Across
- 4. Thread-like structures containing tightly coiled DNA.
- 5. Group of organisms of the same kind living in the same place.
- 7. Process by which species change over time in response to environmental conditions.
- 8. A section of DNA that determines an inherited characteristic.
- 10. Is the number of species in an ecosystem.
- 11. A molecule found in the nucleus of cells that contains genetic information.
Down
- 1. Animal and plant species living today descended from species that existed in the past.
- 2. No more individuals of a species remain.
- 3. When two or more living things struggle against each other to get the same resource.
- 6. Differences between individuals of a species.
- 9. A species that is at risk of extinction.