Ithink its a i'm just double checking because ragweed cant hurt you but your body dosnt realize that
what happens when a person who is allergic to ragweed encounters ragweed?

a. ragweed antigens bind to mast cells, which release histamines.

b. ragweed antibodies attack the immune system.

c. mast cells release antihistamines into the bloodstream.

d. the cells of the immune system become weakened.

Tall, cone-shaped mountains in which layers of lava alternate with layers of ash are called a. shield volcanoes. b. cinder cone volcanoes. c. composite volcanoes. d. lava plateaus. select the best answer from the choices provided a b c d i need asap

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.