| A | B |
|---|
| filter feeding | getting food by straining it out of the water |
| digestive tract | a tube-like digestive space with an opening at each end |
| gratrovascular cavity | a digestive space with a single opening |
| diffusion | the movement of materials from an area of high concentration to an area of low concentration |
| respiration | the process of gas exchange in which animals take in oxygen and release carbon dioxide |
| circulatory system | the system that moves blood throughout the body. |
| atrium | a heart chamber that receives blood returning to the heart. |
| ventricle | a heart chamber that pumps blood out of the heart |
| asexual reproduction | reproduction that involves one parent and no egg or sperm |
| egg cell | a female sex cell |
| ovary | the female sex organ that produces egg cells |
| sexual reproduction | reproduction that involves an egg from a female and sperm from a male |
| sperm cell | a male sex cell |
| testes | male sex organs that produce sperm cells |
| fertilization | the joining of an egg cell and sperm cell |
