I.The Genetics Revolution Watson Crick Mendel Introducing DNA

I.The Genetics Revolution

Watson

Crick

Mendel

Introducing DNA

Questions

Who is NOT one of the founders of modern genetics?a. Francis Crickb. James Watsonc. James Garfieldd. Gregor Mendel

In which of the following processes is DNA not directly involved?a. Respiration b. Protein synthesis c. Self-replication

I. The Genetics RevolutionA. DNA, genes, and chromosomesB. Applications

1. The Human Genome Project2. DNA profiling 3. Human origins and connections 4. Genetic engineering

C. Genetics Principles1. Genotypes and phenotypes2. Transmission Genetics3. Autosomes and sex

chromosomes4. Pedigrees5. Polygenic traits6. Genes and the environment 

A. DNA, Genes, and Chromosomes

base

nucleotide

S=Deoxyribose

P=Phosphate Bases: ATCG

Deoxyribonucleic acid

Secret of Life

Base pairNucleotide:

3 billion base pairs in Human Genome

DNA structure

A. DNA, Genes, and Chromosomes

• Genes code for proteins

Exons make up less than 2% of our DNA

• Codons code for amino acids

Gene = introns and exons

Average gene = 10000 bases

Largest gene = 2.4 million bases

Significance of Proteins

keratin

collagen

fibrin

hemoglobin

Myosin and actin

•Structural •Enzymes •Hormones

A. DNA, Genes, and Chromosomes

chromosomes

homologous

20,500 genes in human genome

X y

nucleus

Autosomes

Sex chromosomes

Questions

Which of the following would you guess is not a base found in DNA?a. Adenine b. Thymine c. Phosphorine d. Guanine

What are the building blocks of DNA called?a. Amino acids b. Fatty acids c. Neutrinos d. Nucleotides

Which of the following is the coding sequence of a gene?a. Introns b. Exons c. Genes d. Nucleotides

Which of the following is a DNA codon?A. ATP b. AUG c. AAA d. more than one of these

Approximately, how many genes are in the human genome?a. 20, 000 b. 2,000,000 c. 2000 d. 20

Approximately, what percent of our DNA consists of exons?a. 20 b. 0.2 c. 80 d. 2

• DNA is a cookbook

• Genes are recipes for proteins

• Codons are the words in the recipes

• ATCG are the letters of the words

DNA Analogy

• Amino Acids are the ingredients

• Ribosomes are the ovens

• RNA is the cook

• Proteins are the cookies

From DNA to Population

Gene Pool

Multifactorial Traits

Polygenic traits

Questions

What is a gene pool?a. All the genes found in a single familyb. All the genes found in a populationc. All the genes found in an individuald. All the genes found in all living things

A single trait controlled by multiple genes is called _________ .a. Multifactorial b. Polygenic c. Multigenic d. Polyfactorial

If one side of a DNA molecule had the bases, GTA CTC, what would the other side have?

B. Applications•Chromosome 21: 225 genes•Chromosome 22: 545 genes

1. The Human Genome ProjectThree broad goals of the HGP

•Chromosome Y: 78 genes

•Chromosome X: 1080 genes

Mouse genome

QuestionsWhich of the following is NOT one of the broad goals of the HGP?a. Identifying loci of genesb. Identifying functions of genesc. Identifying base pair sequencesd. Changing genes to improve human health

Why is genetic research on mice important for understanding the human genome?a. Mice are relatively easy to breedb. We can do experiments on mice that we can’t do on humansc. Mice have relatively short life spans, so we can see results more readilyd. The genes of mice and humans are 99% analogouse. All of these are reasons why the mouse genome is important

2. DNA profiling

2. DNA profiling

3. Human origins and connections

Three domains

Genetic homology implies biologicalrelationship which implies common ancestry.

Genome Comparisons

Bonobo

Chimp

98.7% homology6 to 8 mya

3. Human origins and connections

The human family

Human origins

99.9% homologyThe Genographic Project

caveat

4. Genetic engineering

a. transgenic species

b. agriculture

c. medicine

zygote

egg sperm

Germ line therapy

1. Gene therapy

2. Pharmacogenetics

SCID

Genetic Testing

DNA microarrays (chips)

Genes and disease

Genes and disease

d. reprogenetics

In vitro fertilization (IVF)

Preimplantation Genetic Diagnosis (PGD)

d. reprogenetics

PGD•Cystic fibrosis

•Hemophilia•Sickle cell trait•Tay Sachs

(preimplantation genetic diagnosis)

IVF (in vitro fertilization)

•Sex determination•Risk diseases

e. stem cells

f. cloning

Brave New World?

C. Genetic Principles

•Alleles

1. Genotypes and phenotypes

•Homozygous recessive

•Homozygous dominant•Heterozygous

2. Transmission Genetics: dominant and recessive traits

Fold hands

3. Autosomes and sex chromosomeskaryotype

4. Pedigrees

Pedigrees

5. Polygenic traits

5. Polygenic traits

Continuous variation

6. Genes and the environment

Nature versus nurtureNature and nurture

D. Determinism•Environmental determinism

•Genetic determinism

Free will?

The End

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