What topics are in biology B2?
AQA B2 Revision Notes
- 1 Cells and Cell Structures.
- 1 Tissues, Organs and Organ Systems.
- 3 Photosynthesis.
- 4 Organisms and their environment.
- 5 Proteins.
- 6 Respiration.
- 7 Cell Division and inheritance.
- 8 Speciation.
What is meiosis for GCSE?
Meiosis is the type of cell division that produces gametes . A human body cell contains 46 chromosomes arranged in 23 pairs. Human gametes are haploid – so their nucleus only contains a single set of 23 unpaired chromosomes.
What happens in Stage 1 of mitosis GCSE?
A growing and dividing cell goes through a series of stages called the cell cycle . The first stages of the cell cycle involve cell growth, then synthesis of DNA . The single strand of DNA that makes up each chromosome produces an exact copy of itself.
Can I do my GCSE Science Online?
Whatever the case may be, the good news is that it’s now easier than ever to resit as you can now study your GCSE Science 100% online – making it a great option, even if you have the busiest of schedules.
What is B3 GCSE?
B3 – Living and growing Molecules of life. DNA chromosomes and cells. Plant Cells and Animal cells.
What is B2 in biology?
B2.1 Cells and simple cell transport To get into or out of cells, dissolved substances have to cross the cell membranes.
What is the difference between mitosis and meiosis GCSE?
Mitosis produces identical diploid body cells for growth and repair. Meiosis produces haploid non-identical sex cells, or gametes . These fuse to form a diploid fertilised egg cell during fertilisation.
What are the six stages of mitosis?
These phases are prophase, prometaphase, metaphase, anaphase, and telophase. Cytokinesis is the final physical cell division that follows telophase, and is therefore sometimes considered a sixth phase of mitosis.
Where does meiosis occur in the human body?
Meiosis occurs in the testes of men and ovaries of women. Meiosis and mitosis differ because: mitosis is a form of cell division which produces two identical, diploid body cells meiosis is a form of cell division which produces four non-identical, haploid sex cells or gametes (sperm and ova in humans)
How are meiosis cells divided to form gametes?
Inheritance, Variation & Evolution 6.1 Reproduction 6.1.2 Meiosis Cells in reproductive organs divide by meiosis to form gametes (sex cells) Otherwise, there would be double the number of chromosomes after they join at fertilisation in the zygote (fertilized egg)
How are meiosis and mitosis similar and different?
Meiosis and mitosis differ because: 1 mitosis is a form of cell division which produces two identical, diploid body cells 2 meiosis is a form of cell division which produces four non-identical, haploid sex cells or gametes (sperm and ova in… More
When does the chromosome number become haploid during meiosis?
This halving occurs during meiosis, and so it is described as a reduction division in which the chromosome number is halved from diploid to haploid, resulting in genetically different cells It starts with chromosomes doubling themselves as in mitosis and lining up in the centre of the cell