biology paper 2 - b14

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what is variation
the differences in the characteristics of people
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what is environmental variation, and an example
variation due to the environment you are in, a scar from an accident
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what is genetic variation
genetic causes for variation, inheritting information, for your nose, eyes, dimples
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what are some examples of combined causes of variety
parents genetically give you your skin colour, but if you live in an area where you recieve a lot of sun, your skin tone will darken
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what is natural selection
organisms that gain advantages are more likely to breed and survive
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what is a mutation
a change in the DNA code
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when can mutations take place
whenever a cell divides
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what happens when gametes are forming and a mutation happens
it may affect the phenotype in the offspring and introduce new variants into the genes of a species
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what can mutations do to the offspring in terms of survival
it can have no effect, can be dangerous and kill it, or can cause an organism to be better suited to its environment or gives it an advantage if there is an environmental change
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what is the theory of evolution by natural selection
all species of living things have been evolving from the simplest life forms to devloping to how they are now
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what does evolution through natural selection produce
changes in the inherited characteristics over time, so that organisms are well suited to their environment and may result in a new species
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in a wide species, could the individual organisms be really different
yes, a wide range of phenotype and genetic variation
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if individuals are better sutied to an eenvironment, what is it most likely able to do
survive and reproduce successfully
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if they alleles have enabled the species to survives what happens
they are passed on to the next generation
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if two populations become so different what can they no longer do
interbreed and produe a fertile offspring, so two new species are formed
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what can mutations do
make an individual better suitef for tempurature change, resistant to disease, colour of skin
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what is selective breeding
a process where humans breed plants and animals for desired characteristics
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what might some farmers want in an offspring or crop
more meat/milk production, disease resistance in food crops/garden plants, domestic dogs with gentle nature, large/ brightly colour flowers, heavily scented
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what are some problems with selective breeding
reduces the number of alelles in the population, as the individuals with the chosen alleles are allowed to breed, reduces variation, and the variation in the alelles for a characteristic.
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why can a lack of variation in an alelle be a problem
when conditions are stable it is fine, but when a new disease or tempurature is changed the animal or plant cannot cope. which can mean a population dies out.
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what is another problem with selective breeding, (oher than lack of variation)
inbreeding, prone to certain diseases due to lack of variation
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what is genetic engineering
involves modifying the genetic material of an organism
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what happens to the gene that is repsonsible for the desirable characteristic
it is cut out of the organism, transferred to genetic material in the cells of another organism which gives the genetically engineered organism a new, desirable characteristic
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what a used to isolate and cut out the required gene
enzymes
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what happens to the cut out gene after being collected
int=serted into a vector, using more enzymes
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what usually is the vector
a bacterial plasmid or a virus
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what is the vector used for
to insert the gene into the required cells, which may be bacteria, animal, fungi, or plants
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where are the genes tranferred to
to the cells, at an early stage of of development, as it grows it will develop new desired characteristics from the other organism.
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in plants, where are the genes often inserted
into the meristems
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what happens when a bacterial cell recieves a human gene
human cell, with insulin gene in DNA, insulin gene cut out by enzyme, a plasmid taken out +split up by an enzymes, gene inserted into plasmid, other enzyme, taken up by bacterium, mutiples many times, insulin switched on, harvested
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what are GM crops
crops that have been modified genetically
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what do GM crops often improve what
their resistance to insect attack or herbicides and produce a higher yield, meaning more crops survive to provide food
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what does it mean if GM crops are more resistant to herbicides
farmers, can spray and kill weeds effectively without damaging their crops
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what can GM crops sometimes increase
size of fruit, nutritional value
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what is a huge potential benefit to GM crops
cure human disorders (inherited), the cells of an early embryo could be engineered so that the indicidual would be healthy
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what are some benefits to genetic engineering
genetically engineered microorganisms- large quantities of human proteins in a very pure form, improved growth rates, increased food values (bigger yields), desired to grow well in certain conditions, resistant to herbicies, produce own pesticides
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what are some concerns about the long term effect of GM crops
if insects become resistant to the pesticide if they constantly eat them plants, effects of GM crops and the human health, infertility gene if spread to rare flowers, ethical issues, dont intrfere with crops or babies
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Other cards in this set

Card 2

Front

what is environmental variation, and an example

Back

variation due to the environment you are in, a scar from an accident

Card 3

Front

what is genetic variation

Back

Preview of the front of card 3

Card 4

Front

what are some examples of combined causes of variety

Back

Preview of the front of card 4

Card 5

Front

what is natural selection

Back

Preview of the front of card 5
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