Cell Wall and Mark Schemes Essay

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Pages: 15

GCE AS
Biology
January 2008

Mark Schemes
Issued: April 2008

NORTHERN IRELAND GENERAL CERTIFICATE OF SECONDARY EDUCATION (GCSE)
AND NORTHERN IRELAND GENERAL CERTIFICATE OF EDUCATION (GCE)
MARK SCHEMES (2008)
Foreword
Introduction
Mark Schemes are published to assist teachers and students in their preparation for examinations.
Through the mark schemes teachers and students will be able to see what examiners are looking for in response to questions and exactly where the marks have been awarded. The publishing of the mark schemes may help to show that examiners are not concerned about finding out what a student does not know but rather with rewarding students for what they do know.
The Purpose of Mark Schemes
Examination papers are set and revised by teams of examiners and revisers appointed by the
Council. The teams of examiners and revisers include experienced teachers who are familiar with the level and standards expected of 16- and 18-year-old students in schools and colleges.
The job of the examiners is to set the questions and the mark schemes; and the job of the revisers is to review the questions and mark schemes commenting on a large range of issues about which they must be satisfied before the question papers and mark schemes are finalised.
The questions and the mark schemes are developed in association with each other so that the issues of differentiation and positive achievement can be addressed right from the start. Mark schemes therefore are regarded as a part of an integral process which begins with the setting of questions and ends with the marking of the examination.
The main purpose of the mark scheme is to provide a uniform basis for the marking process so that all the markers are following exactly the same instructions and making the same judgements in so far as this is possible. Before marking begins a standardising meeting is held where all the markers are briefed using the mark scheme and samples of the students’ work in the form of scripts. Consideration is also given at this stage to any comments on the operational papers received from teachers and their organisations. During this meeting, and up to and including the end of the marking, there is provision for amendments to be made to the mark scheme.
What is published represents this final form of the mark scheme.
It is important to recognise that in some cases there may well be other correct responses which are equally acceptable to those published: the mark scheme can only cover those responses which emerged in the examination. There may also be instances where certain judgements may have to be left to the experience of the examiner, for example, where there is no absolute correct response – all teachers will be familiar with making such judgements.
The Council hopes that the mark schemes will be viewed and used in a constructive way as a further support to the teaching and learning processes.

iii

CONTENTS
Page
AS 1: Module 1

1

AS 2: Module 2

7

AS 3A: Module 3A

13

v

ADVANCED SUBSIDIARY (AS)
General Certificate of Education
January 2008

Biology
Assessment Unit AS 1 assessing Module 1: Cell Biology
[ASB11]
TUESDAY 15 JANUARY, AFTERNOON

MARK
SCHEME

ASB1W8

3310.01

1

/ denotes alternative points
; denotes separate points
Comments on mark values are given in bold

AVAILABLE
MARKS

Section A
1

3

[4]

(a) Facilitated diffusion involves protein carriers, while diffusion does not; both involve the movement of substances along the concentration gradient/passive/does not involve energy expenditure;

[2]

(b) Ascorbic acid moves through the protein component of the membrane; since this contains a hydrophilic (water-soluble) core/either by active transport or facilitated diffusion; calciferol moves across the lipid component of the membrane; since it is soluble in lipid;

2

Interphase synthesis/S mitosis/karyokinesis
metaphase…