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:
Answer:
Frequency of allele A1- 0.41
Explanation:
In Hardy weinberg equilibrium,
P refers to the dominant allele
q refers to the recessive allele
The allele frequency will be p+q=1
The genotypic frequency is- P²+q²+2pq=1
P²= genotype of dominant trait ( A1A1)- 77
2pq= genotype of heterozygotes (2pq)- 65
q²= genotype of recessive trait (A2A2)- 123
Total number of offsprings= 77+ 65+ 123
= 265
Now to calculate allele frequency of A1=
= 77/265 + 1/2( 65//265)
= 0.290+ 0.122
= 0.413
Thus, 0.41 is correct.
<span>Some features you may expect to see at the site where two plates converge, or a convergent boundary, would be mountains and volcanoes. It may even form a chain of volcanoes. Earthquakes are likely as well.</span>
Answer:
When light energy is absorbed by a chlorophyll molecule its electrons gain energy and move to higher energy levels in the molecule
They show how all creatures have adapted such as giant dinosaurs are now tiny lizards =D<span />
