Biology · AQA Paper 2
Reproduction and Meiosis
How organisms reproduce, with sexual reproduction, which involves meiosis and the fusion of gametes and gives variety, and asexual reproduction, which involves one parent, mitosis only and gives genetically identical clones. It covers how meiosis halves the number of chromosomes in the gametes, how fertilisation restores the full number, and how the embryo develops. It also covers the advantages and disadvantages of sexual and asexual reproduction, with examples of organisms that use both methods. Matches AQA 4.6.1.1 to 4.6.1.3. Sexual and asexual reproduction (4.6.1.1) and meiosis (4.6.1.2) are for both Trilogy and separate Biology. The advantages and disadvantages of sexual and asexual reproduction (4.6.1.3) are marked biology only in the specification, so they are for separate Biology only.
Lessons
Ticks are remembered on this device only.
-
1
Sexual and Asexual Reproduction
Some organisms need a partner to reproduce, and others can reproduce alone. This lesson covers the difference between sexual and asexual reproduction, and…
9 terms -
2
Meiosis and Fertilisation
A human sperm cell and a human egg cell each have only half of the chromosomes of an ordinary body cell. This lesson explains how meiosis halves the number of…
9 terms -
3
Advantages and Disadvantages of Sexual and Asexual Reproduction
Some organisms reproduce only one way, but many use both, depending on the circumstances. This lesson is for separate Biology only: Trilogy students do not…
9 terms -
Knowledge organiser
The whole chapter on a page or two of A4 — to revise from on screen or print.
Key terms in this chapter
All 27, gathered from every lesson.
- Sexual reproduction
- Reproduction that involves the fusion of male and female gametes.
- Asexual reproduction
- Reproduction that involves one parent, and no fusion of gametes.
- Gamete
- A sex cell, such as a sperm cell or an egg cell.
- Fertilisation
- The fusion of the nuclei of a male gamete and a female gamete.
- Mitosis
- Cell division that forms two genetically identical cells.
- Meiosis
- Cell division that forms gametes, which are genetically different.
- Clone
- An organism that is genetically identical to its parent.
- Variation
- Differences between individuals in a population.
- Pollen
- The male gametes of flowering plants.
- Meiosis
- Cell division in the reproductive organs that forms four genetically different gametes.
- Gamete
- A sex cell with half the number of chromosomes of a body cell.
- Fertilisation
- The fusion of the nuclei of a gamete from each parent.
- Chromosome
- A structure in the nucleus that is made of DNA, and carries genes.
- Embryo
- A ball of cells, formed by the division of the fertilised egg.
- Differentiate
- To become specialised for a particular job.
- Reproductive organs
- The organs that make gametes, such as the testes and ovaries.
- Mitosis
- Cell division that forms two genetically identical cells.
- Zygote
- The cell formed when a male gamete fuses with a female gamete.
- Variation
- Differences between the individuals of a population.
- Natural selection
- The process by which the best adapted organisms survive and reproduce.
- Selective breeding
- The process by which humans breed plants and animals for particular characteristics.
- Spore
- A tiny reproductive structure of a fungus, which grows into a new fungus.
- Runner
- A stem that grows along the ground and forms a new plant.
- Bulb division
- The division of a bulb into new bulbs, which grow into new plants.
- Malarial parasite
- The microorganism that causes malaria.
- Host
- An organism that a parasite lives in or on.
- Clone
- An organism that is genetically identical to its parent.