Altered bacteriophage infection of an E.coli cell. - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 02-13-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,406
Threads: 118
Thanked 644 Times in 408 Posts
Reputation: 654
Bacteria Altered bacteriophage infection of an E.coli cell.

During bacteriophage T7 infection of a single E.coli cell, 1000 bacteriophage particles are released. One of these particles contains a fragment of the E.coli chromosome rather than the T7 chromosome. Will this phage be able to inject its DNA into an E.coli cell, and, if so, how many T7 particles will be produced by this cell?

A. Yes, 1000
B. Yes, 100
C. Yes, 1
D. Yes, 0
E. No, 0
__________________
"inflammable means flammable!? What a country."
Reply With Quote Quick reply to this message



  #2  
Old 02-13-2012
USMLE Forums Addict
 
Steps History: Not yet
Posts: 175
Threads: 18
Thanked 63 Times in 48 Posts
Reputation: 73
Default

D........
Reply With Quote Quick reply to this message
  #3  
Old 02-13-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 646
Threads: 52
Thanked 761 Times in 256 Posts
Reputation: 772
Default

A. Yes, 1000
B. Yes, 100
C. Yes, 1
D. Yes, 0
E. No, 0
Reply With Quote Quick reply to this message
 
  #4  
Old 02-13-2012
USMLE Forums Veteran
 
Steps History: Not yet
Posts: 226
Threads: 60
Thanked 29 Times in 23 Posts
Reputation: 39
Default

a but not sure and if d please need explanation as it says fragment of e.coli , which mean bacteriophage still keeps its DNA intact
Reply With Quote Quick reply to this message
  #5  
Old 02-14-2012
USMLE Forums Addict
 
Steps History: 1 + CK
Posts: 124
Threads: 27
Thanked 35 Times in 21 Posts
Reputation: 55
Default explanation anyone

i don't get it....
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message
  #6  
Old 02-14-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,406
Threads: 118
Thanked 644 Times in 408 Posts
Reputation: 654
Default

Quote:
Originally Posted by mbbs2010 View Post
A. Yes, 1000
B. Yes, 100
C. Yes, 1
D. Yes, 0
E. No, 0
could you explain please?
__________________
"inflammable means flammable!? What a country."
Reply With Quote Quick reply to this message
  #7  
Old 02-14-2012
USMLE Forums Veteran
 
Steps History: Not yet
Posts: 270
Threads: 34
Thanked 223 Times in 119 Posts
Reputation: 233
Default

What's the explanation???

It says the original DNA is still there...don't get it.
Reply With Quote Quick reply to this message
  #8  
Old 02-14-2012
Hitman's Avatar
USMLE Forums Master
 
Steps History: Not yet
Posts: 928
Threads: 17
Thanked 539 Times in 375 Posts
Reputation: 549
Default

Quote:
Originally Posted by khushi.chahal View Post
During bacteriophage T7 infection of a single E.coli cell, 1000 bacteriophage particles are released. One of these particles contains a fragment of the E.coli chromosome rather than the T7 chromosome. Will this phage be able to inject its DNA into an E.coli cell, and, if so, how many T7 particles will be produced by this cell?

from the Qs its clear that the bacteriophage has fragment of the E.coli chromosome rather than the T7 chromosome ........

now the Qs saysthat this bacteriophage inject its DNA into an E.coli cell, but now its DNA refers to the Ecoli dna rather then T7 as it no longer has T7 but it can still inject its dna into bacteria so Yes ... now it inserts Ecoli dna instead of T7 so no T7 will be formed ........ so ans = D. Yes, 0 .............
Reply With Quote Quick reply to this message
The above post was thanked by:
Dr.NickRiviera (02-15-2012)
  #9  
Old 02-14-2012
USMLE Forums Veteran
 
Steps History: Not yet
Posts: 270
Threads: 34
Thanked 223 Times in 119 Posts
Reputation: 233
Default

oh boy...I didn't read the question properly...it clearly says e.coli rather than T7. These mistakes kill me on question blocks.
Reply With Quote Quick reply to this message
  #10  
Old 02-14-2012
USMLE Forums Master
 
Steps History: Not yet
Posts: 590
Threads: 8
Thanked 239 Times in 192 Posts
Reputation: 249
Default

Quote:
Originally Posted by Hitman View Post
from the Qs its clear that the bacteriophage has fragment of the E.coli chromosome rather than the T7 chromosome ........

now the Qs saysthat this bacteriophage inject its DNA into an E.coli cell, but now its DNA refers to the Ecoli dna rather then T7 as it no longer has T7 but it can still inject its dna into bacteria so Yes ... now it inserts Ecoli dna instead of T7 so no T7 will be formed ........ so ans = D. Yes, 0 .............
Thanks for the explanation!
I was confused at first...
Reply With Quote Quick reply to this message



Reply

Tags
Microbiology-, Step-1-Questions

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
E. coli septisemia in Infant sayid USMLE Step 1 Buzzwords 1 09-11-2011 07:13 AM
Bacteriophage Infection and Calculation! Amenah USMLE Step 1 Forum 3 08-08-2011 02:11 PM
Medication that caused altered mental status! aghammoud85 USMLE Step 2 CK Forum 6 06-01-2011 03:19 PM
E. coli Mnemonic Seetal USMLE Step 1 Mnemonics 4 03-28-2010 10:23 PM
E. coli Virulence factors DrSeddik USMLE Step 1 Bits & Pieces 0 11-30-2009 01:12 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)