Biology

4. is a protein that detects a signal molecule and performs an action in response.
8. is the use and application of living things and biological processes
9. are cylinder-shaped organelles made of short microtubules arranged in a circle
11. includes using our senses to study the world
13. is a physical environment with different species that interact with one another and with nonliving things
14. is a proposed answer for a scientific question. A hypothesis must be specific and testable
15. is the movement of molecules in a fluid or gas from a region of higher concentration to a region of lower concentration
17. is the scientific study of all forms of life
19. The conditions that do not change during an experiment

1. are organelles that carry out photosynthesis
2. is the study and comparison of genomes both within and across species. Here again, biologists need to use computers
3. is the smallest basic unit of matter.
5. is the basic unit of life. In fact, microscopic, single-celled organisms are the most common forms of life on Earth.
6. are catalysts for chemical reactions in living things
7. provides an enlarged image of an object
10. is an organized group of related parts that interact to form a whole.
12. is the change in living things over time. More specifically, evolution is a change in the genetic makeup of a subgroup, or population, of a species
16. is any individual living thing. All organisms on Earth share certain characteristics
18. is a fluid-filled sac used for the storage of materials needed by a cell
20. is a proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence