I think it’s
A) Calcium Sulfide
Answer:
A. engulfing of small photosynthetic prokaryotes by larger cell
Explanation:
The endosymbiotic theory states that some of the organelles in today's eukaryotic cells were once prokaryotic microbes. In this theory, the first eukaryotic cell was probably an amoeba-like cell that got nutrients by phagocytosis and contained a nucleus that formed when a piece of the cytoplasmic membrane pinched off around the chromosomes. Some of these amoeba-like organisms ingested prokaryotic cells that then survived within the organism and developed a symbiotic relationship.
Some Evidence for this is based on the following:
1. Chloroplasts are the same size as prokaryotic cells, divide by binary fission, and, like bacteria, have Fts proteins at their division plane.
2. The mitochondria are the same size as prokaryotic cells, divide by binary fission, and the mitochondria of some protists have Fts homologs at their division plane.
3. Mitochondria and chloroplasts have their own DNA that is circular, not linear.
4. Mitochondria and chloroplasts have their own ribosomes that have 30S and 50S subunits, not 40S and 60S.
5. Several more primitive eukaryotic microbes, such as Giardia and Trichomonas have a nuclear membrane but no mitochondria.
Answer:
If you got a flu shot this year, next year you'll need it again.
Explanation:
This is because the virus changes, usually rendering the previous year's vaccine partly or totally useless. hope this helps you :)
They use C, thermal heat. This is because the vents use heat from the earth and it warms up the organisms that are very deep in the ocean. The reason they do not use sunlight is because they are so deep down in the ocean that sunlight will not reach them.