Sexual vs Asexual Reproduction
Chromosomes and Cells
Human cells contain 23 pairs of chromosomes (diploid).
Gametes (sperm and egg) are haploid, containing 23 single chromosomes.
Gametes are produced by meiosis, which produces non-identical cells.
Regular body cells divide by mitosis, producing identical cells.
Sexual Reproduction
Involves fusion of male and female gametes (fertilization).
Genetic information is mixed → offspring are genetically different from both parents.
Variation is seen in offspring (e.g., puppies with different traits).
Occurs in animals and flowering plants (pollen + egg).
Asexual Reproduction
Only one parent is involved.
No gametes, so no mixing of genetic material.
Offspring are genetically identical → called clones.
Only involves mitosis.
Examples:
Aphids: reproduce without a partner.
Plants: form buds that drop off and grow into new genetically identical plants.
Summary
Feature | Sexual Reproduction | Asexual Reproduction |
|---|---|---|
Number of parents | Two (male + female) | One |
Gametes involved | Yes (sperm & egg) | No |
Type of cell division | Meiosis (gametes) | Mitosis |
Genetic variation | Offspring are genetically different | Offspring are genetically identical (clones) |
Mixing of genetic information | Yes | No |
Examples | Humans, flowering plants (pollen + egg) | Aphids, budding plants |
Number of chromosomes in gametes | Haploid (23 single in humans) | N/A |
Purpose | Produces variation in offspring | Produces identical offspring quickly |