Unit 1 From Single Cells
to
Body Systems Review
1. Cell
 Basic unit of structure and function of all living things.
2. Cell Membrane
 Thin cell covering that holds the parts of the cell together.
3. Nucleus
 Organelle that controls a cell’s activities.
4. Cytoplasm
 Jellylike substance that contains many chemicals to keep a cell
functioning.
5. Diffusion
 Process by which particles of a substance move from an area where there
are many particles of the substance to an area where are fewer particles of
substance.
6. Osmosis
 Movement of water and dissolved materials through the cell membrane.
7. Tissue
 Cells that work together to perform a specific function.
8. Organ
 Tissues that work together.
9. System
 Organs that work together to perform a function.
10. Capillaries
 The circulatory system transports blood through various-sized tubes called
arteries, veins, and capillaries.
11. Alveoli
 The smallest of these tubes are blood vessels so tiny that blood cells have
to move through them in single file. In the respiratory system, air travels
into and out of the lungs through tubes. The smallest tubes in tiny sacs
called alveoli, which are surrounded by capillaries.
12. villi
 Nutrients move from the digestive system into the blood by traveling
through villi, tiny tubes sticking out of the wall of the small intestine.
13. nephrons
 In the body’s excretory system, urea and water travel from the blood into
the kidneys and diffuse into nephrons.
14. bone marrow
 Bones have a hard outer membrane and a soft center that contains bone
marrow.
15. joints
 This soft material is connective tissue that produces red and white blood
cells. Bones are attached to each other in places called joints.
16. tendons
 Tough bands of tissue called tendons attach bones to muscles.
17. ligaments
 Other bands of tissue called ligaments attach bones to each other.
18. neurons
 To move, a muscle must receive a signal from the nervous system.
Specialized cells called neurons, detect conditions in the body’s
environment.
19. Osmosis
 Allows water to flow into the roots of plants.
20. Diffusion
 Osmosis is one kind of diffusion.
21. Reproduce
 Plants and animals grow when cells reproduce.
22. Epithelial tissue
 An animal’s skin is an example of epithelial tissue.
23. Respiratory system
 Oxygen enters the body through the respiratory system.
24. Circulatory system
 Oxygen travels to every cell in the body through the circulatory system.
25. Digestive
 The system that breaks down food into nutrients is the digestive system.
26. Heart
 The heart is a muscle.
27. Hip
 The hip is a ball-and-socket joint.
28. Signals
 The nervous system carries signals to and from the brain.