Feb 1st Review section

Mitosis: Put steps in order.
Cross out steps that don't apply.
_3_ Microtubules attach to centromeres of chromosomes, pull chromatids apart.
_2_Chromatids lined up at metaphase plate
_1_DNA wrapped around histones and condense
_X_FtsZ ring forms in between daughter cells

The last answer is the only one that DOESN'T apply. The others are in order.

Mutant RB, such that cannot be phosphorylated (meaning adding phosphate, which would activate or deactivate many protein enzymes, causing or preventing the mechanisms of diseases such as cancer and diabetes-Thank you wikipedia).
Which of following would you predict to be true of cells with this mutation?
__a) Cells would be cancerous

__b) There would be no change to phenotype of cells

__c) Cell could not replicate its DNA/enter S-phase

__d) An organism with this mutation could not develop past fertilization

C and D are correct. On the test, circle them. Good chance this question will be on the test!

DxRR: I do love me this question. Do bear in mind, however, that there are likely to be slight wording changes, and that the order of answers is vanishingly unlikely to be the same as it is here, even if the exact same wording is used.

Would B also we an answer to this question because if the cell is the replicating how can the phenotype change?
—> That's what I was wondering, too, but I think she's just talking about the phenotype of the cell itself, not the organism.

Cdk=cyclin-dep-_Kinase_(enzyme that adds phosphate to other protein)
Cancer cells KEEP replicating, Mutant RB would not allow cells to replicate at all.

None of the multiple-answer questions will have an answer of none of the above!

Nucleotide substitutions (this isn't a question, just know this stuff!)
*Can happen when DNA replicated
*So DNA sequences of organisms can be compared to determine likely relatedness of organisms
*Synonymous vs. Nonsymonymous substitution

Synonymous- no change to phenotype of organism
Nonsymonymous- results in a change in amino acid sequence which means a change in the phenotype of an organism.

Compare gene for protein that T4 virus binds to on E. coli:
*original colony (Susceptible)
*colony on T4 plate on Thursday (Resistant)
So substitution must be non-symonymous.

*Maynard is a reh-tard. A retard? No a reh-tard
-Dear Catie,
I'm trying to be helpful for those who can not be here!

Differences between cytokinesis (division of cytoplasm) and karyokinesis (replicating and division of DNA, nuclei)
a) Karyokinesis is essential for cell division
b) Cytokinesis is the division of the cell cytoplasm
c) Karyokinesis is the division of the nuclei
d) Cytokinesis in animal cells is facilitated by the formation of a contractile ring made of myosin

B,C, and D are the answers. DxRR: Again, in this case. DON'T MEMORIZE the order of answers for questions on this wiki. Even if I use the question, the order of answers is very likely to change.

To answer this question, take out the word it is asking about (cytokinesis or karyokinesis) and filling it in with the other word you are comparing it to. If the statement is still true when you switch words, the statement becomes a similarity, which is not what this question is looking for.

Myosin is protein used to pinch apart eukaryotic, animal cells.

Common descent
Which of the following observations would disprove evolution of humans from other animals?
A alien from outer space has DNA that is 99.99 percent identical to humans while closet earth organism (Chimpanzees) are only 98.5% identical.
B Chimpanzee DNA is 98.5% identical to human DNA.
C Humans have unique traits (ability to use fire and walk on two feet) not seen in other animals. (Can determine this by taking out “humans” in the answer and question and putting in the words “Great Danes.”

Know how to determine number of bacteria colonies from serial dilution

Lab Techniques
Serial Dilution
Logic underlying
Possible short answer – make dilution of chemical (can write via bullet points)
Patient who has bacterial infection in hospital. Take blood sample. Total volume is 5 mL. Do serial dilution. Plate 1:1 (initial: 5 mL blood), 1:10 (10^1 concentration .9 mL sterile broth, put .1 mL from 1:1), 1:100 (10^2 concentration .9 sterile broth .1 mL from 1:10). From each test tube dilution, you plated .1 mL

Number of bacteria colonies
1:1 lots – too many to count
1:10 26
1:100 3

26 X 10 bacteria in 0.1 mL of 1:1 tube

How many bacteria were in total blood sample?
26 is better to use than 3– less room for error
26 X 10 (from 10^1 tube) = 260 in .1 mL. Multiply 260 by 50 (5 mL/0.1 mL = 50).

Add amount of zeroes that is on left side of chart (10 = add 1 zero) to number of bacteria colonies. 26 bacteria in 10^1 so, add one zero to 26 to find out total number of bacteria colonies in .1 mL. Then, multiply by 50.

Another possible Lab Technique question that could be asked: Phage resistance

DxRR: not that could, that will. Again, everything that chapters 22 and 24 are about are stated more elegantly by the data in the E. coli-T4 phage experiment. If you understand what this experiment is about, you understand everything about 22 and 24.

Could be compare and contrast question for cytokinesis vs karyokinesis. Which of the following are differences between cytokinesis vs kayokinesis?
A Karyokinesis is essential for cell division (Is a true statement, but it isn’t a difference)
B Cytokinesis is the division of the cell cytoplasm
C Karyokinesis is the division of the nuclei
D Cytokinesis in animal cells is facilitated by the formation of a contractile ring made of myosin




For the qestions that you have to put the answers in an order when she is grading it, she will not count them all wrong if you miss one at the beginning. She will follow your order and if the rest is correct you will only lose points for that one.

Thanks Laura! Very helpful. :)

Agreed this is very helpful and I also want to thank Laura for starting this and everyone else that has contributed…this is helping out a lot :)

What is the relationship between myosin and tubulin? One of the questions we went over in this review session says cytokinesis is facilitated by myosin, but my notes say stuff about FtsZ vs. tubulin. Can anyone explain this to me?

Answer from DxRR: In eukaryotic (and especially animal, as opposed to plant) cells, the pinching off between the two "daughter" cells is done by myosin. This is ANALOGOUS to the action of FtsZ, the bacterial protein that pinches off the boundary between the two new bacterial cells during bacterial cell division. So cytokinesis is largely accomplished through the action of myosin, even though tubulin is necessary for the chromosome-separating steps of mitosis (i.e., tubulin is necessary for karyokinesis.)
Part of the confusion, I think, is that FtsZ is an evolutionary homologue of tubulin (i.e., the FtsZ and tubulin amino acid sequences are very similar); while tubulin is obviously very important for eukaryotic cell division (since it's tubulin that makes up the microtubule "spindles" that pull the replicated chromosomes apart, and since it's tubulin that makes the centrosomes that the microtubule spindles attach to), tubulin doesn't pinch apart the new cells during cytokinesis. Again, myosin does that.

So, roles in eukaryotic cell division:
Myosin: pinches apart new cells during cytokinesis
Tubulin: Makes the microtubules that pull the replicated chromosomes apart. Also forms the centrosomes that the microtubules attach to, and that establish the orientation of cell division.

Roles in prokaryotic cell division:
FtsZ: Pinches apart new cells

FtsZ is similar in amino acid sequence to tubulin, but it is similar in function to myosin (w/r/t/ cell division)

I hope this helps!! -DxRR

This helps a ton thanks!


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