5. The biological clock that operates in human beings to adjust their functioning to night-and-day periodicity is referred to as * 0 points (A) spontaneous neural activity (B) the biofeedback monitor (C) a fixed-interval schedule (D) a circadian rhythm (E) active consciousness

D) circadian rhythm

Explanation:

The Circadian Rhythm is often referred to as a "biological clock". This gives the impression that it governed by the organism and without the complete influence of abiotic factors but there are some influences none the less. The rhythms, include physical, mental and changes in behaviour. This is in alignment with the day-night cycle. Most organisms that follow a circadian rhythm respond to a pattern of light and dark. This influences the sleep-wake pattern.

(D) A circadian rhythm

Explanation:

A circadian rhythm is a natural process that occured internally when the sleep wake up cycle is been regulated to repeat every 24 hours due to the fact it always run in the background of the brain and cycles between sleepiness and alertness at every regular intervals leading to physical, mental, and even behavioral changes when the body system tend to follow a daily cycle.

CIRCADIAN RHYTHM help us to sleep at night and being awake during the day due to the sleep wake cycle process that occur. Which is why it is a biological clock that operates in human beings to adjust their functioning to night-and-day on a 24 hour daily cycle.

explanation:

with the profits from the european sales, merchants purchased europe's manufactured  goods, including tools and weapons. then the merchants shipped those manufactured  goods, along with the  american  sugar and rum, to west africa where they were bartered for  slaves.

the correct answer is modern american cars are not available due to trade restrictions.

trade between cuba and the united states have serious restrictions. the u.s. imposed an economic embargo on cuba, that among other things means that modern american cars are not available due to trade restrictions.

in response to some governmental actions of the authorities from cuba, president john f. kennedy proclaimed an embargo on trade between both countries in february 1962. the trade embargo remains active until this day and was implemented directly by the departments of commerce and the department of treasury.

in president trump’s administration, there is a national security presidential memorandum that "strengthens the policy of the u. s.", affecting trade with cuba.