Which describes a constant in an experiment?

a.

the variable changed by the experimenter

b.
the quantity that must remain the same

c.
the variable that changes in response to the experiment

d.
the statement that is worded to test the experiment

hi, natural selection of the peppered moth during the industrial revolution in 19th-century england is an example of an outlier in the study of evolution. during this time, pollution from factories filled the forests, coating trees in a layer of soot—turning white trees black

mark as brainlest

gokuson

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.