Bio 326 Genetics Dr. Jennifer Schisa (Skee-za)

Bio 326 Genetics

Dr. Jennifer Schisa (Skee-za)

Brooks 230A - sign up for appointmentsEmail: [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]

We Learn:

10% of what we read20% of what we hear30% of what we see

50% of what we see and hear60% of what we write

70% of what is discussed80% of what we experience

95% of what we teach.

TextLecture

Lab report

Doing labs

Presentations

Philosophy of learning

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/

1.Name 2. Lab code (ex. T-2)

3.Campus address4.Email address5.Year in school6.Major7.Bio courses taken previously8.Bio courses taking now9.Goals after college/career plans10. Particular genetics topic of interest

Introduction card

On sheet of paper - Pre-test: No name, not graded

1. What is a gene?2. What is a chromosome?3. Name one well-known geneticist.4. Who won the 2001 Nobel Prize in Medicine? What was their scientific contribution?5. What does it mean to be diploid?6. What would happen without meiosis?7. Where does transcription occur in a cell?8. 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

**Debate continued into 1800’s**

How are traits transmitted from parent to child?

1. Lamarck: “pangenesis” - particles migrate to sex cells to transmit each cell’s characteristics

2. Weismann: nuclear “determinants”; not every determinant goes into every cell. Only cells destined to become egg or sperm retain all “determinants”.

egg spermor

19 generations later

Tail length remained constant; progeny do NOT inherit characteristics from the body of the parent.

Expt. Cut tails of newborn mice for several generations

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 ofinformation

(central dogma)

DNA

RNA

Protein

Trait

How many chromosomes does an organism have?

• But this is 2 copies of each type of chromosome (1 from mom and 1 from dad); the haploid # is 23.

• 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.

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)

ex. Cri-du-Chat syndrome

Small part of chromosome 5 is lost: results in heart problems, mental retardation, and other problems

•What happens if chromosomes are not duplicated correctly?

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?

•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

egg2n + 2n

sperm,then 4n

embryoIf

•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?

III. How do we investigate genetics?

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 knowledgedirectly 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

Historically: eugenics taken to the extreme- Nazi Germany 1930’s

What about in USA???

Genetics and Society, cont.

These policies were flawed by NOT understanding the genetic basis of various characteristics

1907- Indiana passed a law to require sterilization of those people considered genetically inferior

Over half of the states passed such laws!

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 peopleex. 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