Why is it necessary to chelate the metal ions from solution during the boiling/lysis step at 100 degree celsius?

You must use a chelating agent because it grabs metal ions out of the solution and traps them, and they are cofactors in enzymatic reactions.

meiosis is the first to occur after the nuclei of opposite of opposite mating types fuse

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.