Question

охарактеризуйте второй этап гаметогенеза-период созревания половых клеток мужских и женских организмов.какие особенности имеет этот период?почему в гаметах в процессе созревания формируется измененный или новый набор генов?

Answer 1

Второй этап это рост. Соответствует интерфазе . Увелич. объём цитолазмы клеток. Происходит репликация ДНК и удвоение хромосом. Клетки называются сперматоциты первого порядка(муж) и ооциты первого порядка(жен)

Answer 2

The Second Stage of Gametogenesis: Maturation Period of Male and Female Gametes

The second stage of gametogenesis is the period of maturation of the male and female gametes. This stage involves the development and maturation of the germ cells into functional gametes, which are sperm in males and eggs in females.

During this period, several key features and processes characterize the maturation of gametes in male and female organisms:

1. Maturation of Sperm (Male Gametes): - In males, the process of spermatogenesis occurs in the testes, leading to the formation and maturation of sperm cells. - Spermatogenesis involves the differentiation of diploid germ cells (spermatogonia) into haploid sperm cells (spermatozoa) through meiosis. - The maturation period of male gametes involves the development of spermatozoa, including the formation of the head, midpiece, and tail, which are essential for motility and fertilization.

2. Maturation of Eggs (Female Gametes): - In females, the process of oogenesis takes place in the ovaries, resulting in the production and maturation of egg cells. - Oogenesis also involves meiosis, leading to the formation of mature haploid eggs from diploid germ cells (oogonia). - The maturation period of female gametes includes the growth and development of the egg cell, as well as the formation of structures such as the zona pellucida and corona radiata, which are important for fertilization.

3. Specialization and Differentiation: - During the maturation period, both male and female gametes undergo specialization and differentiation to acquire the necessary structures and characteristics for successful fertilization. - This process involves the formation of specialized organelles and structures, such as the acrosome in sperm cells and the cortical granules in egg cells, which play crucial roles in the fertilization process.

Formation of Altered or New Set of Genes in Gametes

During the process of gamete maturation, the formation of an altered or new set of genes occurs due to the following reasons:

1. Meiotic Recombination: - Meiosis, the type of cell division involved in gametogenesis, includes a process called meiotic recombination. This process involves the exchange of genetic material between homologous chromosomes, leading to genetic diversity in the resulting gametes. - Meiotic recombination contributes to the formation of gametes with unique combinations of genetic information, resulting in altered gene sets in the sperm and egg cells.

2. Random Assortment of Chromosomes: - Another factor contributing to the formation of altered gene sets in gametes is the random assortment of chromosomes during meiosis. - As chromosomes segregate independently during meiosis, different combinations of maternal and paternal chromosomes end up in the resulting gametes, leading to further genetic diversity and the potential for new gene sets.

In conclusion, the maturation period of gametes involves the development of specialized male and female reproductive cells with distinct structures and characteristics. Additionally, the process of gamete maturation leads to the formation of altered or new sets of genes in the resulting sperm and egg cells, primarily due to meiotic recombination and the random assortment of chromosomes during meiosis.