Each of the following statements concerning hair is true except

A. scalp hairs grow constantly throughout life.
B. the cortex of the hair is composed of hard keratin.
C. the medulla is the soft core of the hair.
D. club hair is hair that has ceased growing.
E. terminal hairs are heavy and more darkly pigmented than other types of hair.

A. scalp hairs grow constantly throughout life.

Explanation:

Hair is a squamous keratinized epithelium which is consist of multi-layered flat cells.  Hair are made up of protein called "keratin".

The statement "scalp hairs grow constantly throughout life" is false because at a particular age or due to several factors scalp hairs stop growing.

Scalp hair growth rate depends on three main factors including sex (female hair grows faster than male), age (hair growth slows with age), and ethnicity (Asian hair grows slower than Caucasian hair).

Scalp hair growth stops because of  follicle devitalization when the hair length become two or three feet.

Hence, the correct answer is A. "scalp hairs grow constantly throughout life".

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.