01/06/10

Basically we spent all of class debating the answers to the HW

Mr. Finley understands why we are angry at the school website because he is angry too so try to persevere and deal with it:

Suggestions if the HW page appears blank

1 Try logging in...

2 Try calling someone people with working computers...

3 Try restarting your computer...

4 Update all links that you have and make new ones...

On a happier note everyone in this class got 1/2 of a point extra credit for doing their homework!!!!

The HW answers ( If you are still stumped with this HW look at Simrin's HW sheet with the explained hw answers in tonights HW section found )

1 The cell expanded and grew fatter in the cell. Also, the arrows pointed towards the cell. This is because there is less water in the cell and more water outside so osmosis made the water want to go from high concentration to lower concentration.

2 The cell shrunk. There was more water inside the cell too so it went out.

3 The size of the plant cell didn't change because of a cell wall. All three shrunk in the hypertonic and all got bigger in the hypotonic solution.

4 No it couldn't survive because the amount of salt was hypertonic to the amount in the freshwater. So they would shrivel up and get dehydrated in the salty water.

5 You should put the salt on afterwards because if you put it on before the steak will dehydrate and dry out because salt absorbs water because the salt would act like a hypertonic solution of salt so the higher concentration of water in the cell would get out of the cell so the salt could go in.

6 The salad would act like the steak because the salt in the dressing would shrivel because of the salt.

7Same as the above answer accept for weeds. Watch the video for lettuce at the bottom to see what the lettuce looked like after being in the water and what would happen if it went back into water...

Other Notes taken:

For all cells in the hypotonic solution all sucked in water, isotonic stayed the same, and hypertonic got rid of water.

Net movement means the final movement. (Ex. I found $2 and then lost $2 so because I started with nothing I lost $0)

Elodea: Only the insides shrunk also, it only changed size a littlebit because the cell wall was keeping the cell in the same shape. Also, the vacuole was the major thing that shrunk along with the cytoplasm.

For #1 on the HW the amount of water was higher outside but the amount of stuff was hypotonic.

For those of you who don't understand diffusion try these video links:

Explanation: http://www.youtube.com/watch?v=AYNwynwaALo

Examples in the kitchen with lettuce and an egg.

Lettuce: http://www.youtube.com/watch?v=H6N1IiJTmnc&feature=related

Egg: http://www.youtube.com/watch?v=0c8acUE9Itw&feature=fvw For this video wait until it's loaded then quickly go through the whole thing because it's pretty long...

KD

(3rd)