California Standard What It Means 7.1.a Students know cells function similarly in all living organisms. Cells perform the same actions in all living things. 7.2.e Students know DNA (deoxyribonucleic acid) is the genetic material of living organisms and is located in the chromosomes of each cell. DNA is the material that determines what traits are passed from one generation of living things to the next. DNA is found in the chromosomes of each cell. Write the standard on left side, write the meaning on the other. DIRECTIONS:

Chapter 7, Section 1 What Does DNA Look Like? Key Concept The structure of DNA is a double helix, which is shaped like a twisted ladder. What You Will Learn The discovery of the structure and function of DNA is a major achievement in life science. DNA is made up of nucleotides arranged in two strands. Together, the two strands form a double helix. The structure of DNA relates to how it functions, including how it is replicated. Why It Matters The structure of DNA allows for the storage of your genetic information.

Deoxyribonucleic acid is the genetic material of organisms. Shaped like a double helix or twisted ladder.

Cytosine always pairs with guanine and thymine always pairs with adenine. It divides like a zipper where the bases attach.

DNA is made of sub units called nucleotides. A nucleotide consists of a sugar, a phosphate, and a base. The nucleotides are identical except for the base.

James Crick and Francis Watson concluded that DNA is shaped like a long twisted ladder. They were able to build the first model of DNA.

Discovered that the amount of adenine always equals the amount of thymine.

Was able to capture images of DNA on film. The images suggested that DNA has a spiral shape.