Reproduction: Ability of organisms to produce a new generation
Two types:
• Asexual: Production by 1 parent
• Sexual: Production by 2 parents
• Asexual:
- 1 parent
- One stage (mitosis)
- No gametes formed
- O spring genetically identical (no variation)
- Thrive in stable environment
- Fast process
- More energy e cient
- No outside agents needed
- Can't adapt to environment easily
- Low possibility of evolution (no genetic variation)
• Sexual:
- 2 parents (di erent genders)
- 2 stages (meiosis & fertilisation)
- Gametes formed
- O spring are genetically di erent to parents
- Can adapt to changing environment
- Slow process
- Less energy e cient
- Pollinators often needed
- High possibility of evolution
, • Advantages of asexual reproduction:
- All individuals can produce o spring
- Process is simple & fast
- Useful in unchanging conditions
- Favourable mutation can spread rapidly
• Disadvantages of asexual reproduction:
- No gametic variation
- Overcrowding may occur
• Advantages of sexual reproduction:
- Variation
- Basis of evolution
- Better chance of survival in unstable environments
- Prevent spread of disease
• Disadvantages of sexual reproduction:
- High expenditure of energy
- Slower process
- Unfavourable mutations expressed
- Outside agents needed
• Sexual reproduction process:
- Diploid parent produces gametes (haploid cells) in gonads by meiosis
- Male & female gametes brought together by pollination (plants) or mating (animals)
- Gamete nuclei fuse = fertilisation
- New zygote cell is diploid
- Zygote grows by mitosis