Bio Questions....

[biocupid]

(I) What are the effects on blood volume and blood pressure if excess sodium ions remain in the body due to the failure of the kidneys to excrete them?

(II) A kidney transplant is most likely to be successful if the kidney comes from an identical twin.Why is this so? If a person does not have an identical twin,who would be the next donor?

[dark_angel]

(I) If excess sodium ions remain in body, the osmothic pressure increases so it makes the body retain water. This leads to a bigger blood volume. If the volume is bigger, the blood exerts a higher pressure on blood vessels => higher blood pressure

(II) The imune system is tolerant to "self" components but it rejecs anything that it could be identified as foreign. Thw kidney derived from a twin brother has exactly the same properties as the one of the receivar (identical twins are genetically identical)