What is the correct sequence of events for activation of a b cell by a t-dependent antigen? (1) the b cell binds to a cytokine and then interacts with the th cell. (2) this causes the b cell to bind the antigen, and then the b cell is activated. (1) immunoglobulin receptors on the b cell recognize and bind the antigen. (2) an antigen fragment in complex with mhc class 2 is displayed on the b cell's surface. (3) the mhc-antigen complex binds a receptor on a th cell. (4) the th cell secretes cytokines that activate the b cell. (1) identical repeating subunits on the antigen bind to many of the antibodies on the surface of the b cell. (2) this activates the b cell. (1) the t cells bind to an antibody on the b cell. (2) the t cell secretes cytokines. (3) the b cell binds the antigen. (4) the b cell is activated by binding to the antigen.

1. this system transports blood through the body and heart. 2. this system relates to the process by which an organism gets rid of its waste. 3.this system is responsible for movement of bones and fluids throughout the body. 4. this system receives and transmits information and responses. it depends upon electrical impulses created by the movement of charged particles. 5. this system relates to the process by which an organism replicates. sexually reproduction usually involves male cells (sperm) meeting female cells (eggs) to produce a fertilized egg or zygote. 6. this system gets oxygen to the cells of the body and rids the body of waste gases. some organisms use their skin. this is also a cell-level process. 7. this system relates to the structure and support of an organism. it is made of salts and proteins and found in vertebrate animals. 8. this is the system of organs which circulate blood around the body of most animals. 9. this system controls the glands that secrete hormones. 10. this organ system to protect the body from damage. itembank : system circulatory digestive system endocrine system excretory integumentary system muscular system nervous system reproductive system respiratory system skeletal system cardiovascular system