The species theory, polygenism, held that human races were of different lineages and suggested a hierarchy outlined in the Chain of Being that positioned Africans between man and lower primates.
No, they are involved in the Circulatory System which is responsible for pumping and channelling blood to and from the body and lungs with heart, blood and blood vessels. no veins are not considered an organ because they are a grouping of different tissues like a organ.
The Anatomy and Physiology of Animals/Tissues Worksheet. 1. A tissue is: a collection of nuclei / a collection of organelles / a collection of cells / a collection of organs. 2. The four major tissue types are: epithelial / fat / connective / bone / muscle / nervous / blood. 3. Epidermal tissue: protects and supports the body / covers body surfaces / is responsible for movement / lines hollow organs / transmits nerve impulses / forms glands. 4. The inside of blood vessels is lined with: cuboidal epithelium / squamous epithelium / transitional epithelium / columnar epithelium.