Answer:
DNA is made of chemical building blocks called nucleotides. These building blocks are made of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating.
The nervous system helps:
Receptors in muscles provide the brain with information about body position and movement.
The brain controls the contraction of skeletal muscle.
The nervous system regulates the speed at which food moves through the digestive tract.
The nervous system regulates respiratory rate
The nervous system regulates heart rate and blood pressure.
Source: https://faculty.washington.edu/chudler/organ.html
Administer varicella vaccine to the health 6-year old child (who does not have evidence of immunity to varicella) was exposed to a confirmed case of varicella 2 days ago.
Explanation:
It is seen that if a child receives varicella vaccine between 3 to 5 days of exposure, he is safe as disease will not appear in him and would be saved for future infections.
Varicella vaccine is given for prevention against small pox. It is expected once immunised with varicella body will produce antibodies for a span of twenty years or more.
C. Agar provides a solid surface for bacterial growth.
Agar is a substance obtained from red algae which when added to a culture media, provides a solid surface for the growth of bacteria. When the agar is not added then the culture media remains as the broth and when the agar is added then the broth gets solidified.
Agar is added 1.5-2% in the broth to get solidified. The growth of the bacteria depends on the amount of agar added. Agar is used for the growth of bacteria because it has gel like properties which holds the nutrients evenly and the bacteria can use it accordingly.
