1, O because if either shows present it's O.
Answer:
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.
Explanation:
Hope this helps
Answer:
She should look for a cell wall outside the cell membrane.
Explanation:
The answer should be d, they are in domain eukarya so their cells are eukaryotic.
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
