cells

1. - a highly contagious disease caused by the varicella-zoster virus; symptoms include an itchy rash and small, fluid-filled blisters that scab over.
3. - RNA virus, such as HIV, with reverse transcriptase in its core.
5. - substance that is able to kill or inhibit the growth of bacteria.
6. - a virus that attacks the immune system, specifically the white blood cells.
9. - a cell that is part of the immune system and helps the body fight infections and other diseases; develop from stem cells in the bone marrow and become different types of white blood cells.
10. - body system that consists of organs and substances and includes the skin, mucus, and white blood cells.
12. - the central membrane-bound organelle that manages cellular functions and contains DNA.
14. the semipermeable membrane that surrounds the cytoplasm.
15. - an organism that causes disease in a host.
16. - an organism that is infected with or fed upon by a parasitic or pathogenic organism.
17. unicellular organism with membrane-bound nucleus and organelles; generally larger and more complex than a prokaryote.
19. - microscopic, unicellular organism without a nucleus or other membrane-bound organelles.
20. - a contagious respiratory illness caused influenza viruses that infect the nose, throat, and sometimes the lungs.

2. Plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside.
4. - specialized structure that carries out a specific cell function in different parts of the cell at the same time.
7. - a preparation that is used to stimulate the body’s immune response against a specific disease.
8. flexible, selectively permeable boundary that helps control what enters and leaves the cell.
11. regulation of an organism’s internal environment to maintain conditions needed for life.
13. - a virus that infects a bacteria and reproduces inside of it.
18. - a highly contagious upper respiratory disease caused by the SARS-CoV-2 virus.