January 2010 BY1 past paper

HideShow resource information
  • Created by: Ffion
  • Created on: 30-12-12 13:08
Preview of January 2010 BY1 past paper

First 146 words of the document:

Candidate Centre Candidate
Name Number Number
2
GCE AS/A level
1071/01
BIOLOGY/HUMAN BIOLOGY ­ BY1
A.M. TUESDAY, 12 January 2010
1
1 /2 hours
For Examiner's use only
1
Maximum Mark
Question
Mark Awarded
W10 1071 01
1 6
2 6
3 11
4 11
5 12
6 14
7 10
Total 70
INSTRUCTIONS TO CANDIDATES
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet.
INFORMATION FOR CANDIDATES
The number of marks is given in brackets at the end of each question or part-question.
You are reminded of the necessity for good English and orderly presentation in your answers.
The quality of written communication will affect the awarding of marks.
JD*(W10-1071-01)

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Examiner
only
1. Two types of nucleic acid, DNA and RNA are found in cells. Statements in the table, may apply to
DNA, RNA or both. Complete the table by putting a tick () if the statement is true or a cross (×) if
the statement is not true. [6]
DNA RNA
Contains a pentose sugar
Found in the nucleus
Thymine is never present
Consists of a double helix
Molecules short lived
Associated with ribosomes
(Total 6 marks)
2.…read more

Page 3

Preview of page 3

Here's a taster:

Examiner
only
3. The diagram below shows a biosensor that uses the enzyme urease to measure urea in either the
blood or urine.
display
amplifier
transducer/electrode
ammonium ions
NH4+
immobilised urease
partially permeable membrane
3
molecules of
other solutes urea molecules
W10 1071 01
(a) (i) Name one method that could be used to immobilise the urease. [1]
....................................................................................................................................................................................................................
(ii) State three advantages of using immobilised enzymes. [3]
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
(b) (i) Describe the function of the partially permeable membrane in this biosensor.…read more

Page 4

Preview of page 4

Here's a taster:

Examiner
only
(c) If the biosensor was used to test two blood samples, explain why the temperature of the two
samples should be the same. [2]
....................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................
....................................................................................................................................................................................................................................
(d) Name a medical condition which a biosensor can detect. [1]
....................................................................................................................................................................................................................................
(Total 11 marks)
4. The drawing shows a simplified diagram of the cell cycle. The size of each segment indicates the
relative length of each phase.…read more

Page 5

Preview of page 5

Here's a taster:

Examiner
only
(c) Name the stage of mitosis where each of the following occurs.
(i) Chromatids line up at the equator. [1]
.............................................................................................................................................
(ii) Centromeres split. [1]
.............................................................................................................................................
(iii) Spindle fibres contract and shorten. [1]
.............................................................................................................................................
(iv) Chromosomes are first visible as a pair of chromatids. [1]
.............................................................................................................................................
(v) Nuclear membrane reforms. [1]
5
.............................................................................................................................................
W10 1071 01
(Total 11 marks)
(1071-01) Turn over.…read more

Page 6

Preview of page 6

Here's a taster:

Examiner
only
5. The diagram shows cells taken from the stem of a plant. Cells A, B and C are adjacent cells and
the figures give the water potential of each cell.
A = ­ 400kPa
B = ­ 380kPa
C = ­ 360kPa
(a) (i) Draw arrows on the diagram to show the overall direction of water movement
between these three cells. [1]
(ii) Explain your answer in terms of water potential. [2]
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................…read more

Page 7

Preview of page 7

Here's a taster:

Examiner
only
(i) Calculate the water potential, , of cell X. Show your working. [2]
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
(ii) State the name of the condition shown by cell Y and explain how this condition could
have arisen. [3]
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
(c) (i) Cell X has the higher pressure potential p. Explain how this pressure potential is
7
built up in cell X. [3]
W10 1071 01
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................
....................................................................................................................................................................................................................…read more

Page 8

Preview of page 8

Here's a taster:

Examiner
only
6. Heteropolysaccharides consist of long chains of monosaccharides. Each monosaccharide is
attached to a non-carbohydrate part.
Bacterial cell walls are made from a heteropolysaccharide consisting of two different
monosaccharides ­ abbreviated to NAG and NAM.
The linear polymer is made up of alternating NAG and NAM molecules, linked by glycosidic
bonds.
These chains are arranged in the same way as cellulose of plant cell walls.
The glycosidic bonds can be broken by the enzyme lysozyme.…read more

Page 9

Preview of page 9

Here's a taster:

Examiner
only
(b) The diagram shows a molecule of the enzyme lysozyme.…read more

Page 10

Preview of page 10

Here's a taster:

Examiner
only
(c) Catalase is an enzyme which breaks down hydrogen peroxide into water and oxygen.
Hydrogen peroxide is a highly toxic waste product of metabolism.
An investigation was carried out to determine the relative amounts of catalase in samples of
potato, liver and apple. The samples were ground to a pulp and added to hydrogen peroxide
in measuring cylinders. The table shows the height of the resulting bubbles in the cylinders.…read more

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »