CONDITIONS SUPPORTING

LIFE

by Sarah Galea

MSS 4307 PGCE Biology Seminar

2015

WEEKS DEDICATED • Number of week - 5 weeks

• Number of Lesson

20 single lessons (40 minutes) or

10 double lessons (80 minutes)

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MISCONCEPTIONS

‘’Students understanding of ecological relationships depends on their concepts of ‘plant’ and ‘animal’, and also on their knowledge of habitats and use of physical principles. For instance, many students consider only large land animals as animals.’’

‘’Carnivores can exist in a plant free world if they reproduce enough.’’

‘’Few students think of oxygen need as a reason why animals can’t live without plants.’’

‘’A change in the population of one species would affect only those species related to it directly as predator or prey.’’

‘’A change in the size of prey population would have no effect on its predator population.’’

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RECURRING THEMES

• That all organisms in an ecosystem depend on their physical environment to survive

• That animals cannot survive without the presence of plants in their ecosystem

• Plants do not need animals in their ecosystem to flourish and grow

• How biotic organisms react to both biotic and abiotic conditions in their ecosystem determines population size

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INTRODUCING THE TOPIC

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• Probe for prior knowledge of concepts related to ecology.

• What the students think animals and plants need to survive.

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ECOLOGISTS

ECOSYSTEMS

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Ecosystems Limiting Factors

Lack of RainNon-Living

ThingsLiving Things

Abiotic

Biotic

Population

Communities

All of the organisms of the

same species living in an area

All the populations of

different species in an ecosystem

are

contain contain

are

are affected

by

defined as

defined as

form

form

USING A CONCEPT MAP

example

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LIGHT

TEMPERATURE

WATER

NUTRIENTS &

SOIL

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ABIOTIC FACTORSThe Physical Environment

PRODUCERS

CONSUMERS

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THE BIOLOGICAL FACTORS

DECOMPOSERS

BIOTIC FACTORS

HUMANS ARE NOT PART OF THE ENVIRONMENT.

• Humans are important biotic factors in the environment. Many of our activities directly affect other organisms and their populations.

• Our activities also affect abiotic factors in the environment; for example, when people alter a landscape and waterway by building a dam.

MISCONCEPTION

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COMPETITIONAll living organisms produce more offspring than can possibly survive therefore ︎competition for factors (resources) necessary for life such as:

• food and light in plants • space • breeding partners

Resources +

Space

Food

Breeding Partners or Mates

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INTRA-SPECIFIC COMPETITION

Competition︎ between members of the same species

• For territory, food, nesting sites and mates.

• Best adapted offspring survives only healthiest characteristics of a species are passed on to next generations.

Animals compete for resources, but plants DO NOT

Plants compete for sunlight, water, space, and soil nutrients. There are even plants that secrete toxic chemicals into the soil, which prevents other plants from growing nearby.

MISCONCEPTION

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Competition ︎between different species.

For Territory, food and nesting space.

A. Weeds compete with crops plants for soil nutrients, light, etc.

B. Pest insects compete with humans for food (by feeding on crops).

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INTER-SPECIFIC COMPETITION

PREDATOR-PREY RELATIONSHIPSCandidates should be able to illustrate these principles through specific examples, ideally taken from the local environment.

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USE OF ANIMATION

http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/environment/2_compete_or_die2.shtml

SIMULATION WITH GRAPH

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SYMBIOSIS

PARASITISM COMMENSALISM MUTUALISM

A RELATIONSHIP WHICH IS BENEFICIAL TO ONE ORGANISM BUT HARMFUL TO THE OTHER.

A RELATIONSHIP IN WHICH ONE ORGANISM DERIVES BENEFITS WHICH DO NOT HARM THE OTHER.

A RELATIONSHIP IN WHICH BOTH ORGANISMS DERIVE BENEFITS.

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PARASITISM & MUTUALISM

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PEST CONTROL

Biological Pest Control

Organisms in an ecosystem will have to learn to compromise in order to survive.

Misconception

Organisms which are harmful to humans or their interests. Destroy crops or stored foods

PESTS

Ladybirds — Aphids

Mutualism as demonstrated by the relationship between gut flora and herbivorous mammals, and root- nodule bacteria and leguminous plants.

MUTUALISM

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LIGHT

TEMPERATURE

WATER

NUTRIENTS &

SOIL

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ABIOTIC FACTORSAbiotic and biotic factors limit the population size and spread. Candidates should appreciate that the uncontrolled growth of any species has negative effects on the environment and the survival of the same species.

(i) Major temperature variations on Earth (polar, temperate and tropic regions) and their effect on the distribution of vegetation.

TEMPERATURE

Type of vegetation is influenced by temperature need be considered.

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ecosystems workshop — diff climate animals

T E M P E R AT E Z O N E

T E M P E R AT E Z O N E

P O L A R Z O N E

T R O P I C A L Z O N E

T R O P I C A L Z O N E

P O L A R Z O N EWORLD CLIMATES

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http://www.abpischools.org.uk/res/coResourceImport/modules/skin/en-flash/skinstructure.cfm

INTERACTIVE ANIMATION

Structure of the skin and its role in temperature regulation.

TEMPERATURE CONTROL IN HUMANS

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HOT TEMPERATURE

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COLD TEMPERATURE

EPIDERMIS

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Candidates should appreciate the characteristics of endothermic (homoiothermic) animals, such as humans, and ectothermic (poikilothermic) animals.

ectoterms do not need a constant body temp - false try very hard to maintain a set temp but can’t control their metabolism !!!!!!!

Transpiration and adaptations of plants to reduce water loss.

TRANSPIRATION

Candidates are expected to have performed experiments investigating environmental factors that affect the rate of transpiration.

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The Potometer Experiment

THE POTOMETER EXPERIMENT

http://www.passmyexams.co.uk/GCSE/biology/measuring-transpiration.html#top

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Since potometers are not readily available for each student it is ideal that the teacher performs a demonstration but students can used this simulation in an IBL

‘’Plants absorb water through their leaves.’’

MISCONCEPTIONS

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‘’Plants take their food in through the roots and then store it in their leaves. .’’

RESPONSE OF PLANTS TO ABIOTIC FACTORS - TROPISMS • Positive phototropism of stems

• Geotropism of roots and stems

• Important concepts to be understood by students

• Inquiry based learning a possibility

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Search no. 1

• Write a definition for the word Tropisms

• List two main plant tropisms and define them

• List the hormone involved in the plant tropisms

Search no.2

Look at diagrams as well as websites for Phototropism and give

• a) An example of positive and negative phototropism • b) A simple mechanism through which tropisms occur.

Search no.3

Look at diagrams as well as websites for Geotropism and give

• a) An example of positive and negative phototropism • b) A simple mechanism through which tropisms occur

BROWSE THE INTERNET & ANSWER THE FOLLOWING QUESTIONS

IBL Activity

• Bitesize

• Controlling Plant Growth

• Great Resources

• Concise & Factual Information

http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/living/controlplantgrowthrev1.shtml

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http://www.sumanasinc.com/webcontent/animations/biology.html

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• Great Website for Animations

• Some of them are too advanced for this stage but can be edited to suit your needs during lessons

PHOTOTROPISM - AUXIN EFFECT

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COVERING THE TIP OF THE STEM

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GEOTROPISM

HUMAN POPULATIONCandidates should appreciate that the great increase in the human population is mainly the result of its success in controlling most of the abiotic and biotic factors controlling it.

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• Human species shares Earth’s resources with all other living organisms.

• Up to a few thousand years ago, human population fitted into food web and Earth’s natural cycles just like any other organism.

• Changed in last 300 years ︎human population has grown a lot ︎—effect on environment has become one of largest factors affecting our planet.

• Improved Agricultural Methods

• Improved Living Conditions

• Medicine & Health Technologies

POPULATION GROWTH & SUSTAINABILITY

Finite Resources

THANK YOU FOR LISTENING