100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
OCR A Level Biology A H420/03 Unified biology June 2024 Exam Question paper Authentic Marking Scheme Attached £7.74   Add to cart

Exam (elaborations)

OCR A Level Biology A H420/03 Unified biology June 2024 Exam Question paper Authentic Marking Scheme Attached

1 review
 60 views  3 purchases
  • Module
  • OCR A-LEVEL BIOLOGY
  • Institution
  • OCR A-LEVEL BIOLOGY

OCR A Level Biology A H420/03 Unified biology June 2024 Exam Question paper Authentic Marking Scheme Attached

Preview 4 out of 46  pages

  • May 29, 2024
  • 46
  • 2023/2024
  • Exam (elaborations)
  • Questions & answers
  • OCR A-LEVEL BIOLOGY
  • OCR A-LEVEL BIOLOGY

1  review

review-writer-avatar

By: michellegrambow2 • 2 weeks ago

reply-writer-avatar

By: RevisionKing • 2 weeks ago

Thank you For Your Review You Can Hit Me UP If u need More Exams Especially now we are nearing the The Exam Period HMU Via Inbox Or E m ail hybridgrades101 at G Mail

avatar-seller
Oxford Cambridge and RSA

Friday 24 June 2022 – Morning
A Level Biology A
H420/03 Unified biology
Time allowed: 1 hour 30 minutes

You can use:
* 9 0 9 6 2 9 8 3 3 0 *




• a ruler (cm/mm)
• a scientific or graphical calculator




* H 4 2 0 0 3 *




Please write clearly in black ink. Do not write in the barcodes.

Centre number Candidate number


First name(s)

Last name


INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.

INFORMATION
• The total mark for this paper is 70.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 24 pages.

ADVICE
• Read each question carefully before you start your answer.




© OCR 2022 [601/4260/1] OCR is an exempt Charity
DC (ST/CT) 301309/5 Turn over

, 2
Answer all the questions.

1 The heart can be affected by a variety of disorders, some of which involve the immune system.

(a) Fig. 1.1 shows the roles of three different types of antibody, labelled R, S and T.

R S
Pathogen

Pathogen
Antibody Receptor




White
Antibody
blood cell




T

Antibody




Harmful molecules
released by pathogens
Fig. 1.1

State the names of the three different types of antibody shown in Fig. 1.1.

R ...............................................................................................................................................

S ...............................................................................................................................................

T ...............................................................................................................................................
[3]

(b) A condition called rheumatic heart disease can occur when a person’s antibodies attack
antigens on their own heart cells.

State the name of the type of disease represented by rheumatic heart disease.

.............................................................................................................................................. [1]




© OCR 2022

, 3
(c) Fig. 1.2 shows two electrocardiogram (ECG) traces:
• an ECG of normal heart activity
• an ECG of a person with a type of heart disease




Normal




Heart
disease




Fig. 1.2

Describe how the ECG trace of the heart with heart disease is different from the ECG trace
of a normal heart.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [2]




© OCR 2022 Turn over

, 4
(d) Gene therapy is a possible future treatment for heart disease.

The AC6 gene codes for one form of the enzyme adenylyl cyclase.

Clinical trials have tested the effect of increasing levels of the AC6 gene in heart cells.

(i) Suggest how using gene therapy to increase levels of the AC6 gene in heart cells may
improve heart function.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

(ii) State one method for inserting the AC6 gene into the heart cells during gene therapy.

...................................................................................................................................... [1]

(iii) The results from gene therapy trials are published in peer-reviewed journals.

State why the results from gene therapy trials are published in journals.

...........................................................................................................................................

...................................................................................................................................... [1]




© OCR 2022

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

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

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

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 RevisionKing. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £7.74. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

73091 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling
£7.74  3x  sold
  • (1)
  Add to cart