Across
- 3. a species that is threatened and may become extinct
- 4. the features of species change over time
- 5. a harmful substance released into the environment
- 7. oxygen + glucose --> carbon dioxide + water
- 8. the connection between two different species
- 12. a species that can be used to measure how polluted a habitat is [9,7]
- 14. looking after a species; keep the population at a healthy size
- 15. how carbon compounds are reused and recycled in the environment [6,5]
- 17. a relationship between two species where they both benefit
- 18. something needed and used light light, food, water, a mate, shelter.
- 19. the number of individuals of a species living in a particular area
- 20. a relationship between two species when one lives off the other
Down
- 1. an animal that hunts and kills other animals
- 2. a feature of a species that makes it well suited to live in a particular habitat
- 4. when all the individuals in a species have died
- 6. how nitrogen compounds are reused and recycled in the environment [8,5]
- 9. an animal that is hunted and eaten by other animals
- 10. carbon dioxide + water --> glucose + oxygen
- 11. the cause of evolution; where only the best adapted individuals go on to reproduce and pass on their genes [7,9]
- 13. where a resources is not used up quicker than it is replaced
- 16. when different species or individuals need the same resource