DNA Structure and History Honors Biology DNA is

DNA: Structure and History Honors Biology

DNA is a chemical!! Strawberries Human

Functions of DNA: -stores all your body’s information -Passes information from parents to offspring (heredity or hereditable characteristics)

DNA is made of smaller parts called: Nucleotides • Nucleotides contain 3 parts: – – – Phosphate Sugar Nitrogen Base

Things to Know: • There are four types of nitrogen bases in DNA: A- adenine T- thymine C- cytosine G- guanine

Things to Know: • There are two sides to DNA • Appears like a ladder: – Sides are phosphate and sugar – Steps are the base pairs Base Pair Rule: A-T are complimentary C-G are complimentary

Can you see the ladder?

The DNA ladder is twisted This twist is called a “helix”

DNA is called the double helix because it is a two sided, twisted ladder.

History… • 1952 – Rosalind Franklin used X-ray diffraction to show helical structure of DNA

The biggest event in DNA history… • 1953 – James Watson and Francis Crick discover the 3 -D structure of DNA

The Basics 1. All living things have DNA 2. The amount and sequence (or order) of ATGC makes us different from each other and other living things

• 3. Small parts of the DNA that contain a specific instruction is known as a gene

4. Genes in the DNA are the body’s directions for making proteins • Proteins make us: – look the way we do – function the way we do – develop and grow the way we do – behave the way we do – think the way we do

• You and the person next to you have 99. 9% the same DNA!! How is that possible? Discuss and Explain!!!

5. Chromosomes are: • packaged DNA • found in the nucleus of all eukaryotic cells

6. All species have a set number of chromosomes. Humans= 46 chromosomes (23 pairs) Fruit fly= 8 chromosomes Rice = 12 chromosomes Dog= 72 chromosomes Yeast= 32 chromosomes Goldfish= 100 chromosomes

Which of the following would correspond to DNA, genes and chromosomes? Alphabet Sentence Words