Answer:
1.
•After the left ventricle contracts, the aortic valve closes and the mitral valve opens, to allow blood to flow from the left atrium into the left ventricle.
•As the left atrium contracts, more blood flows into the left ventricle.
•When the left ventricle contracts again, the mitral valve closes and the aortic valve opens, so blood flows into the aorta.
2.
•Diffusion is defined as the movement of individual molecules of a substance through a semipermeable barrier from an area of higher concentration to an area of lower concentration.
Explanation:

Answer:
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Popliteus muscle
from: https://en.m.wikipedia.org/wiki/Popliteus_muscle
Answer:
These spheres are closely connected. For example, many birds (biosphere) fly through the air (atmosphere), while water (hydrosphere) often flows through the soil (lithosphere). In fact, the spheres are so closely connected that a change in one sphere often results in a change in one or more of the other spheres.
Explanation:
i hope this helped
Answer:
Option-1 and 4
Explanation:
Fatty acids can be distinguished into two types: saturated and unsaturated fatty acids.
The saturated fatty acids are the fats that do not contain any double bond as a result of which they are tightly packed and are found in solid-state whereas unsaturated fatty acids are the acids that contain double bond in their structure and are found in liquid form.
The cold-tolerant species show an adaptation to survive in cold species by modifying their cell membrane composition that is they increase unsaturated fatty acids which help in maintaining the fluidity of the cell membrane.
Thus, in the given question option-1 and 4 show, this adaptation and are true options.