| A | B |
|---|
| cartilage | strong tissue that supports the body and is softer and more flexible than bone |
| atrium | large muscular chamber that serves as a one-way compartment for blood that is about to enter the ventrincle |
| ventricle | a thick-walled, muscular chamber, is the actual pumping portion of the heart |
| cerebrum | responsible for all voluntary activitiesof the body |
| cerebellum | coordinates body movements |
| medulla oblongata | controls the functioning of many internal organs |
| lateral line system | most fishes can, however, detect gentle currents and vibrations in the water with sensitive receptors that form |
| swim bladeer | many bony fishes have an internal, gas-filled organ |
| oviparous | fishes whose eggs hatch outside the mother's body |
| ovoviviparous | species, such as guppies, the eggs stay in the mother's body after internal fertilization |
| viviparous | animals, the embryos stay in the mother's body after internal fertilization, as they do in ovoviviparous species |
