First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.
Answer:
Explanation:
1) Excitation brings about contraction.
2) Contraction leads to an increase in blood pressure.
3) Changes in blood pressure results in the opening and closing of the heart valves.
4) The opening and closing of heart valves then regulates the flow of blood and it's volume.
Rather than helping one species you can help a entire ecosystem. if you think about it, you would be saving more in a ecosystem then you would in just 1 single species
Answer:
b progesterone
Explanation:
The plug is formed as soon as there is implantation of fertilized eggs. The thickness of the cervical mucus becomes different as hormone levels changes in pregnancy.
The progesterone, encourages the production of thick fluid/ mucus which brings about the formation of a plug. This prevents bacteria from getting into the uterine cavity.
