Biology Question 14, Biology . Solve the 12th question

Analysis: There are two genotypes of yellow cats in the offspring: RR and RR, because RR:

RR = 1:2, so the RR genotype in the child generation of yellow cats is 1 3, and the RR is 2 3, then the proportion of black cats (RR) in the second generation of children is 2 3 times 1 2 = 1 3, and the yellow cat is 1-1 3 = 2 3, so yellow cat: black cat = 2:1

A: Organic matter content. without dry soil.

Alcohol lamp burning burns off the organic matter in the soil, and the difference in organic matter content between the two soils can be determined by measuring the difference in the quality of the soil before and after.

Mistake: When measuring the organic matter content of the soil, it is necessary to use dry soil, otherwise the evaporation of water will also show a decrease in soil weight when the alcohol lamp is burned.

（1）①③

2) Nucleus.

3) Cell wall.

4) Phospholipids. 5) Centrosomes and ribosomes.

（1）1,4,6,9

2) Presence or absence of nucleus.

3) Cell wall.

4) Lipids, sugars, proteins.

5) Centrosomes, ribosomes.

Select d to parse:

The solution that can cause red blood cells to burst must have the concentration of the solution》 The concentration of the cell fluid (a) Because it is normal saline, it does not break and does not shrink.

The concentration is greater than the concentration of the cell fluid, so it all shrinks.

d can be seen as clear water with a concentration of 0

The answer is: d.

The genotype and phenotype of AAB were crossed with AAB, and the genotype and phenotype of AA offspring of AA and clump AA were AA:AA=1:1;

The genotype and phenotype of the offspring of BB and BB are b-:bb=3:1, therefore, the genotype and proportion of the offspring are crossed.

aab-：aabb：aab-：

aabb=3：1：3：

1, so the progeny phenotypes are 4, and the ratio is 3:1:3:

1. Since there are three genotypes of BB and BB offspring, and there are two types of base royal intous of AA and AA offspring, there are 6 genotypes of offspring.

(1) Cellular, parasitic.

2) Small, bacterial.

3) The cause of the formation of hyaline plaques is that bacteriophages parasitize staphylococci and eventually break them down.

Cells parasitize small bacterial phages that parasitize the body of staphylococci and eventually break it down

1) According to the different parasites, viruses are divided into three categories: viruses that are specifically parasitic in animal cells are called animal viruses such as influenza viruses, viruses that are specifically parasitic in plant cells are called plant viruses such as tobacco mosaic virus, and viruses that are specifically parasitic in bacterial cells are called bacterial viruses, also called bacteriophages such as Escherichia coli bacteriophages Therefore, bacteriophages are a class of microorganisms without cell structure, and their main physiological characteristics are that individuals are very small and must parasitize in the living cells of other organisms in order to express life activities

2) From the data, it can be seen that phages parasitize in bacteria, relying on the genetic information in their own kernels, using the substances in the host cell to make new phages The size of phages is small compared to bacteria, and the basis is that they can pass through bacterial filters

3) When phages parasitize staphylococcus, they will cause staphylococcal cells to rupture and die, and transparent plaques will appear on the colony

(1) Bacteriophages are a class of microorganisms with no cell structure, and their main physiological characteristics are that they must parasitize in bacteria.

2) The size of the phage is small compared to bacteria, which is based on the fact that it can pass through the bacterial filter.

3) The formation of hyaline plaques on staphylococcal colonies is caused by the phage parasitizing staphylococci and eventually breaking it down.

The cell structure parasitic is smaller bacteria because the phage breaks through the cell membrane and the hyaline plaque is a staphylococcal colony destroyed by the phage.