Monday November 29, 2010

Exploring the CellToday’s Objectives: • Understand that cells, the smallest unit of life, have all of the unifying characteristics of life.•Understand the size of cells, relative to other organic molecules.•Review progress from the midterm assessment, and introduce the unit plan for the next three weeks.

Let’s go inside of a cell!!!http://en.vidivodo.com/280909/in

ner-life-of-cell

Pretend you are inside of a white blood cell that is being attacked by outside invaders! Let’s see what it would look like inside……..

What do we know about cells?Rate your conceptual flow (map)

ideas from 1 to 4.

1 (I know little about this)

4 (I understand this very well)

What are the unifying characteristics of life?

EvolutionHomeostasisEnergy, Matter, and OrganizationContinuity (Reproduction and DNA)

DevelopmentInteraction with other living things (Ecology)

What does this tell us about cells?

Every biological problem must finally be sought in the cell; for every living organism is, or at some time has been, a cell.

- E.B. Wilson, Renowned Cell Biologist

What do we already know about organization?

So exactly how big are cells?Card sorting activity.

Work in groups of 2.

Sort 14 cards from smallest to largest.

http://learn.genetics.utah.edu/content/begin/cells/scale/

Exam FeedbackAverage: 78% (21.5/25)

Most commonly missed questions:#4 – 32% incorrect#6 – 43% incorrect#8 – 72% incorrect#12 - 43% incorrect#20 – 65% incorrect#22 - 50% incorrect

#4The plasma membrane of cells

contains more than the phospholipid bilayer. Which of the following are components of the membrane? a. Phospholipids c. Cholesterol b. Transport proteins d. All

are components that are found in the plasma membrane.

#6What would happen if the plasma

membrane were composed solely of phospholipids and no proteins? a. All movement of molecules across

the membrane would cease. b. Active transport would not occur. c. Diffusion and osmosis would not

occur. d. Movement of molecules across the

membrane would not be affected.

#8Solutions that cause water to enter cells by osmosis are termed a. isotonic. c. hydrophilic. b. hypotonic d. hypertonic.

#12. If there is a higher solute concentration inside the cell than outside the cell, the cell is in what type of solution?

a. Hypertonic c. Osmoticb. Hypotonic d. Isotonic

#20

What hypothesis was being tested with groups II and IV?◦ if salt reduces Daphnia survival, then saltier water

will have a smaller population ◦ if warmth inhibits reproduction, then higher water

temperatures will lead to fewer Daphnia ◦ if Daphnia digest salt, then their body size will

increase ◦ if dissolving salt releases heat, then more salt will

cause the water temperature to increase more

Group Temperature Grams of Number of Daphnia

Salt Added After 21 Days

I 30 C 10 120

II 30 C 0 240

III 25 C 10 75

IV 25 C 0 160

#22

How many variables are being tested in the experiment?

Independent Variables: temperature, grams of salt

Dependent Variable: number of daphnia

Which variable is tested in an experiment?

Group Temperature Grams of Number of Daphnia

Salt Added After 21 Days

I 30 C 10 120

II 30 C 0 240

III 25 C 10 75

IV 25 C 0 160

Homework

Read pg. 8-14 in NIH’s Inside the Cell.  

Complete worksheet chart about function of cell parts.

Bring book and worksheet to class tomorrow.

Exit Slip .. This will be graded!Write a summary of what you’ve learned

about each objective today.

1. Understand that cells, the smallest unit of life, have all of the unifying characteristics of life.

2. Understand the size of cells, relative to other organic molecules.

3. Review progress from the midterm assessment, and introduce the unit plan for the next three weeks.