Differentiate between the various areas of the brain listed below. What area of the brain connecting the ventral tegmental area to the nucleus accumbens is considered a primary circuit to "reward pathways," and therefore, plays an important role in the biological basis of addiction?

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

the correct answer is 2 and 4