The picture represents a structure of the respiratory system. Alveoli in the lungs.

Which is the function of this structure?

to bring air into the body

to exchange oxygen with carbon dioxide

to carry air to the lungs

to release oxygen from the body

What type of appendages do sponges cnidarians roundworms annelids mollusks arthropods echinoderms and vertebrate have? jointed, not jointed, absent  

Which anatomical plane is the only one that could not show both the sternal region and vertebral region

1. isogamy 1 organisms with gametes of the same size and shape 2. anisogamy organisms with gametes of different sizes and shapes 3. oogamy 2 organisms with gametes of the same shape but different sizes 4. gonads gamete-producing organs in lower plants 5. gametangia gamete-producing organs in animals