Polar Science 2006

Challenge Questions

Members of both the Polar Science Ice Team and Lab Team will be posting Challenge Questions here each week for classes to solve. You may not have time to answer all questions. That's ok, just choose as many as you have time for!

Tasks

Teams working in this field will collaborate to solve the following problems:

• Discuss the Challenge Questions in your class.
  

  Decide how you will find the answers.

  • Is this something you already know?
  • Will you need to research the answer?
  • Will you need to perform an experiment to test your hypothesis?
  
  
• Submit your answers.
  

  Once you think you know the answer to each question, go to the Messages area, choose Challenge Questions from the Shared Forums list, and Post a New Message.

• Discuss the answers in your class.
  

  The Polar Science teams will post the answers to the Challenge Questions in the Challenge Questions Shared Forum. Discuss them in your class. Were you correct? Do you have further questions, ideas or thoughts you'd like to share? If so, post a new entry in your Blog.

• Challenge Questions from the Ice Team
  

  Challenge Question #1 Oct. 5, 2006: Christchurch, New Zealand
  	Based on topography and latitude which US or Canadian cities have a climate similar to Christchurch and why?
  Challenge Question #2 Oct. 5, 2006: Christchurch, New Zealand
  	During the flight to New Zealand, we were flying at approximately 39000 feet above sea level and the air temperature was -40 degrees celsius which is similar to the temperature in Antarctica. Why, if you are approximately 7 miles closer to the sun, is the temperature not warmer?
  Challenge Question #3 Oct. 14, 2006: McMurdo Station, Antarctica
  	During the summer when you are outside under the intense Sun a nice breeze is very welcome. However, when you’re in the cold of Antarctica it is not only unwelcome, it is very dangerous. Why is this? And what would you do to keep this problem minimized while working in the field?
  Challenge Question #4 Oct. 21, 2006: McMurdo Station, Antarctica
  	So why is it easier for seals to maintain breathing holes closer to islands or natural cracks than in the middle of the sound?
  Challenge Question #5 Oct. 21, 2006: McMurdo Station, Antarctica
  	Pictured below is a Weddell seal. Since they have such short front flippers, how do they maintain a breathing hole?
  Challenge Question #6 Oct. 28, 2006: McMurdo Station, Antarctica
  	What are the terms used to describe the 4 ways in which animals lose heat to their environment?
  Challenge Question #7 Oct. 28, 2006: McMurdo Station, Antarctica
  	Given your understanding of these 4 avenues of heat loss, name the avenues of heat loss for a seal holding its breath swimming under water, a seal sitting in water breathing at an ice crack, and a seal sitting on ice.
  Challenge Question #8 Oct. 28, 2006: McMurdo Station, Antarctica
  	Why might a seal pup loss more heat to the environment then its mother? Consider the heat loss equation for conduction: Q = k A (T1-T2)/l, where Q is heat loss, k is the conductive property of the insulation (blubber) which affects heat loss, A is the surface area available for heat loss, T1-T2 is the difference in temperature between the seal and the environment, and l is the distance separating the heat exchange objects.
  Challenge Question #9 Nov. 5, 2006: McMurdo Station, Antarctica
  	One of the reasons scientists work with Weddell seals is because they are extremely docile and gentle by nature. In contrast, many species of seals that live in the Arctic Circle are skittish and difficult to approach. Why do you think that Weddell seals are not aggressive toward humans? (Hint: it is related to predator-prey relationships.)
  Challenge Question #10 Nov. 12, 2006: McMurdo Station, Antarctica
  	Looking at the temperature graph in the Week 6 update from the Ice Team answer the following question: Why are the seals’ skin temperatures intermediate to that of their core body temperatures and the air temperature. Think about how the animal does this physiologically and why this is important for the seal’s survival?
  Challenge Question #11 Nov. 12, 2006: McMurdo Station, Antarctica
  	Looking at the blubber graph in the Week 6 update from the Ice Team answer the following questions: Why would you expect that juveniles might need thicker blubber (thicker “winter coat”) than adults? What property of blubber may explain why we did not find this pattern?
  Challenge Question #12 Nov. 12, 2006: McMurdo Station, Antarctica
  	A Weddell seal pup is born at about 20 kg and after 4 weeks of nursing a pup can weigh 80 kg. Calculate how many kg this pup gains per day? Assuming that the mother’s milk is comprised of 70% fat and 30% protein and that the pup assimilates 100% of its mother’s milk, how many calories does the pup ingest per day? Given the calorie value for milk and the amount of calories ingested by the pup per day, how many liters of milk did that pup drink per day? Also calculate the total liters of milk consumed by the pup over the entire 28 day nursing period.
  Challenge Question #13 Nov. 19, 2006: McMurdo Station, Antarctica
  	You must review the pictures of the seal skulls in the Week 7 Report from the Ice Team, (see the link below), to answer the challenge question for this week. You will find that tooth structure varies widely across the three seal species found in Antarctica. In biology, structure dictates function. Thus, tooth morphology (shape, size) is related to diet. Describe the shape of the teeth for each seal, and explain how each particular tooth structure aids in the capture of a particular prey type. Hint: You will have to research prey types for Weddell, Crabeater, and Leopard Seals.
  New! Challenge Question #14 Nov. 26, 2006: McMurdo Station, Antarctica
  	Read the Week 8 Report from the Ice Team, (see the link below). Why do you think that the seal pup had the thickest blubber while the juvenile pup had the thinnest blubber?

• Challenge Questions from the Lab Team
  

  Challenge Question #1 Oct. 9, 2006: York University, Toronto
  	What does the prefix “cryo-” mean in “cryosectioning”?
  Challenge Question #2 Oct. 9, 2006: York University, Toronto
  	Based on what you were told about the job of the muscle satellite cell, can you think of things that make them active? (See the Week #1 Report from the Lab Team below.)
  Challenge Question #3 Oct. 9, 2006: York University, Toronto
  	Now that you know what cell receptors are, why do you think it is important for cells to have receptors? (See the Week #1 Report from the Lab Team below.)
  Challenge Question #4 Oct. 16, 2006: York University, Toronto
  	Why does water expand as it freezes? (See the Week #2 Report from the Lab Team below.)
  Challenge Question #5 Oct. 16, 2006: York University, Toronto
  	Why do slow twitch muscle fibres have a red colour? If you are eating chicken for dinner, and you ask for a piece of dark meat, what kind of muscle fibre are you eating: fast or slow twitch fibres? (See the Week #2 Report from the Lab Team below.)
  Challenge Question #6 Oct. 16, 2006: York University, Toronto
  	In humans, what type of athlete would have a larger proportion of slow twitch fibres and which would have a greater proportion of fast twitch fibres? What type of athlete would have intermediate fibres? (See the Week #2 Report from the Lab Team below.)
  Challenge Question #7 Oct. 25, 2006: York University, Toronto
  	Myoglobin molecules from which muscle groups will donate O2 molecules to mitochondria when you are: Running Playing basketball Eating (See the Week #3 Report from the Lab Team below.)
  Challenge Question #8 Oct. 25, 2006: York University, Toronto
  	What are some of the difficulties Peter, Jesse and Sophia may encounter when attempting to combine serial muscle cross-sections? (See the Week #3 Report from the Lab Team below.)
  Challenge Question #9 Nov. 1, 2006: York University, Toronto
  	As described in my update, skeletal muscle cells have many nuclei within a single cell. What is the job of the nucleus within a cell? Why do you think skeletal muscle cells have more than one nucleus? (See the Week #4 Report from the Lab Team below.)
  Challenge Question #10 Nov. 8, 2006: York University, Toronto
  	Based on the physiology of muscle fibre types discussed in my last update, (Week #2 Report from the Lab Team), why would slow twitch muscle fibres have more intramuscular fat than fast twitch fibres? (See the Week #5 Report from the Lab Team below.)
  Challenge Question #11 Nov. 15, 2006: York University, Toronto
  	It is clear that the Weddell seal undergoes physiological changes as it matures from a pup to a juvenile to an adult. Many of these changes have been discussed throughout the past few weeks. Difficulty level 1: Do you think these changes are caused by the aging of the seal or by their change in swimming ability? Difficulty level 2: What do you think myoglobin immunohistochemistry stain would look like on the heart tissue? Difficulty level 3: How do you think the Weddell seal’s daily diet effects these physiological adaptations?
  Challenge Question #12 Nov. 22, 2006: York University, Toronto
  	What three characteristics is Peter looking for in his immunohistochemistry results that will allow him to verify the presence of a muscle satellite cell? (See the Week #7 Report from the Lab Team below.)
  Challenge Question #13 Nov. 22, 2006: York University, Toronto
  	Put the following three substances in order from most dense to least dense (Instead of looking for the answer on the internet, try designing your own experiment to test your hypothesis. Tell us how you designed your experiment when you answer the question.) a. water b. lead c. ice
  New! Challenge Question #14 Nov. 30, 2006: York University, Toronto
  	Based on what you have learned about the feeding habits of the Weddell seal and muscle physiology in general, why do you think the Weddell seal muscle has a high percentage of Type I, slow twitch fibres? Why would these animals also have some Type IIa intermediate muscle fibres?

Useful Links

• Dr. Hawke's Team Blog
• Dr. Kanatous's Team Blog
• Week 1 Report from the Ice Team
• Week 1 Report from the Lab Team
• Week 2 Report from the Ice Team
• Week 2 Report from the Lab Team
• Week 3 Report from the Ice Team
• Week 3 Report from the Lab Team
• Week 4 Report from the Ice Team
• Week 4 Report from the Lab Team
• Week 5 Report from the Ice Team
• Week 5 Report from the Lab Team
• Week 6 Report from the Ice Team
• Week 6 Report from the Lab Team
• Week 7 Report from the Ice Team
• Week 7 Report from the Lab Team
• Week 8 Report from the Ice Team
• Week 8 Report from the Lab Team
• Week 9 Report from the Ice Team
• Week 9 Report from the Lab Team

Teams

There are 33 teams working in this field.