Unit 4 Flashcards
What is a niche?
the role of an organism within it’s community. A niche has boundaries and it’s role includes:
- what it eats
- what eats it
What is an ecological niche?
When both organisms share the same habitat and same food but hunt at different times, meaning they both survive
Name the 3 things there is competition for:
- Territory
- Mates
- Resources
True or false: 2 species can occupy the same niche, habitat and resources?
No 2 species can occupy the same niche in the same habitat at the same time for the same resource
What is a species?
A group of organisms with similar morphology, physiology and behaviour which can interbreed to produce fertile offspring
What is a habitat?
the place where organisms live
What is a population?
a group of interbreeding individuals
What is a community?
all the organisms living in a habitat
Describe what a behavioural adaptation is and give an example:
A behavioural adaptation is an action by an organism which helps it survive or reproduce; an example is nocturnal animals
Describe what a physiological adaptation is and give an example:
A physiological adaptation is a feature of the internal working of organisms that help them to survive and reproduce; an example is scurvy grass
Describe what a anatomical adaptation is and give an example:
An anatomical adaptation is an adaptation we see when we observe or dissect organisms; an example is the pollen basket on the hind legs of bees
Explain evolution by natural selection
Organisms with better are adaptions will create a population with ideal characteristics as they’re more likely to survive, more likely to reproduce and more likely to pass on their advantageous alleles
What is evolution?
a change in allele frequency in a population over time
Is an organism more or less likely to survive if they’ve got non-advantageous alleles?
They’re less likely to survive
What is a gene pool?
The complete range of alleles in a population
When is the Hardy Weinburg equation valid?
When random mating occurs
What is the Hardy Weinburg equation?
P^2 + 2pq + q^2
What do the letters stand for in the Hardy Weinburg equation?
P^2 = homozygous dominant 2pq = heterozygous / carrier q^2 = homozygous recessive
The ability of a population to adapt to new conditions will depend on what things?
- the reproductive rate of an organism
- The strength of the selection pressure
- the size of the gene pool
What has to happen for a new species to arise?
reproductive isolation
What is the most effective method of reproductive isolation?
A geographical feature such as high mountains as it prevents a group of individuals from breeding with the rest of the population.
What is speciation?
When two groups of organisms become less like each other due to selection pressures. They eventually may not be able to interbreed
What is biodiversity?
The richness and variety of life
What is taxonomy?
The science of classification
