#L-3 CORN LAB

BACKGROUNDPlants use the pigments (mainly chlorophyll) in chloroplasts to make glucose. This is called photosynthesis. It occurs as follows:

↓6H2O + 6CO2 → C6H12O6 + 6O2

BACKGROUNDIn 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)

BACKGROUNDWhile many organisms can inherit the albino genes:

BACKGROUNDPlants that inherit these recessive alleles will die, because they cannot make food.

PROBLEMYou 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. HYPOTHESISIf the parent(s) carry the recessive, albino, allele, then about ¼ or ____ % of the offspring will show the albino phenotype.Gg x Gg(Copy this slide into Lab Report- fill in Punnett square & list expected GR & PR)

  G g

G

g

3. MATERIALSList all of the materials required for this experiment.

(List the materials in your lab report).

See your rough draft that I passed back.

4. PROCEDUREList the procedure for this experiment.

(List the procedure in your lab report).

See your rough draft that I passed back.

5. RESULTSCopy this table and show in your lab report.

Albino vs. Green Corn. Class ResultsGroup Number

# of Green # of Albino

1    2    3    4    5    6    7    8    9    10    TOTAL    

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