Presentation on theme: "Relationships of Living things. All living things within an ecosystem interact in many different ways. They can…. Hunt together in packs Stick together."— Presentation transcript:
Relationships of Living things
All living things within an ecosystem interact in many different ways. They can…. Hunt together in packs Stick together for safety Defend each other against harm Huddle for warmth Share food supplies..Or… For food For space For mates For light For power/dominance Collaborate Compete
Whether they are in or if the organisms are from the same species their relationship is known as…. ….and if the organisms are from different species their relationship is known as… And a handy general term to describe an intimate relationship between organisms is…
Let’s look at the different kinds of relationships between species according to the outcomes for those species involved….. What are the possibilities? One is Harmed One Gains One is indifferent BothGain 1. Predator/Prey relationship 2. Parasite/Host relationship 4. Mutualism 5. Commensalism 3. Allelopathy
Let’s begin with a simple food chain…...or if we want to look at trophic levels….. ….or if we want to look at it terms of predator/prey… Prey (rarely Predator) Prey & Predator Top Predator Producer 1 o Consumer Herbivore 2 o Consumer 1 o Carnivore 3 o Consumer 2 o Carnivore 1 st trophic level 2 nd trophic level 3 rd trophic level 4 th trophic level
1) Predator/Prey Relationships This type of relationship is severe as one organism – the prey - is killed to benefit the other – the predator. There can be 4 different outcomes for the groups of predators or prey: Both predator and prey die Predator dies and prey lives Predator lives and prey dies Both predator and prey live Which is the most beneficial to both organisms? Each of the four graphs on your worksheet shows one of these 4 outcomes – can you identify them?
1) Predator/Prey Relationships Predators: Usually less abundant than prey Compete for prey and so can adapt to do so better. For example echolocation in bats Collaborate by hunting in packs Prey: Usually more abundant than predators Need to defend themselves can employ a series of methods; a)Counter attack b)Mimicry c)Camouflage Some examples…
1) Predator/Prey Relationships Counter attack: Can take a huge variety of forms and can be adaptations that are physical, behavioural or physiological Aim is to defend prey from predator Examples include: Horns, antlers Offensive smells Tough outer shells Burrowing Speed Poisons How does this squid counter attack? Squirts out black ink to confuse the predator!!
Counter Attack A female insect protects her eggs with sharp crystals. Breathing or eating these crystals could be fatal to another insect. X2,000 1) Predator/Prey Relationships
Mimicry – When organisms copy or imitate each other. Can be two types: Mullerian mimicry is when poisonous organisms share the same warning patterns or colours. Examples are the patterns of black with yellow or orange used by frogs, bees and monarch butterflies. Batesian mimicry is when the organism is not poisonous but copies or mimics the poisonous one. It is behaving like a fraud. Examples are caterpillars looking like vipers or octopuses mimic sea snakes by swimming with equal number of tentacles in front as well as behind them.
1) Predator/Prey Relationships Camouflage is when an organism hides itself in or around its surroundings and blends in by taking on a similar appearance. The organism can do this by using colour, shape or texture. Examples include stick insects, pepper moths, chameleons, (the game ‘Where’s Wally’ works on the camouflage principle). Not good camouflages!! Better!!
2) Parasite/Host Relationships This common form of symbiosis, consists of one organism benefiting to the detriment of another. There are two forms: This is when the parasite lives outside the host body. Examples include ticks, fleas and fungal skin infections EndoparasitismEctoparasitism This is when the parasite lives inside the hosts body. Examples include tapeworm, liver flukes, bacteria and viruses
Fleas are parasites because they suck blood from other animals. Usually a particular species of flea will bite a different kind of animal, unless they get really hungry! Their cuticle has to be thick as their host is always trying to kill them. Many bug sprays will kill the adult but not the eggs, so fleas are hard to get rid of. Note the small eyes. Why don’t they need good eyesight? Their bodies are narrow to fit easily through hair and fur. Fleas can spread disease - the most famous being the plague or Black Death. x180 2) Parasite/Host Relationships
3) Allelopathy This is a relationship where one organism directly hinders or stops the growth of another by releasing chemicals It occurs most often between plants and botanists initially thought it was simply competition of resources that allowed one species to dominate an area over another Now, agriculturalists are exploring the possibility of using allelochemicals as growth regulators and natural pesticides for crop growing
3) Allelopathy Plants can release allelochemicals through the roots... …or through the leaves
3) Allelopathy Several species of sage (Salvia) use chemicals to inhibit the growth of other vegetation. Sage is often surrounded by bare areas separating them from adjacent grasses, they grow into the bare areas pushing grasses further back. The chemical that is produced by the sage leaves gives it the quality of a spice. Another example of allelopathy is the production of flammable oils by eucalyptus trees; the oils promote frequent fires, which kill seedlings of competitors
4) Mutualism Mutualism is a form of symbiosis when both organisms in the relationship benefit. Examples include: Fish swimming together in shoals Small fish who clean parasites from the gills of larger predator fish Pollinators and seed dispersers Microscopic organisms that help larger herbivores digest cellulose
4) Mutualism This pollen has a prickly coat that sticks to insects better than smooth pollen, this improves its chances of reaching another flower. X3,000 Pollinators carry pollen from one plant to another: Plant benefits from pollinator (insect or bird) by having pollen carried to another plant for cross fertilization Pollinator benefits from the plant by directly eating the pollen or by inadvertently taking pollen while feeding on plants nectar Pollen can adapt to increase their chances of hitching a ride Pollinators can adapt to collect more pollen Female bees comb pollen between hairs that grow in rows on their back legs. One worker may collect millions of pollen grains in a single trip. The bees feed the larvae the pollen (as well as the honey made from nectar). X1,000
Hooks on a burdock seed pod can attach themselves to passing animals, including people, who spread the seed far and wide. x174 4) Mutualism Seed dispersers carry seeds away from the plant: Plant benefits as it has a chance to reproduce and spread its species Dispersers (usually a bird) benefit as they can eat the seeds Seeds can adapt so they have greater chance of sticking to their disperser and travelling great distances Did you know that Velcro was modelled on these seed hooks and looks almost the same under the electron microscope?
5) Commensalism This form of symbiosis is usually very hard to define as scientists don’t always understand fully the relationships between organisms. Examples could include: Trees that support other vegetation – orchid seeds rest on branches and grow from there Soft bodied sea dwelling animals that use discarded shells to live in Clown fish and poisonous anemones
Biological Control Biological control is when scientists use one organism to control the population of another by introducing them in close proximity. What kind of symbiotic relationship does this exploit? Examples include: The cane toad (1935) introduced to control sugar pests Weevils (1980) to control weeds Myxomatosis (1950) to control rabbits Calicivirus (1996) to control rabbits Moth (1925) to control prickly pear Successful? No Yes
Biological Control ……an example Aphids use their proboscis to suck the juices from leaves. They can be killed by poisons, but some gardeners prefer to use ladybugs that can eat aphids in their thousands. Aphid cornicles provide the one defense system aphids have against ladybugs. When attacked they squirt a sticky cement which sticks the ladybug to the leaf and gums up its wings so it can’t fly away. x250 EM of an aphid x68..but… What is another biological term for this kind of defence the aphid has against its predator the ladybug? Counter Attack!!