Answer:
DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA's instructions, or genetic code.
Explanation:
Salt or bad products that enters ur body
Seasonal changes occur because of earth's tilt
Answer:
Scientists need instruments to measure the world. Instruments and sensors are needed to collect data - that takes engineering to design and build them.
Explanation: