Search found 31 matches

by jsmith613
Sun Oct 06, 2013 11:10 pm
Forum: Genetics
Topic: Telomere and DNA replication
Replies: 0
Views: 3054

Telomere and DNA replication

After the first division of a particular cell, both daughter cells will contain DNA with one parent strand and one daughter strand 5'_________3'(parent strand - complete telomere) 3'_________5'(daughter stand) The daughter stand is shorter owing to lost telomeres. I have discoerved, from private res...
by jsmith613
Mon Apr 09, 2012 12:24 pm
Forum: Genetics
Topic: Gene Technology
Replies: 1
Views: 3178

Gene Technology

I have attached a question from a past paper that is confusing me. The answer on the MS is (white) blue lilac white I have absolutely no idea why the second and third are correct. I have presumed that with no enzyme there will be no colour change so the petals will remain white (as per the mark sche...
by jsmith613
Sun Mar 25, 2012 8:20 pm
Forum: Genetics
Topic: Sequencing Primers
Replies: 4
Views: 5781

Sequencing Primers

Gene sequencing involves the use of primers BUT how do we know which primers to use? How did the first ever scientists find out which primer was needed for the sequencing of the very first gene (when we knew NOTHING about any other gene)?
by jsmith613
Sat Feb 25, 2012 6:45 pm
Forum: General Discussion
Topic: Transcription
Replies: 3
Views: 1792

Re: Transcription

JackBean wrote:
jsmith613 wrote:So the DNA base sequence that CODES is on the sense strand

are you sure?


yes??
by jsmith613
Fri Feb 24, 2012 4:50 pm
Forum: General Discussion
Topic: Transcription
Replies: 3
Views: 1792

Transcription

Link: m Look at Q1bii) "Give the DNA base sequence that codes for threonine" -------- So the DNA base sequence that CODES is on the sense strand mRNA is complementary to the anti-sense strand and identical to the sense strand (except T is replaced by U) So the codons on mRNA should be the ...
by jsmith613
Tue Feb 07, 2012 8:52 pm
Forum: General Discussion
Topic: Menstural cycle
Replies: 0
Views: 1240

Menstural cycle

It seems (from the book and several websites) that initially, at low conc. oestrogen inhibits FSH and LH. As the follicle matures and oestrogen levels rise FSH and LH are stimulated. My questions are 1) If low levels of oestrogen inhibit FSH (and LH) how can the follicles mature (they are matured by...
by jsmith613
Sun Dec 18, 2011 12:29 pm
Forum: General Discussion
Topic: Electron transport chain
Replies: 1
Views: 1353

Electron transport chain

http://store.aqa.org.uk/qual/gceasa/qp- ... -JUN06.PDF

Look at Q7biii) "A further investigation..."

Please can someone explain why the order is
Y, X, W, Z

thansk
by jsmith613
Sat Dec 03, 2011 4:54 pm
Forum: General Discussion
Topic: Succession
Replies: 6
Views: 6134

Re: Succession

oooh
thanks so much 4 this!
by jsmith613
Fri Dec 02, 2011 2:43 pm
Forum: General Discussion
Topic: Succession
Replies: 6
Views: 6134

Re: Succession

surely the graph is asking for EXPLANATIONS for the different NOT EXPLANATIONS for what could happen if trees went?
by jsmith613
Thu Dec 01, 2011 6:39 pm
Forum: General Discussion
Topic: Succession
Replies: 6
Views: 6134

Re: Succession

Here is the exact marking guide for 3cii) a lot of species on dead trees endangered cf live trees; there are fewer dead trees (than previously); reason for dead trees being removed; a lot of beetles on dead trees endangered cf live trees; dead trees a habitat for more species, so more affected; by l...
by jsmith613
Thu Dec 01, 2011 7:18 am
Forum: General Discussion
Topic: Succession
Replies: 6
Views: 6134

Re: Succession

(c) The graph shows the number of species from three insect groups which are thought to be extinct or close to extinction in three different habitats in the UK. (i) Farming often produces temporary areas of bare soil on which colonisation may start, but these data show that many species of insect as...
by jsmith613
Wed Nov 30, 2011 10:31 pm
Forum: General Discussion
Topic: Succession
Replies: 6
Views: 6134

Succession

m I am struggling with question 3 (here is the mark scheme but it makes little sense) m I understand a and b When it comes to question ci) and cii) I am not entirely sure what they way I for sure don't understand what they want for 3cii) Here is my intepretation of 3ci) Succession would be interrupt...