In: Biology
The cell cycle is composed of interphase (G?, S, and G? phases), followed by the mitotic phase (mitosis and cytokinesis), and G? phase.
In interphase:
G1: Also called gap phase, the cell grows physically larger, copies organelles, and makes the molecular building blocks it will need in later steps.
S phase: Also called synthesis phase. Complete copy of DNA with nucleus is synthesized. Duplication of centrosome happens which separate DNA during M phase.
G2 phase: Also called second gap phase. Cells grow bigger and make proteins and organelles and its contents get reorganised for mitosis. G2 phase ends when mitosis starts.
M phase: The cell divides its copied DNA and cytoplasm to make two new cells. During mitosis, the nuclear DNA of the cell condenses into visible chromosomes and is pulled apart by the mitotic spindle, a specialized structure made out of microtubules. Mitosis involves 4 phase: Prophase, metaphase , anaphase and telpohase.
Cytokinesis: Cytokinesis usually begins just as mitosis is ending, with a little overlap. Cytokinesis takes place differently in animal and plant cells.
Answer for B attached
Answer for C: Genetic diversity plays an important role in the survival of a species. When a population's habitat changes, the population have to adapt for survival; the ability of the population to adapt to the changing environment will determine their ability to cope with an environmental challenge. It mainly strengthen the population where some induviduals are able to survive major disturbances and make the group less susceptible to genetic disorders.