4. Mark the following statements as true or false. If a statement is false, correct it to make a true statement.
a. Erythrocytes are biconcave discs with prominent nuclei.
b. The main function of erythrocytes is to transport oxygen on the protein
hemoglobin.
c. Hemoglobin forms oxyhemoglobin when it binds to oxygen.
d. Hemoglobin consists of two polypeptide chains bound to a heme group.

Describe the iron sulfide hypothesis and the lipid membrane hypothesis.

Mike was adopted, and his biological family history is unknown. although he is healthy, he would like some understanding of his genetic makeup, including potential health risks and genes that he could pass on to his children. mike has heard about commercial laboratories that can compare segments of your dna to those of people with common hereditary diseases in order to give you some idea of how susceptible you are to the diseases. the results of these types of tests are highly inconclusive. if mike's dna showed that he shares similarities in a segment of dna with people who have a given disease, his chances of developing that disease or passing it on to his children may be slightly elevated, but they are not 100 percent. these tests can cost more than $2,500 and are not covered by many insurance companies. do you think that mike should undergo the genetic tests? explain your answer. what are the potential pros and cons of having such tests done? describe how the availability of these genetic tests might affect the frequency of genetic diseases in individuals and populations.

Aperson with age is more likely to catch diseases that healthy people usually don’t catch. what are these infections called?