DNA is double stranded helix, connected by what could be described as "ladder rungs". These rungs are actually nucleotides, the building blocks of DNA. A sequence of three of these nucleotides is known as a codon. Codons are important in the composition of proteins, because each codon calls for a specific .

Look at the figure above. which atmospheric layer has around 80 percent of the mass of the earth's atmosphere? (hint: it's where the clouds seen on earth are formed.) a. exosphere b. troposphere c. stratosphere d. thermosphere

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

Tara sees a commercial for a brand of pills that promise to boost energy and people perform better in work and school. as people in the commercial talk about how much better they feel when taking the pill, tara notices a message on the bottom of the screen that reads, "this pill is not approved by doctors and has not been tested in controlled experiments." what is the best conclusion that tara should make about the commercial? it is making scientific claims based on subjective observations. it is making scientific claims based on opinions instead of pseudoscientific facts. it is making pseudoscientific claims based on objective observations. it is making pseudoscientific claims based on opinions instead of scientific facts.