Sexual vs Asexual Reproduction

Study Notes

Plants use pollen, released as male gametes, to fertilize eggs. Pollen can be spread by the wind or carried by pollinators.
In humans and other mammals, females produce eggs (ovum) and males produce motile sperm.
Gametogenesis is the process of making sex cells. Both oogenesis (egg production) and spermatogenesis (sperm production) involve a diploid parent cell undergoing mitosis and meiosis to create haploid daughter cells.
In humans, oogenesis starts in the pre-natal stage and continues throughout life. Spermatogenesis takes place in the reproductive system of males.
In oogenesis, a primary oocyte undergoes meiosis and produces a secondary oocyte and a polar body. The secondary oocyte will complete meiosis II and become a true ovum upon fertilization.
Spermatogenesis involves the division of diploid spermatogonia into haploid spermatocytes, which then undergo meiosis to form haploid spermatids. Spermatids undergo a morphological change to become fully functional sperm cells.
Mitosis is a cellular division process that results in diploid cells. It is a means of asexual reproduction but is not used for sexual reproduction as it does not halve the genetic material.
Meiosis is a process specifically used for sexual reproduction to produce haploid gametes.
Asexual reproduction involves the splitting of a parent cell to produce identical daughter cells, while sexual reproduction involves the fusion of gametes from two parents to produce a genetically diverse offspring.
Humans and most mammals, amphibians, fish, and birds reproduce sexually. Plants can reproduce both sexually (producing seeds and pollen) and asexually (through budding, fission, or vegetative propagation).