AQA GCSE (9-1) Biology Teacher Pack Look Inside by Collins

Chapter 1: Cell Biology

Cell Biology: Introduction When and how to use these pages This unit builds on the idea that the cell is the building block of life. Cells can be specialised and may be part of multicellular organisms or unicellular organisms (like bacteria). This chapter links to all chapters in which the structure and functions of different systems are considered, for example, Photosynthesis, and Health, and to chapters in which meiosis is explained.

Looking at cells

Describe the structure of eukaryotic cells and functions of subcellular components.

The light microscope

How to observe animal and plant cells using the light microscope and its limitations.

In this unit, students will learn about the structure of plant, animal, prokaryotic and eukaryotic organisms, and the functions of major structures. They will compare the level of detail revealed by light and electron microscopes, calculating magnifications. Students will describe how cells divide by mitosis and the application of this in cloning techniques. The use of stem cells in producing new tissues and organs will be evaluated in terms of ethical and moral considerations. Students will consider the differences between aerobic and anaerobic respiration, and learn about the uses of anaerobic respiration in baking and brewing. They will learn how to grow cultures of bacteria safely and investigate the effectiveness of different disinfectants on bacterial growth.

Looking at cells in more detail

Compare the light microscope with the electron microscope, explaining how the development of the electron microscope has increased our understanding of cells.

Required practical: Using a light microscope to observe and record animal and plant cells

How to look at everyday material and cells using a light microscope. Understand the difference between low and high power; draw and describe images at high and low magnification.

Primitive cells

Describe the differences between prokaryotic and eukaryotic cells, and how they might have evolved over time.

This unit offers a number of opportunities for the students to use mathematics to carry out magnification calculations, plan and carry out investigations into the use of anaerobic respiration in baking, evaluate the effectiveness of disinfectants by preparing bacterial cultures and use graphical skills to analyse data in a number of different contexts. Students will debate the use of embryonic stem cells in terms of moral and ethical considerations.

Cell division

Describe the process of mitosis using models.

Cell differentiation

Explain the importance of cell differentiation and link specialised cells to their tissues, organs and body systems. Describe the organisation within a multicellular organism.

Cancer

Describe what cancer is and the factors that can trigger cells to become cancerous.

Stem cells

Describe the functions and uses of stem cells. Compare the use of embryonic and adult stem cells and the ethical implications of their use.

Stem cell banks

Explain the uses and risks of using stem cells in medicine, evaluating their benefits and disadvantages.

Key concept: Cell development

Revise ideas about cell structure, division and stem cells. Describe how plant meristems can be used in cloning.

Cells at work

Explain the process of aerobic respiration.

Life without oxygen

Describe the process of anaerobic respiration and compare it to aerobic respiration. Plan an investigation into factors affecting anaerobic respiration in dough-making.

Growing microorganisms

Describe how to prepare uncontaminated cultures of microorganisms and how bacteria reproduce.

Testing new antibiotics

Describe the disc-diffusion technique and how to use techniques to ensure samples are representative.

Required practical: Investigating disinfectants

Investigate and evaluate the effectiveness of disinfectants on the growth of bacteria.

Maths skills: Size and number

Making estimates, ratio and proportion, standard and decimal form.

Overview of the unit

Obstacles to learning Students may need extra guidance with the following terms and concepts:

• Cells and related topics use abstract concepts and are hard to visualise. The use of cell models may help

some students to make connections between different types of cells. Students often believe that cells are inactive, two-dimensional structures and the use of videos and electron micrographs will enable them to see this is not the case.

• Mitosis is also a difficult concept to follow, and the use of models will help students to see the process more clearly and follow the stages more easily. Students often think that cells grow by simply becoming bigger, rather than by cell division.

• The idea that a stem cell can become a nerve cell or a muscle cell, for example, can be difficult for students to understand.

• Students may believe that bacterial cells are the same as animal cells. • Respiration is often confused with breathing (ventilation), and needs to be linked to the mitochondria within cells so its role within each cell can be emphasised.

Practicals in this unit In this unit students will do the following practical work:

• (Required practical) prepare plant and animal slides and observe them using a light microscope

• investigate the amount of energy in food • prepare uncontaminated cultures of bacteria • (Required practical) investigating disinfectants.

Collins GCSE Science •• AQA GCSE Biology: Teacher Pack

AQA GCSE Biology: Teacher Pack

Chapter 1: Cell Biology

Lesson 12: Cells at work

• Ask low and standard demand students to summarise aerobic respiration as a word equation. [O2] • Ask high demand students to summarise it as a balanced symbol equation. [O2]

Lesson overview

Consolidate and apply

AQA Specification reference

• Ask students to look at the different cell types on the worksheet. Ask them to rank these in order of which

carries out the most aerobic respiration and ask them to say where the greatest concentration of mitochondria is likely to be found. They should analyse the data and use this to help them and answer the questions. [O2, O3]

AQA 4.4.2.1

Learning objectives • Explain the need for energy.

Extend

• Describe aerobic respiration as an exothermic reaction.

Ask students who are able to progress further to:

Learning outcomes

• carry out some research and find out whether the statement ‘animals respire more than plants because they

• Identify a range of different reasons why different organisms need energy. [O1] • Explain aerobic respiration as a word equation, with glucose as the source of energy. [O2] • Relate the activity of a cell to the amount of mitochondria present. [O3]

Plenary suggestions

Skills development

move about more’ is true or false. They should use evidence they uncover to back up their arguments.

• Present students with the key words from the PowerPoint slide. Ask them to make up five sentences about what they have learnt using as many key words as possible. [O1, O2, O3]

• WS 2.4 Carry out experiments appropriately having due regard for the correct manipulation of apparatus, the accuracy of measurements and health and safety considerations.

• WS 2.6 Make and record observations and measurements using a range of apparatus and methods. • WS 3.5 Interpret observations and other data (presented in verbal, diagrammatic, graphical, symbolic or numerical form), including identifying patterns and trends, making inferences and drawing conclusions.

Resources needed Worksheet 1.12; Practical sheet 1.12; Technician’s notes 1.12 Digital resources PowerPoint 1.12 Key vocabulary active transport, aerobic respiration

Teaching and learning Engage • Ask students to work in pairs to write a list of why animals and plant cells need energy. They should use the pro forma in the worksheet. Ask pairs to team up with another pair, comparing and adding to their lists. Take feedback from the students and show them the PowerPoint, to see if they have identified all the different reasons organisms need energy. [O1]

Challenge and develop • Demonstrate the ‘screaming jelly baby’ experiment which shows energy release from glucose through a chemical reaction. See Practical worksheet 1.12 for details. See the video of this reaction on the BBC website (www.bbc.co.uk) by searching for ‘aerobic and anaerobic respiration’. [O2]

• Explain that bread is made of starch, which comes from glucose. Ask students to carry out an investigation whereby they burn a known mass of bread over a boiling tube of water and determine the increase in temperature of the water. Ask students to make some inferences about glucose from the reactions. They should deduce that, when glucose is burnt in oxygen, an exothermic reaction takes place and lots of energy is released. Use the PowerPoint slide to explain what is happening. [O2]

Answers to Worksheet 1.12 1. Energy is needed: • to drive the chemical reactions that are needed to keep us alive • to build large molecules like proteins from smaller ones, such as amino acids • for movement • to make our muscles expand and contract • to keep our bodies warm and at a constant temperature • to transport substances around the body • for cell division • for active transport, whereby molecules are moved from a low concentration to a high concentration, for example, in mineral uptake in plants • to transmit nerve impulses. 2. Glucose comes from food – molecules are broken down in the digestive system and absorbed by the blood. They are transported by the blood to all cells. Oxygen comes from the air and is absorbed by the lungs into the blood. It is transported to all cells by red blood cells in our blood. The heart pumps the blood around the body to reach all cells. glucose + oxygen C6H12O6 + 6O2

carbon dioxide + water 6CO2 + 6H2O

3. Muscle cell; sperm cell; nerve cell; red blood cell. Muscle cells will have the most mitochondria. 1) Retinal eye cells have the most mitochondria and may be the most actively respiring cells. 2) No; bacteria cells respire but do not use mitochondria; they have alternative mechanisms.

• Ask students to relate these demonstrations to what happens inside cells. Ask them to identify where

glucose and oxygen come from and how they get to the cells. Remind students of the role of mitochondria in cells using the PowerPoint slide. [O2, O3]

Explain • Ask students to annotate the diagram of the human body on their worksheet to explain where the most sugar and oxygen are likely to be found. High demand students should write a full explanation of how these materials reach the cells, including the role of the heart and lungs. [O2]

AQA GCSE Biology: Teacher Pack

Chapter 4: Health matters

Lesson 16: Looking at plant diseases

Explain • Students should complete the table on Worksheet 4.16.1 (low demand), Worksheet 4.16.2 (standard

Lesson overview

demand) or Worksheet 4.16.3 (high demand). Low demand students have been given a help sheet, which contains the information needed to complete the table. [O1, O2]

AQA Specification reference

• Discuss with high demand students the different ways plant diseases can be detected; they will already be

AQA 4.1.2.3; AQA 4.3.3.1

familiar with some of these from the discussions about the different diseases. [O2]

Learning objectives • Recall the causes of plant diseases. • Describe the symptoms and identification methods of some plant diseases. • Explain the use of monoclonal antibodies in identifying plant pathogens.

• Explain to high demand students how diseases are identified. Students should then use the Internet to

identify some different diseases listed on Worksheet 4.16.3. The information is sourced from www.planetnatural.com (go to ‘Learning centre’, then ‘Plant diseases’) and could be printed if the Internet is not available. [O2, O3]

Consolidate and apply

Learning outcomes • Recall the causes of plant diseases as bacteria, viruses, fungus and insects. [O1] • Describe the symptoms of infection by pathogens and damage by ion deficiency. [O2] • Understand how plant disease can be identified using monoclonal antibodies. [O3] Skills development

• Low and standard demand students research one of the plant diseases mentioned and produce a poster

(see Worksheet 4.16.1 or 4.16.2). If there is no Internet, they can use the information in the Student Book. [O1, O2]

• High demand students should produce a fact sheet for inexperienced gardeners about plant diseases. The

fact sheet should include indicators to look out for and advice on how to get the diseases identified. [O2, O3]

• WS 1.4 Explain everyday and technological applications of science. Evaluate associated personal, social, economic and environmental implications, and make decisions based on the evaluation of evidence and arguments.

• WS 3.8 Communicating the scientific rationale for investigations, methods used, findings and reasoned

conclusions through paper-based and electronic reports and presentations using verbal, diagrammatic, graphical, numerical and symbolic forms.

• WS 4.1 Use scientific vocabulary, terminology and definitions. Resources needed Image of plant with rose black spot; image of a plant with tobacco mosaic virus; video of aphids feeding; poster material; access to Internet. Worksheet 4.16.1 (low demand); Worksheet 4.16.2 (standard demand); Worksheet 4.16.3 (high demand); Technician’s notes 4.16

Extend Ask students able to progress further to:

• discuss why using chemical insecticides to kill aphids may not be the best solution. [O3] Plenary suggestions • Read out the statements on the Technician’s notes – some are true and others are false. Ask the students to identify if they are true or false – this can be done with thumbs up or thumbs down. Once a false statement is identified, can they change it to make it true?

Answers to Worksheet 4.16

Digital resources Key vocabulary chlorosis

Sample answers for table

Teaching and learning

Plant disease or deficiency

Engage

tobacco mosaic virus

• Show students an image of a plant with rose black spot. [O1] • Ask students to write down what is wrong with the plant, what might have caused it and why it is a problem

for the plant. This can be done in small groups using mini-whiteboards and should be revision from the lesson on fungal diseases. [O1]

• Each group reports back to the class to build up a picture of what they remember about fungal plant

aphid infection

diseases. [O1]

Symptoms

Cause

Treatment or control

mottling or discoloured leaves

infection by a virus

use insecticide to kill insects

curled leaves

that spread the disease

stunted growth

destroy any infected plants

yellow streaks or spots on leaves

clean infected tools

decreased growth rate

aphids feeding on the

insecticides or removing the

mottled or yellow leaves

sap

aphids by hand or using

wilting

Challenge and develop

natural predators

low yields

• Use the introduction to discuss causes of disease in plants; explain that as well as bacteria, fungi and

nitrate deficiency

stunted growth

not enough nitrates in

viruses, insects will also damage plants. [O1]

add minerals to soil

soil

• Show students a video of aphids feeding. Ask the students to suggest what they are feeding on and what

magnesium deficiency

chlorosis (yellow leaves)

damage that will do to the plant, including the spread of diseases. [O2]

not enough

add minerals to soil

magnesium in soil

• Show students an image of a plant with tobacco mosaic virus. Ask them to describe the symptoms and suggest why it will affect the rate of photosynthesis. [O1, O2]

• Ask students to recall what they remember about mineral deficiency in plants. Remind them of the symptoms

Identifying plant diseases 1. brown rot, 2. apple scab, 3. club root, 4. blossom end rot

of nitrate deficiency and introduce the term ‘chlorosis’, caused by magnesium deficiency. [O1, O2]

AQA GCSE Biology: Teacher Pack

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AQA GCSE Biology: Teacher Pack

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Chapter 4: Health matters

When and how to use these pages: Check your progress, Worked example and End of chapter test

Percentage

Check your progress

Total marks Q. 18 (AO2, A03) 2 marks Q. 19 (AO2) 2 marks Q. 20 (AO3) 6 marks

Check your progress is a summary of what students should know and be able to do when they have completed the chapter. Check your progress is organised in three columns to show how ideas and skills progress in sophistication. Students aiming for top grades need to have mastered all the skills and ideas articulated in the final column (shaded pink in the Student book).

Most Demanding [Higher Tier]

Q. 17 (A02) 5 marks

Check your progress can be used for individual or class revision using any combination of the suggestions below:

More Challenging [Higher Tier]

Q. 13 (AO2) 2 marks Q. 12 (AO2) 4 marks Q. 11 (A01) 2 marks



Q. 14 (A01) 1 mark



Ask students to construct a mind map linking the points in Check your progress Work through Check your progress as a class and note the points that need further discussion Ask the students to tick the boxes on the Check your progress worksheet (Teacher Pack CD). Any points they have not been confident to tick they should revisit in the Student Book. Ask students to do further research on the different points listed in Check your progress Students work in pairs and ask each other what points they think they can do and why they think they can do those, and not others

Q. 15 (A02) 1 mark



Q. 16 (A01) 2 marks

 

Worked example Going Further [Foundation and Higher Tiers]

Give students the Worked example worksheet (Teacher Pack CD). The annotation boxes on this are blank. Ask students to discuss and write their own improvements before reviewing the annotated Worked example in the Student Book. This can be done as an individual, group or class activity.

Q. 9 (A01) 1 mark Q. 8 (A02) 2 marks Q. 7 (A02) 1 mark



Q. 10 (A01) 1 mark

The worked example talks students through a series of exam-style questions. Sample student answers are provided, which are annotated to show how they could be improved.

End of chapter test

AQA GCSE Biology: Teacher Pack

Student Name

Getting Started [Foundation Tier]

Marking Grid for End of Chapter 4 Test

Q. 1 (A01) 1 mark

Q. 2 (A01) 1 mark

154

Q. 3 (A01) 2 marks

AQA GCSE Biology: Teacher Pack

Q. 4 (A01) 1 mark



Questions could be used as a test once you have completed the chapter Questions could be worked through as part of a revision lesson Ask Students to mark each other’s work and then talk through the mark scheme provided As a class, make a list of questions that most students did not get right. Work through these as a class.

Q. 5 (A01) 1 mark

  

Q. 6 (AO2) 1 mark

The End of chapter test gives students the opportunity to practice answering the different types of questions that they will encounter in their final exams. You can use the Marking grid provided in this Teacher Pack or on the CD Rom to analyse results. This shows the Assessment Objective for each question, so you can review trends and see individual student and class performance in answering questions for the different Assessment Objectives and to highlight areas for improvement.

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Chapter 7: Variation and evolution

Biology

Chapter 7: Variation and evolution

Check your progress

Worked example

You should be able to:

Scientists in Germany have investigated the resistance of rats to two poisons – warfarin and bromadiolone.



distinguish between variation caused by genes and by the environment

➞



describe how variation contributes to an organism’s survival



describe how natural selection leads to a struggle for existence

➞



understand the mechanism of genetic variation



explain how environmental change operating with natural selection leads to the evolution of a new species

Olfen

Berlin



recall early ideas about evolution

recall that the theory of evolution was developed independently by Darwin and Wallace identify reasons why evolution was not, to begin with, accepted

recall and use the classification system developed by Linnaeus

identify the causes of extinction

➞ 

➞ ➞



describe the evidence that led to the development of the theory of evolution by Darwin and Wallace identify the reasons why genetics and evolution were not linked until the twentieth century explain the features used to develop evolutionary trees

describe how new species, predators and competitors can lead to extinction

➞ 

➞ ➞



explain the evidence for the occurrence of evolution and natural selection

Stadtlohn

GERMANY

Dorsten 300 km

Drensteinfurt Ludwigshafen

Some of their results are shown below. explain how the scientific work of many scientists contributed to the gene theory explain how microscopic examination, fossils and biochemistry have led to modern evolutionary trees evaluate circumstances that may lead to another mass extinction

Town

Not resistant to either poison (%)

Resistant to Resistant to warfarin alone (%) both poisons (%)

Dorsten

Drensteinfurt

Ludwigshafen

100

Olfen Stadtlohn 1

Explain why the data collected are evidence for natural selection.

In a population, some rats will be resistant to the rat poisons, and survive their use. These will pass on their resistant genes. These will spread through the population as the rats breed, until most of the rats become resistant. 2

Suggest reasons for the differences in the degree of resistance to the poisons.

Resistance is greatest in Stadtlohn and Olfen. There is no resistance to the poisons in Ludwigshafen. This could be because of the locations of the towns. If the towns are close together, populations can interbreed so that the resistant gene(s) spread. Ludwigshafen is further away.

AQA GCSE Biology: Teacher Pack

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AQA GCSE Biology: Teacher Pack

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This is a concise answer, but one that is not fully detailed. The student should have mentioned that some rats in a population will be resistant to the rat poison because of mutations. It is also important to say that these mutations will spread rapidly through the population because of the rats’ rapid reproductive rate.

In this answer the student has overlooked the fact that mutations arise spontaneously in populations, as well as being spread by sexual reproduction. These could also arise at a greater rate in Stadtlohn and Olfen, perhaps because of the numbers of rats in the different towns, which we do not know from the data given. The data suggest that resistance arises first to warfarin, followed by bromadiolone. You do not need to know the reason for this, but warfarin was a ‘first generation’ poison, while bromadiolone was developed because rats became resistant to warfarin.

Introduction Maths

Introduction to the course

Science has always had a strong relationship with maths and this continues. What has been

Welcome to the Collins GCSE Science course. These materials have been developed by a team of experts drawing on many years’ experience in teaching, curriculum development and educational publishing. They have been produced to support you, the professional in the classroom, teach more effectively and your students to make good progress. The aim is to both develop students’ interest in science and enable them to attain grades that reflect a mastery in the subject. The course is not intended to be prescriptive or restrictive, shoe horning teachers into a very particular way of teaching, but to be used in a range of ways. On the other hand, it doesn’t offer a bewildering array of options which require a lot of filtering and selection of activities.

strengthened in this set of courses is the specificity of the location of the skills and the role of the skills in exams. It has been made very clear in the specifications which skills relate to which topics and the exams will disadvantage candidates who can’t demonstrate mastery of the relevant skills. In the course we have taken a ‘two pronged approach’. Mathematical skills are used in context as key concepts are covered. They are reflected in questions that are set and students are shown how they are drawn upon at particular points. However, we know that for some students this won’t be sufficient. Therefore, we have developed other spreads that will focus on a particular set of mathematical skills and explore how they develop. These always place the skills into a scientific context, so it is clear why they are relevant, but the text is led

We are aware that specifications sometimes seem to change at an alarming rate. We have tried to reflect both the key features of the new specifications and the classic elements of high quality teaching.

by the developing mathematical skill.

Practical skills Practical work has a strong role in supporting students’ developing understanding of science, and many people involved in the British system are passionate about ensuring this role is

Key changes for the courses introduced in 2016 Non-modular The new specifications have a non-unitised structure. Content can be covered in any order deemed appropriate. This doesn’t mean that the order doesn’t matter. There are a number of principles that can be used when selecting a ‘running order’, including: •

deciding which topics are more accessible for students at an earlier stage in their

maintained. In recent years much of the debate is about how it should be assessed, and successive specifications have used different approaches. In this series there is no direct assessment of practical skills. Instead the approach is being taken that enquiry will be put in a better place if students are assessed on their mastery of skills and processes in the final exams. A minimum of 15% of marks will be allocated to questions relating to the stipulated practical investigations. However, these won’t necessarily be AO1 questions; as well as understanding and recalling the procedures, candidates will

GCSE studies

also be expected to apply the skills to other contexts and to interpret and evaluate evidence.

•

identifying which topics need to be covered to give access to which other concepts

•

using topics that have possibly greater appeal, due to the role of practical work or

As well as covering the effective running of the investigations themselves, the Collins course

engaging contexts, to sustain interest over the whole course. However, what is also important is to build in assessment, tracking and intervention. You need to know if students are developing an understanding that at least corresponds to their ability and to be able to respond.

also offers guidance on placing these in a wider context, so that students can see how their skills and understanding can be used and assessed.

Synoptic questions Another of the key changes is the introduction of synoptic questions, drawing upon more than one set of ideas. The justification behind this is that scientists often need to draw upon

The Collins course offers a particular route. The exams are designed to assess one part of

ideas and processes from different areas of science. Again, this is reflected in the

the content in Paper 1 and the other part in Paper 2. One approach is to teach the ‘Paper 1

assessment approach developed.

content’ first and then the ‘Paper 2 content’. This means that a past Paper 1 could be used as a ‘half way assessment point’. However, the materials don’t have to be used in this order. It may be decided that the needs of students are not best served by concentrating all the material on one topic in one place, but rather by revisiting it later on. AQA GCSE Teacher Pack Collins Biology: GCSE Science

Extended written responses Unlike the previous set of specifications, QWC (Quality of Written Communication) is no longer being assessed in science. However, there is a requirement for candidates to be able to display an ability to develop and sustain a longer response. This is reflected in the

AQA GCSE Teacher Pack Collins Biology: GCSE Science

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