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.
Best Answer: Humans, or human beings, are classified as bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or thinking man) under the family Hominidae (the great apes).[1] Humans have a highly developed brain capable of abstract reasoning, language, and introspection.