respectively"?

Answer: Bacteriophages are a type of virus that can only multiply in live bacteria. This sentence can be changed to "use phages to infect E. coli cultured with 35S and 32P, respectively".

3.Why don't polyploids go through callus, but haplotypes do?

Polyploidy species are chromosome doubling at the beginning, and germinated seeds or seedlings are treated with colchicine without going through a tissue culture process. In the haplotype species, the anthers of a certain plant are first cultured in vitro, and then doubled with colchicine after being cultivated to the seedling stage. In the stage of ex vivo culture of anthers, calli are formed.

1. The first sentence asks if it is the same substance, which is a bit of a problem, in terms of chemical composition, they are the same substance, but the plasmid is a small piece of genetic material outside the nucleoid, they are different, and the fault is that the DNA replication of bacteria will also occur in the plasmid.

2.Bacteria containing radioisotope 35S and radioisotope 32P should be cultured, and phages should be cultured with these bacteria.

3. Polyploidy is the mutagenesis of seeds or plants, and what grows is polyploidy; Haplotype is the culture of the germ cells of plants, and in order to change from cells to plants, of course, it is necessary to go through callus.

1 dipeptide has 1 peptide bond, 2 pentapeptides have (4*2) peptide bonds, 3 hexapeptides have (5*3) peptide bonds, 3 heptapeptides have (6*3) peptide bonds, and there are a total of 42 peptide bonds.

There are no free amino acids in short peptides, but there are 1+2+3+3 free amino groups.

The total number of water molecules required to break down into these small peptides is equal to the number of peptide bonds, 42 water molecules.

According to the title, there are 9 short peptides (including dipeptides and polypeptides) (1+2+3+3). Because each short peptide has at least one amino group (excluding the amino group on the R group), the minimum value of the total number of amino groups in these short peptides (i.e., the number of free amino groups is at least) is 9; From "number of peptide bonds = number of amino acids - number of peptide chains", the total number of peptide bonds obtained is 42 (51-9); To break down into these 9 short peptides, 8 peptide bonds need to be broken, and the number of peptide bonds = the number of water molecules lost, the number of water molecules (i.e., the number of water molecules consumed) required to form these short peptides is 8.