Biology Inherited Traits Labs

Perform the following lab. You will need to submit complete lab reports. A lab report template is provided.  Please read all instructions, and review uploaded files.  The attached lab report template must be used twice, once for 7b, and another one for 8, as well as a short paragraph response for 7a.

Lab #7: Inherited Human Traits (parts A and B)

There are three parts to this lab. For part A you will submit a paragraph response. For parts B and C you will need to complete a lab report. Include the following in the lab reports: title, problem, results, discussion/analysis answer, and a conclusion.  

Part A: Your Inherited Traits

Read the information about , then download and complete ‘Part A’ of the worksheet (see assignment resources below – Unit4-Lab-InheritedHumanTraitsForm.pdf). The worksheet is a form that you can complete. (If you can’t use the form you will need to print the worksheet and circle the traits you have). You will upload the completed worksheet when you’re finished, and then write a short paragraph describing the traits youve inherited, use the online text box for this paragraph. Explain why everyone shares the same basic traits (ex. the trait for hair or the trait for a nose). Explain why peoples traits are different. 

Part B: Inherited Traits 

On the Unit4-Lab-InheritedHumanTraitsForm.pdf you will complete Part B and a lab write-up.

Problem: Explain how traits are inherited.  

Materials: 2 coins, pencil, figure 1 (from resources)

Method:

Note: There are two genes for each trait, one from each parent. 

You can find a partner to help you do this lab or just flip two coins at the same time. Determine which partner will toss for the male and which will toss for the female. 

1. Have the partner who is representing the male flip a coin to determine the sex of the offspring. If the coin lands heads up, its female. If it lands tails up, its a male.
2. Both partners now flip their coins at the same time. The coins should be flipped only once for each trait. For all coin tosses you will now make, heads represents the dominant gene and tails represents the recessive gene. 
3. Continue to flip the coins for each trait listed in the Part B “figure 1” page of the Inherited Human Traits form. Record the traits of your offspring on the form.
4. Using the recorded traits, draw the facial features of your offspring. Photograph or scan your picture and upload it with the form and lab write-up, be sure to give the file a name that clearly identifies what it is e.g. FacialFeaturesDrawing. 

Results: 

Drawing of offspring, figure #1

Discussion/Analysis:

1. What percent chance did you and your partner have of producing a male offspring? A female offspring?
2. Would you expect other pairs of students to have an offspring similar to yours? Explain. 
3. How might it be possible for you to show a trait when neither of your parents shows it?

Conclusion: What is the answer to the problem question? Was your hypothesis correct? Were there sources of error? What could be done differently next time? What did you learn?

Lab #8: Expected vs Observed Results (part C)

Problem: Explain if a punnett square predicts actual ratios.

Research: 

Probability is the likelihood an event will occur. There are two rules when gathering data about probability: you need a large sample size and previous events do not affect future outcomes. 

What is the expected probability if we cross two heterozygous hairy-armed people? Use a punnett square to show this. Be sure to draw out the punnett square in your lab report. 

Materials: 2 coins, a partner if possible (or you flip both coins at the same time)

Method:

Note: The completely made-up trait you are examining is having hairy arms. Hairy arms (H) is the dominant trait and is represented by the heads side of the coin. No hair on the arms (h) is the recessive trait and is represented by the tails side of the coin. 

1. One partner is going to represent the female, the other the male. The two coins represent the alleles that combine when a sperm and egg join. 
2. Flip the two coins at the same time. Record the phenotype of your offspring using tally marks. Remember that HH = hairy arms, Hh = hairy arms, and hh = no hair on the arms. 
3. Repeat step 2 for a total of 100 times. Record the phenotype each time. 
4. Repeat the experiment again.  

Results:

Discussion/Analysis:

1. What combination occurred most often for your data in trial #1? In trial #2?
2. What were the ratios of homozygous hairy arms, heterozygous hairy arms, and non-hairy arms for your data in trial #1? In trial #2?
3. How did your expected results from the punnett square compare with your actual results?
4. Does chance affect allele combination? Explain. 
5. How could you get actual results closer to the expected results?

Conclusion: What is the answer to the problem question? Was your hypothesis correct? Were there sources of error? What could be done differently next time? What did you learn?