REVIEW CELL CYCLE

What are chromosomes composed of? ________ DNA

Where are chromosomes found in the cell? nucleus

Chromosomes/DNA contain ________ that are the instructions for making proteins. genes A gene is a section of DNA that codes for a protein.

How many chromosomes are there in human body cells? 46

Interphase What are the three stages of the cell cycle? Mitosis Cytokinesis

What happens during interphase? The cell grows, works, and copies its DNA

What happens during mitosis? The nucleus divides forming two identical nuclei.

What happens during cytokinesis? The cytoplasm divides forming two identical cells.

46 46 92 46 What happens during mitosis? One cell divides to . . . . . . 46 46 DNA is duplicated 92 cell divides 46 one cell Two identical cells Same number of chromosomes!

MITOSIS 4 chromosomes One cell Two identical cells 4 chromosomes

MITOSIS produces two cells with the same number of chromosomes as the original cell produces two identical cells

Interphase DNA duplicates

Prophase The duplicated chromosomes condense. cell

Metaphase Chromosomes line up along the middle of the cell.

Anaphase Chromosomes are pulled apart and move to opposite ends of the cell.

Telophase The chromosomes gather at opposite poles of the cell forming two nuclei.

Cytokinesis The cytoplasm divides, forming two identical cells.

interphase

prophase

metaphase

anaphase

telophase

cytokinesis

proteins How do cells know when to divide? The cell cycle and cell division is regulated by proteins

Cancer A disorder in which body cells lose the ability to control cell growth and cell division. Cancer

What causes cancers? A defect or mistake in a gene (DNA), that results in a defective protein that is not able to regulate the cell cycle, and the cell divides uncontrollably.