Lab Write-up needs to be typed! And follow the lab format on the purple sheet!

Title- Variation Lab

Purpose (Problem on purple sheet)- To observe a typical pattern of variation for a trait among a variety of organisms.

Background Information-

• Evolution occurs as a POPULATIONS gene frequency changes over time.

• INDIVIDUALS have variations.

• How do variations form?

Mutations- changes in DNA

Recombination- reassortment of genes during meiosis (creates new combinations)

Crossing over- portions of chromosomes switching places

point mutations- one DNA nucleotide is deleted, inserted, or changed.

• Hypothesis- what trend/pattern do you think you will see in the trait you have selected?

• Variables- What are the IV, DV, and controlled variables

• Materials- leave space and fill this in after you determine what you will use. What materials and equipment do you need?

• Procedure- (must be modified for what you do!!)

1. Choose anything living or once living (from outside, us, seeds, etc)BE CAREFUL STILL OF POISON IVY!!!

2. Determine a MEASUREABLE TRAIT (g, mm, cm, etc)

3. Collect data- at least 30 is a good sample size!

4. Tally the data.

5. Graph data- then tape one on whiteboard so classmates can view your results.

• Data- raw data should be recorded in a chart. Then TALLY the data to see the pattern in the population.

(i.e. # of individuals that have 2 cm length, how many have 3 cm, then 4 cm,etc)

• Graph- Everyone must have a graph on their lab writeup.

*Please tape one on the whiteboard until classmates have had a chance to view the pattern for your trait so they can answer one of the conclusion questions.

• Analysis Discussion- explain the meaning of your graph.

Conclusion Questions- Answer questions in full sentences.

Answer 4 bulleted questions on purple lab handout first.These should be numbered 1-4.

5. What is the typical pattern in the variation for the trait you studied, look at your bar graph, what does it tell you?

6. How does your trait’s pattern compare with the other traits that were studied by your classmates? Similarities/differences?Look at their graphs- what do they tell you?

7. Predict the pattern you would observe if you looked at theheights of all the students at South High School. What would the pattern look like?

8. Why is variation so important to evolution? See pages 379-381