Ask for a detailed summary of high school biology, preferably in detail. Thank you

1. Genes, chromosomes are a real substance, there are many genes on it, no, the genotype is composed of multiple groups of genes (such as AAB, AA) 2.There are as many tetrads as there are homologous chromosomes (i.e., chromosomes of the same size and morphology), choose d, 3Seedless watermelon is produced because the chromosomes are singular and the association is disordered (just like a love triangle, it will always fall out!).

After colchicine treatment, the chromosomes can be doubled, because there are originally three sets of chromosomes, and after replication, there are six chromosome groups that are the same in pairs, producing three gametes, choose A

To select a haploid, it must be manually doubled in order to have the ability to reproduce. Because haploids cannot produce gametes.

Artificial doubling makes the alleles homozygous, so that the inbred offspring of such plants do not have trait separation.

b；There is no indication of manual doubling.

c；Two haploids cannot be hybridized.

d；Mistake.

Homozygous is obtained directly, without multi-generational culture.

The order of the bases of this mRNA is as follows:

a—u—u—c—g—a—u—g—a—c—37—c—u—c—u—u—a—u—c—u;

The start codon is AUG, that is, starting from the 6th base, (the first 5 bases a-u-u-c-g are not counted,).

a—u—g—a—c—37—c—u—c—u—u—a—g—a—u—c—u;

The stop code is UAG, because the stop codon does not determine amino acids, so the next bright paragraph: u-a-g-a-u-c-u does not determine the amino acid residue bond, and the remaining bases are a-u-g-a-c-37-c-u-c, a total of 5+37+3=45, determining 15 amino acids.

This question is b, because the number of bases should be counted from the starting password.

a The genes in germ cells are half that of somatic cells (nuclear genes only). From the conditions, it is concluded that somatic cells have 7*10 9 pairs of deoxynucleotides (note, here is a pair, not a one). Divide by the average number of deoxynucleotides in each gene.

= 10 7pcs.

The DNA in germ cells is half that of somatic cells.