Question

Какой закон проявится в наследовании признаков при скрещивании организмов с генотипами: Аа х Аа?​

Answer 1

Ответ:

Первый закон Менделя (закон единообразия, закон доминирования).

Объяснение:

При скрещивании чистых линий (гомозигот) все потомство получается одинаковое (единообразие первого поколения, расщепления нет). P AA x aa G (A) (a) F 1 Aa. У всех потомков первого поколения (F 1) проявляется доминантный признак (желтый горох), а рецессивный признак (зеленый горох) находится в скрытом состоянии.

Answer 2

При скрещивании гетерозигот первого поколения между собой мы получаем расщепление по генотипу 1АА:2Аа:1аа и по фенотипу 3(1АА+2Аа):1(аа) (если доминирование полное).
Это всё проявления второго закона Менделя — закон расщепления

Answer 3

Inheritance of Traits in Organisms with Genotypes: Aa x Aa

When considering the inheritance of traits in organisms with genotypes Aa x Aa, we are dealing with the principles of Mendelian genetics. In this case, the organisms are heterozygous for a particular trait, meaning they have one dominant allele (A) and one recessive allele (a) for that trait.

Mendel's Law of Segregation: - When two heterozygous organisms (Aa x Aa) are crossed, the alleles for a particular trait segregate during gamete formation, and each gamete carries only one allele for the trait.

Mendel's Law of Independent Assortment: - This law states that different traits are inherited independently of each other. However, it's important to note that this law applies when the genes for the traits are located on different chromosomes or are far apart on the same chromosome.

Phenotypic Ratio: - When two heterozygous organisms are crossed (Aa x Aa), the phenotypic ratio among the offspring is expected to be 3:1. This means that in a large number of offspring, approximately three-quarters will exhibit the dominant phenotype, and one-quarter will exhibit the recessive phenotype.

Genotypic Ratio: - The genotypic ratio among the offspring of the cross Aa x Aa is expected to be 1:2:1. This means that approximately one-quarter of the offspring will be homozygous dominant (AA), half will be heterozygous (Aa), and one-quarter will be homozygous recessive (aa).

In summary, when organisms with genotypes Aa x Aa are crossed, the principles of Mendelian genetics, specifically the laws of segregation and independent assortment, govern the inheritance of traits, leading to specific phenotypic and genotypic ratios among the offspring.

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