The Bridge Between Generations A. Overview of Division Mechanisms 1. Reproduction begins with the division of single cells. Some Key Points About Chromosomes 1.
Chromosomes are molecules of DNA complexed with proteins.
The cell cycle is a recurring sequence of events that extends from the time of a cell's formation until its division is completed. During interphase the cell's mass increases, the cytoplasmic components approx-imately double in number, and the DNA is doubled. Metaphase a. Sister chromatids become oriented toward opposite poles. All chromosomes are aligned at the cell's equator, halfway between the poles. Anaphase a. Sister chromatids separate and move toward opposite poles.