# Lukas!

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10

1. ## Cell and Molecular Biology Lab

Thanks! I really appreciate this.
2. ## Cell and Molec

The guy who typed up our lab manual did a pretty bad job. This is how he tried to explain transformation efficiency: # colonies/mL/microgram DNA I can't tell if he meant (# colonies)/(mL/microgram) or what...he didn't write out an example either. Anyway. Here's the problem: You need 8x 10E9 colonies. If you only have .0053 micrograms of DNA and you could only have maximum (I know it should be "a maximum", which just goes to show you how little he cares) of 1 mL of transformed cells. What efficiency would you need to get that many colonies? Could somebody please show me how to set up the equations for this? I also need to figure out what efficiency means. I assume it is a way to quantify how many colonies integrated the DNA into their plasmids. However I can't get anywhere if I don't understand the units. I am going to be seeing this on an exam, so I NEED to know how to do this. I got 4.24 E7 micrograms per milliliter. Also, I used dimensional analysis to solve this problem: If you get 400 colonies per plate. How many plates would you need? I got about 20 million. This seems excessive to me. Could somebody let me know if that is correct? Finally it asks me what volume of transformed cells would you be putting on each plate...I got 5 times 10 to the negative 8 mL. I think all of my answers are wrong. I went to the professor who wrote the lab manual for help and he sent me away. He's been a real jerk. HELP!!!
3. ## Is this answer right?

Hi, This question asks which of the following best describes the function of proteins bound at the proximal promoter elements in eukaryotic genes? a. The bind to RNA polymerase subunits b. They bind DNA as well as proteins c. They play catalytic roles in transcription d. They unwind DNA to promote polymerase binding e. Their roles are only for activation of transcription The answer is apparently B. but I thought C. was equally correct. What am I missing?
4. ## Gene mapping

NVM! I figured it out. Wow.
5. ## Preparation for Calculus

If you want you can download calculus class podcasts from UCSD or UCB, just google that. My favorite calculus book was the Hughes-Hallett book from the Wiley publishers. It is a very simple book for single and multivariable calculus. If you are a mature student I would suggest doing your best to solve a problem by reading each chapter carefully. A subscription to *******.com might help to check your answers and make sure you understand the material, but if you cheat and just copy answers instead of working problems you are bound to fail. Calculus can actually be a whole lot of fun believe it or not. Good luck!
6. ## Cell and Molecular Biology Lab

My professor hasn't been very helpful and I need some help with this. You wish to perform a restriction digest in a 20 microliter volume. Your DNA is .60 micrograms/microliter and you wish to digest 6.0 micrograms. Your restriction enzyme is provided as 2U/microliter. What are the appropriate volumes of Water: 10x buffer: DNA: Restriction enzyme: I saw one of the professors watching movies on his computer during his office hours and he said, "read the lab manual" when I asked him for help. He wrote the lab manual, and did a pretty poor job. Can anybody explain to me how to solve this problem? First off, what is the activity? (I think it's the "U" but I don't know what that means). What is the component "buffer"? What would really help me is the equations without the numbers and an explanation of why I'm making the calculations step by step. I really hope someone can help me.
7. ## down syndrome

You could also see Down from something called a Robertsonian translocation. In this case, when the meiocytes divide, some chromosomes are "part 21" and "part 14". If the gamete split leaves one with the Robertsonian 14-21 combination AND the normal 21, upon fertilization the zygote will have 3 copies of 21 INFORMATION, thus resulting in Down syndrome.
8. ## Faster than lightspeed achieved?

Can somebody please tell me what's going on with the faster than light neutrino? For such a big claim, you'd think it would be in the news more...
9. ## Gene mapping

Hi, I found this website to help me figure out gene mapping: http://www.brown.edu/Courses/BI0020_Mill… I know how to figure out the parentals. I just pick out the row of phenotypes that are in greatest number. That's the 417 and 430 right? However, how do I know which numbers (this under "gene mapping-an example) will show me the distance between sc and ec, and which ones will show me the distance between vg and ec? i.e. how do I know which numbers I'm plugging into the map distance equation correspond to the distance sc to ec and which ones for vg to ec, how did they choose those!
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