Chromosomes and DNA - Cell Division

Overview

• Chromosomes carry genetic information in DNA.
• Mitosis: A type of cell division ensuring identical genetic information in new cells.

DNA and Chromosomes

• DNA (Deoxyribonucleic acid): Material in cell nuclei carrying genetic info.
• Chromosomes: Structures housing DNA, coding characteristics for organisms.
• Gene: DNA section controlling cell chemistry, especially protein production.
• Chromosome Formation:
  • Each chromosome: Single DNA molecule.
  • DNA replicates, coils, and condenses into chromosomes during cell division.

Chromosome Count in Humans

• Human body cells: 46 chromosomes (23 pairs).
• Sex Chromosomes:
  • Female: XX (identical shape chromosomes).
  • Male: XY (one chromosome different in shape).

Additional Resources

• Explore DNA and genome with Dr. Alex Lathbridge on BBC Sounds.

More Guides on the Topic

• Cell structure - AQA
• Interactive activity: Mitosis - AQA
• Transport in cells - AQA
• Sample exam questions - cell biology - AQA

Related Links

• Biology: Exam-style questions
• Biology revision resources
• Bitesize revision podcasts
• Jobs that use Biology