Infants between the ages of six and 12 months are especially at high risk for contracting measles because they are too young to receive the vaccine. infants are often protected until they are about 6- months-old by maternal antibody. their mothers either had measles, or were vaccinated against it, before they became pregnant, but as these babies get older, that protection fades. which of the following is the maternal antibody that protects infants for the first six months of life?
a. iga
b. igd
c. ige
d. igg
e. igm

The correct answer is d. IgG

Explanation:

During pregnancy the fetus is attached to the mother body by placenta and IgG is the only antibody which can cross the placenta and reach the fetus. This antibody is very important for an infant to get protection from infections.

Measles is a viral disease that usually infects infants who are not vaccinated against it. Until the vaccination is done the infant is protected by the passive immunity given by his mother through passing the IgG antibody.

This maternal antibody is capable of protecting infants for the first six months of life after which vaccination is required to protect the infant from measles.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.