Cell Division and Chromosomes

Cell Division

• Process where a single cell divides into two or more daughter cells
• Enables growth, development, and repair in multicellular organisms

Chromosomes

• Contain genetic information in the form of DNA and RNA
• Essential for inheritance and cell function

DNA

• Deoxyribonucleic acid
• Stores the genetic code that determines an organism's traits
• Contains the instructions for growth and development

Human Chromosomes

• Humans have 23 pairs of chromosomes, totaling 46 chromosomes
• 22 pairs are autosomes, responsible for non-sexual traits
• 1 pair is sex chromosomes (X and Y)
• XY determines male sex, XX determines female sex

Mitosis

• A type of cell division that produces two daughter cells genetically identical to the parent cell
• Essential for growth, repair, and asexual reproduction
• Consists of four main stages: prophase, metaphase, anaphase, and telophase

Interphase

• The period between mitotic divisions when the cell grows and replicates its organelles and DNA
• Prepares the cell for the next round of division

Prophase

• The first and longest stage of mitosis
• Chromosomes condense and become visible
• The mitotic spindle forms, which will pull the chromosomes apart
• The nuclear envelope breaks down

Metaphase

• The second stage of mitosis
• Chromosomes align at the center of the cell, forming the metaphase plate
• The spindle fibers attach to the centromeres of the chromosomes

Anaphase

• The third stage of mitosis
• Sister chromatids separate and move to opposite poles of the cell
• The cell elongates as the poles move further apart

Telophase

• The final stage of mitosis
• The chromosomes reach the poles, and the nuclear envelope reforms around each set of chromosomes
• The chromosomes decondense
• The cytoplasm divides, forming two daughter cells