Across
- 3. A protein found in red blood cells that carries oxygen.
- 4. Humans have 46 of these in the nucleus.
- 5. The movement of food along the gut.
- 8. A negative human impact on biodiversity.
- 10. Another name for carbon fixation.
- 14. The species who's presence or absence indicate the level of pollution.
- 17. The artery that supplies the heart muscle with its own blood supply.
- 18. The gene that masks the appearance of another.
- 19. 'Skin' of the leaf which is water proof and contains stoma.
- 21. Photosynthesis is an ___________ controlled process.
Down
- 1. It is the sequence of _______ that determine the sequence of amino acids and therefore the protein structure.
- 2. The competition that occurs between different species.
- 6. To increase yield, farmers use methods like intensive farming, pesticides and what?
- 7. The type of bacteria that converts ammonium compounds into nitrites and then nitrates.
- 9. The part of the brain that controls balance and co-ordination.
- 11. The site of chemical reactions.
- 12. Trachea and bronchi are held open by this.
- 13. Transports sugar up and down the plant.
- 15. All of the species living together.
- 16. The fibres from the poles that attach to the centromere and pull chromatids to opposite poles during mitosis.
- 20. A resource that animals compete for.