1. what is the first line of defense against infection for the human body?
a. white blood cells
b. saliva
c. skin
d. red blood cells

The instructions for the genetic traits of an organism are directly determined by the a-numbers of a,t,c and g units in a sugar molecule b-sequence of the bases in dna molecules c-length of a dna molecules d-way the bases are paired in the two strands of a dna molecule

During sunny hours, a large amount of build up between the hours of 1: 00-5: 00 pm. a. ozone b. mercury c. lead d. sulfuric acid

List five ways we are indebted to phytoplankton