Could animals have lived on Earth when Earth had its
second atmosphere? Why or why not?

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

Time ! for a smell to begin the process of registering in your brain, first you must a) inhale odor molecules into the nasal cavity b)transduce scent chemicals c)have a scent to inhale d)all answers can work

When analyzing tree rings, what do scientists assume a thin ring indicates?