Here is a question about this article: Most organisms studied to date utilize a rewardpunishment mechanism: for instance, worms and insects can alter their behavior to seek food sources or to avoid dangers. In vertebrates, the reward-punishment system is implemented by a specific set of brain structures, at the heart of which lie the basal ganglia, a set of interconnected areas at the base of the forebrain. There is substantial evidence that the basal ganglia are the central site at which decisions are made: the basal ganglia exert a sustained inhibitory control over most of the motor systems in the brain; when this inhibition is released, a motor system is permitted to execute the action it is programmed to carry out. Rewards and punishments function by altering the relationship between the inputs that the basal ganglia receive and the decision-signals that are emitted. The reward mechanism is better understood than the punishment mechanism, because its role in drug abuse has caused it to be studied very intensively. Research has shown that the neurotransmitter dopamine plays a central role: addictive drugs such as cocaine, amphetamine, and nicotine either cause dopamine levels to rise or cause the effects of dopamine inside the brain to be enhanced.
What is the answer to this question: Which neurotransmitter plays a large role in drug abuse?
****
So... dopamine

Here is a question about this article: The elimination of wolves from Yellowstone National Park had profound impacts on the trophic pyramid. Without predation, herbivores began to over-graze many woody browse species, affecting the area's plant populations. In addition, wolves often kept animals from grazing in riparian areas, which protected beavers from having their food sources encroached upon. The removal of wolves had a direct effect on beaver populations, as their habitat became territory for grazing. Furthermore, predation keeps hydrological features such as creeks and streams in normal working order. Increased browsing on willows and conifers along Blacktail Creek due to a lack of predation caused channel incision because they helped slow the water down and hold the soil in place.
What is the answer to this question: What animal's food sources were greatly affected with the loss of wolves in Yellowstone National Park?
****
So... beavers

Here is a question about this article: The current "Precentor" (Head of Music) is Tim Johnson, and the School boasts eight organs and an entire building for music (performance spaces include the School Hall, the Farrer Theatre and two halls dedicated to music, the Parry Hall and the Concert Hall). Many instruments are taught, including obscure ones such as the didgeridoo. The School participates in many national competitions; many pupils are part of the National Youth Orchestra, and the School gives scholarships for dedicated and talented musicians. A former Precentor of the college, Ralph Allwood set up and organised Eton Choral Courses, which run at the School every summer.
What is the answer to this question: How many organs does Eton house?
****
So...
eight