The answer is C, twisted ladder
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.
Northern hemisphere : Summer because it is tilted towards the sun.
Southern Hemisphere : Winter because it is tilted away from the sun.
The answer is; A gopher snake occupies a burrow made by the desert rat
Commensalism involves a relationship between two organisms where one benefits while the other is unaffected. In this case, the gopher snake gets from the burrow made by the desert sake. The desert rat is unaffected (does not benefit or lose) by this action by the snake.
Answer:
DNA is duplicated, or copied
Explanation:
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