#L-3 CORN LAB
BACKGROUND
Plants use the pigments (mainly chlorophyll) in
chloroplasts to make glucose. This is called
photosynthesis. It occurs as follows:
↓
6H2O + 6CO2 → C6H12O6 + 6O2
BACKGROUND
In corn, the allele for making chlorophyll is
dominant (G). A recessive allele (g) codes for no
pigment. If a plant inherits two recessive alleles
it will not produce chlorophyll and will be albino.
GG or Gg = green (has chlorophyll)
Gg= albino (no chlorophyll)
BACKGROUND
While many organisms can inherit the albino
genes:
BACKGROUND
Plants that inherit these recessive alleles will die,
because they cannot make food.
PROBLEM
You want to plant some corn as a crop for
food, but are concerned that your seeds (parents)
carry the recessive allele for albinism. You don’t
want to waste your time if much of your corn will
die.
In order to determine if the parents have the
lethal allele, you will plant some of the seeds and
observe if any of the offspring are albino.
1. PURPOSE
To determine the unknown genotypes of corn
plants by observing the offspring phenotypes.
(Copy this slide into your lab report)
2. HYPOTHESIS
If the parent(s) carry the recessive, albino, allele,
then about ¼ or ____ % of the offspring will show
the albino phenotype.
G
g
Gg x Gg
(Copy this slide into Lab
Report- fill in Punnett
square & list expected
GR & PR)
G
g
3. MATERIALS
List all of the materials required for this
experiment.
(List the materials in your lab report).
See your rough draft that I passed back.
4. PROCEDURE
List the procedure for this experiment.
(List the procedure in your lab report).
See your rough draft that I passed back.
5. RESULTS
Copy this table and show in your lab report.
Albino vs. Green Corn. Class Results
Group Number
1
2
3
4
5
6
7
8
9
10
TOTAL
# of Green
# of Albino
5. RESULTS (CONT’D)
(Calculate the percent green and percent albino
corn and report in results section.)
Percent green = # green plants x 100
total # plants
Percent albino = # albino plants x 100
total # plants
6. CONCLUSION
(Report whether or not you accept your
hypothesis and state why).
Ex. The corn plants must/must not carry the
albino alleles because……………….
7. ANALYSIS