Welcome to
AS and A2 Biology
Introduction, Information
And Summer Assignment
Contents:
1) Course overview
2) Unit 1 Specification
3) Recommended books
4) Key Exam Words Glossary
5) How Science Works Key Word Glossary
6) Summer task instructions
7) Questions
For your information:
Notes, handouts, tasks need to be filed lesson by lesson.
Folders will be checked by every fortnight
Homework will be given weekly, it may involve:
 Independent research task
 Investigation/ practical write-up
 Analysis of data
 Exam question
 Essay
You will be expected to catch up on work that is missed, including
homework.
Text Books:
AQA AS Biology: Recommended AS Biology book
Biology for You: A general textbook for AS & A2
Note: They contain a lot of information that we
don’t use.
Both of these books can be ‘hired’ from Science for a refundable £10
Order forms available in Sept 2011.
.
Revision Guides:
CGP Revision guides are useful to summarise work.
They can be purchased through the Science department at a reduced
price.
Order forms available in Sept 2011.
Key Exam Words Glossary:
What am I being asked to do?
In most questions there will be a keyword which guides you towards the
required approach. In order to successfully answer the question you will
need to highlight and interpret these keywords, targeting your writing
accordingly.
Here are some of the most common key words and a suggested meaning
for each:
Account for
Explain the cause of
Analyse
Separate down into its component parts and show how they inter
relate with each other
Put notes on (usually a diagram)
Estimate the value of, looking at both the positive and negative
attributes
The only requirement is a numerical answer, expressed in
appropriate units.
The additional instruction, “Show your working”, will be used if
details or methods are required.
To make critical or explanatory notes/observations
Point out the differences and the similarities. This question needs
to be carefully organised to produce a logical answer.
Point out the differences only and present the results in an orderly
fashion.
This can be used in one of two ways.
1) The translation of information from one form to another,
For example, “Describe the shape of the curve” requires a
translation of information from one form to another.
This involves a description of the shape of the curve, relating the
trends or patterns to key points or values.
2) Giving an account of a process. For example, “Describe an
experiment” means give an account of how such an experiment
should be carried out.
An account of how something should be done by you as a
student working in the context of an A level specification in an
ordinary school or college laboratory (often used when asking
questions about experimental design).
Present arguments for and against the topic in question. In
discussion questions you may also give your opinion.
Annotate
Assess
Calculate
Comment
Compare
Contrast
Describe
“give a
description
of …”
Describe
how you
should…
Discuss
Distinguish
Evaluate
Explain
Give
Give the
evidence
from…
Justify
List
Name/
What is
the name
of…
Outline
Relate
Review
Sketch
Suggest
Summarise
To what
extent….
What is
meant by
Identify the difference between.
Judging the worth of something. Looking at both the positive and
negative attributes (More than just listing advantages and
disadvantages).
The word ‘explain’ means that you have to give a reason or an
interpretation. You have to explain why rather than just define.
E.g. “Explain the curve on a graph” requires biological reasons for
any change of direction or pattern which is evident. It is a good idea
to start answers that require an explanation with “Because…”
A statement or an account of the similarities/ differences between
two or more items is required e.g ‘Give two differences between X
and Y’.
Follow the instructions in the questions.
Marks are always awarded for appropriate references to the
information provided.
Here you will need to present a valid argument about why a specific
theory or conclusion should be accepted.
A number of features or points, often no more than a single word,
with no further elaboration or detail required.
A technical term or its equivalent.
Give the main features or general principles of a subject, omitting
minor details and stressing structure.
EITHER – show how ideas or events are linked into a sequence. OR –
compare or contrast.
To make a survey of, examining the subject critically.
This term refers to the drawing of graphs. “Sketch” requires a
simple estimate of the expected curve, and can be made on ordinary
lined paper. Even in a sketched graph, the axes should be correctly
labelled.
This question may not have a fixed, direct answer. Give a range of
responses. Answers should be based on a general understanding of
biology.
State the main features of an argument, omitting all that is only
partially relevant.
Asks you to justify the acceptance or validity of an argument
stressing the need to avoid complete acceptance.
A statement giving the meaning of a particular term or of a word
used in a comprehension passage. Use of appropriate scientific
terminology.
How Science Works Key Word Glossary
Accuracy
Anomalous
data
Calibration
Causal link
Chance
Confounding
variable
Control
experiment
Control
group
An accurate measurement is one which is close to the true value.
Anomalous data are those measurements that fall outside the
normal, or expected, range of measured values. Variation is a
characteristic of all living organisms, and it is often difficult in
biological investigations to distinguish between data that reflect
this variation and those that are genuinely anomalous. A large
number of readings allows anomalous data to be identified with
greater certainty.
When using a measuring instrument, calibration involves fixing
known points and constructing a scale between these fixed points.
A change in one variable that results from or is caused by a change
in another variable.
Chance is essentially the same as luck. If a coin is tossed in the
air, whether it comes down heads or tails is purely due to chance.
The results of any investigation could have a genuine scientific
explanation but they could be due to chance. Scientists carry out
statistical tests to assess the probability of the results of an
investigation being due to chance.
A confounding variable is one that may, in addition to the
independent variable, affect the outcome of the investigation.
Confounding variables must be kept constant or the investigation
will not be a fair test. In some investigations, ecological
investigations in particular, it is not always possible to keep
confounding variables constant. In such cases, these variables
should be monitored. In this way it may be possible to decide
whether or not the factor concerned affects the outcome of the
experiment. Confounding variables are sometimes referred to as
control variables.
A control experiment is one that is set up to eliminate certain
possibilities. In a well designed investigation, the independent
variable is changed and all confounding variables are kept
constant. The possibility exists, however, that something else
other than the independent variable might have produced the
results that were obtained. A control experiment is one that is
designed to eliminate this possibility.
A control group is one that is treated in exactly the same way as
the experimental group except for the factor that is being
investigated. This allows scientists to make a comparison. It
ensures that the data that are collected are valid because any
Correlation
differences between the results for the experimental group and
those for the control group will be due to a single independent
variable.
A correlation shows that there is a relationship between two
variables, however, it might not be a causal one.
The dependent variable is the variable the value of which is
measured for each change in the independent variable.
Dependent
variable
Double-blind A trial, usually used in the context of medicine, when assessing the
effects of a new drug or treatment on humans. Neither the
trial
patients nor the scientists concerned know which treatment a
particular individual is receiving until after completion of the trial.
This helps to avoid bias and increase the validity of the trial.
Errors
Evidence
Fair test
Hypothesis
Errors cause readings to be different from the true value.
The data or observations that are used to support a given
hypothesis or belief.
A fair test is one in which only the independent variable has been
allowed to affect the dependent variable. A fair test can usually
be achieved by keeping all other variables constant or controlled.
Sometimes known as an experimental hypothesis, this is a possible
explanation of a problem that can be tested experimentally.
The independent variable is the variable for which values are
changed by the investigator.
Independent
variable
A statistical test requires a clear hypothesis to test. It is often
Null
hypothesis difficult to predict what would happen as the result of an
investigation. It is much easier to phrase a hypothesis in terms of
there being no difference or no association. A hypothesis worded
in this way is called a null hypothesis. As the result of carrying out
a statistical test, a decision can be made about whether to accept
or reject this null hypothesis.
Placebo
Precision
A placebo is a dummy pill or injection given to members of a
control group in medical trials. Where a placebo is in the form of a
pill, it should be identical to the pill used with the experimental
group. The only difference should be that that the placebo does
not contain the drug being trialled. The use of placebos helps to
ensure that the data collected from a trial are valid.
Precision is related to the smallest scale division on the measuring
instrument that is being used. A set of precise measurements will
have very little spread about the mean value.
Probability
Protocol
Random
Random
errors
Raw data
Reliability
Probability is the likelihood of an event occurring. It differs from
chance in that it can be expressed mathematically. In statistical
tests, probabilities are usually expressed as a decimal fraction of
one. Thus a probability of 0.05 means that an event is likely to
occur 5 times in every 100.
Once an experimental method has been shown to produce valid and
reliable results, it becomes a protocol used by other scientists.
A random distribution is one that arises as a result of chance.
When distribution investigating, for example, variation in living
organisms, the data collected will only be valid if they have been
collected at random. This avoids observer bias and allows
statistical tests to be used in an analysis of the results of the
investigation.
Random errors occur in an unpredictable way. They may be caused
by human error, faulty technique in taking measurements or by
faulty equipment.
Raw data are instrument readings and other data collected at the
time of the investigation. These data may subsequently be
processed and used to calculate percentages and standard
deviations.
The results of an investigation may be considered reliable if they
can be repeated. If other scientists get the same results, then
the results of the initial investigation are more likely to be
reliable. The reliability of data within a single investigation can be
improved by carrying out repeat measurements.
Systematic
errors
These errors cause readings to be spread about some value other
than the true value. In other words, all the readings are shifted in
one direction from the true value. Systematic errors may occur
when using a wrongly calibrated instrument.
True value
This is the accurate value which would be found if the quantity
could be measured without any errors.
Validity
Data are only valid if the measurements that have been made are
affected by a single independent variable only. They are not valid
if the investigation is flawed and control variables have been
allowed to change or there is observer bias. Conclusions are only
valid if they are supported by valid and reliable data measured to
an appropriate level of accuracy.
Zero errors
Zero errors are caused by instruments that have an incorrect
zero. A zero error may occur when the needle on a colorimeter
fails to return to zero or when a top-pan balance shows a reading
when nothing is placed on the pan.
Summer Assignment:
The following tasks can be completed in any order over the summer
holidays.
Tasks 1 and 2 are to be completed and brought with you to your first AS
Biology lesson in September.
The tasks have been designed to support your transition from GSCE to A
Level Biology.
Task 1:
Read through the specification for Unit 1: Biology & Disease
Highlight key scientific terms e.g.
For each scientific term write an accurate, concise definition and give an
example of this key word. Giving an example of the word in context is
useful for understanding and to aid memory.
The glossary needs to be of a good quality and neatly presented.
It will accompany the course outline and unit 1 specification in the front
of your Biology folder.
Task 2:
Complete exam style questions.
They are GCSE questions to support your transition to A Level Biology.
They have been selected based on the Unit 1 specification.
Task 3:
Look through some Biology based websites. You will find it useful if you
know how to navigate around the sites before the Biology course begins.
www.biomad.com
www.s-cool.co.uk/a-level/biology
www.biologyguide.net/
www.cellsalive.com/
www.healthline.com/
www.innerbody.com/
www.lungsonline.com/
www.newscientist.com/