Biology

 

1. Below is the chair confirmation of the molecule, glucose
2. a) Based on the number of molecules,

what type of saccharide is glucose?

(1 mark)

 

1. b) Glucose has two isomers, what does

the word isomer mean?

(2 marks)

 

 

1. c) Draw the structural formulae of and

name the two isomers of glucose

(6 marks)

 

 

1. d) Sucrose is formed from one molecule

of glucose and another simple sugar,

which one?

(1 mark)

 

1. e) Draw and name the bond that joins

simple sugars together in

polysaccharides like sucrose.

(2 marks)

 

 

 

2. This molecule is an example of a lipid

 

 

1. a) Looking at the structure,

identify the type of lipid

pictured, explaining your

reasons.

(3 marks)

 

1. b) Describe the difference

between a saturated fatty acid

and an unsaturated fatty acid,

and deduce which group the

pictured lipid belongs to.

(3 marks)

1. c) Name the type of reaction that

forms this type of lipid

(1 mark)

1. d) Describe the THREE main uses

of this type of lipid within the

body, and suggest why its

structure lends itself to these

uses

(4 marks)

 

3. Draw the general structure of an amino acid, identifying the different

parts (6 marks)

 

 

 

3. Below is an example of a polypeptide

 

1. a) Identify the area called the

“peptide bond”

(1 mark)

1. b) In what sort of chemical

reaction are these bonds

formed?

(1 mark)

5. Discuss the FIVE levels of structural organisation in proteins, providing an

example of each where possible.

(12 marks)

 

6. The diagram below shows part of a messenger RNA (mRNA) molecule.

 

 

1. a) i) How many codons are

shown in this section of

mRNA?

(1 mark)

 

 

1. ii) What is specified by a

sequence of codons in an

mRNA molecule?

(1 mark)

 

 

 

1. b) A tRNA molecule carries a complementary sequence for a particular

codon.

 

1. i) Write out the

complementary sequence

for the FIRST codon in the

mRNA sequence.

(1 mark)

 

1. ii) What is the role of tRNA

molecules in the process of

protein synthesis?

(3 marks)

 

 

7. The diagram below outlines protein synthesis in a normal cell.

 

 

1. a) Name stages 1 and 2

(2 marks)

 

1. b) Where does stage 2 take

place?

(2 marks)

 

1. c) Identify the codon that

initiates stage 2

(1 mark)

8. Below is a graph showing the effect of temperature on the rate of a

biological reaction catalysed by an enzyme.

1. a) Account for the shape of

this graph explaining the

key features of the slopes

and the area signified by

the red circle.

(5 marks)

 

 

 

1. b) Produce a rough graph to

represent the general effect

of change in pH on the rate

of an enzyme catalysed

reaction.

(4 marks)

 

 

1. c) Explain the key features of

this graph and the

reasoning behind why it is

shaped like this.

(3 marks)

 

 

9. The diagram below shows four molecules of water.
10. a) What type of bond is “A” on

the diagram?

(1 mark)

 

1. b) Why are water molecules

described as dipolar?

(4 marks)

1. c) Water has a high specific heat

capacity. Why is this important

for organisms that live in

water?

(2 marks)

 

10. Below are the general structures of prokaryotic and eukaryotic cells.
11. a) Identify the parts labelled A, B

and C

(3 marks)

 

 

1. b) Explain the function of the

parts labelled A, B and C

(3 marks)

 

 

1. c) Part c is present in both

eukaryotic and prokaryotic

cells, how do they differ

between the two?

(1 mark)

 

 

1. d) Sketch simple cell diagrams for

a typical plant cell and a typical

animal cell, and discuss the

differences in terms of: –

 Cell walls

 Plastids

 Lysosomes

 Centrioles

 Vacuoles

(14 marks)

11. The diagram below shows the structure of a chloroplast, as seen using an

electron microscope.

1. a) Identify the parts labelled A, B

and C

(3 marks)

 

 

 

 

1. b) The length of this chloroplast

is 2.5μm. Calculate the

magnification of this diagram.

Show your working out.

(3 marks)

12.The diagrams below show chromosomes during stages in the process of

mitosis.

 

 

1. a) Write down the letters as a list

in the order in which these

stages occur.

(1 mark)

 

 

 

1. b) Give two ways in which meiosis

differs from mitosis

(2 marks)

 

 

 

1. c) Name and briefly describe the

stages of mitosis including the

immediately preceding and

subsequent stages

(12 marks)

13. Below are the reproductive systems of male and female humans.
14. a) Give the functions of: –
15. The testes
16. The ovaries

iii. The penis

1. The vagina

(4 marks)

 

 

 

1. a) Briefly describe the processes of
2. Spermatogenesis (2

marks)

1. Oogenesis (3 marks)

 

Classification, Biodiversity, Exchange & Transport

1. The binomial classification system is widely used to classify organisms

based on different levels of relationship.

1. a) Name the EIGHT taxa used in

binomial classification

(8 marks)

1. b) Using this binomial system of

classification, identify the eight

different tax for the polar bear

(8 marks)

 

 

 

 

1. c) What are the FIVE kingdoms?

(5 marks)

2. Charles Darwin’s book “On the Origin of the Species by means of

natural selection” changed our perceptions of evolution in November

1860. a) Describe the FOUR main

observations of Darwin’s

theory of natural selection

(4 marks)

1. b) What are the THREE types of

natural selection? Describe and

give an example of each.

(12 marks)

 

1. c) Outline the difference between

allopatric and sympatric

speciation

(2 marks)

3. The biodiversity index, D, can provide an insight into the health of an

ecosystem and the various species within it. We can calculate the

biodiversity index using the following formula: –

An individual count of species in a small rock pool ecosystem is undertaken

and population numbers of its various species recorded, producing the

following table: –

1. a) Calculate the diversity index, D

for this rock-pool community.

Show your working

(6 marks)

 

 

 

1. b) What is the maximum

diversity for this community

and what does your value for

D say about the diversity here?

(3 marks)

4. Below are two different sized cubes that represent small organisms

and large organisms respectively.

1. a) Calculate for both cubes:
2. i) The area of a face
3. ii) The total surface area

iii) The volume

1. iv) The surface area: volume

ratio

(8 marks)

 

 

 

1. b) Outline the pros and cons of

having a low surface area to

volume ratio as is the case with

large organisms.

(2 marks)

 

 

1. c) Suggest how the human lungs

are adapted for effective gas

exchange, in terms of surface

area distance and

concentration gradient

(3 marks)

 

5. Explain what is meant by the following terms

 

1. a) Osmosis

(3 marks)

 

 

 

1. b) Facilitated Diffusion

(3 marks)

 

 

 

1. c) Diffusion

(3 marks)

 

 

 

1. d) Active transport

(3 marks)

6. Mammals and fish have very different environments in which to thrive

and so their systems for gas exchange have to be adapted in

completely different ways.

 

1. a) Compare and contrast the gas

exchange systems in mammals

and fish

(6 marks)

 

 

1. b) Explain the gas exchange

system of insects, and how

they are adapted for their

lifestyle.

(4 marks)

7. Below is a diagram of a cross section of a plant leaf.

Identify and give the functions of

parts A and B

(4 marks)

8. The diagram below shows a section of a human heart at a

precise stage in the cardiac cycle.

1. a) Name the stage of the cardiac

cycle shown in the diagram

(1 mark)

 

 

1. b) Give two reasons for your

answer

(2 marks)

1. c) Name and give a function for

each of the parts A and B as

shown on the diagram

(4 marks)

9. The graphs below show the changes in pressure in the aorta and in the

left and right ventricles of the heart, during the cardiac cycle. The

figure 0 on the ‘time’ axis indicates the start of atrial contraction.

1. a) What do you notice about

the changes in pressure in

the left ventricle compared

with the changes in the right

ventricle?

(4 marks)

 

 

 

1. b) Compare the changes in the

pressure in the aorta with

those in the left ventricle

and write down your

observations.

(3 marks)

 

1. c) Cardiac muscle is described

as myogenic. Explain how

the cardiac cycle is

coordinated within the heart

– so here you need to think

about the underlying

processes.

(4 marks)

 

 

 

1. d) Describe the differences

between the double and

single circulatory systems

(3 marks)

 

10. Name FIVE risk factors for atherosclerosis and explain your reasoning.

(10 marks)

11. Explain why the haemoglobin of a foetus has a greater affinity for

binding with oxygen than an adult’s haemoglobin.

(3 marks)

12. The uptake of water by a leafy shoot can be investigated using

apparatus like that shown in the diagram below.

1. a) What is the name of this piece

of apparatus?

(1 mark)

 

 

 

1. b)
2. i) Name the assumption

made when this

apparatus is used to

investigate the rate of

transpiration?

(1 mark)

 

1. ii) Name two precautions

that need to be taken in

order to make sure this

experiment works

correctly. (2 marks)

Using this apparatus, four experiments were carried out with the

same shoot in the following order:

 

A: Still air, leaves untreated

B: Moving air, leaves untreated

C: Still air, lower surface of leaf covered with grease

D: Moving air, lower surface of leaf covered with grease

 

The variables of temperature and light intensity were kept constant

during the investigation and the results are shown in the following

graph:

The mean rate of water uptake during experiment A was 3.2 mm3 per

minute and the cross-sectional area of the bore of the capillary tube is 0.8

mm2.

 

1. c) Now calculate the mean rate of

water uptake by the shoot

during experiment B. Show

your working out.

(3 marks)

 

 

1. d)
2. i) Explain the effect of

moving air on the rate of

water uptake in

experiment B.

(3 marks)

1. ii) Give an explanation for

the different effects of

moving air in

experiments B and D.

(3 marks)

Unit 2

Energy for Biological Processes, Microbiology & Pathogens

2. a) In recall the chemical word equation

for aerobic respiration

(2 marks)

 

1. b) In which organelle within cells does

respiration take place?

(1 mark)

 

1. c) Summarise the steps involved in

glycolysis

(4 marks)

 

1. d) Name the two subsequent stages of

respiration

(2 marks)

 

 

1. e) Which stage is responsible for the

bulk of ATP production?

(1 mark)

 

2. In about 150 words, describe the structure of ATP and explain its purpose

in the body

(5 marks)

 

 

3. Anaerobic respiration is another form of respiration that occurs when

the demand for energy exceeds the availability of oxygen.

 

1. a) Describe the process and

conditions of anaerobic

respiration during a period of

intense exercise

(4 marks)

 

 

 

 

 

4. The following statements refer to the light-dependent and light-

independent (dark) reactions of photosynthesis.

 

You need to indicate whether the statements are light dependent or

light independent reactions: –

(5 marks)

 

Uses light energy to split water

Carbon dioxide fixed

Occurs in stroma

Uses NADPH and H

Produces ATP

5. The diagram below shows the structure of a chloroplast as seen under

and electron microscope.

Name the parts labelled A, B and C

(3 marks)

 

1. a)
2. i) Name compound X

(1 mark)

 

1. ii) Name gas Y and describe

how it is produced.

(3 marks)

 

iii) Where does the light-

dependent reaction take

place in a chloroplast?

(1 mark)

 

 

1. iv) Give the name of a pigment

responsible for the capture

of light during the light-

dependent reaction of

photosynthesis.

(1 mark)

 

 

 

 

1. v) Discuss, using sketched

graphs, how photosynthesis

is limited by: –

 Temperature

 Light intensity

 Carbon dioxide

concentration

(12 marks)

 

7. State whether the following features are present in bacteria, fungi,

neither or both.

DNA and RNA

Surrounded by protein coat

Cell wall containing chitin

70S ribosomes

Membrane bound organelles

(5 marks)

8. The diagram below shows the structure of the human

immunodeficiency virus (HIV)

1. a) Name the parts labelled A and B

(2 marks)

9. The flow chart summarizes the response of lymphocytes in the blood to a

bacterial infection.

1. a) Explain what is meant by the term antibody.

(1 mark)

 

 

1. b) Suggest why the cloning of lymphocytes by

mitosis is important in the production of an

antibody.

(2 marks)

 

 

1. c) The process shown in the flow chart would lead

to active immunity.

Explain why this is.

(3 marks)

 

 

 

1. b) Describe how the phospholipid bilayer

contributes to the infection of the host

cell.

(3 marks)

 

 

1. c) Once the virus has infected the cell there

is a dormant period. Describe the role of

the RNA in this period.

(1 mark)

10. A vaccine contains disease-causing organisms, which have been made

harmless but which act as antigens. In order to achieve full protection,

it is often necessary to give two injections of a vaccine. The following

graph shows how levels of antibodies change in the body following two

injections of a vaccine.

1. i) Compare the changes in

the level of antibodies in

the body following the

first and second

injections of the vaccine.

(3 marks)

 

 

1. ii) Explain how vaccination

can bring about an

increase in the level of

antibodies.

(2 marks)

 

 

 

1. b) Explain how passive immunity

differs from active immunity

(3 marks)

 

1. a) i) Describe how you would prepare a 1 x 106 dilution of bacterial

culture.

(4 marks)

 

 

1. ii) To estimate the population density of the culture, several plates are

inoculated with a number of different dilutions of the culture. Why is it

usual to inoculate several plates with each separate dilution?

(3 marks)

 

1. b) An agar plate inoculated with 0.1 cm3 of a 1 × 106 dilution produced 31

colonies of bacteria. Calculate the population of bacteria that would be

found in 1 cm3 of the original culture. Show your working.

(2 marks)

12. Describe TWO common methods of measuring the growth of

microorganisms

(6 marks)

13. Describe the FIVE steps required for a pathogen to cause disease.

(20 marks)

14. An infection is caused when pathogenic microorganisms enter the

tissues of the host organism and multiply. The symptoms of the

infection may result from the production of toxins by the

microorganism or from the destruction of host tissue.

1. a) Food poisoning can be caused by a number of pathogenic

bacteria, including Salmonella and Staphylococcus

 

1. i) Name the type of toxin produced by Salmonella

(1 mark)

 

 

1. i) The symptoms of food poisoning caused by

Salmonella occur 1–2 days after eating

contaminated food. However the symptoms,

resulting from infection by Staphylococcus occur

within a few hours after infection – explain this.

(4 marks)

 

 

 

 

 

 

1. b) Salmonella is Gram negative whereas Staphylococcus is

Gram positive. Describe how the colour of these bacteria

would differ after gram staining had been carried out.

(4 marks)

Modern Genetics & Origins of Variation

1. Outline the steps of cloning genes using the polymerase chain reaction

(PCR)

(5 marks)

2. Post-transcriptional modifications of the RNA created in transcription

are required for a number of reasons

 

1. a) Specify the TWO main reasons why post-transcriptional modification

is necessary

(2 marks)

 

1. b) Briefly describe the THREE processes involved in post transcriptional

modification

(6 marks)

 

1. c) Describe the opposing effects of DNA-methylation and histone

acetylation.

(6 marks)

 

3. A stem cell is a non-specialised cell from a multicellular organism that

has the potential to develop into more cells of any type. They show

much promise in the medical field and may lead to cures and

treatments for a variety of disorders.

1. a) Explain the differences between: –
2. i) Pluripotent cells
3. ii) Totipotent cells

iii) Multipotent cells

(3 marks)

1. i) Somatic
2. ii) Fibroplasts

(2 marks)

 

 

1. c) In what way do Induced Pluripotent Cells (iPS) potentially provide a

less ethically questionable solution than human embryonic stem cells

(hES)?

(4 marks)

 

 

4. Genetic engineering involves the altering of genes within a genome of

a living organism to produce a genetically modified organism.

1. a) List SIX different techniques for genetic engineering

(6 marks)

 

 

1. b) Briefly outline the function of DNA ligase, including how it can be

used in conjunction with restriction enzymes

(6 marks)

 

 

1. c) Outline ONE way in which gene transfer can be achieved with

vectors containing the genes we desire.

(3 marks)

 

 

1. d) What are genetic markers used for?

(1 mark)

 

5. Genetic variation can occur in a variety of ways.

 

1. a) Describe the THREE possible phenotypic effects of mutations in germ cells

(6 marks)

1. b) Name the THREE ways in which sexual reproduction can result in genetic

variation

(3 marks)

 

 

1. c) Explain the concept of random fertilisation.

(4 marks)

 

 

6. Cystic fibrosis is a common inherited disorder among Europeans, and it

is caused by a single gene. The diagram below shows part of a family

pedigree showing the inheritance of this disorder.

1. a) From the diagram, identify evidence that suggests that the allele causing

the inherited condition is

1. i) Recessive
2. ii) Autosomal

(2 marks)

 

 

1. b) Let the dominant, non-CF allele be C and the recessive CF allele be c.

 

Create a punnet square diagram that shows the chances of Person 3’s

children being affected if the mother is also a carrier of CF.

(4 marks)

If the percentage of children born with cystic fibrosis is a known

quantity then it is possible to calculate the probable frequency of the

recessive allele in the population. This information can be used to

estimate the percentage of people in the population who are

heterozygous for this gene using the Hardy-Weinberg equation: –

 

p2 + 2pq + q2

2 = 1

= 1

 

p is the frequency of the dominant allele

q is the frequency of the recessive allele for cystic fibrosis

p2 is the frequency of people homozygous for the normal allele

q2 is the frequency of people homozygous for the recessive allele

2pq is the frequency of heterozygous carriers

 

 

1. c)
2. i) If p is 0.978 and q is 0.022, calculate the frequency of the

heterozygous genotype in the population.

(2 marks)

 

 

1. ii) Give an explanation of the significance of the frequency of the

heterozygous genotype of this genetic condition in the

population.

(2 marks)

 

 

1. d) A person whose family includes people with cystic fibrosis may wish to

know if they or their partner or perspective partner are carriers of this

disease, before deciding to have children. How could this be

determined?

(2 marks)

 

7. Explain the difference between the following pairs of terms

 

1. a) Monohybrid & dihybrid inheritance

(2 marks)

1. b) Continuous and discontinuous variation

(2 marks)

 

 

8. Fabry’s disease is a sex-linked recessive genetic disorder that causes

mental retardation. A study was carried out into the inheritance of this

disorder in a family, and the results of the study are shown in the

pedigree chart that follows:

 

 

1. e) Look at the pedigree chart and explain why Fabry’s disease is

described as a sex-linked recessive genetic disorder.

(4 marks)

 

1. f) Using the symbol A for the dominant allele and a for the recessive

allele, what is the genotype of person 2?

(1 mark)

 

1. g) Explain why person 3 is not affected, but one of his children is.

(4 marks)

 

1. h) What are the chances of the children of persons 6 and 7 having

Fabry’s disease? Support your answer with evidence

(5 marks)

9. A gene pool is a name for the total number of alleles for the various

different genes present within a population of a species.

1. a) Recall the equation used to calculate allele frequency

(1 mark)

 

 

1. b) Explain, including diagrams to highlight the ideas, the terms:
2. i) Genetic drift
3. ii) Migration

(6 marks)