half-term 1- pg 8-19- variation, classification, survival Flashcards
species
Group of organisms that can interbreed and produce fertile offspring.
variation
The range of characteristics across individuals of the same group.
biodiversity
The range of different organisms within an ecosystem.
ecosystems
A community of organisms along with the non-living components (such as air, water, soil).
classification
The way that scientists group organisms, for example into a genus or species.
continuous variation
Variation that is distributed along a continuum, rather than in discrete categories, e.g. weight and height.
discontinuous variation
Variation that is distributed in discrete categories, e.g. eye colour, left or right handedness.
correlation
How well sets of data are linked; high correlation shows that there is a strong link between two sets of data.
inbreeding
Breeding with close relatives.
inherited
A feature or characteristic that has been passed on genetically.
genetic
Caused by genes, inherited.
selective breeding
Mating of two individuals chosen because of their characteristics, to produce offspring with a combination of desired characteristics.
natural selection
Process by which characteristics that can be passed on in genes become more common in a population over many generations if they help the organism survive.
evolution
The change in a species over a long period of time.
what does biodiversity ensure?
clean air and water, fertile soils
why is it important for ecosystems to have a high level of biodiversity?
an ecosystem with a high level of biodiversity is more able to survive changes, there is a greater chance of one of the species having features that enable it to adapt to change.
how did the american scientist show people that races had distinct characters and all people can be divided into 5 races.
he collected sculls and stuffed each scull with peppercorns, then he poured the peppercorn into a container and measured its volume. he thought the higher the volume the more intelligent the person was- he claimed white people were the most intelligent.
what did the american scientist use his measurements for?
to justify the institution of chattel slavery in the USA
name 1 reason why his conclusions about peppercorns was wrong
the volume = mass of a brain does not relate at all tot he intelligence of a person
why can’t a good biologist be racist?
biology shows us that the whole category of race is wrong
1 good example of variation
not all rabbits are killed by the viral disease myxomatosis, some are resistant and can survive an outbreak.
1 bad example of variation
albino giraffes do not survive in the wild.
what does the classification system help us to do?
- clarify relationships among organisms
- remember organisms and their typical features
- communicate the identity of organisms being studied
on the planet in which two places are ecosystems with the greatest biodiversity?
- tropical rain forests
- coral reefs
what is one cause of variation in organisms?
environment + climate + food
which 4 features are entirely inherited and not affected by the environment?
- eye colour
- blood group
- hair colour
- inherited diseases
give an example of a feature caused by the interaction of genetic and environmental factors
a persons skin may have birthmarks and moles but during their lifetime scars may form and tattoos may be added.
what was Charles Darwin’s view that living organisms ensure their offspring have survival advantage?
organism struggle for survival and reproduce to ensure some survive, the fittest have to survive long enough to reproduce and pass on the feature.
what were Darwin’s conclusions?
- all organisms produce more offspring than needed
- organisms have a fairly constant population size.
- there is a wide range of features within a species
- some variations are inherited by the offspring
what did Charles Darwin do?
studies birds in the Galapagos islands and discovered evolution
what are dogs jobs?
to hunt/guard property or livestock
why are some dogs selected for selective breeding?
their desirable traits such as floppy ears, short legs, flattened faces
what issues has breeding dogs caused
- exaggerated physical features can reduce a dogs quality of life
- lack of inherited variation can lead to an increase in inherited disorders
give and example of an exaggerated physical feature that can reduce a dogs quality of life
-dogs with short, flat faces often have narrow nostrils and abnormal windpipes so they can have difficulty breathing and walking.
