For daily information, click on the class title to the left. For entertaining science links, go here.
They constantly amaze me.
"Bizarre" Octopuses Carry Coconuts as Instant Shelters (at National Geographic)
Ms. Jones home with sick baby.
In Class Today, answer the questions about Chapter 7, Cell Membrane.
Reminder Due Tomorrow:
1. Anything that the cell takes in, such as oxygen of food, or lets out, such as carbon dioxide, must pass through the cell membrane. Which of the measurements of your model cells best represents the surface area of the cell membrane?
2. The cell contents, including the nucleus and the cytoplasm, use food and oxygen and produce wastes. Which two measurements best represent the contents of one of your model cells?
3. As the cell grows larger and accumulates more contents, will it need more or less cell membrane to survive? Explain your answer.
4. As a cell grows larger, does the surface area-to-volume ratio get larger, get smaller, or remain the same?
5. As a cell grows larger, what happens to the surface area-to-mass ratio?
6. Which cell model has the greatest surface area-to-volume and surface area –to-mass ratio?
a. Why can cells not survive when the surface area-to-volume ratio and surface-area-to-mass ratio become too small?
b. Which cell model then has the greatest chance of survival?
8. How many cells with s=1 would fit into a cell with s=2?
9. Which as more total surface area, one cell with s=3… or 27 cells, each with s=1?
10. How can the surface area-to-volume and surface area-to-mass ratios be increased in a large cell?
11. As the length of a side doubles in a cell, what happens to the distance that nutrients must travel to reach the center of the cell?
12. Was your hypothesis supported by your data? Why or why not?
Pick some sort of "abiotic factor" that affects life. Wind, something in the water, a nutrient, amount of light, pH, whatever you want. Design an experiment to see how it affects the growth of Halobacteria.
Link to the form to sign up for your topic:
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Are you TOTALLY STUCK?
How about you search for one of these lovelies:
Good times in the Precambrian and early Paleozoic!
1. a. DNA has ATCG, RNA has AUCG
b. DNA: deoxyribose; RNA: ribose
c. DNA: double stranded; RNA: single stranded
2. 2 identical strands of DNA
6. Polypeptide (protein)
8. a. Phosphate
b. Nitrogen-Containing base
9. a. mRNA: sends message to be translated
b. tRNA: brings amino acids to ribosome
c. rRNA: forms ribosome
10. a. amino acid
12. Sequence of 3 nucleotides that code for a peptide
13. Mutation of just one nucleotide
14. A T G C C C C G C T G A T T
15. A U G C C C C G C U G A U U
16. met pro ala stop
UAC GGG GCG ACU
17. Circle around "AUG"
18. Square around "UGA"