Question

why?an organism monitors its internal environment to stay healthy and to carry out its life functions. recognizing when foreign cells or other potentially harmful substances are in the body is one way to prevent damage and fight off infection by pathogens. human red blood cells have a system for being recognized so that cells that belong in the body are kept safe while cells that do not belong can be destroyed.model 1 – red blood cells and antibodies1. blood types in the human population are characterized by the presence or absence of antigens on the surface of the red blood cells.a. according to model 1, how many blood types are found in the human population?b. what shape is used in model 1 to represent an a antigen?c. what distinguishes a type a red blood cell from a type b red blood cell?human blood cell typing

Explanation:

a. Model 1 explicitly lists four distinct blood type columns for humans.
b. Observing the "Cell with attached antigen" row for Type A, the A antigen is a circle with triangular spikes.
c. Comparing Type A and Type B red blood cells in Model 1, the key difference is the specific antigen on the cell surface and the corresponding antibody produced.

Answer:

a. 4
b. A circle with triangular spikes (sun-like shape)
c. Type A red blood cells have A antigens on their surface and produce anti-B antibodies, while Type B red blood cells have B antigens on their surface and produce anti-A antibodies.