When scientists copy dna, they first have to cut out the part they want to
copy. what molecule do they use to do this?
o
a. reverse transcriptase a
b. gel electrophoresis
o
c. dna polymerase
o
d. restriction endonuclease

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.

this is more of a statement than a question. is there answers to go along with this, or is it opinion based?