Extended Response Higher Biology

Types of Questions There are two types of ER questions, structured and unstructured. On your exam you will be asked to do 1 of each All questions are worth 10 marks but the different types are assessed differently

Strategy Start with a plan List as many RELEVANT points as you can think of under headings (if given) Put your points in a sensible order Write into a coherent paragraph Check your grammar – if it doesn’t make sense you won’t get the mark even if we ‘know what you mean’ You will be awarded 1 mark for each acceptable point. Aim for 1.5 points per mark – there will be lots of things that aren’t going to be worth a mark

Structured These questions are divided into sections and marks are awarded to each section. Example: Discuss transport in plants under the following headings: Transport of food (5) Transport of water and dissolved minerals (5) This means that you can get a MAXIMUM of 5 marks per section. You would aim to give 7 or 8 relevant points for each section. These need to be written in sentences to form a paragraph.

Unstructured These questions are more open and you will be awarded just 8 marks for the points you make. Additionally 1 mark will be awarded for relevance. this means you must not include points that don’t answer the question To get this mark you need AT LEAST 4 marks from your points The last mark is for coherence – your answer must be in the form of a sensible paragraph Example: Discuss transport in plants (10)

Tips Make a plan – even if you think you know the answer well 2. Include labelled diagrams wherever possible 3. Writing must be as concise as possible. Avoid trying to say the same thing in different ways. 4. Include as much detail as you can – this is where the marks come from.

Discuss transport in plants (10) Try this one! Discuss transport in plants (10)

Discuss transport in plants (10) Materials in plants can be transported by phloem or xylem. Phloem transports dissolved glucose (food). This food is transported from where it is produced in the leaves all around the plant. Phloem vessels are made of living cells.

Water and dissolved minerals are transported in the xylem Xylem is made of hollow dead tubes that run from the roots to all parts of the plant Water can only travel in an upward direction through xylem Xylem tubes are strengthened by rings of lignin

From the 2008 paper Write notes on: (i) the control of lactose metabolism in E. coli; (6) (ii) phenylketonuria in humans. (4)

Marking Instructions from the SQA site 1. the regulator gene produces/codes for repressor (molecule/substance/ protein) NOT gene* 1 2. lactose is the inducer 1 3. lactose binds with repressor (molecule/substance/protein) 1 4. in the presence of lactose operator switches on structural gene 1 5. in the presence of lactose/so enzyme/B galactosidase made OR structural gene codes for enzyme NOT wrong enzyme 1 6. in absence of lactose repressor (molecule/substance/protein) binds to operator 1 7. in the absence of lactose/so operator cannot switch on/switches off structural gene 1 8. in the absence of lactose/so/when structural gene switched off enzyme not made 1 9. (E. coli) conserves resources/energy OR does not waste energy NOT only made when required 1 Maximum 6

* Note – repressor gene – penalise only once (ii) 10. phenylalanine is involved in a metabolic pathway 1 OR show in diagram of pathway 11. each step (in a metabolic pathway) is controlled by an enzyme 1 12. PKU is caused by mutation (of a gene)/inborn error of metabolism and leads to an altered/absent enzyme 1 13. phenylalanine builds up/is not broken down/converted to a toxic compound/phenylpyruvate 1 14. damage to nervous system development/description, eg brain damage/ 1 mental retardation/learning difficulties Maximum 4 Total (10)