genes and inheritance

• Genes


  Part of a chromosome that helps to determine a characteristic
• Chromosomes


  Thread-like structure contained in the nucleus of a cell
• DNA


  A chemical with molecules shaped like a twisted ladder
• Inheritance


  The passing on of DNA from parents to offspring
• Environmental factors affecting features


  • Large wrists from heavy work
• Variation


  The differences that occur both between different species and within the same species
• Species


  A group of organisms that can reproduce with each other to produce viable offspring
• Fusion of gametes to produce a fertilised egg

  1. Sperm (sex cells in males)

  2. Egg (sex cells in females)

  3. Fertilisation (fusion of male and female gametes)

  4. Zygote (new cell formed from fused gametes)
• Gametes contain half the normal number of chromosomes