Which of the following statements about extinction is true? a) extinction is the ultimate fate of all species
b) extinction can occur in small areas
c) extinction can be caused by the introduction of exotic species
d) all of the above

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

Why is it important to study each branch of earth science?

Anurse is caring for a 42-year-old client who is scheduled for an amniocentesis during the fifteenth week of gestation because of concerns regarding down syndrome. what other fetal problem does an examination of the amniotic fluid reveal at this time?