Most insects have small holes in the exoskeleton called which open and close to regulate air flow. a. bronchi b. alveoli c spiracles d. trachea

Which blood cell spend most of their time in the lymphatic system?

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

The empty trna moves off and picks up another matching amino acid from the cytoplasm in the cell. the anticodon of the trna, with its attached amino acid, pairs to the codon of the mrna, which is attached to a ribosome. this sequence is repeated until the ribosome reaches a stop codon on the mrna, which signals the end of protein synthesis. the ribosome forms a peptide bond between the amino acids, and an amino acid chain begins to form. when a second trna with its specific amino acid pairs to the next codon in sequence, the attached amino acid breaks from the first trna and is bonded to the amino acid of the second trna.