NAME:_____________________________________CLASS:_________

Objective:       Students should be able to identify the relationship between genes, traits, variation,survival, and reproduction.

Procedure:     

1.                  Count your toothpicks to make sure you have 8 of each color.

2.                  Complete the chart of genotypes and phenotypes that could result.

3.                  Answer the following questions:

·        Can 2 red fish mate and have green offspring? Why/Why not?_________________________________________

·        Can 2 orange fish mate and have yellow offspring? Why/Why not?________________________________

·        Can 2 green fish mate and have orange offspring?Why/Why not?____________________________________

4.                  Read the following scenario:

The stream where the fish live is very lush with lots of vegetation.  The green fish are very well camouflaged from predators in this environment as are the red and orange fish.  However, none of the yellow fish survive or reproduce because predators can easily spot them.

5.                  Make a first generation of fish- pull out 2 genes (toothpicks) in

Pairs without looking and set them aside so they stay in pairs. 

Repeat until the gene pool is empty.  Record the results in your data table.

6.                  Return all surviving fish back into gene pool.

7.                  Make a second and third generation, following the same procedure.

8.                  Answer the following questions?

·        Have all the yellow genes disappeared out of your gene pool? Explain________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

·        Has the population size changed? In what way?_______________________________________________________________________________________________________________________________________________________________________________________________________

·        How does the 3^rd generation compare to earlier generations in terms of color and number?__________________________________________________________________________________________________________________________________________________

9.                  Read the following scenario:

Stop! Ann environmental disaster occurs.  Factory waste harmful to algae is dumped into the stream, killing much of the algae very rapidly.  The remaining rocks and sand are good camouflage for the yellow, red, and orange fish.  Now, the green fish are easily spotted by predators and can’t survive and reproduce.

10.              Using the remaining toothpicks, complete a 4^th generation.  This

Time, the green will not survive. 

11.              Answer the following questions?

·        How has the population changed compared to earlier generations?______________________________________________________________________________________________________________________________________________

·        Have any genes disappeared entirely?_____________________________________________________________________________________________________________________________________________________________________________________________________

·        Which color genes disappeared faster when the environment was hostile to them?Why?_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

·        Which organisms have a better chance of survival if an environmental disaster was to happen- asexually or sexually reproducing organisms?Explain__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

12.              Total class results using the results after the 4^th generation.

13.              Define “Natural Selection”._________________________________________________________________________________________________________________________________________________________

14.              How does this activity model the process of “Natural Selection”?________________________________________________________________________________________________________________________________________________________