Edexcel B3 unofficial markscheme 19th June 2017

what do you guys predict the grade boundary to be?

Restriction enzyme
Ligases enzyme
Sticky ends
Vector
Infection of plant
Incorporation of DNA into plant
I also mentioned crown galls
What did u mention?

Did anyone get the sacchromyces cervisiae for the yeast question?

I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants

Did anyone get the sacchromyces cervisiae for the yeast question?

I wrote that there's a 25% of a child with the disease and 50% chance of a boy with the disease. I put both.

i'm sure

Restriction enzyme
Ligases enzyme
Sticky ends
Vector
Infection of plant
Incorporation of DNA into plant
I also mentioned crown galls
What did u mention?

I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants

I thought you didnt have to write about the enzymes and gene mixing because it already said in the question that the gene was taken out and put into the plasmid which produces a toxin so all i wrote about was that plant leaf discs are infected with it and grow into plants which each contain the toxin making gene and the plasmid acts as a vector when creating the transgenic plants

Technically yes ur correct I just wrote it to ensure I didn't miss easy marks, I mentioned all the stuff u said to I.E. infection of plants to incorporate gene into plant and crown gall and how it can be used as a vector, I used agrobacterium tumfacians as an example

Everyone in my school got 24 but to be honest, they didn't make it clear as to whether the 0.925% and 0.625% was of the entire 16,000 or out of the two 8,000 groups

Yeah that's right, the primary response bit was mentioning first infection of pathogen in body, and an immune response is formed as lymphocytes divide and antibodies bind to the antigen and destroy the pathogen, then memory lymphocytes are in the blood.
A rapid secondary response is triggered with 2nd infection due to the memory lymphocytes which produce a rapid response of lots of antibodies to destroy the pathogen, most likely before symptoms can be felt. I don't think there was anything else to say to get 6/6?

I wrote sacchromyces but not cervisiae. Do you think I will still be able to get the mark?

It asked for the difference between the two groups, and if you don't half it you're assuming both groups has 16000 people rather than 8000

Thankyou - that's what I put!

It asked for the difference between the two groups, and if you don't half it you're assuming both groups has 16000 people rather than 8000

Would i get credited for also mentioning the toxin gene of bacillus thuringiesis