Proven Activities for Teaching Genetics
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Transcript of 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!
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