During which phase of mitosis do the nuclear membrane, nucleolus, and nucleus dissolve?
metaphase
prophase
anaphase
telophase

prophase

Explanation:

It is prophase of mitosis during which nuclear membrane, nucleolus, and nucleus dissolves.

Mitosis is characterized by 4 stages which are mentioned as under:

(1) Prophase

(2) Metaphase

(3) Anaphase

(4) Telophase

Prophase is the first stage of mitosis in which two major events occur. In this stage particularly, the nuclear membrane breaks down and nuclear envelop disappears. Apart from this, the chromatin which is present inside the nucleus of the cell starts to condense to become chromosome which unlike chromatin is a thick and clearly visible structure.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

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.