The T lymphocytes capable of killing invading cellular organisms such as bacteria, protists, or fungi are cytotoxic T cells also known as CD8+ cells. These cells are capable of recognizing whether a cell has a major histocompatibility complex I (MHC I) surface protein or not. Those with absent MHC I surface protein will be killed by the cytotoxic T cells. Those with the MHC I surface protein expressing an invading antigen will also be killed by cytotoxic T cells. Those with the MHC I surface protein without an antigen will be spared by the cytotoxic T cell.
Butterflies belong to the phylum Arthropoda.
Answer:
Explanation:
1. Microbes play defense. The oodles of microbes that live on and inside us protect us from pathogens simply by taking up space
2. Microbes boost the immune system
3. Microbes protect us from auto-immune diseases.
4. Microbes keep us slim. Microbes play an important role in our body shape by helping us digest and ferment foods, as well as by producing chemicals that shape our metabolic rates.
5. Microbes detoxify and may even fight off stress.
Answer:
A radioactive (unstable) phosphorus isotope is made to replace a nonradioactive isotope of phosphorus in the molecule
Explanation:
Phosphorus has both unstable (radioactive) and stable isotopes. In any compound that contains phosphorus, the phosphorus atom present may be either a stable isotope of phosphorus or an unstable isotope of phosphorus.
However, if the molecule contains a stable nonradioactive isotope of phosphorus, it is possible to convert this isotope in the molecule to the unstable radioactive isotope by carefully carrying out exchange reactions in which the phosphorus isotope replaces the nonradioactive isotope in the molecule.
This is usually done in order to create radioactive tracers which are used to study chemical reactions and biochemical processes.
