Questions in AS and A2 Biology are designed to assess a number of assessment objectives. For the written papers in AS Biology the main objectives being assessed are:
• recall of facts, terminology and inter-relationships
• understanding of principles and concepts and their social and technological applications and implications
• explanation and interpretation of principles and concepts
• interpreting information given as diagrams, photomicrographs, electron micrographs tables, data, graphs, passages
• application of knowledge and understanding to familiar and unfamiliar situations.

In order to assess these abilities and skills a number of different types of question are used.

In A2 Level Biology unit tests these include short answer questions, structured questions requiring both short answers and more extended answers, together with free-response and open-ended questions.

Short-answer questions
A question will normally begin with a brief amount of stimulus material. This may be in the form of a diagram, data or graph. A short-answer question may begin by testing recall. Usually this is followed up by questions which test understanding.

Often you will be required to analyse data. Short answer questions normally have a space for your responses on the printed paper. The number of lines is a guide as to the amount of words you will need to answer the question. The number of marks indicated on the right side of the papers shows the number of marks you can score for each question part. Here are some examples. (The answers are shown in blue).

The diagram below shows a gastric pit.

(a) (i) Label cell X (1)
oxyntic cell
(ii) What is secreted by cell X? (1)
hydrochloric acid
(b) (i) Protein enters the stomach. What must take place before the hydrolysis of the protein begins? (2)
Hydrochloric acid acts on pepsinogen, to produce pepsin
(ii) After the protein has been hydrolysed, what is produced? (1)
polypeptides

Structured questions
Structured questions are in several parts. The parts are usually about a common context and they often progress in difficulty as you work through each of the parts. They may start with simple recall, then test understanding of a familiar or unfamiliar situation. If the context seems unfamiliar the material will still be centred around concepts and skills from the Biology specification. (If a student can answer questions about unfamiliar situations then they display understanding rather than
simple recall.)

The most difficult part of a structured question is usually at the end. Ascending in difficulty, a question allows a candidate to build in confidence. Right at the end technological and social applications of biological principles give a more demanding challenge. Most of the questions in this book are structured questions. This is the main type of question used in the assessment of both AS and A2 Biology.

The questions set at A2 Level are generally more difficult than those experienced at AS Level. A2 includes a number of higher level concepts, so can be expected to be more difficult. The key advice given by this author is:

• Give your answers in greater detail,

Example: Why does blood glucose rise after a period without food?
Answer: The hormone glucagon is produced X not enough for credit!). The hormone glucagon is produced which results in glycogen breakdown to glucose.

• Look out for questions with a ‘sting in the tail'. A2 questions structured questions are less straight forward, so look for a ‘twist'. This is identified in the example below.

When answering structured questions, do not feel that you have to complete a question before starting the next. Answering a part that you are sure of will build your confidence. If you run out of ideas go on to the next question. This will be more profitable than staying with a very difficult question which slows down progress, return at the end when you have more time.

Extended answers
In A2 and AS Biology questions requiring more extended answers will usually form part of structured questions. They will normally appear at the end of a structured question and will typically have a value of four to twenty marks. Longer questions are allocated more lines, so you can use this as a guide as to how many points you need to make in your response. Often for an answer worth ten marks the mark scheme would have around 12 - 14 creditable answers. You are awarded up to
the maximum, ten marks, in this instance.

Depending on the awarding body, longer, extended questions may be set. These are often open response questions. These questions are worth up to twenty marks for full credit. Extended answers are used to allocate marks for the quality of communication.

Candidates are assessed on their ability to use a suitable style of writing, and organise relevant material, both logically and clearly. The use of specialist biological terms in context is also assessed. Spelling, punctuation and grammar are also taken into consideration. Here is a longer response question.

Question
Urea, glucose and water molecules enter the kidney via the renal artery. Explain what can happen to each of these substances.

In this question one mark is available for communication. (Total 13 marks)

Urea, glucose and water molecules can pass through the blood capillaries in a glomerulus. (1) This is as a result of ultrafiltration, (1) as the podocytes of Bowman’s capsule cause a pressure build up.(1)

The three substances pass down the proximal tubule. 100% glucose is reabsorbed in the proximal tubule (1) so is returned to the blood. Carrier proteins on the microvilli aided by mitochondria, actively transport the glucose across the cells. (1) Around 80% of the water is reabsorbed in the proximal tubule. (1) Remaining water and urea molecules continue through the loop of Henlé. Urea
continues through the distal tubule to the ureter then the bladder. (1)

More water can be reabsorbed with the help of the countercurrent multiplier. (1) The ascending limb of the loop of Henlé (1) actively transports Na+ and Cl– ions into the medulla. (1) Water molecules leave the collecting duct by osmosis due to the ions in the medulla. (1) Cells of the collecting duct are made more permeable to water by the hormone, ADH. (1) Some water molecules pass into
the capillary network and having been successfully reabsorbed (1) Some water molecules continue down the ureters and into the bladder. (1)

Communication mark (1)

Remember that mark schemes for extended questions often exceed the question total, but you can only be awarded credit up to the maximum. In response to this question the candidate would be awarded the maximum of 13 marks which included one communication mark. The candidate gave two more creditable responses which were on the mark scheme, but had already scored a maximum. Try to give more detail in your answers to longer questions. This is the key to A2 success.