The document contains questions about early scientists who observed bacteria and the most abundant chemical in living cells, as well as the three parts of the cell theory. It also discusses DNA replication, including that DNA makes a copy of itself before mitosis, DNA replication ensures each new cell has the genetic information it needs, and in 1953 Watson and Crick figured out the structure of DNA and how it copies itself. DNA looks like a twisted ladder or double helix with sugars and nitrogen bases making up the sides.

1. DQ 2/9/10 Who was the first scientist to observe what are now called bacteria (p 29)? What is the most abundant chemical found in living cells (p19)? What are the three parts of the cell theory (p 30)?

2. DNA guided reading p 78-79 A cell makes a copy of ____ before mitosis occurs DNA replication ensures that each ___________ __________ will have all of the genetic information it needs to carry out its activities By the early _________ the work of several scientists showed that DNA carries all of the cell’s instructions

3. In 1953, _________ and __________ figured out the structure of DNA and how DNA copies itself A DNA molecule looks like a _______ ________ or __________ __________ Because of the shape of a DNA molecule, it is often called a _________ ___________ The 2 sides of the DNA ladder are made up of a sugar called _______, alternating with molecules known as ________.

5. There are 4 kinds of nitrogen bases: A = T = G = C = See figure 20. During DNA replication, a DNA molecule __________ between its paired bases. DNA replication begins when the 2 sides of DNA molecule _______ and separate, like a zipper unzipping.

6. The order of the ______ _______ in each new DNA molecule will exactly match the order of the orginal DNA molecule.