The two main types of cell division in the human life cycle are mitosis and meiosis.
Mitosis
Mitosis is the process of cell division that creates new body cells. It's responsible for growth, repair, and the replacement of worn-out cells. During mitosis, a single cell divides into two identical daughter cells, each with the same number of chromosomes as the parent cell. This ensures genetic continuity. Most cell division we refer to is actually mitosis.
Example: When you cut yourself, mitosis helps heal the wound by generating new skin cells.
Meiosis
Meiosis is a specialized type of cell division that produces gametes (sex cells)—sperm in males and eggs in females. Unlike mitosis, meiosis involves two rounds of cell division, resulting in four daughter cells, each with half the number of chromosomes as the parent cell. This reduction in chromosome number is crucial for sexual reproduction. When sperm and egg unite during fertilization, the resulting zygote has the correct number of chromosomes (a combination of genetic material from both parents).
Example: The formation of sperm and egg cells relies on the process of meiosis to ensure genetic diversity in offspring.
The provided references explicitly state that mitosis and meiosis are the two main types of cell division. One reference highlights that meiosis ensures the correct chromosome number across generations. Another source mentions that cell division is essential for growth and repair (pointing to mitosis). Therefore, the question is answered comprehensively by the two cell divisions mentioned.
