Answer:
The proportion of oxygen went up because of photosynthesis by plants. The proportion of carbon dioxide went down because: it was locked up in sedimentary rocks (such as limestone) and in fossil fuels. it was absorbed by plants for photosynthesis.
Explanation:
When water is transferred from land to atmosphere by evaporation from the soil and by transpiration plants.
<h3><u>Answer;</u></h3>
A. Gas exchanges takes place by diffusion.
B. It is an open system.
<h3><u>Explanation</u>;</h3>
- Most molluscs and arthropods have an open type of circulatory system.
- Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.
- Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
The correct answer is Lysosomes
Lysosomes are used for digestion of materials in the cell.
