Collagen is a part of the connective tissue that in the skin helps in firmness, suppleness and constant renewal of skin cells. Collagen is vital for skin elasticity. Ligaments are another type of connective tissue that attach two bones and consequently hold the joints together.
There are at least 33 phyla (plural of phylum) of animals. Humans are members of the phylum Chordata. All of the chordates have elongated bilaterally symmetrical bodies. That is to say, the left and right sides are essentially mirror images of each other.
But animals are not humans! Humans are a species of animal. Animal is a term that refers to multi-celled heterotrophs (in other words, they eat other l â¦ iving things to survive) that are mobile. Humans are a species of animal that belong to phylum Chordata (vertebrate).