A Level Biology Practice Exam

What process is defined as the death of cells that occurs normally during growth and development?

1. Mitosis

2. Necrosis

3. Apoptosis

4. Meiosis

The correct answer is: Apoptosis

The correct answer, apoptosis, refers to the programmed cell death that plays a crucial role in growth and development. This process helps in shaping tissues and organs by removing unnecessary or damaged cells in a controlled manner. During development, for example, apoptosis is responsible for eliminating the cells in between fingers in a developing embryo, allowing for the proper formation of separate digits. Apoptosis is characterized by specific cellular changes, such as cell shrinkage, chromatin condensation, and fragmentation into apoptotic bodies, which are then cleared away by other cells without causing inflammation. This orderly process contrasts with necrosis, which is an uncontrolled form of cell death often resulting from injury or disease, leading to inflammation and damage to surrounding tissues. Mitosis and meiosis, on the other hand, are processes related to cell division and reproduction, not cell death. Mitosis results in the formation of two identical daughter cells, whereas meiosis leads to the production of gametes for sexual reproduction. Unlike apoptosis, these processes do not involve the selective elimination of cells during normal development.