Lecture 9 Chapter 7 - Introduction to Genetic Analysis...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
    1 Introduction to Genetic Analysis Ninth Edition Anthony J. F. Griffiths, Susan R. Wessler, Richard C. Lewontin,  and Sean B. Carroll CHAPTER 7 DNA: Structure and Replication Copyright 2008 © W H Freeman and Company
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    2 After Mendel before April 1953… Genes - hereditary ‘factors’ determining specific traits. Their physical and chemical nature was not understood Mutations - alter gene function and generate new alleles.  The mechanism and nature of mutation was not understood One-gene-one-protein hypothesis suggested gene function is mediated through proteins. Genes were known to be located on chromosomes. Chromosomes were known to consist of DNA and protein. It was not clear whether genetic material was protein or DNA.
Background image of page 2
    3 The Double Helix In April 1953 James Watson and Francis Crick proposed a  model for the structure of DNA.   Their Model  Accommodated all of key properties of DNA . Defined genes in chemical terms. Paved the way for understanding at the molecular level gene - function  gene - role in heredity
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    4 Evidence that led to the discovery DNA is the transforming principle
Background image of page 4
    5 Evidence that led to the discovery  1.  Frederick Griffith  Experiment-transforming principle The ability of a virulent strain of  Streptococcus pneumoniae. .   to kill a host mouse… was transferable to a non-virulent strain.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    6 Evidence that led to the discovery  2.  Avery, MacLeod and McCarty Experiment Polysaccharides, proteins, fats and RNA ruled out as  the transforming agent. 
Background image of page 6
    7 Evidence that led to the discovery  2.  Hershey and Chase Genetic material of bacteriophage T2 is DNA and  not protein.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    8 Solving a three-dimensional puzzle DNA structure must accommodate the three key properties  of DNA 1. Ability to faithfully self replicate. 1. Ability to encode heritable traits.  1. Ability to generate alternate alleles that slightly alter the  traits.  
Background image of page 8
    9 FUNDAMENTAL PROPERTIES OF  DNA Self-Replication. Encode hereditable traits. Mutation
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    10 Three key facts from previous  discoveries or work. 1. The chemical nature of DNA, 1. Chargaff’s rules of base composition. 1. X-ray diffraction analysis of DNA from  Rosalind Franklin   and Maurice Wilkins.
Background image of page 10
    11 Chemical nature of DNA DNA is made of three components. 1. Phosphate 1. Sugar – Deoxyribose 1. Four Nitrogen bases  1. Adenine  (A) 2. Guanine (G) 3. Cytosine (C) 4. Thymidine. (T)
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    12 Nucleotides are the building blocks (units)  of DNA A Nucleotide = sugar + phosphate + base
Background image of page 12
    13 There are four possible nitrogen bases in  the DNA molecule
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/15/2009 for the course BIOLOGY 3301 taught by Professor Gunaratne/roman during the Fall '07 term at University of Houston.

Page1 / 67

Lecture 9 Chapter 7 - Introduction to Genetic Analysis...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online