Final answer:
Sperm and egg cells are haploid sex cells that combine to form new offspring. They have half the amount of DNA as regular 'body' cells. When a sperm cell fertilizes an egg cell, they form a diploid zygote, which develops into a multicellular organism.
Step-by-step explanation:
Sperm and egg cells are haploid sex cells that combine to form new offspring. Sperm cells are produced by the male reproductive system through a process called meiosis, which divides the cells and results in cells with half the amount of DNA as a regular 'body' cell. Similarly, egg cells are produced by the female reproductive system through meiosis, also resulting in cells with half the amount of DNA. When a sperm cell fertilizes an egg cell, they combine to form a zygote, which is a diploid cell with the full number of chromosomes. The zygote then undergoes mitosis to develop into a multicellular organism.
Haploid sex cells that combine to form new offspring are called gametes. Gametes are reproductive cells that have half the number of chromosomes (n) compared to the somatic cells of an organism (which are diploid, 2n). In sexual reproduction, a male gamete (sperm cell) fertilizes a female gamete (egg cell or ovum), resulting in the formation of a diploid zygote. The fusion of gametes during fertilization restores the diploid chromosome number in the zygote, which then undergoes cell division and development to form a new organism. The process of combining gametes to form a zygote is essential for genetic diversity and the perpetuation of species in sexually reproducing organisms.