Questions

Stoichiometry is a branch of chemistry deals with the calculations on reactants and products. It is based on the Law of conservation of mass where total mass of reactants is equal to total mass of products.

In general, polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes.
As water molecules are polar, polar molecules dissolves in water.

Parvovirus B19 causes severe anemia because it preferentially infects erythrocyte precursors.

a. Parvovirus B19 binds preferentially to the erythrocyte blood group P antigen on erythroid precursor cells.

Answers B, C, D are incorrect:

b. after entry the single-stranded viral DNA genome is transported to the cell nucleus where the host DNA polymerase synthesizes the complimentary DNA strand.

c. Parvovirus B19 infection can be diagnosed by direct detection of viral DNA not RNA.

d. the fetus of a seropositive mother is protected from infection by maternal circulating antibodies.

Demography is the scientific study of Birth and death, The well being and the Growth of population. In brief, it is the study of human populations based on their size, composition and distribution across space – and the process through which populations change.

Thyroxin or Thyroxine is the thyroid hormone that regulates carbohydrate metabolism in the human body.