An anatomy and physiology instructor scratches chalk across the blackboard causing a screeching sound. Several students get a feeling like their "hair is standing on end." This response is part of the sympathetic stress reaction and is called what?

Explanation:

The sympathetic nervous system directs the body's rapid involuntary response to dangerous or stressful situations

The feeling of "hair is standing on end" gives goosebumps or technically we one can say pilorection

Pilorection is defined as erection of the hair of skin due to contraction of the tiny arrectores pilorum muscles that elevate the hair follicles above the rest of the skin and move the hair vertically, so the hair seems to stand on end

Charles Darwin was born to a physician and his wife from Wedgefood family in 1809. He was a naturalist whose life changed on the Voyage of Beagle.

Explanation:

Charles Darwin was born in 1809 and was acclaimed for his vast contribution to study of evolution.

His mother passed away when he was only 8. His father was a physician.

Charles Darwin's love and curiosity for nature made him leave his medical education.

He is one of the most influenced personality.

He proposed the Theory that all species have evolved by a common ancestor over a period of time.

He became a marine investigator after studying the same from Christ's College, Cambridge University.

His historical Beagle voyage of five years made him extensively observe the varied flora and fauna. This was the turning point in his early career establishment.

The fossils he collected on the Beagle voyage and his observations made him establish Natural Selection theory.

He studied human evolution in 1871. His famous works include The Descent of Man, and selection in Relation to Sex and by The Expression of emotions in Man and animals. His research on plants was recorded in a book named formation of vegetable mould.