The Hazeley Academy

A LEVEL BIOLOGY

TRANSITION UNIT

Name: _________________________________________________________

Secondary School _______________________________________________

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Contents

Introduction………………………………………………………………………2

Task 1:Exam technique………………………………………………..3

Task 2: Enzymes & the digestive system…………………….. 6

Task 3:Factors affecting enzymes………………………………… 9

Task 4: Microscopes & Organelles………………………………….. 11

Task 5: Movement across membranes…………………… 15

Task 6:Gas exchange ……………………………………………………… 17

Task 7: The heart……………………………………………………… 19

Task 8: Causes of disease &Immunity ……………………. 21

Task 9: Interpreting data & HSW ………………………………… 23

Task 10: Revision for GCSE biology exam……………………. 24

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Introduction

Some students find the transition from GCSE to A-level Biology very challenging. To help make this transition smoother and to give you the best possible start, we have prepared this booklet for you.

It is important that you read through this booklet and then complete all the questions. If you require more space then you can use lined paper. Many of the topics are GCSE topics which you should have already covered. You will need secure knowledge of these topics before you start the course in September. In addition to this there are several questions that require you to research a topic so that you become familiar with new vocabulary and concepts.

At the beginning of the course you will be given a test to check how well you have understood the topics. If you do not pass this test, you will be put into an intervention class. This class will help you to bring your knowledge and understanding up to the required standard.

To help you complete this booklet the following resources will be useful:

The tasks in this booklet must be completed by the first biology lesson and will be presented to the teacher in your first Biology lesson.

Task 1Exam technique 3

In order to be successful in A- level Biology exam technique is essential. A key

area of exam technique is understanding the command words in the question.

1. Define the following keywords:

a) Describe

b) Explain

c) Suggest

d) Evaluate

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2. The Galapagos Islands are in the Pacific Ocean, 1400 km from South America. A type of bird called a ground finch lives on the islands.

The picture shows a ground finch.

The size of the seeds the ground finch can eat depends upon the size of the beak. To eat large seeds, a large beak is needed. The bar charts show the sizes of the beaks of ground finches on one island, in 1976 and in 1978.

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2 (a) The population of the ground finches and their beak sizes changed between 1976 and 1978.

Describe these changes.

2 b) In 1977 there was very little rain on the island. The lack of rain affected the seeds that the finches ate.

The table shows how the seeds were affected.

Suggest an explanation for the changes in beak sizes between 1976 and 1978.

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Task 2 Enzymes & the digestive system

1. Match each part of the body to its correct function:

Part of the body Function

The large intestine

The oesophagus (gullet)

Makes digestive enzymes, and is where digested food is absorbed into the blood

Contains teeth to cut and grind food

The mouth Is where water is absorbed

The stomach Joins the mouth with the stomach

The small intestine Makes digestive enzymes and acid

The liver Makes insulin and digestive enzymes

The pancreas Makes bile

2. What is the function of digestive enzymes?

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3. How does chewing food help to speed up digestion?

4. Complete the following table:

Enzyme Where is this What food group What are the

enzyme produced? does the enzyme products of the

break down? breakdown?

Carbohydrase

Amylase

Protease

Lipase

5. Which one of the following structures is not part of the alimentary canal?

(a) duodenum (c) liver

(b) mouth(d) stomach:

6. What name is given to the muscular contraction which moves food along the alimentary canal?

7. Are the contents of the stomach (a) acid, (b) alkaline,{c) neutral?

8. What is the function of bile in digestion?

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9. How is the surface area of the small intestine increased?

10. Describe how you would test for:

Fat Starch Protein

11. Name the structures labelled A to I. A __________________

B __________________

C __________________

D __________________

E __________________

F __________________

G __________________

H __________________

I __________________

12. Find out what the following mean and give one example for each one:

a) Monosaccharide

b) Disaccharide

c) Polysaccharide

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Task 3: Factors affecting enzymes

1. What two things affect the activity of enzyme?

2. Enzymes in the human body have an optimum of 37oC. What does this

mean?

3. What is the minimum amount of energy required for a reaction to take place called?

4. How do enzymes speed up chemical reactions?

5. If an enzyme-controlled reaction normally takes place at 10ºC, in general terms how will the reaction be affected by:

(a)a fall in temperature to 2°C

(b) a rise in temperature to 20°C. (c) a rise in temperature to 65°C?

6. If an enzyme is denatured, why does it no longer work?

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7. The graph shows the rate of an

enzyme reaction at different

levels of acidity or alkalinity

(pH). From the graph, what is the

optimum pH for this enzyme? (a) pH 2 (c) pH 10 (b) pH 7 (d) none of these.

8. A protein-digesting enzyme when mixed with starch solution would:

(a) have no action (c) produce glucose

(b) produce amino acids (d) digest the starch?

9. What are the 2 models for enzyme action?

10. In enzyme inhibition there are 2 inhibitors, find out what these are called

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Task 4: Microscopes& Organelles

1. Label the microscope below:

2. Find out the difference between light microscopes and electron microscopes.

Light microscopes Electron microscopes

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3. You will be using lots of new scientific vocabulary on the biology course find out the meanings of the following keywords:

a) Resolution

b) Magnification

c) Nucleolus

d) Golgi apparatus

e) Lysosome

f) Ribosome

g) Rough endoplasmic reticulum 4. You must know the following units of measurement when working with

microscopes. They are all in comparison to a metre. Complete the table below.

Unit Symbol Equivalent in metres

kilometre km 103

metre

mm 10-3

micrometre 10-6

nanometre nm

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5. Place a tick in the box to indicate where the organelle is found. Some organelles can be found in both plant and animal cells.

Organelle Plant Cell Animal Cell

Cell Wall

Chloroplast

Cytoplasm

Endoplasmic

reticulum

Golgi apparatus

Lysosome

Nucleolus

Nucleus

Plasma membrane

Ribosome

Vacuole

Mitochondria

6. Cells are categorised as either prokaryotes or eukaryotes. Find out what this means and give 1 example for each of these categories.

Prokaryote Eukaryote

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7. The diagram shows an animal cell

a) Name each labelled part and give its function

A Name ___________________________________________________

Function__________________________________________________

________________________________________________________

B Name____________________________________________________

Function__________________________________________________

_________________________________________________________

C Name____________________________________________________

Function __________________________________________________

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Task 5: Movement across membranes

1. Place the following features in the correct part of the Venn Diagram using the letters given.

A Involves water only

B Requires energy

C Is passive

D Movement of particles

E How minerals get into rootn hair

cells

F High to low concentration

2. Why does active transport require energy? G Against a concentration

gradient

3. What is this energy in the form of?

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4. Some students set up the experiment below to investigate osmosis

a) What is osmosis?

b) What will happen to the water level in the capillary tube during the investigation? Explain why this happens

c) Describe two examples where osmosis is used in living things

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1. Task 6: Gas exchange

2. Where does gas exchange take place? 3. Describe how the lungs are adapted for gas exchange

4. Label the parts of the lung in the diagram below:

4. Describe the process of breathing in (inspiration)

5. Smoking causes emphysema, what is emphysema? 6. Tuberculosis is caused by two species of bacteria. Find out the name

for both these bacteria

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7. Pulmonary ventilation is the total volume of air that is moved into the lungs in one minute. Find out the equation for pulmonary ventilation.

8. The diagram below shows a vertical section of a leaf. Name structures A-F.

A _________________________

B _________________________

C _________________________

D _________________________

E _________________________

F _________________________

G _________________________

H __________________________

9. Where does gas exchange take place in a leaf?

10. What is the role of the stomata in gas exchange

TASK 7: THE HEART

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1. Label the diagram and complete the gap fill exercise below.

The P____________ A__________

Takes blood to the ___________

V_______

C_______

R_______

A_______

R_______

V_______

The A______ takes blood to the ________

P________

V_______

L_______

A_______

L_______

V_______

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2. Complete the passage below:

The heart is made out of ____________ Muscle. It is a double _________

that squeezes the blood around the ________ and to the ________. The

_________ side pumps blood to the lungs to pick up ______________. The

_________ side pumps blood around the rest of the body.

3. Find out another term that is used for a heart attack

4. Which side of the heart is thicker and why?

5. Name the artery that only supplies the heart?

6. Name 3 blood vessels

7. Which blood vessel contains valves?

8. What is the function of valves?

9. What causes heart disease?

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Task 8: Causes of disease & immunity

1. What are the three main types of microorganisms? 2. What is a pathogen? 3. Define the term antigen 4. List 3 things that white blood cells do 5. What is the difference between an antibiotic and an antibody? 6. What is found in a vaccination? 7. Match the description on the left with the term on the right by writing

the correct letter in each space.

8. Find out what causes cholera and describe the symptoms of this disease. 22

9. Oral rehydration therapy is used to treat cholera. Find out what this rehydration solution contains.

10. What is the name of the chemical found in cigarettes that causes cancer?

11. Disease causing microorganisms gain entry into the body via one of its interfaces with the environment such as the skin. Name 2 other examples of interfaces through which microoganisms may gain entry into the body.

12. How do pathogens cause disease?

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Task 9: Interpreting data& HSW

1. What is the difference between an independent variable and a dependent

variable?

2. Which axis has the independent variable on a graph? 3. What term is used for the variable we keep the same throughout an investigation?

4. What is the sensitivity of a balance? 5. What does correlation mean? 6. What does the term directly proportional mean? 7. How can the reliability of an experiment be increased? 8. How can the pH of a solution be controlled? 9. What does standard deviation mean?

You will be expected to sit a unit 3 AQA GCSE biology exam at the start of the course and will

be used to help inform your working at grade for the first report.

Below is the specification to work from and a link to try past papers.

You are expected to work through the specification provided over the remainder of the summer holidays. It is expected that you spend at least 2 hours per week reviewing the relevant material and preparing for the test. It is your responsibility to ensure you are adequately prepared for the test paper. This may mean you need to spend more than 2 hours if you are finding the subject matter more difficult. Remember that that the material you learn now will help you improve your understanding of AS‐Level.

http://www.aqa.org.uk/subjects/science/gcse/biology-4401/past-papers-and-mark-

schemes/old-past-papers-and-mark-schemes

The cells in animals and plants all need oxygen to be able to release energy for the jobs they do. They all produce carbon dioxide as a waste product. Candidates should use their skills, knowledge and understanding of how science works: • to explain how gas and solute exchange surfaces in humans and other organisms are adapted to maximise effectiveness. Their skills, knowledge and understanding of how science works should be set in these substantive contexts: • Dissolved substances move by diffusion. • Substances are sometimes absorbed against a concentration gradient. This requires the use of energy from respiration. The process is called active transport. It enables cells to absorb ions from very dilute solutions. Other substances, such as sugar and ions, can also pass through cell membranes. • Many organ systems are specialised for exchanging materials. • In humans: − the surface area of the lungs is increased by the alveoli − and that of the small intestine by villi. • The lungs are in the upper part of the body (thorax) protected by the ribcage and separated from the lower part of the body (abdomen) by the diaphragm. • The breathing system takes air into and out of the body so that oxygen from the air can diffuse into the bloodstream and carbon dioxide can diffuse out of the bloodstream into the air. • The alveoli provide a very large, moist surface, richly supplied with blood capillaries so that gases can readily diffuse into and out of the blood. • The villi provide a large surface area with an extensive network of capillaries to absorb the products of digestion by diffusion and active transport. • In plants: – carbon dioxide enters leaf cells by diffusion – most of the water and mineral ions are absorbed by root hair cells. • The surface area of the roots is increased by root hairs and the surface area of leaves by the flattened shape and internal air spaces. • Plants have stomata to obtain carbon dioxide from the atmosphere. • Plants lose water vapour from the surface of their leaves. This loss of water vapour is called transpiration. Transpiration is more rapid in hot, dry and windy conditions. Most of the transpiration is through stomata. The size of stomata is controlled by guard cells which surround them. If plants lose water faster than it is replaced by the roots, the stomata can close to prevent wilting.

13.2 How are dissolved materials transported around the body? Substances are transported around the body by the circulation system (the heart, the blood vessels and the blood). They are transported from where they are taken into the body to the cells, or from the cells to where they are removed from the body. • The heart pumps blood around the body. Blood flows from the heart to the organs through arteries and returns through veins. In the organs, blood flows through capillaries. Substances needed by cells in the body tissues pass out of the blood, and substances produced by the cells pass into the blood through the walls of the capillaries. • There are two separate circulation systems, one to the lungs and one to all the other organs of the body. • Blood plasma transports: − carbon dioxide from the organs to the lungs − soluble products of digestion from the small intestine to other organs − urea from the liver to the kidneys. • Red blood cells transport oxygen from the lungs to the organs. Red blood cells have no nucleus. They are packed with a red pigment called haemoglobin. In the lungs haemoglobin combines with oxygen to form oxyhaemoglobin. In other organs oxyhaemoglobin splits up into haemoglobin and oxygen. 13.3 How does exercise affect the exchanges taking place within the body? The human body needs to react to the increased demand for energy during exercise. Candidates should use their skills, knowledge and understanding of how science works: • to interpret data relating to the effects of exercise on the human body. Their skills, knowledge and understanding of how science works should be set in these substantive contexts: • The energy that is released during respiration is used to enable muscles to contract. • During exercise a number of changes take place: − the heart rate increases − rate and depth of breathing increases − the arteries supplying the muscles dilate. • These changes increase the blood flow to the muscles and so increase the supply of sugar and oxygen and increase the rate of removal of carbon dioxide. • Glycogen stores in the muscle are used during exercise. • If muscles are subjected to long periods of vigorous activity they become fatigued, ie they stop contracting efficiently. If insufficient oxygen is reaching the muscles they use anaerobic respiration to obtain energy. • Anaerobic respiration is the incomplete breakdown of glucose and produces lactic acid. As the breakdown of glucose is incomplete, much less energy is released than during aerobic respiration. Anaerobic respiration results in an oxygen debt that has to be repaid in order to oxidise lactic acid to carbon dioxide and water. 13.4 How do exchanges in the kidney help us to maintain the internal environment in mammals and how has biology helped us to treat kidney disease? People whose kidneys do not function properly die because toxic substances accumulate in their blood. Their lives can be saved by using dialysis machines or having a healthy kidney transplanted. Candidates should use their skills, knowledge and understanding of how science works: • to evaluate the advantages and disadvantages of treating kidney failure by dialysis or kidney transplant. Their skills, knowledge and understanding of how science works should be set in these substantive contexts: • A healthy kidney produces urine by: − first filtering the blood − reabsorbing all the sugar − reabsorbing the dissolved ions needed by the body

− reabsorbing as much water as the body needs − releasing urea, excess ions and water as urine. •Sugar and dissolved ions may be actively absorbed against a concentration gradient. • People who suffer from kidney failure may be treated either by using a kidney dialysis machine or by having a healthy kidney transplanted. • In a dialysis machine a person’s blood flows between partially permeable membranes. The dialysis fluid contains the same concentration of useful substances as the blood. This ensures that glucose and useful mineral ions are not lost. Urea passes out from the blood into dialysis fluid. Treatment by dialysis restores the concentrations of dissolved substances in the blood to normal levels and has to be carried out at regular intervals. • A kidney transplant enables a diseased kidney to be replaced with a healthy one from a donor. However, the donor kidney may be rejected by the immune system unless precautions are taken. • To prevent rejection of the transplanted kidney: − a donor kidney with a ‘tissue‐type’ similar to that of the recipient is used − the recipient is treated with drugs that suppress the immune system. 13.5 How are microorganisms used to make food and drink? People from many different cultures have known for thousands of years how to use microorganisms to make various types of food and drink such as bread, beer, wine and yoghurt. • Microorganisms are used to make food and drink: − bacteria are used in yoghurt and cheese manufacture − yeast is used in making bread and alcoholic drinks. • Yeast is a single‐celled organism. The cells have a nucleus, cytoplasm and a membrane surrounded by a cell wall. • Yeast can respire without oxygen (anaerobic respiration), producing carbon dioxide and ethanol (alcohol). This is called fermentation. In the presence of oxygen yeast carries out aerobic respiration and produces carbon dioxide and water. Aerobic respiration provides more energy and is necessary for the yeast to grow and reproduce. • In brewing beer and wine‐making, carbohydrates are used as an energy source for yeast to respire. For making beer: − the starch in barley grains is broken down into a sugary solution by enzymes in the germinating grains, in a process called malting − the sugary solution is extracted then fermented − hops are then added to give the beer flavour. • In wine‐making the yeast uses the natural sugars in the grapes as its energy source. • In the production of yoghurt: − a starter of bacteria is added to warm milk − the bacteria ferment the milk sugar (lactose) producing lactic acid − the lactic acid causes the milk to clot and solidify into yoghurt. 13.6 What other useful substances can we make using microorganisms? Microorganisms are used on a large scale to make many useful substances including antibiotics such as penicillin, foods such as mycoprotein and fuels such as biogas and ethanol. • The fungus Fusarium is used to make mycoprotein, a protein‐rich food suitable for vegetarians. The fungus is grown on starch in aerobic conditions and the biomass is harvested and purified.