Exam (elaborations)
EDEXCEL IAL BIOLOGY UNIT 3 QUESTIONS
- Course
- Institution
EDEXCEL IAL BIOLOGY UNIT 3 QUESTIONS
[Show more]
Content preview
EDEXCEL IAL BIOLOGY UNIT 3 QUESTIONSDescribe the difference between a semi-quantitative and a quantitative test - Answers-
A semi-quantitative test gives {an estimate / a range} of the concentration of a
substance
A quantitative test determines the exact concentration of a substance
Describe how you could test for protein - Answers- addition of {biuret reagent / base
and copper sulfate}
it turns to a purple colour
Some of the total nitrogen content of a food is not due to protein. Give one other type of
organic molecule that contains nitrogen. - Answers- nucleic acids, lipids, amino acids,
ATP
Describe how a suitable pH could be decided on experimentally. - Answers- carry out
the experiment described at constant {temperature / substrate / enzyme concentration}
At a range of pHs (controlled by buffers) choose the pH which gives a time which is not
{too short / too long} (for practicality)
Describe a safe method to prepare and examine the structure of human cheek cells. -
Answers- bud into disinfectant/sterile/fresh bud/toothpick/wear gloves/ goggles/safe use
of microscope/slides/careful use of bud/stain to prevent injury
use of cotton bud, followed by use of stain/dye, place cells (on slide) under coverslip,
use of high power of microscope
State two differences you would observe between a plant cell and a human red blood
cell when using a light microscope. - Answers- plant cell has nucleus, RBC does not
allow one mark if both statements correct but not comparative
plant has /vacuole/large(r) vacuole/chloroplasts/cell wall/regular shape unlike RBC
Explain the role of the pollen tube in plant reproduction. - Answers- it {carries /
transports} the male gametes / nuclei / generative nucleus to the ovule / micropyle /
ovary / ovum / female gamete to {fuse with / fertilise} {ovum / egg (cell) / female gamete
/ female nucleus / polar nuclei digest tissue of style
Explain why pollen tubes grow in the same direction from the stigma, after pollination. -
Answers- the tubes grow towards the {micropyle / ovule / ovary / ovum / female gamete}
{due to chemicals (released by the embryo sac) / it is chemotropic}
Explain why changes in temperature will affect an investigation. - Answers- it involves
{enzymes / (chemical) reactions} and enzymes / (chemical) reactions are affected by
temperature
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller GEEKA. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
76799 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now