| A | B |
|---|
| What cells unite in sexual reproduction? | sperm and egg |
| What contains a network of blood vessels that provide the embryo with oxygen and nutrients from the mother's blood? | placenta |
| What is the main function of the male reproductive system? | to produce sperm |
| What kind of cell is created when an egg’s nucleus joins with a sperm’s nucleus? | zygote |
| How do pairs of skeletal muscles work together? | While one muscle in the pair contracts, the other returns to its original length. |
| What are the two types of muscles? | voluntary and involuntary |
| What is the main function of the biceps? The triceps? | To bend the arm; to straighten the arm |
| What type of muscle allows the heart to continuously pump blood? | cardiac |
| What would happen to a person if muscles did not work in pairs? | His ability to move would be greatly decreased because muscles only contract. |
| When do muscles cause bones to move? | when the muscles pull on bones |
| When walking across a room, what types of muscles are mainly involved? | skeletal and voluntary |
| Which muscle type is attached to your bones for movement, and helps protect your inner organs? | skeletal |
| Which organ contains smooth muscle tissue? | muscle tissue |
| Which type of human body tissue can contract, or shorten? | smooth |
| Your body moves food through the digestive tract by using which type of muscles? | oxygen can diffuse from the alveoli into the blood |
