Answer:
haemoglobin
Explanation:
Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body
A mutation is a change in a gene
Answer:
by their species or genus
Explanation:
D because to help preserve environment everyone has to work together
Answer:
i don't know if im right but honestly i could be A B or C
Explanation:
but i would say if its humans adapting to the environment and if an animal probably the same thing but maybe A more than C