What happens when two nitrogen atoms share electrons? A. They form an oxygen molecule.
B. They form an ionic bond.
C. They form a water molecule.
D. They form a covalent bond.

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

Which soil would most likely be found in the arctic? andisols gelisols histosols spodosols

Internal feedback works to maintain homeostasis when your a. heart rate decreases as your white blood cells increase b. breathing rate decreases as your red blood cells decrease c. heart rate increases as your liver is cleaning blood d. breathing rate increases as your heart rate increases