Answer:
pleura
Explanation:
Pleura is a soft tissue that protects the lungs
Natural variation provided the phenotypes that natural selection then acted on, over time causing evolution
Answer:
Homologous structures can be described as the structures which are similar to one another present in different organisms. These similarities depict that the organisms might have a common ancestor i the past. For example, the forelimb of man, birds, dogs.
Analogous structures can be described as structures in different organisms which perform the same function but might not have a common origin. For example, the wings of bats and birds.
Amino acids are considered as the building blocks of proteins.
Proteins in the body consist of 20 different amino acids, some of which can be synthesized by the body itself.
Each unique protein is formed by the combination of these proteins in several ratios and sequences.
