Answer:d.) protozoa
Explanation:protozoa is a unicellular eukaryotic organism that belongs to kingdom protista. Protozoans depends on other organism for there food because they do not produce there own food. Some protozoa can be parasitic in nature.
Example of protozoa is amoeba.
Answer:
B) Viruses are killing some of his B cells and becoming incorporated into the genomes of others.
Explanation:
Epstein-Barr virus causes infectious mononucleosis by following mechanism.
1) Epstein-Barr virus attaches to and infects epithelium of the throat where it replicates and causes pharyngitis.
2) Virions enter the lymphoid vessels and are carried to the lymph nodes. Some virions escape the lymphnode trap and are carried to the bloodstream.
3) Virions attach specifically to B lymphocytes and infect them, producing either latent infection or productive infection.
4)The infected B lymphocytes actively replicate and differentiate into cells producing random immunoglobulins.
5)T cells respond to infection and destroy the lymphocytes replicating EBV vitus.
6) Latently infected B lymphocytes become immortal. They are not attacked by T cells.
Answer:
12-14 october
Explanation:
The probable period of exposure is calculated as follows:
- Know the range of the incubation period
- Start counting back from the days of the first case by subtracting the first number of incubation period range
- Count back the days from the last case by subtracting the last number of incubation period range.
- This will give a range which will be the period of exposure.
From the question,
- Incubation period range 1-15
- Date of first case = october 15
- Therefore, first date of exposure = 15 -1 = 14
- Date of last case = 22
- Therefore, last date of exposure = 27 - 15 = 12
- Thus, the range is 12-14 october which is the probable period of exposure.
Formula of a triangle: length*breadth/2
