High School 2 Biology 1 Biology 2 College Entrance Examination Biology 2 Questions

I'm also a sophomore in high school, but unfortunately I won't

Very simple.

Please look at the figure carefully, the first question A and B One cell becomes multiple cells, the total volume remains the same, and the total surface area increases. It can also be said that the surface of each small cell has increased, and the volume and the volume are the volume of the original cell, and the surface area and the absence are greater than the original surface area, so the surface area corresponding to the unit volume is more, the ratio of surface area to volume is increased, and the exchange capacity is enhanced.

Question 2, The cell is growing, and the surface area and volume are increasing. However, the surface area does not increase as fast as the volume, and the original surface area to volume ratio is 2:1.

When it grows, it may become :1. So in fact, the ratio of surface area to volume decreases, and the exchange capacity decreases.

The key is that in the first question, the number of B cells has increased (several small cells), and the surface area is |The volume will increase, and the cells in the middle circle 2 of question 2 will not increase, so it is wrong. Think for yourself.

Question 1: Select C.

Because 15 N first appeared in the nucleus and then transferred to the cytosol and ribosome, it means that the mRNA synthesized in the nucleus contains 15 N, and there can be no thymine on the RNA chain, so the labeled base cannot be thymine.

The second question has 3 nucleic acid molecules and 4 strands, so it can be preliminarily determined to be a double-stranded DNA molecule and two single-stranded RNA molecules. From the fact that there are five bases (A, T, G, C, U), it can be determined that there are both DNA and RNA in the three nucleic acid molecules. The eight nucleotides also illustrate the problem of containing both DNA and RNA molecules, four types of deoxyribonucleic acid (AGCT) and four types of ribonucleic acid (AGCU).

Please give me a point

D, five bases to get DNA and RNA, 4 nucleosides to get 2 RNA, DNA is deoxynucleoside.

Position of the shock: The first shock is 5 mm away from the merging muscle, and the second is at 50 mm, a difference of 45 mm.

So 45 mm milliseconds = 30 mm milliseconds.

B is wrong, DH is the whole process, EH is only minus two.

1.Magnesium is the core element of chlorophyll, and magnesium deficiency leads to the inability to form chlorophyll.

2.Silica is meant to be ground sufficiently.

The reason for adding calcium carbonate is that the environment in which chlorophyll works is alkaline, and the cell fluid is acidic, which causes the cell fluid to flow out during grinding, and the addition of calcium carbonate can neutralize this acidity, otherwise the structure of the chloroplast will change, resulting in the loss of activity;

Acetone is added because: acetone is an organic solvent, and chlorophyll is easier to dissolve into organic solvents and is easier to extract.

Answer: d

Exclusion method B should be investigated in the patient's home.

c Immediately investigate.

Checked, investigation of the mode of inheritance should be carried out in the genetic family.

c, the incidence should be investigated in the general population.

d, the more samples are investigated for incidence, the better, but to ensure that the samples are representative.

B, correct, according to the principle of sampling, the principle of randomness, the number of samples taken should be large A is unfounded, and monogenic polygenic has no effect.

c is obviously wrong, of course, the patient's family inherits a lot of people.

Item D lacks a precondition, although the more samples, the smaller the error, but it ignores a premise, if the sample is from the same family, no matter how large the amount is, the error is quite large.

It's a multiple-choice question, right?

c must be right, hehe, I'm a freshman ......