Answer:
Variations are caused by mutation. random mating between organisms.
Explanation:
Answer: The solid is a mixture
Explanation:
Here's the complete question:
If a solid contains some particles that melt at 50°C and other particles that melt at 110°C, what must be true about the solid?
A. The solid is an element.
B. The solid is a mixture.
C. The solid is a pure substance.
D. The solid has three boiling points.
It should be noted that an element consist of an atom but in this scenario, there are different particles that also have different melting points. Therefore, it's not an element, but rather a mixture.
Also, the solid in this case is not a pure substance and doesn't have three boiling points.
Therefore, the correct option is B.
Answer:
When you sit on a plane for 6 hours without moving, blood accumulates in your veins, and the moment you get up, gravitational forces affect venous return, cardiac output, blood pressure, and venous pressure. That way, when you're sitting on a plane, the gravitational force is the same at the upper and lower extremities, such as the chest, abdomen, and legs, causing venous blood pressure and volume to be evenly distributed throughout the body. However, when one gets up, one becomes dizzy because of abnormal regulation of blood pressure. This is because gravity causes blood to accumulate in the lower extremities (veins of the legs and trunk). This lowers the blood pressure and the blood that the heart pumps. By causing blood to accumulate in the lower extremities, and as venous compliance increases, the veins expand with blood that causes the volume of blood to shift in the veins. This increases the volume and venous pressure in the lower extremities when standing. And the volume of thoracic venous blood is less and less central venous pressure. This leads to a decline in stroke volume. Cardiac output and mean arterial pressure also decrease as left ventricular stroke volume decreases, reducing pulmonary venous return. Decreased standing blood pressure, referred to as orthostatic or postural hypotension. Thus, lowering blood pressure decreases cerebral blood flow, which means less range of blood in the brain causing dizziness.
Explanation:
DNA
plasma membrene
cytoplasm
Ribosomes
