Definitions

4. a group of organisms that can reproduce to produce fertile offspring
5. a change in the base sequence of DNA
6. the movement of small food molecules and ions through the wall of the intestine into the blood
8. the maintenance of a constant internal environment
12. the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration
14. a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs
15. the removal of the nitrogen-containing part of amino acids to form urea
19. a group of organisms of one species, living in the same area, at the same time
20. a junction between two neurones
21. as the ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
22. a length of DNA that codes for a protein

1. a group of cells with similar structures, working together to perform a shared function
2. a permanent increase in size and dry mass by an increase in cell number or cell size or both
3. changing the genetic material of an organism by removing,changing or inserting individual genes
7. a thread-like structure of DNA, carrying genetic information
9. having two different alleles of a particular gene
10. defence against a pathogen by antibody production in the body
11. any substance taken into the body that modifies or affects chemical reactions in the body
13. the probability of an organism surviving and reproducing in the environment in which it is found
16. a unit containing the community of organisms and their environment, interacting together
17. a version of a gene
18. a network of interconnected food chains