What are the two main energy-absorbing and energy-releasing reactions that occur in cells? A) chemosynthesis and photosynthesis
B) photosynthesis and respiration
C) respiration and chemosynthesis
D) endocytosis and exocytosis

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Restriction enzymes are used in making recombinant dna. describe the role restriction enzymes perform when constructing recombinant dna.

What is one energy transformation that is taking place in the photo? radiant energy to thermal energy thermal energy to nuclear energy chemical energy to thermal energy radiant energy to chemical energy