Questão | Responda |
how might an animal adapt to a hot environment? | large surface area little/ no fur sandy coloured water efficient nocturnal |
how might an animal adapt to a cold environment? | small surface area thick fur greasy coats thick layer of blubber white coloured |
how might plants adapt to a hot environment? | small spikey leaves waxy body long roots water storage tissue |
how might animals and plants adapt to deter predators? | armour (e.g. thorns) poisons warning colours mimicry |
what living factors cause environmental change? | occurrence of infectious diseases number of predators number of prey or food availability number or types of availability |
what non-living factors might cause a change in the environment? | change in average temperature change in average rainfall change in level of air/ water pollution |
what are living indicators? | organisms which are sensitive to changes in their environment |
what examples of living indicators are there and what they can indicate? | lichen - air pollution (e.g. sulphur dioxide) - lots of lichen = no pollution bacteria - will increase with raw sewage and use up oxygen invertebrate animals - (e.g. mayfly larvae) - only live where there is lots of dissolved oxygen in the water |
what non-living indicators are there and what do they indicate? | satellites - temperature of sea surface/ amount of ice cover automatic weather stations - atmospheric pressure - thermometers rain gauges - rainfall each year dissolved oxygen meters - water pollution |
what can cause a decrease in the energy passed on through a bio-mass pyramid? | movement respiration waste not all of the food eaten heat loss |
what makes a compost bin decompose waste? | extra decomposers added warmth generated helps decomposition finely shredded waste - large surface area mesh sides to let air in |
how is carbon returned to the atmosphere? | plants and algae respire - releasing carbon when plants die - detritus feeder take in carbon compounds when they are burnt - carbon dioxide animals respire - release carbon carbon passed through the food chain |
rank these in order of which if found within which: chromosome/ DNA/ nucleus/ gene | nucleus chromosome gene DNA |
what is an allele? | alternate version of a gene |
are the offspring in sexual reproduction clones or genetically different? | genetically different as there is the mixture of genes |
how many parents does asexual reproduction involve? | one |
are the offspring of asexual reproduction genetically identical or genetically different? | genetically identical (clones) |
how does asexual reproduction occur? | X chromosomes have identical halves chromosome splits down the middle two identical sets of half-chromosomes membrane forms around sets two identical cells are formed |
what are the two different methods of plant cloning? | tissue culture cuttings |
how can you produce clones with cuttings? | cuttings are taken from the parent plant each cutting has a new bud cuttings are kept in moist conditions planted and grown clone plant created |
how can you clone plants using tissue culture? | few plant cells are added to growth medium with hormones |
what are the advantages of cuttings and tissue culture? | quick cheap (cuttings) requires little space (tissue culture) grown all year (tissue culture) |
how can you clone an animal using adult cell cloning? | nucleus is removed from unfertilised egg cell nucleus from body cell is inserted into egg electric shock applied to cause cell to divide to form embryo embryo implanted into surrogate mother |
what are the issues with cloning? | reduced gene pool - could be wiped out by disease/ virus can lead to greater understanding of embryos and ageing/ age disorders could preserve endangered species with cloning might not be as healthy if cloned |
How can genetic engineering be used to produce something more useful (e.g. Insulin)? | USING ENZYMES: gene cut out from DNA (e.g. insulin gene) bacteria plasmid opened gene inserted into plasmid bacteria grown produces product (e.g. insulin) |
Pros of GM crops | can increase the yield can add nutrients, such as in LEDCs where there is little nutrients GM crops already grown worldwide without problems |
cons of GM crops | affecting number of weeds/ insects can affect biodiversity people might develop allergies to crops genes may get out into the natural environments (e.g. herbicide resistance may produce superweed) |
how does variation occur? | an individual shows variation (as a result of a random mutation) the characteristic makes it better adapted to the environment and therefore has a better chance of survival they breed and the genes are passed on to the next generation |
why didn't people agree with Darwin? | it went against religious beliefs - showed there was no need for a "creator" Darwin couldn't give a good explanation as people didn't know about genes and inheritance there wasn't enough evidence |
what were Lamarck's ideas? | if a characteristic was used a lot then it would develop over a life-time (e.g. stretching a short nose to reach leaves) the acquired characteristic would then be passed on to the next generation (e.g. they would then also have a stretched nose) |
what was the current theory at the time? | CREATIONISM - that God had already created everything and it was simply being released bit by bit (everything was already on the earth somewhere) |
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