Download Life Science Vocabulary 2014-2015

Structures and Functions of Living Things
(Cells and Human Body)
1. cell – the basic unit of structure and function in living things.
2. microscope – an instrument that makes small objects look larger
3. cell theory- a widely accepted explanation of the relationship between cells and living things
4. organelle – a tiny cell structure that carries out a specific function within the cell
5. cell wall – a rigid layer of nonliving material that surrounds the cells of plants and come other
organisms.
6. cell membrane – a cell structure that controls which substances can enter or leave the cell
7. cytoplasm – the region between the cell membrane and the nucleus; in organisms without a nucleus,
the region located inside the cell membrane.
8. nucleus – a cell structure that contains nucleic acids, the chemical instructions that direct all the cell’s
activities.
9. chromatin – material in cells that contains DNA and carries genetic information
10. nucleolus – can be found floating in the nucleus. This is where ribosomes are made.
11. mitochondria- rod-shaped cell structures that produce most of the energy needed to carry out the
cell’s functions.
12. endoplasmic reticulum – a cell structure that forms a maze of passageways in which proteins and
other materials are carried from one part of the cell to another.
13. ribosomes – a small grain-like structure in the cytoplasm of a cell where proteins are made.
14. golgi bodies – a structure in a cell that receives proteins and other newly formed materials from the
endoplasmic reticulum, packages them, and distributes them to other parts of the cell.
15. chloroplasts – a structure in the cells of plants and some other organisms that captures energy from
sunlight and uses it to produce food.
16. vacuoles – a water-filled save inside a cell that acts as a storage area.
17. lysosomes – A small round cell structure that contains chemicals that break down large food particles
into smaller ones.
18. bacteria – a cell that is usually smaller than a plant or animal cell and does not contain a nucleus. The
only other organelles it shares with plants and animals are a cell wall, cell membrane and ribosomes.
19. prokaryote – an organism without a nucleus such as bacteria
20. eukaryote - an organism whose cells DO have a nucleus and other organelles
21. nutrient – substances in food that provide energy for an organism to carry out essential processes
22. amoeba – single celled organism with no fixed shape
23. euglena – single celled organism that can both make its own food like a plant – or consume it
24. volvox – a single celled organism that is a type of algae
25. paramecium – single celled organism found in freshwater, brackish and marine environments
26. cilia – hair-like organelles that provide movement or move fluids and particles along ducts in
multicellular forms.
27. pseudopod – part of a cell’s cytoplasm that allows for movement or food gathering. A “false foot”
28. contractile vacuole –an organelle that pumps excess water out of a cell
29. food vacuole – an organelle where food is digested
30. eye spot - a small, light-sensitive patch of pigment in certain algae and unicellular organisms
31. flagella – a long whip-like structure that acts like a little motor for movement
32. chlorophyll – the green pigment found inside a chloroplast.
33. photosynthesis –the process by which a green plant turns water and carbon dioxide into food when
the plant is exposed to light.
34. autotroph - an organism that creates its own food through photosynthesis
35. heterotroph – an organism that cannot produce its own food and must eat other organisms to survive.
36. tissue – a group of similar cells that perform a specific function in an organism
37. organ – a structure that is composed of different kinds of tissue
38. organ system – a group of organs that work together to perform a major function in the body
39. muscle tissue – a body tissue that contracts or shortens, making body parts move
40. nervous tissue – a body tissue that carries electrical messages back and forth between the brain and
every other part of the body
41. connective tissue – a body tissue that provides support for the body and connects all of its parts
42. epithelial tissue – a body tissue that covers the surfaces of the body, inside and out
43. homeostasis – the process by which an organism’s internal environment is kept stable in spite of
changes in the external environment.
44. stress – the reaction of a person’s body to potentially threatening, challenging or disturbing events.