The building block of DNA is called the nucleotide, which is composed of a nitrogenous base (adenine, guanine, cytosine, or thymine), a five-carbon sugar (deoxyribose in DNA), â¦ and one to three phosphate groups. + 16 others found this useful.
Special cases of minimum ages and intervals. Two childhood vaccines require a bit more explanation regarding scheduling: â¢. MMR at age 1 year â Many statesâ school and childcare regulations specify that the minimum age for receipt of MMR vaccine be âon or after the first birthday,â with no allowance for a grace period.
Be aware, though, that MMR is a live vaccine, so the two doses should be given at least four weeks apart. If your child has received a live single vaccine, they will have to wait at least four weeks until they can have the MMR vaccine. Read more about the difference between live and killed vaccines.