Final answer:
Gametes are sex cells like the egg and sperm, involved in sexual reproduction. They are produced by a process called meiosis and are haploid, containing half the number of chromosomes compared to other cells. These cells are crucial for the fusion process that leads to the formation of a new organism, known as a zygote.
Step-by-step explanation:
Gametes: Definition and Role in Reproduction
Gametes are specialized cells that play a critical role in sexual reproduction. They are the sex cells, such as the egg (female gamete) and sperm (male gamete), which fuse during fertilization to form a zygote. This zygotic cell then develops into a new individual. Gametes are produced through a process called meiosis, where the number of chromosomes is halved, making them haploid. As opposed to spores, which can be involved in both asexual and sexual reproduction in plants and fungi, gametes are exclusively for sexual reproduction purposes.
The process begins within the gonads, where spermatogenesis occurs in the testis to produce sperm, while oogenesis occurs in the ovaries to produce eggs. In plants, gametes are produced by the gametophyte, which undergoes mitosis to create these sex cells. The alternation of generations in plants involves both diploid (sporophyte) and haploid (gametophyte) stages, and it's during the gametophyte stage that gametes are formed. The pollen in seed plants represents the male gametophyte and is critical for the transfer of the sperm to the female gametophyte, enabling fertilization and the subsequent zygote formation.