Across
- 3. a species endangered when the total number of remaining members may not be sufficient to produce enough offspring to ensure survival of the species
- 4. any species of plant or animal that occurs naturally in an area, not introduced by humans
- 9. the protection, improvement, and wise use of natural resources by humans for present and future generations
- 13. plants or animals that are not native to an area and which establish themselves and overcome or outcompete pre-existing native species
- 16. the category of animals that feed on both plants and animals
- 17. a plant that lives for two years of growing seasons - producing leaves the first season and flowers and seeds the second
- 18. the beginning of plant growth from a seed
- 20. a broad term that includes non-domesticated animals but not inclusively mammals, birds, reptiles, and amphibians
Down
- 1. a plant that has leaves year-round
- 2. a male sheep
- 5. a female sheep
- 6. a mix of organic and synthetic materials spread on or worked into soil to increase its capacity to support plant growth
- 7. decomposed plant material that adds nutrients to the soil and improves soil composition
- 8. a female horse
- 9. the green coloring matter in plants - essential to photosynthesis
- 10. the geographic area in which a species occurs
- 11. the category of animals that feed on plants
- 12. the category of animals that prey or feed upon animals and insects
- 14. a plant that completes its growth cycle in one season
- 15. a male horse
- 19. a dynamic complex of plants, animals, and other organisms along with their non-living environment, interacting as a functional unit