Descent (noun) the state or fact of being related to a particular person or group of people who lived in the past:
She's a woman of mixed/French descent.
They trace their line of descent back to a French duke.
He claims direct descent from Mohammed.
Descend (verb)
[I or t] formal to go or come down:
The path descended steeply into the valley.
Jane descended the stairs .. [I] literary if darkness or night descends, it becomes dark and day changes to night.