please help on some general science, it has to be done today:/

1. a general term for microscopic forms of life capable of living under extreme conditions?

2. the smallest microscopic form of life?

3. a general term for any disease-causing organism?

4. cancer-causing irritants which trigger viruses?

5. injections containing antigens which cause the body to produce antibodies??

please help, i looked all through the book. and yes i am homeschooled. thanks!