We heard that some was seriously injured. what verb need corrected or is it right?

The that needs to be corrected is "was." "Was" refers to a singular noun, however, in this sentence it is modifying "some," which is plural. The verb "were" should be used instead.

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.