During swallowing, the air passageway of the phaynx is covered by the epiglottis
Answer: Purine
Explanation:
A purine is a nitrogenous base found in nucleic acids, and contains a 6-membered pyrimidine ring fused to the 5-membered imidazole ring. The most common examples of purine bases are adenine and guanine.
Thus, the nitrogen base pictured is adenine, and the nucleotide considered is a purine
Answer:
An extraneous variable is eliminated, for example, if background noise that might reduce the audibility of speech is removed as Unknown extraneous variables can be controlled by randomization.
A process that only occurs in the biosphere is transpiration.
