What is the dominant and recessive nature of genes, and what is the relationship between them and tr

<>1. Dominant gene: A dominant gene refers to such an allele, whether the gene is homozygous or heterozygous, it will be expressed. When this allele is present, the epiremitic type of the organism will show dominant characteristics.

2. Recessive genes: recessive genes are genes that dominate recessive traits in the beat. In diploid organisms, genes that can be phenotypically displayed in the homozygous state, but not in the heterozygous state are called recessive genes.

When the dominant gene and the recessive gene exist at the same time, the traits expressed by the biomimetic slag are the dominant traits controlled by the dominant gene, and the recessive traits controlled by the recessive gene cannot be manifested Therefore, the dominant gene and the recessive gene controlled by the sex beam crying state cannot be expressed at the same time, so the statement of the question stem is incorrect

So the answer is:

Because dominant genes take precedence over recessive genes, when both dominant and recessive genes are present. Dominant genes are preferentially expressed, so dominant traits appear.

Because the dominant trait is a form that manifests itself, while the recessive gene is hidden in the body and will not be revealed.

Because (aa) is single (aa) is double (aa) is double (aa) is double.

So the double eyelids are determined by the dominant one, which is explained in the biology textbook.

AA is double, so double is obvious.

If it is single, then it is single.

The dominance and recessiveness of a single gene is determined by its function.

Normal genes Normal, functional proteins.

Recessive genes are abnormal, usually non-functional or non-functioning proteins, so an abnormal phenotype is exhibited only when the allele is also recessive.

Dominant genes are abnormal, often able to disrupt normal protein synthesis or inhibit their function, so only one dominant gene is needed to manifest the abnormality.

The above discussion does not involve co-explicitness.

This is supposed to be the result of long-term evolution, and in organisms some are controlled by recessive genes and some are controlled by dominant genes. If it is always controlled by dominant genes at the beginning, the only way to produce recessive genes is through genetic mutations, such as the albinism gene, which should have been mutated in the first place. It starts out as a recessive gene, but it can also mutate to form a new dominant gene, such as the polydactyly gene in humans.

Both recessive and dominant genes are located on homologous chromosomes. For fully dominant organisms, a pair of homozygous hybrids with relative traits, the traits exhibited by the F1 generation are dominant, such as the hybridization of tall stems and short stems of peas, F1 exhibits tall stems, and tall stems are dominant.