PLEASE HELP! Which statement below describes the properties of a penny on Earth compared to a penny on Mars?

- The density of the penny would change because the mass would change.

- The volume of the penny would change because the weight would change.

- The mass of the penny would change but the density would remain the same.

- The weight of the penny would change but the mass would remain the same.

Are salt and soap nutrients or toxins for yeast? explain.

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.

Why has two different alleles for the same trait?