When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
a. the ph of the matrix increases.
b. atp synthase pumps protons by active transport.
c. the electrons gain free energy.
d. nad+ is oxidized.

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data

Which would best keep the oxygen cycle stable? a. cutting down jungles to create farmland b. eliminating parks in large cities c. dumping toxic chemicals into the ocean d. reducing the amount of deforestation d. reducing the amount of deforestation

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.