Genetic/Hereditary Material (DNA) Standard: S7L3a – Explain the role of genes and chromosomes in the process of inheriting a specific trait. Essential Question – What is genetic/hereditary material (DNA)? Warm-up – Discuss with your partner what you already know about DNA.

DNA = Deoxyribose Nucleic Acid The Blueprint For Life

What do we already know about DNA? It is found in the nucleus DNA makes up chromosomes It is the hereditary material for all cells Eukaryotes AND prokaryotes contain DNA, although prokaryotes do not have a nucleus

Chromosomes and DNA GENES-sections of DNA that contain instructions for characteristics Our genes are on our chromosomes. Chromosomes are made up of DNA. {Ask students where the chromosomes are in this picture. Or ask them where the DNA is. Remind them that the mitochondria also have DNA.} CHROMOSOMES

DNA In humans, the DNA molecule, if fully extended, would have a total length of 1.7 meters. If you unwrap all the DNA you have in all your cells, you could reach the moon ...6000 times!

DNA by the numbers The average human has 75 trillion cells. DNA has a diameter of only 0.000000002 m. If you unravel all the DNA in the chromosomes of just ONE of your cells, it would stretch out 2 meters. The earth is 150 billion m, or 93 million miles from the sun. If you unravel all the DNA in the chromosomes of ALL of your cells, it would stretch from here to the sun more than 400 times! If you unravel all the DNA in the chromosomes of one of your cells, it would stretch out 2 meters. If you did this to the DNA in all your cells, it would stretch from here to sun more than 400 hundred times!

The Double Helix - Discovery Watson and Crick = scientists that discovered the shape of DNA IN 1953 Franklin = Contributed to discovery with X-ray photo of molecule in 1952

DNA Structure 3 PARTS OF DNA Nucleotide = Sugar = Deoxyribose Phosphate Nitrogen Base *Nucleotides link with sugar & phosphates alternating and bases sticking out in middle

DNA Structure- Nitrogen Bases 4 bases of DNA (GCAT): 1.Guanine (G) 2.Cytosine (C) 3.Adenine (A) 4.Thymine (T)

Complimentary Bases Two Strands are held together by the bases in the middle. G & C always bond. A & T always bond

Important: Adenine and Thymine always join together A T Cytosine and Guanine always join together C G

DNA is a series of nucleotides connected together COMPONENTS

The Double Helix = Shape of DNA: 2 sides of Nucleotides,` link in the middle at the bases, then twist

Partial chemical structure DNA Models Hydrogen bond Ribbon model Partial chemical structure Computer model Figure 10.3D

DNA Replication Occurs during Interphase DNA makes an exact copy of itself Occurs in the nucleus of the cell Why is this necessary?

DNA Replication-STEPS DNA separates or unzips Nucleotides pair with bases on old chain G-C A-T Two strands created: ½ is the OLD strand; ½ is the NEW strand.

Exact copies of original DNA Unzipped DNA And Replication Of DNA Exact copies of original DNA Figure 10.4B

Complete The 2nd Strand Of DNA From Replication A A T T T G C C G G A T A C G -OLD T T A A A C G G C C T A T G C -NEW T T T G G C A T T G A T C G C C -OLD A A A C C G T A A C T A G C G G -NEW A T A C G A C T T T A A A G G T -OLD -NEW T T A G C A T T A G C A T A T T -OLD G G G C C C A A A T T T C A T -OLD