Science Biology

4. The movement of blood through the body's blood vessels.
8. The process by which plants convert sunlight into energy.
11. A reproductive cell (sperm or egg) that fuses during fertilization.
15. The ability of an organism to maintain internal stability.
16. A specialized structure within a cell that carries out specific functions.
18. The process by which organisms release energy from food.
21. A community of living organisms in conjunction with their environment.
22. The fusion of male and female gametes to form a zygote.
24. The grouping of organisms based on shared characteristics.
26. A protein that speeds up chemical reactions in living organisms.
27. The process of combining simpler substances to form more complex ones.
29. The production of offspring by a sexual or asexual process.
30. An organelle that contains enzymes for digestion within cells.

1. A change in the DNA sequence that can lead to genetic variation.
2. The ability of an organism to resist infection or disease.
3. The control center of a cell, containing genetic material.
5. Proteins produced by the immune system to fight off foreign substances.
6. The hereditary material in organisms.
7. The study of heredity and variation in living organisms.
9. Chemical messengers that regulate bodily functions.
10. Thread-like structures that carry genetic information in cells.
12. A characteristic that helps an organism survive and reproduce in its environment.
13. The process of breaking down food into simpler substances for absorption.
14. Cell division that results in two identical daughter cells.
17. The process of gradual change in species over time.
19. Chemical messengers that regulate bodily functions.
20. The movement of water across a semipermeable membrane.
23. Cell division that results in four genetically unique daughter cells.
25. The basic unit of life.
28. The early stage of development in a multicellular organism.