The right answer is A patient who is Rh– can receive only Rh– blood.
The blood group is not the only thing that matters, it adds a category: rhesus. Rhesus refers to a red blood cell antigen that is on their wall. There are two blood group systems: Rh positive (Rh +) and Rh negative (Rh-).
Rhesus is positive in people who have this antigen. It concerns the majority of the population. Negative rhesus refers to people without the antigen. This rhesus factor is especially useful to know if a blood transfusion is feasible between two people.
The blood transfusions can be "iso-rhesus", that is to say between Rh + and Rh- but only in one sense: Rh- can give to Rh + but Rh + can not give to Rh-. Again because of the presence of antibodies directed against the antigen in Rh- people.
They are found in bacteria and eukaryotes is false
I think the correct answer from the choices listed above is option A. Directional selection can be distinguished from disruptive selection by the elimination of extreme variations of traits. Directional selection is a natural selection where an extreme phenotype is favored than others.
Answer:
The correct option is b
Explanation:
Phospholipids are lipids that contains a phosphate group, which forms the "head" of the molecule and is hydrophilic (water loving). The "tail" of phospholipids is made of two fatty acids which are hydrophobic (water fearing). The phospholipid in the cell membrane acts as a selectively permeable barrier that regulates what goes in and out of the cell <u>thereby protecting the cell from some external molecules and ions</u>.
