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With the aid of a diagram describe the events occurring in the neurone leading to the establishment of an action potential

Voltage-gated Na + channels and Voltage-gated K + channels are closed at rest, Once a stimulus is applied, the neurotransmitters activate chemically-gated (CG) channels within the cell membrane. CG Na + chan...
OY
Answered by Olga Y. • Biology tutor
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An individual is seated in a darkened room. What would you expect their pupils to look like? A light is shone onto their eyes and a change in their pupils is noted, what change would you expect and why?

In dark/dim conditions the human pupil dilates (diameter increases) to allow more light in.In bright conditions the pupil constricts (diameter decreases) and less light enters the eye.This is through a combi...
TB
Answered by Tom B. • Biology tutor
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Calculate the frequency of genotypes in a population in Hardy Weinberg equilibrium with the allele frequencies of A=0.6 and a=0.4. Thus calculate the number of individuals with each genotype in a population of 150

A= 0.6 a= 0.4 p+q=1 where p=A and q=a p 2 +2pq+q 2 =1where AA=P 2 Thus AA frequency in the population = 0.6 2 = 0.36Aa=2pq Aa frequency in the population = 2(0.4 X 0.6) = 0.48aa=q 2 aa frequency in the popul...
HB
Answered by Harvey B. • Biology tutor
7133 Views

How can diuretics be used to decrease blood pressure?

Diuretics can reduce the amount of Na+ that is reabsorbed by the nephron (leads to excretion of more salt and water in the urine) The reabsorption of Na+ from the kidney tubule back into the capillaries lowe...
KK
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How do the alveoli within the lungs create an efficient gas exchange surface?

The epithelial cells in the lungs are arranged into structures called alveoli which are found at the end of bronchioles and are adapted for efficient gas exchange. Firstly, there are millions of alveoli with...
KK
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