January 27Learning Target: I will• Identify the father of

genetics• Define and give an example

of a dominant allele• Define and give an example

of a recessive allele

Homework:• Vocab cards, text page 170-

176, 183-184

Agenda:• Check homework (text

176 #1-4)• Mendel Cornell Notes• Which traits are

dominant? NB-85

DO NOW:• Fill out your weekly

planner (NB-84)

Homework vocab cards,Text pages 170-176, 183-184

• Incomplete Dominance

• Codominance• Polygenetic Traits• Multiple Alleles• Dominant Allele

• Recessive Allele• Genetics• Heredity• Trait• Mendel

Let’s go over the vocabulary

DNA

Chromosome

• A compacted form of DNA

Gene

• A strand of DNA that codes for a protein, and, therefore, a trait

Trait

Fur color

Eye color

Fur length

• A characteristic of an individual that is inherited

Allele

• A different version (form) of the same gene, such as eye color

Heredity

• The passing of traits (characteristics) to offspring (babies).

Genetics

• The study of heredity.

Mendel, Gregor

• An Austrian monk, who is often called the father of genetics

True Breeding

• A plant which, when self-fertilized, always produces offspring identical to itself

Self-fertilization

• When a plant pollinates itself, so its own male and female gametes form another plant. (This happens a lot)

Cross-fertilization

• Fertilization of one plant by the pollen of another plant

Dominant Allele

• The allele that is always observed in an organism, even a heterozygote

Dark hair = B

Light hair = b

Recessive Allele

• The allele that is masked by the dominant allele

Dark hair = BLight hair = b

Monohybrid Cross

• A hybrid that is created from two parents that differed by only one trait

Punnett Square

• A table that demonstrates the resulting offspring from mating two individuals

Genotype

• The specific genes that an organism has

• We give them letters, such as Bb

Phenotype

• An observable trait

Brown color

DNA Quiz Results

• 8+ =A• 7.5 =B• 6.5-7 =C

NB-85Which traits are dominant?

Trait Class Ratio Class Guess Real AnswerEarlobes FREE FREE

Widows Peak NONE WIDOWS PEAK

Dimples DIMPLES DIMPLES

Thumbs CURVED STRAIGHT

Pinky STRAIGHT

Mid-digit Hair

NONE

Toe length SHORTER

Tongue-roll ROLLER ROLLER

An Introduction & HistoryAdapted from Stacey Calvert, Central Middle Schoolhttp://www.wayzata.k12.mn.us/cms/index.php?option=com_content&task=view&id=199&Itemid=44

Four O’clock Flowers were one example..

He crossed a white flower..

Mendel got some interesting (but different) results when dealing with other species of plants..

+..with a white flower

Guess what he got???

You don’t seem shocked..

either wasMendel!

Mendel kept up the experiment..(He knows the Scientific Method!)

This time..

He crossed a RED plant..

+..with a RED plant

Any guesses??

Okay, then!-->

are you allstill with me?

“I am!”

Mendel THEN CROSSED..

A WHITE flower

+

with a RED flower

Feel lucky?..do ya??

He kept it going!-->“Let’s get the party started”

Incomplete Dominance

• Dominant allele cannot completely cannot completely maskmask the expressionof another– Example: redred

snapdragons crossed with whitewhite ones yield pinkpink.

Codominance• Both alleles of a gene

contribute to the phenotype of an organism– Example: whitewhite horses

bred with red horses yield roan horsesroan horses, a mix , a mix of white and redof white and red.

– The picture should show R as red and W as white.

• Example of polygenetic heredity– A and B alleles = CODOMINANTCODOMINANT– O allele = RECESSIVERECESSIVE

Blood Groups

Single Effect of Multiple Genes

•• PolygenicPolygenic– Several genes

produce ONE phenotypic result

• Continuous Variation

–– Skin colorSkin color– HeightHeight