How does the environment influence the animals and plants living in a habitat?

•   that different habitats have different features

•   that different habitats support different organisms

•   that the distribution of organisms in different habitats is affected by environmental factors,
eg light, nutrients or water availability

•   to organise, sequence and link what they say so listeners can follow it

•   Ask pupils about environments or habitats they studied at key stage 2 and explain that in the first part of the work in this unit they are going to look at features of habitats.

•   Provide pupils with stimulus material, eg video of the Arctic, poster of woodland life, picture of cacti in a desert, underwater scene, worms in a wormery. Ask the pupils to describe the physical features of each habitat and identify major environmental factors, eg light intensity, oxygen availability, temperature range.

•   With pupils, decide on a limited list of animal and plant species for each habitat. Remind pupils of the importance of making sure listeners can follow their argument, and ask them, in groups, to use secondary sources to investigate how species are adapted to life in one habitat and to present their findings, eg orally, using overhead transparencies (OHTs) or flip charts.

•  identify features, eg light, temperature range, which are different in different habitats

•  describe adaptations to life in a variety of habitats such as:

    – water, eg streamlined shapes help animals move through the water, water plants float or have long stems to reach surface waters

    – underground, eg streamlined shapes, adaptations for tunnelling, poor sight but good senses of smell and vibration

    – woodland, eg colour vision, climbing plants and camouflage, early growth and flowering before the canopy develops

•  pick out appropriate adaptations and explain clearly their significance

•  make an oral group presentation of their findings

•   This activity is intended to help teachers find out what pupils know about habitats and how organisms are adapted to them. Teachers will need to take this into account in later work.

•   Pupils may need help to stay focused on the question of adaptations to the habitat and help in selecting appropriate material from a large quantity of general information on the lives of particular plants and animals.

•   This unit includes work on seasonal changes. It is useful to have a log of species sighted in the school and its surroundings. If possible, encourage pupils to note vegetation and other changes in the school environment over the academic year.

•   Extension: pupils could explore a wider variety of habitats through
an interactive field trip,
eg www.field-guides.com

How do environments vary?

•   that some animals are adapted to daily changes in their habitat

•   how to measure and record changes in environmental factors

•   how to interpret patterns in data

•   Ask pupils to predict how physical environmental factors around the school, eg light intensity, temperature, humidity, noise levels, would change over a 24-hour period and how they could measure the changes. With pupils, set up instruments, eg datalogging equipment with a light probe, automatic weather station, temperature and sound sensors, to monitor changes. Provide pupils with data about environmental changes around the school over a 24-hour period and help them to describe what these show and to identify links between the different changes.

•   Ask pupils to suggest how the population of plants and animals in the school habitat would change over the same time, eg crows and starlings visiting dustbins in daylight, squirrels visiting after school finishes, foxes after dark; slugs, cats, mice, bats active at night. Using their ideas, secondary sources and first-hand observation where possible, help pupils to generate comparative lists of animals active during the day, at dawn and dusk and those which are nocturnal.

•  describe changes in physical environmental factors, eg temperature, light intensity, over a 24-hour period

•  interpret data about daily changes and explain in simple terms, eg beginning to get dark

•  relate changes in variables, eg light and temperature, to each other

•  relate plant and animal activity to environmental changes

•   There is an opportunity to use
datalogging equipment. Secondary sources, eg newspapers, Ceefax and geography weather stations, could be used to confirm readings.

•   Schools near the coast and by tidal rivers have an opportunity to focus on adaptations to changes in these habitats.

•   Schools with CCTV may be able to monitor animal activity at night.

•   how to frame a question to be investigated

•   how to decide what factors are relevant to a question

•   about the importance of sample size

•   to consider results in relation to the sample used

•   Using observations of small invertebrates in the school grounds or elsewhere, ask pupils to generate a suitable question about how the activity of an invertebrate, eg woodlice, snails, brine shrimps, daphnia, varies with environmental changes, eg dampness, light/dark, and to plan and carry out an investigation.

•   Help pupils to produce an account of what they did, focusing on the size of sample they used, the factors they could and could not control and how confident they were in their results.

•  identify a suitable question for investigation

•  identify and control relevant variables

•  choose an appropriate way of obtaining an adequate sample

•  explain why they are, or are not, confident in their results, eg 18 out of 20 times the snails went to the damp, I think this is sufficient; we only used 6 woodlice and 4 of them chose the dark, I think we need to use more than 6 woodlice to be sure

•   Extension: pupils could find out about adaptations to daily changes in two or three plant or animal species.

•   If any animals are brought into the classroom, ensure that they are treated carefully and that they are returned to the habitat from which they came as soon as possible.

Safety

– teachers will need to check pupils’ plans for health and safety before practical work begins

– wash hands after handling animals. Particular pupils may have allergies and these should be appropriately taken into account. Wipe benches with disinfectant

How do environments vary? (Cont.)

•   how some animals are adapted to seasonal changes in their habitats

•   that adaptations may be to avoid climatic stress

•   Provide pupils with overwintering structures or photographs or video clips of these as stimulus material, eg onion bulb, pupa, twig with buds, carrot, plastic bag of hair from a moulting pet. Ask pupils to suggest when they would normally be found and their function. Show videos of habitats at different times of the year and ask pupils to identify differences and describe the consequences of these for the organisms in the habitat. Ask pupils to describe from their own knowledge how plants in the school habitat change over the year and predict the likely effects of the changes on the animals in the locality.

•   Provide pupils with key words and phrases, eg migration, hibernation, overwintering of pupae, dormant structures, making food stores, thicker insulation, and ask pupils to use secondary sources to find out about these and how they help animals avoid climatic stress. Ask pupils to describe what they found out and help them to contribute to a summary sheet about seasonal changes.

•  identify ways in which habitats vary through the year

•  describe some strategies which plants and animals adopt to avoid climatic stress 

•   It may be useful to have data about temperature ranges and daylight hours in the locality of the school to support this work.

•   Some dormant twigs can be frozen successfully for use at other times of year. Ash trees are usually among the last to come into leaf.

Checking progress

•   to summarise and make connections between key ideas about adaptation to a habitat

•   Provide pupils with a list of adaptive animal and plant characteristics and ask them to decide on the six most important for a particular habitat. Ask them to explain their choices and ask others to evaluate these critically, identifying the advantages the adaptation gives the organism. Help pupils to use the results of the work to make generalisations about adaptation.

•  identify adaptations for particular habitats

•  explain the advantages adaptations give an organism

What is a feeding relationship?

•   that animals have features which are adaptations against predators

•   that animals are adapted to their particular food source

•   to collect sufficient data to reduce error and obtain reliable evidence

•   Review pupils’ knowledge of predators and prey by providing stimulus material, eg posters, photos, pictures, video clips, preserved and live specimens, of predatory animals and prey species, eg eagle, dog, pike, bat, spider, rabbit, antelope, snail, and asking pupils to describe how the predators are adapted for finding, catching and killing their prey and how prey species are adapted for detecting and avoiding predators. Help pupils construct tables of general features of predators and prey, eg predators may have eyes forward, acute vision and sense of smell, sharp claws/talons/beaks for piercing and tearing, may ambush or hunt by stealth, whereas prey may have eyes at the side, acute hearing and sense of smell, be easily startled, be nocturnal, camouflaged.

•   Ask pupils to investigate the effect of beak shape in seed-eating birds, eg by using blunt and fine-pointed forceps to pick up and transfer seeds of varying sizes from a dish in one minute. Discuss with pupils how much data they need to gather for reliable conclusions.

•  identify predators and prey from information about commonly encountered animals

•  identify features of predators, eg a hooked beak, sharp claws, acute vision, ability to trap prey

•  identify features of prey animals, eg camouflage, acute senses, armour, speed

•  state how many observations they made and explain why this was appropriate

•   Nature centres, botanical gardens and zoological collections may have outreach teachers who can bring a selection of plants and animals into schools to illustrate adaptations to habitat and food source. In addition, they often have education programmes to support visits to their establishments.

•   Alternatively, pupils could use dough coloured with food dyes, or red and green wool, distributed on a marked-off stretch of grass to investigate the effectiveness of camouflage.

Safety  

– wash hands after handling animals. Particular pupils may have allergies and these should be taken into account. Wipe benches with disinfectant

What is a feeding relationship? (Cont.)

•   about characteristics of predator and prey species

•   to join ideas within sentences using links of cause, eg so, because, since

•   that all the organisms in a habitat can be linked together in food webs

•   that food webs are made up of a number of food chains which start with plants

•   that arrows in a food chain represent energy transfer

•   Establish by quick questions pupils’ understanding from work in key stage 2 of terms related to food chains, eg producer, consumer.

•   Present pupils with stimulus material, eg a habitat poster such as meadowland or woodland, and challenge them to make as many food chains as they can. Ask them to identify producers, consumers, herbivores and carnivores. Explain the direction of the arrows in the food chain and relate to energy transfer, with the Sun as the ultimate source of energy. Ask pupils to write a sentence about each food chain, using links of cause, eg so, because, since.

•   Ask pupils to find examples of animals that occur in more than one food chain and to explain what this shows about their food sources. Show pupils a food web and explain that it is a more accurate representation of feeding relationships.

•   Help pupils use the food chains they have generated to construct a food web for display. Provide pupils with secondary data so they can practise identifying food chains within a food web and constructing food webs from food chains.

•   Establish with pupils that food webs, food chains and terms, eg predator and prey are ways of describing feeding relationships.

•  sort organisms into a food chain

•  explain what is meant by, and identify, carnivore, herbivore, consumer, producer

•  identify food chains within food webs and describe what a food web shows

•  explain the direction of arrows in a food chain,
eg energy from the leaves passes to the caterpillar

•   In unit 7I ‘Energy resources’, the idea that food chains show energy transfer is introduced.

•   Food chains may also start with bacteria or fungi. However, at this stage it is acceptable for pupils to be taught that food chains begin with plants.

•   Pupils do not need to be familiar with the term ‘trophic level’ at this stage.

•   Extension: pupils could be asked to find out about different predators and prey and produce an account of how one of each is adapted.

What do food webs tell us?

•   to make careful observations of plants and animals and sources of evidence about animals’ food

•   to link organisms together in food webs

•   that some plants have adaptations to deter animals from feeding on them

•   to interpret evidence about food sources and draw conclusions from it

•   Ask pupils to suggest likely places to find plants and animals in the locality of the school, what species they think they might find and how the plants and animals might be linked in food webs. Encourage pupils to consider what evidence we use to find out what animals eat, eg owl pellets, remains near lairs and nests, thrush anvils, observations, teeth marks, bird droppings showing coloured berries have been eaten.

•   Show pupils how to use simple equipment and techniques, eg direct observation, pooters, tree beating, and ask them to find, identify and record as many species of plants and animals as possible within the school locality.

•   Ask pupils to record any observations which help to identify a food source, eg a greenfly found on a rose bush, woodlice found under decaying wood, fly entangled in a spider’s web, and to note plant features which may deter animals from feeding on them, eg prickles on holly, thistles, sting on nettles. If appropriate, extend this work using secondary sources.

•   Help the pupils to use the information gathered to construct a database using a data-handling programme.

•  identify plants and animals found in the immediate locality

•  state that a wide variety of organisms is found in quite small habitats

•  describe and explain what might provide evidence about animals’ food

•  identify features of plants which may deter animals from feeding on them

•  interpret evidence about food sources, eg the bird droppings are purple, so they could have eaten blackberries

•   This exercise can be done in very
small-scale habitats, eg flower bed, grass verge. It needs to be clear that the focus of the activities is identification of food webs, because pupils may have visited an area local to their school in key stage 2 to identify organisms, using keys, and to identify food chains.

•   Pupils are likely to be familiar with using keys to identify living things from their work at key stage 2. Some may need more practice.

•   It is not necessary to quantify species at this stage, but it may be useful to count the number of species identified and the number of individuals of different feeding types for possible use in year 8.

•   If any animals are brought into the classroom, ensure that they are treated with respect, their needs are met and that they are returned to their habitat as soon as possible.

Safety

– all off-site visits must be carried out in accordance with school/LEA guidelines

– pupils should wash their hands after handling animals and soil.
Particular pupils may have allergies and these should be taken into account. Dis­infect pooter mouthpieces

What do food webs tell us? (Cont.)

•   that all the organisms in a habitat can be linked together in food webs

•   to find information using contents, index, glossary,
key words or hotlinks

•   Provide pupils with secondary sources, eg reference books, CD-ROMs, databases, to find information about the diet of animals identified in the previous activity, and remind them how to use the index, contents section, key words and hotlinks. Ask them to add the information to the database. Ask them to use the information to construct food chains using the species identified, and to describe what the food chains show. Help the pupils to link their food chains together into a food web. Challenge the pupils to explain any missing links, eg absence of carnivores, such as owls or hawks. Help pupils to produce a display of their food web(s).

•  use organisational features of text to identify relevant information about the diet of animals

•  place food chains within a food web

•  describe how all the organisms in a habitat can be linked together in food webs

•  sequence a food chain

•  recognise that arrows in a food web or food chain show the direction of energy flow

•   Pupils may need reminding that food webs are the focus of the activity, as they may have found out about the food source of a local animal in key stage 2.

•   Pupils often have difficulty with the idea that arrows in a food chain represent energy flow. This could be reinforced here.

•   that factors influencing the number of organisms in one part of a food web have an effect on other parts of the web

•   Challenge pupils to suggest where there is competition between species in the food web. Reinforce their ideas by removing a plant species or adding two or more consumers and ask the pupils to predict the consequences.

•   Extend the work by asking pupils to use food webs, eg those generated in previous activities, to practise predicting the effects of altering the numbers of various organisms in a web. Use ICT simulations to test out the predictions made.

•  predict the effects of altering the numbers of an organism in one part of a food web

•  recognise that organisms living in a habitat compete with each other for food resources

•  recognise the importance of plants as the food source at the start of all food chains

•   This activity provides opportunities to use ICT simulations.

Reviewing work

•   that organisms in a habitat compete for resources from the environment

•   Construct a paper and wool model of a food web identified in the previous activity. Remove one animal species from the web, eg by cutting the strands of wool holding it in place. Ask the pupils what will happen to the animals that feed on that species. Challenge pupils to identify any other effects on the food web.

•   Extend by providing pupils with a food web in which at least one animal is a seasonal visitor and asking them to identify differences in the food web in other seasons.

•  predict and explain the consequences of changes in the organisms making up a food web

•   If the food webs generated earlier are very complex, it may be better to simplify them for this activity.

•   As an alternative, pupils could be given copies of a food web generated earlier, with an animal blanked out.