Answer:
A cell wall
Explanation:
Plant cells are enclosed by a rigid cell wall. When the plant cell is placed in a hypotonic solution , it takes up water by osmosis and starts to swell, but the cell wall prevents it from bursting.
Inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli. This is what happens in the alveoli during gas exchange
The answer is Fist hope I helped
Answer:
????
Explanation:
None of those seem to be correct to me.
1. Observations are made using the five senses- sight, sound, touch, taste, and smell. So this is invalid.
2. Observations and experiments can both be done anywhere
3. See answer to 2
4. It's cut off? But observations can literally be as simple as looking at a stick and noting that it's brown, so from what I can read, it's invalid.