Ascientist uses materials in her lab to separate dna fragments by size. what
process is she using?

a. use of restriction enzymes

b. polymerase chain reaction (pcr)

c. karyotyping

d. gel electrophoresis

Astudent drew the following flowchart to show the movement of nutrients. soil → roots → plants →? where does nitrogen go next? a. directly into nearby animals as nutrition b. directly into aquifers through condensation c. directly into the air through evaporation d. directly into nearby plants during fixation

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.