Bio 326 Genetics
Dr. Jennifer Schisa
(Skee-za)
Brooks 230A - sign up for appointments
Email: [email protected]
http://www.cst.cmich.edu/users/schis1j/bio326-02/index.htm
Labs - Brooks 204
Section
Instructor
Day
Time
Code
16115
Dr. Schisa
Tues.
2-4:50 pm
T2
16107
Jason Hampton
Tues.
6-8:50 pm
T6
16139
Jason Hampton
Wed.
3-5:50 pm
W3
16121
Jason Hampton
Wed.
6-8:50 pm
W6
Contact Jason: Brooks 186; email: [email protected]
Philosophy of learning
We Learn:
10% of what we read
20% of what we hear
30% of what we see
50% of what we see and hear
60% of what we write
70% of what is discussed
80% of what we experience
95% of what we teach.
Text
Lecture
Lab report
Doing labs
Presentations
How to succeed in this course
•Attend lecture regularly
•Study 2 hours for every hour of lecture, ie. minimum 6
hours a week for genetics
•If you are taking 15 credits, then you should be studying at
least 30 hours/ week outside of class
•Make use of office hours when you need help
•Do the practice problems and “web problems”
•http://cwx.prenhall.com/bookbind/pubbooks/klug3/
Introduction card
1.Name
2. Lab code
(ex. T-2)
3.Campus address
4.Email address
5.Year in school
6.Major
7.Bio courses taken previously
8.Bio courses taking now
9.Goals after college/career plans
10. Particular genetics topic of interest
On sheet of paper - Pre-test: No name, not graded
1.
2.
3.
4.
5.
6.
7.
8.
What is a gene?
What is a chromosome?
Name one well-known geneticist.
Who won the 2001 Nobel Prize in Medicine?
What was their scientific contribution?
What does it mean to be diploid?
What would happen without meiosis?
Where does transcription occur in a cell?
What are 2 applications of genetics you are
interested in learning more about?
Outline - Lecture 1.
I. What is genetics and what is its history?
II. Basic concepts that underlie the study of genetics:
DNA, genes, chromosomes
III. How do scientists investigate genetics?
IV. Genetics and society
I. What is Genetics?
•Genetics: the science of heredity and variation
•Heredity: the transmission of traits from parent
to offspring
How are traits transmitted?????
History of Genetics
•Prehistoric times (6000 BC): artificial selection of genetic
variants within populations; ex. plant cultivation
•The Greek influence (400 BC): traits are passed from all parts
of the body into the semen and passed to offspring
•Preformation (1600’s): miniature adult lives in either sperm or
egg; best explained continuity (heredity)
•Epigenesis (1700’s): adult form develops gradually from egg;
best explained variation
How are traits transmitted from parent to child?
**Debate continued into 1800’s**
1. Lamarck: “pangenesis” - particles migrate to sex cells to
transmit each cell’s characteristics
egg
or
sperm
2. Weismann: nuclear “determinants”; not every determinant
goes into every cell. Only cells destined to become
egg or sperm retain all “determinants”.
Expt. Cut tails of newborn mice for several generations
19 generations later
Tail length remained constant; progeny do NOT inherit
characteristics from the body of the parent.
II. Basic concepts
•Gene: unit of heredity, residing at a specific point on a
chromosome; a length of DNA that specifies a
product
•Chromosome: condensed, linear DNA and protein,
containing genes and intervening sequences
•DNA: the genetic material in all living organisms; in
eukaryotes, located in the nucleus on
chromosomes
Biological flow of
information
(central dogma)
DNA
RNA
Protein
Trait
How many chromosomes does an
organism have?
• Most eukaryote species have a specific number of
chromosomes in each cell
• In somatic cells (all cells but sperm and egg), this
number is the diploid number, 2n
ex. Humans have diploid # of 46.
• But this is 2 copies of each type of chromosome (1 from
mom and 1 from dad); the haploid # is 23.
How are chromosomes duplicated
during cell division?
•When do somatic cells divide? ie. Why do cells divide?
•What is this cell division called?
Mitosis (2n to 2n)
•What happens if chromosomes are not duplicated correctly?
ex. Cri-du-Chat syndrome
Small part of chromosome 5 is
lost: results in heart problems, mental
retardation, and other problems
Cri-du-chat syndrome
karyotype
Meiosis- a special cell division
to make gametes (sperm and egg)
Why would a “regular” mitosis be a problem in making gametes?
If
2n
+
egg
2n
sperm,
then
4n
embryo
•Meiotic cell division generates cells with one-half the genetic
material (2n to 1n) - a reduction in chromosome
number
•Source of genetic variation - more on this next time
III. How do we investigate genetics?
•Transmission genetics - how are traits inherited
from parents to offspring?
examine patterns of inheritance of traits
•Molecular genetics - what is the structure and
function of genes at the molecular level?
has led to DNA biotechnology applications
•Population genetics - how do gene frequencies
change (evolve) in populations?
Basic vs. Applied Genetics
•Basic research: knowledge for its own sake
ex. Human genome project; essential for applied research
•Applied research: seeks to improve the well-being of human
or society
ex. Agriculture: selective breeding, genetically modified
foods
Medicine: new methods to diagnose and treat
genetic disorders
IV. Genetics and Society
Late 1800’s: First attempt to apply genetic knowledge
directly for improvement of human existence
• based on Charles Darwin’s theory of natural selection“survival of the fittest”
• “eugenics” was favored by his cousin, Francis Galton: `
one can artificially select human characteristics by
controlling human matings
**Positive vs. negative eugenics
Genetics and Society, cont.
Historically: eugenics taken to the extreme- Nazi Germany 1930’s
What about in USA???
1907- Indiana passed a law to require sterilization of
those people considered genetically inferior
Over half of the states passed such laws!
These policies were flawed by NOT understanding the
genetic basis of various characteristics
Determination of phenotype
Are “superior” or “inferior” traits totally under genetic control?
NO!
•
Genotype - provides the blueprint
•
Environment - internal or external influences
•
Developmental noise - random events during embryonic
development
Should we ever apply genetic knowledge for the
improvement of human existence?
Euphenics: medical or genetic intervention designed to
reduce the impact of defective genotypes on people
ex. Insulin treatment
Advances in agriculture:
• plants - increased yields, increased resistance,
hybrid production, selection of genetic variants
(for better nutrition)
• livestock - higher quality meat; larger size and
number of eggs