8D Ecological relationships

© Tony P. Thould

September 2000

CLASSIFICATION

Every living thing may be placed into one of two groups :-

CLASSIFICATION

© T.P.THOULD

VERTEBRATES

Animals that have vertebrae - a backbone, a spine

INVERTEBRATES

Have no backbone - no vertebrae, no spine

FLOWERING

Have flowers which may be brightly coloured or dull. The flowers make the seeds.

NON-FLOWERING

Do not make flowers but have cones, spores or some other way to reproduce

ANIMALS

Vertebrates Invertebrates

Cat

elephant

Worm

slug

List some examples of each type of animal

PLANTS

Flowering Non-flowering

List some examples of each type of plant

BY NOW YOU SHOULD KNOW…..

•That all living things can be split up into two groups

• That all animals can be split up into two groups

•That all plants can be split up into two groups

CLASSIFICATION SUMMARY

Vertebrates Invertebrates

AN IM ALS

Flow ering Non-Flow ering

PLAN TS

LIVING THING S

VERTEBRATE GROUPS

B irds Ma m m a ls

W a rm B looded

Fish R eptiles Am phib ia ns

C old B looded

VER T EB R AT ES

INVERTEBRATE GROUPS

W orm s Insects Arachnids Molluscs Crustaceans

INVERTEBRATES

FLOWERING GROUPS

M onocotyledons Dicotyledons

FLOWERING

NON-FLOWERING GROUPS

Fungi M osses Conifers Ferns

NON-FLOWERING

GROUP CHARACTERISTICS

Mammals•Vertebrates

•Warm blooded

•Have hair or fur

•Young are born live not in an egg

•Mothers feed young on milk from special glands

BIRDS

•Vertebrates

•Warm Blooded

•Have feathers

•Lay hard-shelled eggs

FISH

•Vertebrates

•Cold Blooded

•Scales cover their body

•Live in water

•Have Gills to breathe

•Have fins

REPTILES

•Vertebrates

•Cold Blooded

•Dry Scales cover the body

•Lay eggs with tough leathery shell

AMPHIBIANS

•Vertebrates

•Cold Blooded

•Have lungs

•Smooth moist skin

•Lay eggs in water

•Live on land and in water

What other groups are there?

A DICHOTOMOUS KEY

Used to identify Plants or Animals by answering a series of questions about what they look like, each of which have a choice

of two answers -

DICHOTOMOUS = Two choices

ALWAYS START AT QUESTION ONE EVERYTIME

Imagine that you do not know the names of the above animals. Use the Dichotomous Key to identify them:-

Q1 Is it mainly black?……………If yes go to Q2

…………….If no go to Q3

Q2 Does it have six legs?…………If yes = Black Ant

………….If no = Collie Dog

Q3 Does it have wings?…………..If yes = Butterfly

…………...If no = Grayling

A B C D

A

B C

D EF

Q1 Is it mainly green?……………….If yes go to Q2

…………...….If no go to Q3

Q2 Does it have six legs?………...….If yes = Grasshopper

……...….If no Frog

Q3 Does it have wings?……………..If yes = Go to Q4

…………...If no = Go to 5

Q4 Is it black?……………………....If yes = Swift

…………………If no = Ladybird

Q5 Does it have legs & pincer……..If yes = Crab

………..If no = Snake

Try writing your own Dichotomous Key

Q1

A B C D

This together with the increase in Bacteria which decompose the dead plants, reduces the Oxygen levels dramatically. Many aquatic animals die due to lack of Oxygen

Nitrate Pollution

Nitrates Nitrates leached

into pond

Bacteria

THE KNOCK ON EFFECT

What happens to the numbers in a food chain if one of the links in the chain is reduced in numbers?

Foe example - The rabbits get the disease Myxomatosis making their numbers fall by half.

Insecticide from the farmers spray kills most of the ladybirds and butterflies.

In both cases the food supply of other animals and the food eaten by the Rabbits, ladybirds and Butterflies are affected

What happens to the NUMBERS of each of these? EAGLE SWIFT SPIDER

MOUSE WHEAT PRIMROSE

BUTTERFLY LADYBIRD RABBIT

Time in Years

Number of

AnimalsRabbits

Eagles

PREDATOR / PREY RELATIONSHIP

What does this graph tell you about the relationship between Predators and Prey

numbers?

Time in Years

Number of

AnimalsRabbits

Eagles

PREDATOR / PREY RELATIONSHIP

How do you explain the change in numbers of the Predators and Prey?

PREDATOR / PREY RELATIONSHIP

As the numbers of prey rise this is then followed a little while later by a rise in the numbers of predators.

As the numbers of prey falls this is then followed by a reduction in the numbers of predators.

As the prey is the food supply for the predators their numbers obviously affect the numbers of the predators.

With more food the predators are healthier and can support larger families.