AP Biology Discussion notes

Goals for the Day 1.Be able to discuss species value 2.Be able to discuss how the concept of extinction came to be. 3.Be able to discuss & recognize a good scientific theory

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3.How much would you spend to save a single amphibian species? What kinds of things do you think we should consider when choosing how to spend our resources and which species to save? (Does it matter how unique a species is, whether it is the last species to have a particular breeding habit for example? Does it matter how large the animal is? How cute?)

Chemicals In Sunscreen Are Harming Coral Reefs, Says New Study OCTOBER 20, :18 PM ET So how much would you spend to save an ecosystem? What if not spending money could save one?

3. Would it matter if it were a symbol of your country? If they were the last ones?

7.Do you think we have a moral obligation to try to save species that we have endangered? a.If so, how far do you think we have to take that obligation? 8.What other global issues do you think deserve our resources and attention?

11. Roughly how long has extinction been a commonly accepted idea? Did this surprise you?

13.What evidence do you have that could be used to persuade Jefferson that species can in fact become extinct?

16.A good scientific theory should be accurate, coherent, flexible, and explanatory. A good theory helps explain current evidence, and also make predictions about future research or findings. After providing evidence that the Mammoth and the Mastadon were likely the remains of species that had died out or gone extinct, what did Cuvier predict existed? (pg. 30)

Lamarckian Evolution First testable theory of Evolution (1809) Use & Disuse –Blacksmith Inheritance of Acquired Characteristics –Giraffe

Lamarckian Evolution First testable theory of Evolution (1809) Change in species is linked to an organism’s environment.

Historical Context continued Georges Cuvier ( ) –Paleontologist Catastrophism - vast geological & biological changes in the earth's history were caused by catastrophes (rather than gradual evolutionary processes). –Extinctions –Fossil Record

24. Catastrophism – which said that in the past, nature had operated differently, more intensely and more savagely than it did in the present. This was his way of explaining extinction. The idea being that since animals alive today appear to withstand present day catastrophes like floods, forest fires, and volcanic eruptions, then past events must have been much greater, and this is the reason animals couldn’t cope with them. What question or questions might you have about this theory?

23.Cuvier is quoted by Kolbert as saying “It is not for us to involve ourselves in the vast field of conjectures that these questions open up.” Cuvier did not want people to think about the questions that this theory or the idea of why Catastrophes happened differently in the past then the present. How do you feel when people don’t want you to ask questions or when people are reluctant to answer your questions?

18.Was Cuvier a proponent of Evolutionary thought, or the idea of transformisme? 21.Did Lamarck believe in Cuvier’s idea of extinction? Why was this? Were there any exceptions? (pg.42)

22.Cuvier analyzed the anatomy of a modern cat and compared it to the anatomy of embalmed cats found in Egypt that were several thousand years old. When finding no evidence of transformation (the cats were relatively the same) he concluded that this was evidence that species were fixed, that no species changes over time. Do you think this evidence is reasonable evidence? Why or why not.

What other questions/thoughts do you have? Next Discussion: Wednesday 10/28 –Pages –Reading Guide 2 Staple & Turn in: –One page reading guide –2 page reading discussion guide WITH article summary

Water Potential Calculations Ψ= Ψ p + Ψ s

Water Potential Ψ= Ψ p + Ψ s Water “potential” – potential refers to water’s potential energy, or water’s ability/capacity to do work.

Water Potential Ψ= Ψ p + Ψ s Water potential – physical property that predicts which direction water will flow. Includes the effects of solute conc. and physical pressure.

Water Potential Ψ= Ψ p + Ψ s Usually measured in MPa. 1MPa = 10x atmospheric pressure, so typical plant cell might have a pressure of.5MPa Pure water in an open container under standard conditions has 0MPa

Water Potential Ψ= Ψ p + Ψ s Solute Potential (Ψ s )– directly proportional to molarity(_________) of the solution Ψ s of pure water is by definition 0

Water Potential Ψ= Ψ p + Ψ s Solute Potential is ALWAYS negative, because it inhibits water’s ability to do work!

Water Potential Ψ= Ψ p + Ψ s Solute Potential (Ψ s )– solutes bind to water molecules, which reduces the capacity of water to move and do work (reduces ) As Molarity (amount of solute) increases the Ψ s becomes more negative

Water Potential Ψ= Ψ p + Ψ s Pressure Potential (Ψ p )– physical pressure of a solution so it can be positive or negative relative to the atmosphere Water in living cells is under positive pressure

Work Time Corrections? –Double check your grade is entered – if something was incorrect on the corrections you turned in I have not entered the grade Chapter 26 questions (DUE…)