“Apoptosis, Crossover, and Tumor-suppressor genes”

For your primary post, please respond to one of the following three topics with a post of at least 125 words that addresses each point given in the instructions. Also, please reply to at least one fellow student on any topic.

Topic 1 : Apoptosis. Watch the Khan Academy video about apoptosis (1)*, then address the following issues in your own words:

• (a) What is the difference between apoptosis and necrosis? 
• (b) What is the role of apoptosis in the normal, healthy development of animals? 
• Reminder: you don’t need to cite the Khan Academy video for this topic, but if you use any other sources, you must cite them.

Topic 2 [article]: Crossover. Read the article from the University of Rochester on a gene that influences crossover rates in fruit flies. Then address the following: 

• (a)  Explain the relationship between crossover, genetic diversity, and natural selection.
• (b)  Summarize the findings regarding a gene that influences crossover.
• Reminder: you don’t need to cite the University of Rochester article for this topic, but if you use any other sources, you must cite them.

Topic 3 [research]: Tumor-suppressor genes versus Proto-oncogenes. This is a library-research topic in which you are required to provide your sources. Mutations in tumor suppressor genes can contribute to or cause cancer, just as mutations in proto-oncogenes can also contribute to or cause cancer. However, tumor suppressor genes are very different from proto-oncogenes.

• (a) Explain why a gain-of-function mutation to a proto-oncogene (or its promoter) may be associated with increased risk of cancer.
• (b) Explain why a loss-of-function mutation to a tumor suppressor gene may be associated with increased risk of cancer. 

References:

1. Khan Academy, No date given. Apoptosis , https://www.khanacademy.org/science/biology/cellular-molecular-biology/stem-cells-and-cancer/v/apoptosis
2. Lindsey Valich, April 19, 2018. Scientists discover gene controlling genetic recombination rates. http://www.rochester.edu/newscenter/genetic-recombination-selfish-dna-may-help-explain-differences-in-fruit-flies-312422/