Biology › Cell cycles, reproduction and development

Cell cycles, reproduction and development

Unit B06 · 6 lessons.

Notes

Illustrated notes for each topic in this unit, with worked examples and a checklist of objectives.

• The cell cycle and mitosis
  The cell cycle through G1, S and G2 to mitosis, the three checkpoints and what each one asks, chromosomes as chromatids after replication, the…
• Stem cells and cell potency
  What a stem cell is and what self-renewal means, the four levels of potency from totipotent to unipotent with a real example of each, the four…
• Gametes, fertilisation and early development
  How sperm and eggs are produced and the ways spermatogenesis and oogenesis differ, how the structure of each gamete suits its function, binding to…
• Sexual reproduction in flowering plants
  The parts of a flower and what each does, how a pollen grain forms in the anther by meiosis and then mitosis, how the embryo sac forms in the ovule…
• Homeobox genes, Hox genes and apoptosis
  The homeobox as a conserved sequence of 180 base pairs, the 60 amino acid homeodomain it codes for and how that homeodomain binds DNA, Hox genes as a…
• Cloning in plants and animals
  Cloning plants naturally through runners, rhizomes, tubers and bulbs, then artificially by cuttings and by micropropagation from explant to plantlet…

Practical work

The practical capabilities this unit's work belongs to, each with its techniques, its calculations and the errors that cost marks.

• Preparing biological material: squashes, sections and mounts