Cell Divison and Mitosis

Why are cells small?

Because the exchange of waste and nutrients is more efficient and DNA can't keep up with cell demands.

What is an ideal cell configuration?

Large surface area to small volume (large SA/V ratio).

Why do cells divide?

For growth, repair, and reproduction (both sexual and asexual).

What is a chromosome?

A single package of DNA; the number of chromosomes depends on the species.

What are the chromosomes in a human?

What defines the cell cycle?

The period from birth to reproduction of a cell.

What are the two main phases of the cell cycle?

Interphase and Mitotic phase.

What occurs during Interphase?

The cell is doing its job and preparing to divide.

What happens during the Mitotic phase?

The nucleus and cell divide.

What are the stages of Mitosis?

Prophase, Metaphase, Anaphase, Telophase.

What occurs during Prophase?

Chromosomes become visible, nuclear envelope breaks up, and spindle forms.

What happens in Metaphase?

Chromosomes line up across the cell, and spindle connects to sister chromatids at centromere.

What happens during Anaphase?

Sister chromatids get pulled apart toward opposite ends of the cell.

What occurs during Telophase?

The spindle disappears, nuclear envelopes reform, and chromosomes uncoil.

What is cytokinesis?

The splitting of the cytoplasm at the end of cell division.

How does cytokinesis differ in animal and plant cells?

In animals, the plasma membrane pinches in; in plants, a cell plate forms.