Answer:
A gene is a section of a double-stranded molecule known as DNA. This molecule is found within the nucleus of the cell, contained in threadlike structures called chromatin. The two strands form a double helix linked by a series of paired bases. The base adenine is always linked to thymine and the base cytosine is always linked to guanine.
Cell Size and Scale, an elegant and deceptively simple interactive from the University of Utah's Genetic Science Learning Center, enables you to compare the sizes of various really small things. The interactive is available free on the Internet and works on desktop computers, smart phones, and tablets.
Cytoplasm is the gel-like fluid that fills the cell and surrounds the organelles.
