WARM-UP ACTIVITY1) Choose a partner.

2) On the piece of paper provided, write down one of each of the following letters:

B or bC or cW or wD or dL or lF or fP or p

3) Hang on to your paper – don’t show any other group!

Example: b C W D l f P

INTRODUCTION INTRODUCTION TO TO

GENETICSGENETICS

NOTE:Terms in green are definitions

– these are key terms to know

Terms in blue are important words or concepts – please make note

Who was Gregor Mendel?

•1822-1884

• Austrian monk•Known as the “Father of Genetics”

Gregor Mendel•Studied the inheritance of traits (characteristics) in pea plants

• Found that the plants’ offspring retained traits of the parents

•From these experiments, Mendel developed The Laws of Inheritance

Definitions:

trait: a characteristic that can be passed from parent to offspring

heredity: the passing of traits from parents to offspring

genetics: the study of heredity

Inheritance• Mendel stated that physical traits are

inherited as “particles”

• Mendel did not know that the “particles” were actually chromosomes and DNA

Traits in Pea Plants

Pea plants have many different traits

Some traits are dominant over others

Allele: a form of a gene (different

bases along the DNA)

Dominant: allele that is expressed (regardless of its counterpart allele); represented by a capital letter (e.g. T)

Recessive: allele that is expressed only when its counterpart allele is also recessive; represented by a small letter (e.g. t)

Examples of traits in pea plants

PUNNETT SQUARE• Used to help solve genetics problems•Shows what the offspring of a female and male parent will look like

An example of a Punnett square

Male

Female

PUNNETT SQUAREWhat alleles will the offspring of two parents have?

What will the offspring look like?

Genotype: the combination of alleles for a trait

e.g. TT, Tt, tt

Phenotype: the physical feature resulting from a genotype

e.g. tall, short

Short

GENOTYPE AND PHENOTYPEGenotype of alleles:P = purple flowerp = white flower

All genes occur in pairs, so 2 alleles affect a characteristic

Possible combinations are:Genotypes PP Pp pp

Phenotypes purple purple white

GENOTYPESHomozygous genotype: gene combination involving 2 dominant or 2

recessive genes (e.g. TT or tt); also called pure 

Heterozygous genotype: gene combination of 1 dominant and 1

recessive allele (e.g. Tt); also called hybrid

Note: Heterozygous offspring will express the dominant allele (T) over the recessive allele (t) because the dominant allele is ‘stronger’ than the recessive allele

GENERATION “GAP”

Parental P1 generation: the parental generation in a breeding experiment.

F1 generation: the 1st generation offspring in a breeding experiment (1st filial generation)• Result from breeding individuals from the P1 generation

F2 generation: the 2nd generation offspring in a breeding experiment (2nd filial generation)• Result from breeding individuals from the F1 generation

GENERATION “GAP”

Parent generation

(P1)

1st filial generation

(F1)

2nd filial generation

(F2)

BREED THE P1 GENERATION

P1 = tall (TT) x short (tt) pea plants

T T

t

t

BREED THE P1 GENERATION:SOLUTION

P1 = tall (TT) x short (tt) pea plants

t

t

T T

Tt Tt

Tt TtAll Tt = tall(heterozygous tall)

produces theFF11 generation generation

BREED THE F1 GENERATION

F1 = tall (Tt) x tall (Tt) pea plants

T t

T

t

BREED THE F1 GENERATION:SOLUTION

F1 = tall (Tt) x tall (Tt) pea plants

T t

T

t

TT Tt

Tt tt

produces theFF22 generation generation

1/4 (25%) = TT1/2 (50%) = Tt1/4 (25%) = tt

1:2:1 genotype 3:1 phenotype

FOLLOWING THE GENERATIONS

Cross 2 pure plantsTT x tt

Results in all hybrids

Tt

Cross 2 hybrids, results in

3 Tall & 1 ShortTT, Tt, tt

GREGOR MENDEL RAPhttp://www.youtube.com/watch?

v=EvR_Sdm1orU

ACTIVITY!As budding scientists, you will get the chance to see the results of a cross of

the P1 parental generation!

How, you may ask?

Well, by making your own sperm and eggs!

INSTRUCTIONS1) Working with a partner, you will be assigned the task of making either a paper maché sperm or an egg.

2) Add your group’s piece of paper with your genetic code inside the balloon provided.

3) Blow up your balloon, tie it off, and begin paper maché-ing! The supplies will be provided on your lab bench.

4) Only put 2 layers of newsprint around your balloon or it won’t dry.

5) Leave your balloon to dry on top of a big piece of newspaper.

6) Add your group members’ name to the tie of the balloon using a piece of masking tape.

HOMEWORK FOR NEXT CLASS: Complete the Genetics Practice Problems

worksheet Read over class notes and check out the

class blog: http://msoonscience.blogspot.com/

WORKS CITEDImages taken from the following sources:http://www.softchalk.com/lessonchallenge09/lesson/genetics/index.htmlhttp://dj003.k12.sd.us/SCHOOL%20NOTES/chapter_03.htmhttp://www.exploringnature.org/db/detail.php?dbID=22&detID=2290http://cmcweb.lr.k12.nj.us/webquest/sidelsky/genetherapy.htmhttp://www.emc.maricopa.edu/faculty/farabee/biobk/

biobookgenintro.htmlhttp://ghshonorsbio.blogspot.com/2006_03_01_archive.htmlhttp://www.anselm.edu/homepage/jpitocch/genbio/geneticsnot.htmlhttp://en.wikipedia.org/wiki/File:Punnett_square_mendel_flowers.svghttp://www.goldiesroom.org/Note%20Packets/18%20Genetics/

00%20Genetics--WHOLE.htmhttp://www.dreamstime.com/royalty-free-stock-photo-sperm-and-egg-

image14409175PowerPoint source: http://www.biologyjunction.com/pwpt_biology.htmCopyright C. Messengale