Amarine biologist explains that the salmon adapts to its environment through descent with modification. what is "descent with modification"?
a heritable trait can be changed from one generation to another.
a learned behavior can be modified by each generation of fish in a population.
an offspring is similar to its parents but has unique features that distinguish it.
a useful adaptation is always passed down from a parent to its offspring.

Answer: A heritable trait can be changed from one generation to another.

Explanation:

The concept of descent with modification was given by Darwin which simply states that the traits are passed on from the parents to the offsprings. The traits that can be passed on are known as heritable traits. These traits are passed on with the help of the genes.So this passing on of traits explains the term descent in this concept. However, there are always chances that these heritable traits can be changed due to environmental factors or due to the process of recombination and thus the term modification.So descent with modification means that a heritable trait is passed from parents to offspring but it can be changed from one generation to another.

Bis the correct answer.

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein