Final answer:
Dead or damaged cells are replaced through the process of mitosis, not apoptosis, meiosis, or fertilization. Mitosis results in two daughter cells with the same number of chromosomes as the parent cell, and is crucial for tissue growth and repair after damage.
Step-by-step explanation:
Dead or damaged cells are replaced by the process of mitosis. This is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. In contrast, programmed cell death, known as apoptosis, is a different process where cells are systematically dismantled and removed when they are no longer needed or if they are damaged beyond repair.
The event that leads to a diploid cell in a life cycle is fertilization, where two haploid gametes (sperm and egg) unite to form a diploid zygote. The critical period during fetal growth refers to the timeframe when specific parts or organs are most sensitive to damage from external influences and thus develop. Lastly, the part of meiosis that is similar to mitosis is meiosis II, as it resembles a normal mitotic division.