proven activities for teaching genetics

Proven Activities for Teaching Genetics

Rachel Martin

Science Department Head

Getting started…

• When you fall and scrape the skin off your hands and knees, how does your body make new skin cells to replace the skin cells that were scraped off?

• How does your body make sure each new cell has all the chromosomes it needs to have?

• How does a baby get his or her genes?

Meiosis or Mitosis?

• Use the provided table to sort your statements into three categories.

–Meiosis

–Mitosis

–Both

Meiosis vs. Mitosis

Mitosis Both Meiosis

Body cells Cell structures involve spindle fibers

Reproductive Cells

Diploid cellsChromosome replication

Haploid cells

1 cell divisionType of cell division

2 cell divisions

2 daughter cells Occur in phases4 daughter cells

Ways to remember…

• MITosis takes the cell and Makes It Two

• Meiosis has to do with sex

• From the cell’s point of view:–mITosis results in Identical Twins–mEoSis results in Egg and Sperm

Why does the cell organize?

• Place your DNA in the nucleus of your cell.

• You have 2 sets of homologous chromosomes with the alleles marked for hemoglobin, ability to smell, and height.

• Challenge: Separate out these 2 sets of chromosomes while keeping them inside the nucleus.

• How could you tell which chromosomes were homologous?

• Did you have any problems while you were trying to sort out the chromosomes inside the nucleus on your paper?

• How could you make it easier?

Why does the cell organize?

• Wrap each piece of thread around a piece of straw and place inside the nucleus.

• Separate them into 2 pairs of homologous chromosomes while keeping them inside the nucleus.

• What process is this simulating in a cell?

What proteins are coded?

D Defective height allele results in dwarfism

d Normal allele Normal height

Genetics of Sesame Street

Characters

What if Zoe and Elmo fell in love, and had a baby?

What would the baby look like?

Homer Honker

Henrietta Honker

What traits could be

passed on?

Genetics of Sesamus muppetisCharacteristic Type of Inheritance

Eye shape Dominant/recessive

Nose color Incomplete dominance

Lips Dominant/recessive

Body color Multiple alleles, R, B, & O

Incomplete dominance

Hair Sex-linked

Dominant/recessive

Grover

CharacteristicCharacteristic PhenotypePhenotype GenotypeGenotype

Eye Shape Flat ee

Nose color Pink NN, Nn

Lips Has lips ll

Body color Blue BB

Hair type Bald xhyh

Henrietta Honker

CharacteristicCharacteristic PhenotypePhenotype GenotypeGenotype

Eye Shape Eyes Pop Out EE, Ee

Nose color Orange nn

Lips No lips LL, Ll

Body color Purple RB

Hair type Hair xHxH, xHxh

What if…

X = ?

What would their kids look like?

Gene Map

Chromosome 1

Eye Shape

E e

E E

nucleus

e e

Step 1:

DNA replication

Meiosis: eye color

E E e e

Step 2:Homologous

chromosomes line up in center of cell

Nuclear membrane dissolves

E E e e

Step 3:Spindle fibers

separate homologous chromosomes to

opposite sides of the cell.

E Ee e

Step 4:Chromatids line up in

the center of cell.

E Ee e

Step 5:Spindle fibers

separate chromatids.

E Eee

Step 6:Nuclear membranes

separate the chromatids to create

four egg cells.

E

EeMeiosis

complete:

Half the number of

chromosomes

e

Now what eye color traits would Grover contribute?

e e

e e

e

e

E

E

e

e

e

e

?

Ee Ee

ee ee

e e

e

E

Eye Color

Chromosome 2B B

O OE e

E e

Body Color

eO

eB

eB

EO

Eye Color & Body Color

EeBO EeBO eeBO eeBO

EeBO EeBO eeBO eeBO

EeBO EeBO eeBO eeBO

EeBO EeBO eeBO eeBO

EO eO

eB

eB

EeOO x eeBB

Chromosome 3B B

O OE e

e e

XH Xh

Xh Y

e

e

E

E

e

e

e

e

?

O

O

O

O

XH

Xh

Xh

XH B

B

B

B Xh

Xh

Y

Y

Punnett Square

BO BOBO BO

Ee Eeee ee

e e

e

E

O

O

BB

Body Color

Eye Shape

Ll LlLl ll

l l

l

LLips

Punnett Square

NN NN

Nn Nn

N

n

NN

xhxh xhy

xHxh xHy

xh y

xh

xH

Nose Color Hair

Cross ResultsCharacteristicCharacteristic GenotypeGenotype PhenotypePhenotype

Eye Shape 1 Ee : 1 ee Exo : endo

Nose color 1 NN : 1 Nn Orange : Pink

Lips 3 Ll : 1 ll No lips : lips

Body color All BO Magenta

Hair type Xhxh : XHxh

Xhy : XHy

Female bald : carrier Male bald:hairy

The Product RuleEeNn x eeNN

Ee Ee

ee ee

NN NN

Nn Nn

½ Ee

½ ee

½ NN

½ Nn

½ NN

½ Nn

¼ EeNN

¼ EeNn

¼ eeNN

¼ eeNn

Illustrate!

http://techingmadeeasy.wikispaces.com

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