B2 - Adaptions, Natural Selection & Interdependence Flashcards
What do animals compete for?
Food, water, shelter and mates.
What do plants compete for?
Light, water and minerals.
Why will the better-adapted competitors survive and produce offspring?
Because they will get most of the resources.
What does the interdependence of organisms determine?
Their distribution and abundance
What are the two types of competition in an ecosystem?
Interspecific and Intraspecific
What is interspecific competition?
Where individuals of different species compete for the same resources in an ecosystem
What is intraspecific competition?
Where individuals of the same species compete for the same resources in an ecosystem
Why is intraspecific competition more significant?
Because the organisms have the exact same needs
What will similar organisms living in the same habitat have?
Similar prey and nesting sites
What do similar organisms living in the same habitat compete to do?
To occupy the same ecological niche
What is an ecological niche?
The place and function
Define predators.
Animals that kill and eat other animals
Define prey.
Animals that are eaten
Which will there always be more of, predators or prey?
prey
Define parasites
Organisms that survive by living off other organisms.
Give examples of parasites.
Fleas, tapeworms
What is the organism that parasites live off known as?
The host organisms
What is a mutualistic relationship?
When two organisms form a relationship from which both organisms benefit.
Give an example of a mutualistic relationship.
Oxpecker birds live on buffalos’ backs, and get a ready supply of food from the flies and ticks on a buffalo’s skin
Give two ways a buffalo benefits from a mutualistic relationship with oxpecker birds.
The birds get rid of the pests, and act as an early warning system by hissing when predators approach
What are adaptions?
Special features or behaviours that make an organism particularly well suited to its environment.
When climate changes, which organisms will survive?
Those that can successfully adapt to the new conditions will survive
Why does being well insulated help organisms to survive in cold environments?
It reduces heat loss
Why does having a small surface area to volume ratio help organisms to survive in cold environments?
It prevents heat loss
Why does having small ears and large bulk help organisms to survive in cold environments?
It reduces surface area to volume ratio
Name three adaptions that a polar bear has to survive in a very cold climate
Large amount of insulating blubber beneath the skin, thick white fur for insulation and camouflage, large feet to spread its weight on snow and ice, fur on the soles of its paws gives insulation and grip, and it has powerful legs for running and swimming
How do cacti cope with a lack of water?
They have long roots to reach water, a thick waxy cuticle to reduce water loss, and spines to reduce water loss and protect water stored in the spongy layer from predators.
Why do camels store body fat in a hump?
So that there’s very little insulation under the skin
Why do camels drink many litres of water in one go?
Because they store the extra water in the blood
Why do camels have hair-lined nostrils?
They trap moisture in their breath before it is exhaled, so the returned
What are extremophiles?
Organisms that are biochemically adapted to extreme conditions.
Some antarctic fish possess anti-freeze proteins (AFPs). What do these do?
Prevent ice crystals growing inside tissues.
What are specialist organisms?
Organisms that are only suited to certain habitats.
What are generalist organisms?
Organisms that can live in a wide range of habitats, but can easily be out-competed by other organisms
What type of vision does a predator have?
binocular
What type of vision does prey have?
monocular
Animals and plants that are better adapted to their environment are more likely to survive. What is this theory called?
Natural selection
Who first put forward the theory of natural selection?
Charles Darwin
What is evolution?
The slow, continual change of organisms over a very long period of time to become better adapted to their environment.
How do the changes throughout evolution occur?
Through mutations (Changes in DNA)
What are mutations?
Changes in DNA
How are adaptions throughout evolution controlled?
By genes
What are pale peppered moths easily camouflaged against?
The lichens on silver birch tree bark
Why are dark peppered moths more common in areas of high pollution?
Because the bark on silver birch trees is discoloured by soot, therefore the paler moths show up whilst the darker ones are camouflaged.
What was Lamarck’s theory?
That evolution happened by the inheritance of acquired characteristics: organisms change during their lifetime as they struggle to survive. These changes are passed on to their offspring
Why was Lamarck’s theory rejected?
Because there’s no evidence that changes that happened in an individual’s lifetime could alter their genes and so be passed on to their offspring. His theory was very different to Darwin’s and had no genetic basis.
What are the four key points to remember about evolution by natural selection?
1 ) Individuals within a population show natural variation
2) There is competition between individuals for limited resources, as well as predation and disease. Weaker individuals die.
3) Individuals that are better adapted to the environment are more likely to survive and produce offspring
4) These survivors will pass on the successful genes to their offspring, resulting in an improved organism being evolved through natural selection.
Why were Darwin’s ideas not popular?
Because they went against those of the church and the bible.
Why won’t groups of the same species who are separated from each other by physical boundaries like mountains be able to breed and share their genes?
Because over long periods of time, the separate groups may specialise so much that they cant successfully breed any longer and so new species are formed.
Explain why binomial names are used to identify a species
Because whatever the language, the binomial name is consistent
How can scientists prove that two animals are not the same species?
Mate them, and if they don’t produce fertile young, they are not the same species
Suggest how in the food chain below, energy is lost
Dead plants -> mushrooms -> humans
Respiration or excretion or egestion
For the food chain below, why is it difficult to construct an accurate pyramid of biomass?
Dead plants -> mushrooms -> humans
Because dead plants, mushrooms and humans all belong to more than one food chain, and dry mass needs to be measured, meaning the human would need to be dead.
What is the role of mushrooms in the nitrogen cycle?
They break down proteins or amino acids into ammonia
In natural selection, similar animals have evolved over time to the point where they are unable to produce fertile young. Why is this?
Because their DNA has become too different.
