What pigment is used in human vision?

A) chlorophyll a

B) beta-carotene

C) retinal

D) vitamin A

E) ferredoxin

Which two species are more closely related: Ursus maritimus, ursus americanus or bufo americanus

What blood type does the cell indicated by the red arrow represent?

Which of the following is the best example of evolution occurring? A. Lions and cows both have hair covering their bodies and give birth to live offspring. B. Some of the trees in places with harsh winters lose their leaves in the fall. C.

Which of the following statements describes enzyme cooperativity? A) A substrate molecule bound to an active site affects the active site of several subunits.

What type of environmental change might stop the development of an organic sedimentary rock?

there is 30 percent more what in earth's atmosphere today than there was before the start of the industrial revolution

Scientists say that conditions must be "just right" for a hurricane to start up. Which is the first step of "just right" in the development of a hurricane? A) Cool ocean water replaces warmer surface water.

What is another name for a tropical savanna?

What is a substance in plant sources that cannot be digested that is 5 letters

What would most likely cause the future acceleration of the expansion of the universe? O radiation from the Sun O the existence of background radiation O the continued existence of dark energy O light shifts identified by the Doppler effect