You want to artificially increase function of the dopamine system in one or more regions of the rat brain. Which of the following methods would be LEAST effective at accomplishing this in rats? Select one:

a.
Optogenetics

b.
A dopamine agonist delivered via intraperitoneal injection

c.
6-hydroxydopamine injection directly into the brain

d.
Putting L-DOPA in the rats' diet

e.
A dopamine agonist delivered via intravenous injection

Aparent with freckles is crossed with a parent without freckles. the punnett square shows the possible genotypes and phenotypes of the offspring. which statement accurately describes the probability of phenotypes? a.the offspring are more likely to have freckles. b.the offspring are more likely to have no freckles. c.the likelihood of the offspring having freckles and not having freckles is the same. d.the likelihood of the offspring having freckles and not having freckles cannot be determined.