INTERNATIONAL AS BIOLOGY BL02 (9610) Unit 2 Biological Systems and Disease Mark scheme

INTERNATIONAL AS BIOLOGY BL02 (9610) Unit 2 Biological Systems and Disease Mark scheme January 2021 Version: 1.0 Final *211XBL02/MS* MARK SCHEME – INTERNATIONAL AS BIOLOGY – BL02 – JANUARY 2021 2 Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates participate in and is the scheme which was used by them in this examination. The standardisation process ensures that the mark scheme covers the students’ responses to questions and that every associate understands and applies it in the same correct way. As preparation for standardisation each associate analyses a number of students’ scripts. Alternative answers not already covered by the mark scheme are discussed and legislated for. If, after the standardisation process, associates encounter unusual answers which have not been raised they are required to refer these to the Lead Examiner. It must be stressed that a mark scheme is a working document, in many cases further developed and expanded on the basis of students’ reactions to a particular paper. Assumptions about future mark schemes on the basis of one year’s document should be avoided; whilst the guiding principles of assessment remain constant, details will change, depending on the content of a particular examination paper. Further copies of this mark scheme are available from Copyright information OxfordAQA retains the copyright on all its publications. However, registered schools/colleges for OxfordAQA are permitted to copy material from this booklet for their own internal use, with the following important exception: OxfordAQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third party even for internal use within the centre. Copyright © 2021 Oxford International AQA Examinations and its licensors. All rights reserved. MARK SCHEME – INTERNATIONAL AS BIOLOGY – BL02 – JANUARY 2021 3 Question Marking guidance Mark Comments 01.1 1. Thick/muscular wall to withstand high pressure (at systole/when LV contracts); 2.(Thick) elastic tissue to stretch and recoil OR to maintain blood pressure/even out surges; 3.Valve to prevent backflow (when LV relaxes/diastole); 4. Wide lumen to carry large volume of blood (with little resistance); 3 max Question Marking guidance Mark Comments 01.2 4200;; 2 Allow 4236 for 1 mark Allow 70.6 100 × 6000 for 1 mark Question Marking guidance Mark Comments 01.3 Large lumen; 1 Question Marking guidance Mark Comments 01.4 To allow (metabolic) exchange; 1 Allow suitable named substance(s) Question Marking guidance Mark Comments 01.5 1. Small intestine/ileum; 2. (Pores would) allow large molecules to pass through OR (Pores would) allow faster movement; 2