Answer: Antigens
Explanation: The ABO system of blood grouping is based on the basis of the type of antigens that are present in the red blood cells. Erythrocytes is another name for the red blood cells. Antigens are molecules that are capable of eliciting immune response. There are two types of antigens: antigen A and B. Blood type A has only antigen A, blood type B has only antigen B, blood type AB has both antigen A and B while blood type O has no antigen (neither A nor B antigen).
Similarly, Rh trait is determined by the presence or absence of rhesus antigen in the erythrocytes. Rhesus antigen is an antigen first discovered in rhesus monkey. Rh+ indicates the presence of rhesus antigen in the red blood cells while Rh- indicates the absence of rhesus antigen in the red blood cells.
Had to look for the missing options and here is my answer.
The one that gives the best description of the most common way how material is added to the continental shelf is this: "Deposition of continental <span>sediments". This deposition includes biological, physical, and even chemical processes that occurred in a span of time. Hope this helps.</span>
The correct answer is option B. The scientists were studying if the mud snails can reproduce both sexually and asexually. The characteristics in the study included parameters such as the mating season, number of offspring, effect of environmental stress conditions and lack of mates. Out of all the parameters being studied can affect asexual reproduction in the mud snail but lack or presence of mates is a parameter required to be studied to determine the mode of reproduction i.e. sexual or asexual because need for mates or mate dependent reproduction occurs in case of sexual reproduction.
PCR allows for the analysis of DNA fragments through the comparison of the base pairs each molecule contains, which can then be used for genetic screening and the identification of individuals and DNA fragments
