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Humans need to remove (excrete) waste products from the bloodstream. Describe the processes that produce waste products and how the products are removed from the body. (6 marks)

Urea is produced via the breakdown of amino acids in the liver, which is removed from the blood by the kidneys and excreted in urine . Carbon dioxide is a waste product of respiration in cells and is breathe...
KJ
Answered by Kizzy J. • Biology tutor
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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
7029 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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