BiologyCode 9700
Passage of information from parents to offspring
What this topic asks you to be able to do
- explain what is meant by diploid (2n) and by haploid (n)
- explain what it means for chromosomes to be in homologous pairs
- explain why a reduction division is required in meiosis when gametes are made
- describe what chromosomes do in animal and plant cells during meiosis, and what the spindle, the nuclear envelope and the cell surface membrane do alongside them (the main stages of meiosis should be named, though not the sub-divisions of prophase I: prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II and telophase II)
- interpret photomicrographs and diagrams showing cells at varied points in meiosis, then pick out its principal stages
- account for how crossing over, plus the random orientation (independent assortment) of homologous chromosome pairs and sister chromatids during meiosis, gives rise to genetically different gametes
- account for how gametes joining at random during fertilisation results in genetically different individuals