biology

3. The variety of life in the world or in a particular habitat or ecosystem.
7. An organism that produces its own food and energy from light or chemical sources; a producer.
9. A specialized subunit within a cell that has a specific function.
11. (Deoxyribonucleic Acid): The molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms.
13. A biological community of interacting organisms and their physical environment.
14. The fundamental structural and functional unit of all known organisms.
15. The ability of an organism to maintain a stable internal state despite changes in its external environment.
18. A segment of DNA that controls a specific physical characteristic or trait.
19. A permanent alteration in the nucleotide sequence of the genome of an organism.
20. A threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

1. A Y-shaped protein produced by the immune system that is used to identify and neutralize foreign objects such as bacteria and viruses.
2. An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.
4. An organism whose cells contain a nucleus and other organelles enclosed within membranes.
5. The process used by plants, algae, and cyanobacteria to convert light energy into chemical energy, through a process that uses sunlight, water, and carbon dioxide.
6. A single-celled microorganism that lacks a distinct nucleus and other membrane-bound organelles.
8. A biological catalyst, usually a protein, that speeds up biochemical reactions in cells.
10. The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the Earth.
12. A poisonous substance produced by living organisms.
16. A close and long-term interaction between two different biological species.
17. An organism that cannot produce its own food and therefore obtains energy by consuming other organisms.