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!!!

packaged DNA found in the nucleus of all eukaryotic cells 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 Which of the following would correspond to DNA, genes and chromosomes? Alphabet Sentence Words