The statement which explains why muscle cells and skin cells do not look and act the same is this: THE GENES IN EACH TYPE OF CELL ARE BEEN EXPRESSED DIFFERENTLY.
All the cells in human's body has the same set of genes, this is because, all the cells in the body originated from a single fertilized egg. Even though all the cells in the body has the same origin, they are different from one another because, the cells use the same set of genes differently.
Answer:
Collagen genes.
Explanation:
Phylogenetics helps to study the evolutionary relationship among the different group of organisms. The different characteristics like DNA sequences, mitochondria sequences can be used for the construction of phylogeny tree.
Collagen genes can be used to study the evolutionary relationship as mammals contains nearly 30% of total protein. The collagen gene shows the most of the conserved sequences among the different group of organisms and shows the most recent evolved characters in vertebrates.
Thus, the correct answer is collagen genes.
Answer: we can make observations directly by seeing, feeling, hearing, and smelling, but we can also extend and refine our basic senses with tools: thermometers, microscopes, telescopes, radar, radiation sensors, X-ray crystallography, mass spectroscopy, etc. And these tools do a better job of observing than we can!