I believe it would be Mitochondria
Answer:
<u>stonewort, and many green algae such as the Spirogyra.</u>
Explanation:
- As it was believed that the land algae were believed to be evolved from the stonewort plant and the blue-green algae like the cyanobacteria and the spirogyra that colonized the lands some 500 mn years ago was a freshwater alga.
- After which the first land plants occur about 470 million years ago, and they were in the form s of moss and liverworts of the vascular in origin.
Answer:
Immune system of the body helps in fighting with the infectious agents that are foreign for the body. So the immune system protects us from infection.
When any foreign substance(antigen) comes in the body B-lymphocyte recognize it by binding the antigen through its receptor. After recognizing the antigen, B cell divides into antibody-producing plasma cell and memory cell.
Antibodies produced by plasma cells help in destroying the antigen by getting the antigen recognized by phagocytic cells or by complement activation.
B cells are antigen-presenting cell which present antigen to T cell and then T cell activates and produce chemicals that kill the antigen. Therefore the immune system has many immune cells that activate when an antigen comes in the body. This is how the immune system functions.
