Biome

•The biosphere is made up of several types of biome.• These are classified due to their major vegetation types, for example TUNDRA or TROPICAL RAINFOREST.

•The biosphere is made up of several types of biome.• These are classified due to their major vegetation types, for example TUNDRA or TROPICAL RAINFOREST.

Ecosystem

• An Ecosystem is a part of a biome.• Biomes themselves are far too large to study so ecology work tends to be based around a particular ecosystem.• Each ecosystem has a characteristic set of plants, animals and microbes.• The organisms in an ecosystem form a self-sufficient unit in balance with their environment.

• An Ecosystem is a part of a biome.• Biomes themselves are far too large to study so ecology work tends to be based around a particular ecosystem.• Each ecosystem has a characteristic set of plants, animals and microbes.• The organisms in an ecosystem form a self-sufficient unit in balance with their environment.

Community

• This is a group of species that occurs at the same place at the same time.• The word is often used to refer to organisms of a particular kind, such as the plant community on a lawn.

• This is a group of species that occurs at the same place at the same time.• The word is often used to refer to organisms of a particular kind, such as the plant community on a lawn.

Population

• Ecosystems and communities contain populations of species.• A population is made up of all the members of a species living together in the same place at the same time.• An example would be all the ash trees in a wood.

• Ecosystems and communities contain populations of species.• A population is made up of all the members of a species living together in the same place at the same time.• An example would be all the ash trees in a wood.

Individual

• Finally each population is made up of many individuals.• The genetic and physiological adaptations of an individual organism to its environment is an important aspect of ecology.

• Finally each population is made up of many individuals.• The genetic and physiological adaptations of an individual organism to its environment is an important aspect of ecology.

Natural Artificial

• Large biodiversity

• Wide variety of food supplies

• Large number of plants and animals

• No pesticides & fertilizers used so nature finds its own level for the population of each species.

• Low biodiversity

• Food supplies limited

• Small number of plants and animals

• Artificial pesticides and fertilizers used to limit biodiversity

Natural vs. Artificial

All ecosystems have to be self supporting apart from an energy source which is usually the sun.

Distribution of Living Organisms

• A transit line is used to map the distribution of organisms.

• A line like a tape measure or a path is laid out.

• Quadrates are distributed either along the line or away from the line at set intervals.

• The population of each species is then counted.

• A kite diagram is then produced from the data collected.

Zonation

• Zonation is the gradual change in the distribution of species across the habitat.

• Gradual changes in abiotic factors (non-living) can result in zonation

Sampling & Identifying Organisms

1. How could you correctly identify the different species collected in a sample?

2. How would you sample an area?3. What would the advantages and

disadvantages of doing this?4. What is the reasoning behind sampling an

area?5. What size would you make the sample and

why?6. Would you sample at random or would you

sample in a specific and logical way?7. How are organisms distributed though a

habitat?8. How would you make the sampling accurate?

Counting Animals – Capture-Recapture

• The capture-recapture method is used to estimate the size of a population

• Populations can be difficult to sample because animal species move around all the time

• Population size = No. in 1st sample (all marked) x no. of 2nd sample (marked

& unmarked)

No. in 1st sample (all marked) x no. of 2nd sample (marked

& unmarked)

No. in 2nd sample which were previously marked

No. in 2nd sample which were previously marked

Assumption of Capture-Recapture

• No organisms have died or born or migrated or emigrated between sampling

• Make sure identical sampling methods are used from 1 visit to the next

• Make sure the marking, tagging does not adversely affect the organism

• The larger the sample size the more accurate the population estimate size

Photosynthesis vs respiration

• All living organisms respire

• You should all know the word equation for aerobic respiration…

• Glucose is needed for plants to respire, as well as oxygen

• Therefore plants need to respire as well as photosynthesise to survive

• The 2 processes have many differences but a few similarities…

C grade B grade A grade

What 3 things do plants need to

survive?

Give the word equation for photosynthesis

Explain why plants have leaves and suggest

adaptations of the leaves that enable this to happen

Other than low amounts of light and carbon dioxide, what else could cause a

plant to die?

What is it inside a plant that absorbs sunlight and what is done with

the light energy absorbed?

How is water and glucose moved around the plant? Where would you find an

increased number of phloem and xylem

vessels?

Plants don’t have blood, veins or

arteries – so how does water and sugar

move around the plant?

Describe the term ‘limiting factor’ giving

examples

What is the symbol equation for

photosynthesis? Try to balance the symbol equation (glucose:

C6H12O6)

C grade B grade A grade

Sunlight, water and

carbon dioxide

Carbon dioxide + water oxygen and glucose

Leaves contain chloroplasts and therefore chlorophyll to absorb light energy. Expect a large surface area, thin cell walls and high

concentrations of chloroplasts lining the leaves.

Competition, animals eating

it, poor nitrates in the soil, damage by humans and weed

killers.

Chloroplasts contain chlorophyll which convert

sunlight energy into chemical energy, which is

stored in glucose.

Vessels called the xylem and the phloem carry water and glucose around the plant. Phloem vessels carry glucose and xylem

vessels carry water. There would be many phloem vessels located in the leaves

where photosynthesis takes place, where as xylem vessels would be found in the

roots and stem.

Xylem vessels carry water and phloem

vessels carry sugar

(glucose)

A limiting factor is a factor that could influence the

growth of a plant. Common limiting factor include light, water and

carbon dioxide.

6CO2 + 6H2O C6H12O6 + 6O2

More keywords…• Cellulose – material used to make cell walls

• Chlorophyll – green pigment in plants used in photosynthesis

• Starch – an insoluble sugar

• Glucose – a soluble sugar

• Sunlight – light energy carries out photosynthesis

• Oxygen – produced by plants, breathed in by humans

• Carbon dioxide – breathed out by humans, plants absorb it

Photosynthesis

What is the equation of photosynthesis?

•In this reaction water is split into oxygen gas and hydrogen ions

•The second stage to photosynthesis is when carbon dioxide gas combines with hydrogen and forms glucose (eventually)

•It is obviously much more complex than this…

Rate of photosynthesis

• Photosynthesis increases during summer so crops grow faster – as well as sunlight what else might affect the rate of photosynthesis?

Increased temperature = increases enzyme activity

• Sunny warm days are the best days for photosynthesis to occur

• If farmers can control conditions, they can increase photosynthesis

Factors affecting photosynthesis

• The rate of photosynthesis is proportional to light intensity

• Gas exchange occurs in the leaves – we will look at how this occurs tomorrow and next week

Osmosis

• Similar to diffusion but the movement of water only

• Used in plants

• Lots of water and not very much solute = high water potential

• Not very much water and lots of solute = low water potential

• Can you draw a picture on your whiteboard to represent a high water potential? What about a low water potential? (you might need a key…)

Osmosis in plants

Osmosis is the movement of water from a high water potential to a low water potential through a

partially permeable membrane.

•Osmosis depends on a difference in the water potential

•No difference – no movement and therefore no osmosis

https://www.youtube.com/watch?v=IaZ8MtF3C6M

https://www.youtube.com/watch?v=nH4WkUo_m-4

Osmosis in plant cells and animal cells

• Use osmosis to describe what you think has happened in each of the diagrams – write your answers under the pictures

• Why do you think we see the effect we see on an animal cell?

• Do you think the same would happen if a plant cell absorbed too much water? Why? (HINT: Think of the cell structure)

The Leaf

• Leaves are adapted so that photosynthesis can take place.

• Plants need carbon dioxide, water, sunlight and chlorophyll to carry out this important process.TASK – Observing a Leaf under a Microscope

Take a leaf and observe it under the microscope. What can you see? Comment on any observations

you make.

How are leaves adapted?

The features of leaf that make it suitable for photosynthesis are:

•A leaf is broad and flat to capture lots of sunlight

•Veins (xylem) carry water to the leaf and take food from the leaf to the rest of the plant. Veins also help to support the leaf

•Certain plant cells contain chloroplasts with chlorophyll

•Small holes called stomata in the underside of a leaf allow gases in and out

Inside a Leaf

The Structure of a Leaf• The epidermis protects

the leaf and is transparent to let light through.

• The palisade mesophyll layer is where photosynthesis mostly takes place. The cells are tall and closely packed to absorb maximum light. They contain many chloroplasts.

The Structure of a Leaf

• The spongy mesophyll layer contains numerous air spaces where gas exchange takes place. It also captures light and makes food

• The veins contain xylem (top part of vein) for water transport and phloem (lower part of vein) to take away dissolved food

• The stomata has tiny holes in the epidermis of the leaf. They are usually on the underside of the leaves. They control the water loss and gas exchange by opening and closing. Since a lot of water vapour can be lost through the stomata they only open for photosynthesis in daylight; at night they close to reduce loss of water vapour.

To start…

Draw a plant with roots, a stem and leaves

•Where would you expect the xylem vessels to run?

•What happens once the water reaches the necessary cells?

Transport in plants

• Water evaporates when it turns to a gas

• In plants this is called transpiration

• This is the movement of water up a plant, through the stem and out of the leaves

https://www.youtube.com/watch?v=mc9gUm1mMzc

Transport in plants

• Xylem transports water through transpiration

• Water is used to dissolve sugars, for photosynthesis, support and to cool it down

• Phloem carries dissolved solutes through translocation

• Sugars are used to form cellulose which in turn forms the cell wall of plants – a complex sugar

• Controlling the levels of water in plants is vital and must be controlled – adaptations in the leaf prevent this loss

Affecting the rate of transpiration

• You can measure the rate of transpiration using a potometer

Explain to the person next to you how this would work…

Stomata and Guard cellsStomata and Guard cellsStomata and Guard cellsStomata and Guard cells

Stomata and Guard cells

Transpiration in detail

• http://www.youtube.com/watch?v=At1BJJDcXhk

• http://www.kscience.co.uk/animations/transpiration.swf

DIFFUSIONDIFFUSION OSMOSISOSMOSIS

ACTIVE TRANSPORTACTIVE TRANSPORT

Involves water only

Requires energy

Is passive

Movement of particles

Needs a semi-permeable membrane

High to low concentration

Against a concentration

gradient

Occurs in nature

How minerals get into root hair cells

How oxygen leaves a leaf

How water keeps plant cells turgid

Involves transport of

solutes

Needed to make chlorophyll Important for photosynthesis

Used for respiration and photosynthesis

Magnesium

Used to make amino acidsNitrates

PhosphatesMake proteins used for

enzymes

Used to make DNA Potassium

Used for root growthUsed for respiration and

photosynthesis

Bell work…

What are these pictures of?

How do they work?

Condition

Reason

The process of decay by micro-organism occurs faster in warm,

moist, oxygen rich conditions

MoistureSpores cannot germinate in dry conditions. Moisture is needed for the microbes to grow and multiply.

Warmth

Microbes reproduce and multiply best in a warm environment. This means that decay occurs faster in warmer temperatures.

OxygenThe aerobic micro-organisms which are responsible for the bringing about of decay, require oxygen to respire.

Decay in food chains

• Dead and decaying animals and plants are called detritus

• Detritivores are maggots, earthworms and woodlice – need detritus to survive

• Both of the species above are needed to maintain food chains and ecosystems Construct a food chain for a forest – you must

have 5 levels of your food chain

Compost production

• Microorganism action is dependant on enzymes

• More enzymes - more decay

• Optimum temperature is 37°C for bacteria and 25°C for fungi

• Respiration of bacteria, digestion and growth all happen faster in warmer conditions

• More oxygen – more decay

Saprophyte

• Organisms such as fungi feed off dead and decaying matter are called saprophytes

• Live in or on decaying matter

• Digestions takes place outside the body and is called extracellular – juices are released onto the dead/decaying matter