Three sequential nucleotides on mRNA are called a triplet.

A. bind the hair root to the dermis:The hair root is anchored to the dermis by the hair follicle itself and connective tissue structures. The receptor does not play a role in binding or physical attachment of the hair root.

B. serve as a source for new epidermal cells for hair growth after the resting stage has passed:New epidermal cells for hair growth arise from the hair matrix at the base of the follicle. The root hair plexus is a sensory nerve ending, not a cell-generating structure.

C. allow the hair to assist in touch sensation:The hair follicle receptor, or root hair plexus, is a network of sensory nerve endings wrapped around the follicle. It detects movement of the hair, making hair an important component of the tactile sensory system.

D. cause apocrine gland secretion into the hair follicle:Apocrine gland secretion is controlled by hormonal and neural signals, but not by the root hair plexus. The plexus functions in sensation, not glandular stimulation.

A. ciliated simple columnar epithelium:The uterine (fallopian) tubes are lined with ciliated simple columnar epithelium. The cilia help move the ovum from the ovary toward the uterus, while secretory cells provide nourishment for the ovum and early embryo.

B. smooth MT:Smooth muscle tissue is present in the walls of the uterine tubes to aid peristaltic movement, but it does not line the lumen. The lining is provided by epithelial tissue, not muscle tissue.

C. simple cuboidal epithelium:Simple cuboidal cells are commonly found in glandular tissues and kidney tubules, where they function in secretion and absorption. They do not have the cilia required for egg transport in the uterine tubes.

D. stratified squamous epithelium:Stratified squamous epithelium is specialized for protection in areas exposed to friction, such as the skin and vaginal canal. It is not suitable for the transport and nourishment functions of the uterine tubes.