What are the major groups?

Kingdoms

Animals Plants Fungi Prokaryotes Protoctista

You need to know the characteristics of the kingdom and examples of each kingdom

What is the difference between invertebrates and vertebrates?

Snail

No internal skeleton

= Invertebrate

FrogInternal skeleton

= vertebrate

Taxonomy

• The science of classification

• Hierarchical scheme• Largest grouping = kingdom

• Smallest grouping = species

Example:• Kingdom = Animalia

• Phylum = Chordata

• Class = Mammalia

• Order = Primates

• Family = Hominidae

• Genus = Homo

• Species = Sapiens

• One of the most significant factors affecting populations.

• The number of a particular animal is critically dependent on the availability of it’s prey.

• Presence/absence of significant predator numbers has a dramatic effect on prey populations.

Predator/Prey Cycles

The Typical Result

• The predator “tracks” the prey with population peaks later in time than the peaks of the prey.

• (Predator numbers will always be fewer than prey)

The Reason for the Cycle

http://www.bbc.co.uk/nature/collections/p006r1w3#p0074tg3

Parasitic fungi attack

http://www.bbc.co.uk/nature/collections/p0057tcr#p004y3c5

Hippo/barbel mutualism

Parasitism

MutualismBoth organisms benefit•An organism that lives on a

host organism•Negative effects for host

SYMBIOSIS-’living together’.

•Organisms are ADAPTED to the habitat they live in.

• They have special features that help them to survive.

•The better adapted an organism it to its habitat, the more successful it will be when competing fro resources e.g. food & mates.

•This increases the organism’s chance of survival and so increases its chance of reproducing

• Saguaro cacti have no leaves :

Spines for defence and shading of the plant

• Stem is able to photosynthesise

Has a thick, waxy layer which is waterproof, reduces water loss

•One large root (taproot) descends to a depth of 4/5 ftGives Saguaro cactus access to water stored deep underground

•Remaining roots lie 3/4 inches under the Earth surface Easy to collect and absorb rainwater

•Long eyelashes keep out dust•Tough mouth for eating thorny plants•Large padded feet to stop sinking into the sand•Stores water in stomach•Tail scares flies away•Light colour to reflect heat•Hair on back for shade

If there was a disease that killed all the trees died, which animals would survive? Which would become extinct? Why?

• The idea was first suggested by Charles Darwin over 150 years ago

Natural Selection

Exam Board Definition:Natural Selection – When certain individuals are better suited to their environment, they are more likely to survive and breed, passing on their characteristics to the next generation.

http://www.bbc.co.uk/nature/life/Gecko#p00cqcl0

http://www.bbc.co.uk/nature/life/Gecko#p00cqcl0

• Reproduction is a very wasteful process.

• Animals and plants always produce way more offspring than the environment can support.

• Why?

Fruit flies produce 200 offspring every 2 weeks!

Survival of the Fittest

Population explosion

3 main effects of pollution: •global warming•ozone depletion•acid rain

Household waste

• A scientist surveyed the distribution of lichens• She counted the number of different species that

grew on tree trunks at various distances from the centre of a polluted city

• She also measured how much sulphur dioxide there was in the air.

Distance to the town centre (Km)

 0 1 2 3 4 5 6 7 8 9 10

Number of different species of lichen

 0 1 2 6 8 10 30 44 51 56 56

SO2 levels/(arbitrary units)

 180

160

145

119

93 71 49 35 11 5 0

1)What is the relationship between the distance from the city and the number of lichen species growing?

2)What does this tell you about lichen?

Examples of pollution indicators Air pollutants dissolved in rainwater, especially sulfur dioxide,

can damage lichens, and prevent them from growing. This makes lichens natural indicators of air pollution.

bushy lichens need really clean air

leafy lichens can survive a small amount of air pollution

crusty lichens can survive in more polluted air

no lichens air is heavily polluted with sulfur dioxide.

Which organisms would you expect to find in

a clean lake? a polluted lake?

Salmon rat tailed maggot

Blood worm may fly larva

Why do animals become extinct/endangered?

?

Skin – used in belts, shoes,

handbags and luggage

Sinews – used in tennis rackets

Teeth – used in buttons, piano keys

and jewellery

Meat – used in pet food and human

food

Bone – used in fertilisers

Oil – used in alcohol, lipstick, crayons,

candles, soap, fertiliser and animal feed