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.
Answer:
If it´s not A then choose C
Explanation
If they were land animal and could not swim then the only logical reasoning would be that the two pieces of land drifted apart from each other and the fossils were in between them and that´s why they ended up in the ocean.
Answer:
The given muscles can be categorized into following categories:
Smooth muscles: These are involuntary muscles and non-striated muscles which are usually found within the walls of internal organs such as stomach, intestine, uterus et cetera.
Cardiac muscles: These are involuntary and striated muscles which are only associated with the heart.
Skeletal muscles: These are voluntary in nature and striated in structure. They are anchored to the bones with the help of tendons. They help in skeletal movement such as maintaining posture, locomotion et cetera. For example, hand muscles and neck muscles.
The three major types of pollution are air pollution, water pollution, and land pollution. Sometimes, air pollution is visible. A person can see dark smoke pour from the exhaust pipes of large trucks or factories, for example. More often, however, air pollution is invisible.
