KS3 Science Now Teacher Pack

Curriculum mapping The mapping table below shows the links between the KS3 Science Now units and topics, and the KS3 Programme of Study and the AQA Combined Science Trilogy Specification. It also outlines the objectives covered in each topic, the working scientifically objectives covered in each unit, and the corresponding topics of the 2014 Collins KS3 Science course.

KS3 Science Now Unit

KS3 Science Now Topic

Objectives

Collins KS3 course

KS3 Programme of Study

1. Cells and organisation

1.1 Organisation of multicellular organisms

- define the terms cell, tissue, organ, organ system, organism - explain the organisational structure in multicellular organisms - compare the strengths and weaknesses of unicellular and multicellular organisms

1.1.7 Understanding organisation in multicellular organisms

1.2 Comparing plant and animal cells

- describe the structures found in plant and animal cells - explain the functions of structures in plant and animal cells - compare plant and animal cells - identify the parts of a light microscope - describe how we observe cells using a light microscope - interpret evidence from microscopes - recognise different types of unicellular organisms

1.1.3 Comparing plant and animal cells

- the hierarchical organisation of multicellular organisms: from cells to tissues to organs to systems to organisms - the functions of the cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria and chloroplasts - the similarities and differences between plant and animal cells

1.3 Studying cells

1.4 Unicellular organisms

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1.1.2 Historical ideas about living things

- cells as the fundamental unit of living organisms, including how to observe and record cell structure using a light microscope

1.1.5 Understanding

- the structural adaptations of some unicellular organisms

AQA Combined Science Trilogy Specification 4.1.1.1 Eukaryotes and prokaryotes 4.1.1.2 Animal and plant cells 4.1.1.3 Cell specialisation 4.1.1.5 Microscopy

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Working scientifically - Understand that scientific methods and theories develop as earlier explanations are modified to take account of new evidence and ideas, together with the importance of publishing results and peer review.

- Select, plan and carry out the most appropriate types of scientific enquiries to test predictions, including identifying independent, dependent and control variables.

- Make and record observations and measurements using a range of methods for different investigations; and evaluate the reliability of methods and suggest possible improvements.

-Interpret observations and data, including identifying patterns and 7

Unit 1: Cells and organisation

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Cells and organisation

PROGRESSION MAPPING Key Stage 3

Key Stage 2

identify that humans and some other animals have skeletons and muscles for support, protection and movement

Key Stage 4

Eukaryotes and prokaryotes

Cells and organisation Identify and name the main parts of the human circulatory system, and describe the functions of the heart, blood vessels and blood

Describe how living things are classified into broad groups according to common observable characteristics and based on similarities and differences, including microorganisms, plants and animals

Describe the simple functions of the basic parts of the digestive system in humans

cells as the fundamental unit of living organisms, including how to observe, interpret and record cell structure using a light microscope

Animal and plant cells

the functions of the cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria and chloroplasts the similarities and differences between plant and animal cells

Cell specialisation

the role of diffusion in the movement of materials in and between cells the structural adaptations of some unicellular organisms

Microscopy

the hierarchical organisation of multicellular organisms: from cells to tissues to organs to systems to organisms.

Identify how animals and plants are adapted to suit their environment in different ways and that adaptation may lead to evolution

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Unit 1: Cells and organisation SEQUENCE RATIONALE We recommend that Part A topics are taught before Part B topics. The table shows how the content progresses.

Part A topics building on prior learning from Key Stage 2

Part B topics building on ideas developed in Part A

1.1 Organisation of multicellular organisms

1.5 Specialised cells

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the hierarchical organisation of multicellular organisms: from cells to tissues to organs to systems to organisms the functions of the cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria and chloroplasts

This topic progresses from Key Stage 2 by developing ideas learned about whole organisms and some organ systems, such as the circulatory system, to provide the bigger picture of organisation to cellular level.

the functions of the cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria and chloroplasts

This topic builds on 1.1 and 1.2 by developing ideas of typical cells. Examples of cells adapted for specific purposes are covered and students apply knowledge and understanding of the functions of cell parts and organelles. This topic builds on 1.3 by using those skills to identify more diverse and specialised cells.

1.2 Comparing plant and animal cells

1.6 Movement in and out of cells: diffusion

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the similarities and differences between plant and animal cells

This topic progresses from Key Stage 2 where students explored common features of plants, animals and microorganisms. These similarities and differences are now studied at cellular level.

the role of diffusion in the movement of materials in and between cells

This topic builds on 1.2 and 1.4 by explaining how substances are transported in and out of cells and unicellular organisms. Calculations of surface area-tovolume ratio and its implications are introduced.

1.3 Studying cells 

cells as the fundamental unit of living organisms, including how to observe, interpret and record cell structure using a light microscope

This topic progresses from Key Stage 2 by observing and comparing the building blocks of plants and animals that students have learned to observe and classify previously as entire organisms.

1.4 Unicellular organisms 

the structural adaptations of some unicellular organisms

This topic progresses from Key Stage 2 where students learned that microorganisms are classified separately from plants and animals. Students learn about the cellular structure of microorganisms and relate structure to function.

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Unit 1: Cells and organisation MATHS AND WORKING SCIENTIFICALLY SKILLS MAPPING 

Understand that scientific methods and theories develop as earlier explanations are modified to take account of new evidence and ideas, together with the importance of publishing results and peer review.

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Select, plan and carry out the most appropriate types of scientific enquiries to test predictions, including identifying independent, dependent and control variables.

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Make and record observations and measurements using a range of methods for different investigations, and evaluate the reliability of methods and suggest possible improvements.

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Interpret observations and data, including identifying patterns and using observations, measurements and data to draw conclusions.

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Present reasoned explanations, including explaining data in relation to predictions and hypotheses.

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Understand and use SI units and IUPAC (International Union of Pure and Applied Chemistry) chemical nomenclature.

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Use and derive simple equations and carry out appropriate calculations.

MATHS AND PRACTICAL SKILLS QUESTION COMMENTARY Q6: This tests students’ ability to convert units, without the distraction of a scientific context. It also introduces nanometres, which may be unfamiliar, but at higher levels, students should be able to use the information given to provide an answer. To achieve at the highest level, students need to show part a iii to one decimal place, in keeping with the rest of the data. For students who struggle, a number line may be useful.

Q8: This tests whether students can design a simple experiment. This type of investigation is observation, rather than the more usual ‘fair testing’. At the higher levels, the distinction should be obvious, but some students may need to be told not to treat this as fair testing with independent, dependent variables, etc.

Q9: This involves two calculations: calculating total magnification and then using the magnification equation.

The subject of the equation needs to be changed, which is an expectation for students at higher levels.

Q10: This tests investigation analysis skills. It asks students to apply the calculation for rate; this is targeted at the higher levels. To be working at the highest level, students are expected to quote the time taken in part b to one decimal place, in keeping with the rest of the data, and to use the correct units in answers, such as g/l in part c.

IDEAS FOR USING THE STARTER ACTIVITIES How many cells?

The first starter activity can be used as an opportunity to revisit what is living and non-living. Some students may not believe that plants and bacteria are living and, therefore, may not recognise that all of these organisms are made of cells. Many may believe that the sponge is a plant, rather than an animal.

Students may identify humans as the most complex organisms because they have organs and carry out processes such as walking and eating. This provides an opportunity to revisit the characteristics of living things to demonstrate that even simple living things feed, move, grow, reproduce, etc.

Seeing cells The second activity allows students to reflect on a world without the developments made into viewing cells, bodies, viruses, etc. Students are first asked to think about how we can see beyond the unaided eye, for example, in hospitals. Students may mention the microscopes used to look at the back of the eye, X-rays and scans (for example, ultrasound, MRI, CT scans).

The ’what if’ question may raise points such as: we wouldn’t be able to diagnose issues, such as cancer; and we may not be able to develop vaccines without being able to study viruses.

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Unit 1: Cells and organisation

1.1

Organisation of multicellular organisms

Misconception or challenge

Response

Students may not identify plants and microorganisms (microbes) as living things, and therefore may not understand that all living things contain cells.

Ensure that plants and microorganisms (microbes) are used repeatedly as examples of living things, rather than focusing only on animals. The characteristics of living things could be revisited and applied to plants and microbes.

Students may believe that all unicellular organisms are bacteria.

Use a range of examples of unicellular organisms, such as yeast, amoeba, paramecium, etc.

Students may find it difficult to understand the relationship between the terms ‘atom’ and ‘cell’, and some may think of them as the same thing; this is because we sometimes refer to each as the ‘building block’ in Chemistry and Biology, respectively.

Refer to atoms when teaching cells; explore the hierarchy and magnitude, and make the distinction. For example, everything is made from atoms, including cells.

QUESTION COMMENTARY Q1–3: The terminology in this topic can be a challenge due to the number of key terms and the similar word roots. These questions test the language of organism organisation. Using the correct language is important when applying learning to human and plant systems later in Key Stage 3, so it is worth ensuring the right language is embedded.

Q9: This relates to the purpose of complexity in multicellular organisms and allows students to practise forming an explanation. This can be a challenge, with some students tending to describe rather than explain.

The use of the word ‘therefore’ in their answer, as given in the worked example, or ‘because’, can support the explanation. ‘Explain’ as a command word causes issues for students at all levels of ability; this, paired with its frequency in exam questions, means it is worth practising for all abilities.

Q10: This dips into the overarching idea of evolution, which was covered in Key Stage 2. Students are expected to sequence the steps of how multicellular organisms evolved. It also leads into the specialisation of cells, which is covered later. This is high-level thinking, and at the highest attainment levels you would expect a logical sequence of steps, for example: grouping of cells, adaptation, formation of tissues, organs, organ systems, etc.

Q11: Students may find it difficult to know where to start with this type of question. Writing out each 20minute step (as shown in the worked example) is a good, simple strategy. At lower attainment levels, scaffolding may be needed, but at higher attainment levels, this should be tackled independently.

INTERLEAVING OPPORTUNITIES 

Organ systems (Units 2 and 3): any body system, such as the digestive system, breathing system or circulatory system, where students can relate organ system structure to the function and hierarchy of cells, tissues, organs, organ systems and, ultimately, organisms.

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Breathing system (Unit 3): especially if students are considering the impact of disease and lifestyle on the gas exchange system.

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Retrieval questions

Unit 1

Retrieval questions

1.1 Organisation of multicellular organisms 1 Describe the key difference between multicellular and unicellular organisms.

2 Identify which two of the following have organ systems: animals plants bacteria 3 Name the organ system that each of the following organs are part of: a brain b small intestine c heart d lungs 4 Arrange the following terms in order of size, from small to large: organ, organism, organ system, cell, tissue, organelle 5 Multicellular organisms have several different types of cells. Explain why having different types of cells is an advantage.

-----------------------------------------------------------------------------------------------------------------------------------------------1.2 Comparing plant and animal cells 1 Name the three parts of cells common to both plant and animal cells.

2 Name three parts which plant cells may have but which animal cells do not.

3 In a cell, where would you find the: a genetic material (DNA)? b organelles?

4 Describe the role of the: a cell membrane b cell wall.

5 Plant cells have more parts (organelles) than animal cells. Give a reason why.

-----------------------------------------------------------------------------------------------------------------------------------------------1.3 Studying cells 1 What is a microscope used for?

2 Name the two types of lens found on a light microscope.

3 Explain why stain is sometimes used on a sample being observed with a microscope.

4 A sample is being observed using an eyepiece lens of ×10 and an objective lens of ×25. What is the total magnification?

5 Convert the following: a 1000 µm to mm b 10 mm to µm -----------------------------------------------------------------------------------------------------------------------------------------------1.4 Unicellular organisms 1 What does the prefix ‘uni’ mean, as in ‘unicellular’?

2 Name three examples of unicellular organisms.

3 Which do we believe existed first: prokaryotes or eukaryotes?

4 Describe how the genetic material is stored in a prokaryote and eukaryote.

5 Some unicellular organisms can move and feed by photosynthesis. What adaptations might these organisms have: a to feed? b to move?

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Retrieval questions 1.5 Specialised cells 1 Is a specialised cell that contains a cell wall and a vacuole an animal cell or a plant cell?

2 Why is it important that living things have specialised cells?

3 a Of the cells shown, which is adapted: i to carry impulses around the body? ii to create movement? iii to carry genetic material to an egg?

A

B

C

b How is each cell adapted to its job?

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a Which cell is adapted to absorb water from the soil? b How is this cell adapted to its job? a Draw a cell that is adapted to carry oxygen around the body. b Explain how this cell is adapted to its job.

-----------------------------------------------------------------------------------------------------------------------------------------------1.6 Movement in and out of cells: diffusion 1 What moves during diffusion?

2 Which part of the cell controls what diffuses in and out?

3 Select the correct answer.

Particles move from a higher / lower concentration to a higher / lower concentration during diffusion.

4 Describe and explain the effect of increasing temperature on diffusion.

5 Of the two objects below, which: a has the largest surface-area-to-volume ratio? b would be more efficient in getting the substances that it needs in and out of the cell?

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