01/26/12

EVOLUTION

Homework: Finish UP p. 5, 13-16, and 25-28. Also we are meeting in the auditorium tomorrow.

Due Today: UP p.19-20

In Class:

Today in class we went over UP p.19-20 about the who supported each theory; Darwin, Lamarack, both, or neither. These were the answers:

1. Darwin 2. Darwin 3. both

4. Lamarack 5. Darwin 6. Darwin

7. Darwin 8. Lamarack 9. Darwin

10. Darwin 11. neither 12. Darwin

13. Darwin 14. Lamarack 15. Lamarack

16. Darwin 17. Darwin 18. Lamarack

19. Darwin 20. Neither 21. Lamarack

22. Darwin 23. Lamarack 24. Darwin

25. Lamarack 26. Darwin 27. Lamarack

28. Darwin 29. Darwin 30. Lamarack

*You do need to know Darwin and Lamarack's theories and how they were different for the test.

We also finished our notes from pages 15-16 where we learned about Natural Selection in Action. Some examples are:

• Evolution of finches on Galapagos Islands: the islands were colonized by finches that strayed from the South American mainland.
• Pesticides-do not create resistant individuals, but selects for resistant insects that were already present in the population.
• 2 populations of trees are separated by a river (particularly isolated from each other). Trees are more likely to breed with members of the same population on the same side of the river. Each side of trees could evolve different traits.

Next we did an in class lab on UP p. 25. In this lab we created an artificial environment to demonstrate the concept of natural selection. Are materials were:

• A piece of patterned fabric (artificial environment)
• 10 different colors of construction paper
• Petri dish

Our group used a zebra print cloth and this is the data we recorded:

Our group concluded that some traits help organisms adapt to their environment just like that dots had colors that camouflage them on the fabric. Therefore the dots/organisms that are best fit to that environment, survive.
Next-VShow Jex

Wednesday, November 30, 2011

Homework Due: None

Homework Assigned: UP p.99-110 due tomorrow, and EC-Lab #37 due thursday.

In Class:

We did a DNA model activity using a pack of tubes and connecters to create strands of DNA, replicate it, then put it through protein synthesis. The purpose of this activity was to learn more about translation. Here is a link to short clip on youtube, that explains translation.

http://www.youtube.com/watch?v=5bLEDd-PSTQ

NOTE: In the beginning of this clip it talks about Poly-A tails and methylated caps, you DO NOT need to know these, we did not cover these in class.

Next Scribe: Jex, you do not need to post until next tuesday

Tuesday October 4, 2011

Tuesday, October 4, 2011

Today we had a quiz in everything we've learned so far in the cells unit. We read over and completed day 1 of the Egg Osmosis DEMO in class. Also we did the "Diffusion Through a Cell Membrane" lab. Due today was to read pages 37-39 in UP.

The Egg Osmosis DEMO

The Egg Osmosis Demo, found on pages 45-47 in the unit packet, talks about hows osmosis is the diffusion of water across a semi-permeable membrane. It also talks about homeostasis and how it is maintained in part by controlling the movement of materials into and out of the cell.

In class Mrs. Andrews held up an egg and we drew a picture of it and made observations like; white, hard shell, and oblong. This was recorded under day 1-raw egg on page 46 in the unit packet.

Diffusion Through a Cell Membrane Lab

1. We drew a diagram of what our materials will look like when they are set up. There is the dialysis tubing that

contains glucose, starch, and water that is placed in a beaker which contains 50mL of water and iodine (brownish yellow color).

2. We proceeded with the lab by adding glucose and starch to the tubing and tying it off then placing it in a beaker filled with iodine and water for 15 minutes.

3. After 15 minutes we came back and the starch in the tubing had turned a blue black color and settled to the bottom. Also the iodine diffused in the tubing because the liquid inside the tubing was a brownish yellow color.

4. By dipping a piece of Tes-Tape (glucose indicator paper) into the liquid in the beaker we found that there was a

presence of glucose outside the tubing because the tape turned a to light green. From this we

concluded that the glucose diffused from inside the dialysis tubing to the beaker.

After 15 minutes the beaker looked like this. With the starch dyed blue/black because of the iodine and iodine diffused into the tubing as well as the glucose diffused into the beaker although you cannot see it.

From these results we concluded that:

1. The iodine diffused from the high concentration in the beaker to the low concentration in the dialysis tubing.

2. The glucose diffused from the high concentration in the tubing to the low concentration on the beaker.

3. The water did a little bit of diffusing both into the tubing and out.

4. Starch molecules are a lot larger than glucose, water, and iodine molecules because they couldn't diffuse through the dialysis tubing membrane.

Due tomorrow is the Diffusion Through a Membrane lab (p.37-39)

up next-Austin