The basic unit of structure and function of all living things.
What is a cell?
100
The circulatory system transports blood through these tubes, in this order.
What are the arteries, capillaries, and veins?
100
This system breaks down food into nutrients.
What is the digestive system?
100
Bones have a hard outer membrane and a soft center that contains __________.
What is bone marrow?
200
Thin cell covering that holds the parts of the cell together.
What is a cell membrane?
200
Tissues that work together.
What is an organ?
200
These blood vessels are so tiny that blood cells have to move through them in single file.
What are capillaries?
200
Bones are attached to each other in these places.
What are joints?
300
A Jellylike substance that contains many chemicals to keep a cell functioning.
What is cytoplasm?
300
Organs that work together to perform a function.
What is a body system?
300
In the respiratory system, air travels into and out of the lungs through tubes. The smallest tubes end in these tiny sacs.
What are alveoli?
300
In this organ of the digestive system, nutrients enter the blood.
What are the small intestines?
300
These are tough bands of tissue that attach bones to muscles.
What are tendons?
400
Process by which particles of a substance move from an area where there are many particles of the substance to an area where there are fewer particles of the substance.
What is diffusion?
400
Cells that work together to perform a specific function.
What is a tissue?
400
Oxygen travels to every cell in the body through this body system.
What is the circulatory system?
400
In the body's excretory system, urea and water travel from the blood into the kidneys and diffuse into _______.
What are nephrons?
400
These bands of tissue attach bones to each other.
What are ligaments?
500
The movement of water and dissolved materials through the cell membrane.
What is osmosis?
500
These nerve cells detect conditions in the body's environment.
What are receptors?
500
The body inhales _______, and exhales _________.
What are oxygen and carbon dioxide?
500
Nutrients move from the digestive system into the blood by traveling through these tiny tubes sticking out of the wall of the small intestine.
What are the villi?
500
These specialized cells transmit and receive nervous-system signals.