OCR Biology A Module 6 content, specifically on the specification point 6.1.1 [a] from the H420 OCR specification. It covers "Types of Mutations." This can be used as active recall during exam season and generally over the two years in Sixth Form. Notes were collated from the OCR Biology A textbook...
Biology - Question and Answer/Active recall
A-level
OCR Module 6
Chapter 1: Cellular Control
Content:
6.1.1 (a) Types of mutations
6.1.1 (b) Regulatory mechanisms
6.1.1 (c) Homeobox genes
6.1.1 (d) The importance of mitosis and apoptosis
6.1.1 (a) Types of mutations
1. what is a mutation?
o a change in the sequence of base pairs in a DNA molecule that
may result in an altered polypeptide
2. when do mutations not have an affect on us?
o the genetic code is degenerate so several different triplets
often code for the same amino acid. Therefore, the mutation
may not alter the actual polypeptide but only slightly alter the
STRUCTURE, but the function remains the same
o mutations (many) also occur in non-coding parts of the DNA
so have no effect on the amino acid sequence at all
3. what are the three main ways that a mutation in the DNA base
sequence can occur?
o insertion
o deletion
o substitution
o …of one or more nucleotides
4. what is an insertion mutation?
o when a nucleotide is randomly inserted into the DNA
sequence
5. how does an insertion mutation cause change to the DNA sequence?
o it changes the amino acid it would have been coded for by the
original base triplet because a new different triplet of bases is
created
o insertion mutation may also have a knock-on effect by
changing the triplets further on in the DNA sequence
(frameshift mutation)
6. what is a deletion mutation?
o a mutation that occurs when a nucleotide is randomly deleted
from the DNA sequence
7. what are the similarities of insertion and deletion mutation?
o like insertion, a deletion mutation changes the amino acid that
would have originally been coded for
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 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 amnamansoor. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.36. You're not tied to anything after your purchase.