Biology Exam Paper Essay

Matriarchal Centre Number For Examiner’s Use Candidate Number Surname Other Names Examiner’s Initials Candidate Signature Question General Certificate of Secondary Education Higher Tier January 2014 Mark 2 3 Additional Science M (modular) MUMBLE 4 Unit Biology 82 5 Biology M (modular) Wednesday 8 January 2014 9. 00 am to 10. 00 am 6 7 TOTAL For this paper you must nave: 0 a ruler. You may use a calculator. Time allowed 0 1 hour Instructions 0 Use black ink or black ball-point pen. 0 Fill in the boxes at the top of this page. 0 Answer all questions. You must answer the questions in the spaces provided.

Do not write outside the box around each page or on blank pages. 0 Do all rough work in this book. Cross through any work you do not want to be marked. Information The marks for questions are shown in brackets. 0 The maximum mark for this paper is 60. 0 You are expected to use a calculator where appropriate. 0 You are reminded of the need for good English and clear presentation in your answers. 0 Question 3 should be answered in continuous prose. In this question you will be marked on your ability to: use good English – organism information clearly – use specialist vocabulary where appropriate.

The students: set up the apparatus shown in the diagram Test tube Beaker Water at 5 co 5 com of 1% starch solution (04) 1 corn of 0. 01% enzyme solution left both test tubes in the beaker of water at 5 co for 10 minutes mixed the contents of the two test tubes put the test tube containing the mixture back into the beaker of water at 5 co removed a small sample of the mixture at 1 minute intervals tested each sample for starch timed how long it took to digest all the starch updated each of the above steps at six different temperatures.

Give two control variables in this investigation. 2 (b) Why did the students keep the starch solution and the enzyme solution in the beaker of water for 10 minutes before mixing them? Question 2 continues on the next page (05) The table shows the students’ results. Temperature in co Time taken to digest starch in minutes 15 11 25 35 45 55 65 no reaction Why did the enzyme take longer to digest the starch at 5 co than at 25 y did the enzyme not digest the starch a (06) The students concluded that the enzyme worked best at 40 co. This is not a valid conclusion.

Describe how the students could improve the investigation to find out the temperature at which the enzyme works best. (5 marks) 13 Turn over for the next question (07) 8 (08) 9 In this question you will be assessed on using good English, organizing information clearly and using specialist terms where appropriate. Plants grow well only if the conditions are right. What environmental factors are needed to help plants to grow? Give a reason why each factor is needed. (6 marks) (09) 10 Long-distance runners may eat a diet high in carbohydrate.

This diet increases the amount of glycogen stored in their muscles. The process is called ‘carbohydrate loading. What is glycogen? An athlete did the following: Step one: ate a diet high in carbohydrate for 3 weeks and did his normal training Step two: did a 2-hour run at the end of the 3 weeks. The athlete then repeated steps one and two, but ate a diet low in carbohydrate. Graph A shows how the concentrations of blood glucose changed during each 2-hour run. Graph B shows how fast the athlete was able to run each time.