Type the word that appropriately completes each statement.

Most fish have gills that aid in gas exchange. First, water enters the mouth and passes over the gills.
from the water is moved into the blood as
from the blood is moved into the water.

Oxygen from the water

Carbon dioxide from the blood

Explanation:

Fish as any other living organism have the same breathing mechanisms. They breath in oxygen and breath out carbon dioxide.

Oxygen from the water

Carbon dioxide from the blood

Explanation:

is this for the e2020 class

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."