Principles of Biology

Description

Lab 7 Biology of sex and errors in meiosis

Purpose: Learn about biology and history of the sex chromosomes by viewing two TED talks explaining the biology of sex and how we have come to name the sex chromosomes as such.

Learning outcomes:

• Identify the sex chromosomes in male somatic cells that are usually used to determine male gender
• Identify the sex chromosomes in female somatic cells that are usually used to determine female gender
• Explain intersex
• Name the areas of biological sex specified in Emily Quinn’s TED talk. One area is genitalia.
• Explain the use of terms “X” and “Y” when these chromosomes were initially discovered – were they meant to be used as we use them today?
• Explain if the X and Y chromosomes control single trait or function
• Explain if the presence of gonads is the same as gender
• Name three different names initially given to the X and Y chromosomes but are no longer used
• Identify several genotypes of male phenotype besides XY
• Identify several genotypes of female phenotype besides XX
• Explain the number of genes that do not function in sex and reproduction on the X chromosome
• Explain nondisjunction and outcomes that may occur as result during meiosis process in gametes

Instructions:  View two TED talk videos in lab 7 subfolder then answer questions 1-17 and upload the work to Assignment Lab 7 by October 6 11PM. Work will be graded based on accuracy and completeness.

7. Listen to Emily Quinn November 2018 TED Talk, “The way we think about biological sex is wrong” (link is in Lab 7 folder in Module 7) then answer questions 1-7.

Emily Quinn TED talk questions:

1. What percentage of humans are born as intersex?
2. What percentage of humans are born as genetic redheads?
3. How many people on Earth are intersex at the time of the TED talk by Emily Quinn in 2019?
4. What methods would be useful to identify a person who is intersex? (karyotype, blood panel for hormone levels
5. Emily Quinn makes a statement in her TED talk about what she wants to change in our society. What does she want to change?
6. What changes in our thinking as a society does she refer to in her talk that support her idea identified in the previous question? List two things she stated society have changed in their thinking as we have evolved in our understanding of our world.
7. What does she mean when she states in her talk “Biological sex is on a spectrum”?
8. Listen to Molly Webster November 2019 TED talk, “The Weird history of sex chromosomes” then answer questions 8-15.

Molly Webster TED talk questions:

8. Are gonads the same as gender? Explain the difference presented by Molly Webster in her TED talk.
9. a). Name three different names that were initially given to X and Y chromosomes (but are no longer used). b). In a general sense, what did these names refer to regarding the X and Y chromosomes?
10. Do the X and Y chromosomes control a single trait or have a single function? Briefly explain.
11. Provide the 3 examples of genotype (genetic basis) for male phenotype. One example given in talk is male phenotype is XY in somatic cells. Exclude the XY example and provide 3 more given in Molly’s talk.
12. Provide the 3 examples of genotype (genetic basis) for female phenotype. One example given in talk is female phenotype is XX in somatic cells. Exclude the XX example and provide 3 more given in Molly’s talk.
13. What new name does Molly want to give the X chromosome and why?
14. a). How many genes are located on the human X chromosome? b). What percent of these genes are dedicated to sex and reproduction? c). Calculate the number of genes that are dedicated to sex and reproduction by dividing the percentage by 100 and multiplying that number by the number of genes on the X chromosome. d). What percentage of genes on the X chromosome have nothing to do with sex and reproduction?
15. Is it possible for a person to have XXY chromosomes in their somatic cells? Explain in general terms how this result occurred during the biological process of gamete production by meiosis.
16. 
    Think about the information you viewed in these two videos and explain your thoughts by answering the questions 16-17.

Reflection questions:

16. What are your thoughts about the information provided by Emily Quinn?
17. What are your thoughts about the information provided by Molly Webster?