Biology Revision 2

4. the movement of particles across a cell membrane from a region of lower concentration to a region of higher concentration against the concentration gradient
8. Anything that transfers material from one organism to another
10. a group of plant hormones that affect the growth and elongations of cells
12. and unspecialised cell
13. A microorganism that causes a communicable disease
15. a communicable disease caused by a bacterium, which causes extreme diarrhoea
16. a protein produced by lymphocytes
17. unaffected or less affected by something
18. an enzyme produced in tears

1. a small mesh tube used to widen narrowed blood vessels
2. a particle that can infect other cells
3. when people choose organisms with certain characteristics and use only those ones for breeding
5. an enzyme that cuts DNA molecules into pieces
6. uncontrolled cell division
7. a hormone that is involved in the ripening of fruit
9. a type of reaction that takes place in all living cells
10. medicine that helps people recover from a bacterial infection
11. a change in one or more characteristics of a population over a long period of time
14. cells cells that open and close plant stomata