Charles Darwin & Evolution/Extinction
- Idea of evolution by natural selection
- Finches on Galapagos islands.
- His boad: HMS Beagle, 22 years old.
- Fossils give us light into the past
Factions which would cause extinction are:
- A new preditor
- A disease
- Competiong for a food source (natural selection) - those whom cannot adapt to get to the food source die out.
- Eviromental changes - e.g climate change, natural surrounding chance, their food course dying off ect..
Human polution growth:
- such as car fuems, burning of non-renewable sources
- continious rise in the human waste levels
- acid raid is formed when a certain level of carbon dioxide is release into atmosphere - has an indisrecret reaction to our enviroment, kills plants and polouts water
- green house affect: due to methane and carbon dioxide levels the atmosphere is constantly rising in temperature
- combustion affects: due to rise of vehicles ect carbon dioxide levels are continiously rising
- affects of deforestation: prevents photosynthesis from happening
- methane affects: cows, rise and methane - rice fields release methane into atmosphere causing polution as do cows by farting
- Lichens grow where air is clean - act as an indicator of how clean the air actual is
- water species indicate polution levels
- Dolly the sheep, a successful accoutn of genetic cloning
- Identical twins are in fact clones...gentically anyway
Different types of cloning:
- Cuttings: Taking a small piece of a stem or leaf and growing it on in the right conditions to produce a new plant
- Tissue cloning: Getting a few cells from a desirable plant to make a big mass of identical cells each of which produce a tiny identical plant
- Asexual reproduction: Reproduction which involves only 1 parent, there is no joing of gametes and the offspring is idental to parent
- Embryo cloning:Splitting cells apart from a developing embryo before they become specialised to produce several identical embryos
We inheritate features from our parents such as our features (e.g unattached earlobe or attached, arched or straight thumb, dimples or no dimples, hair colour, skin tone ect.
It's genetic information passed on to you in the sex cells (gametes)
DNA is where the genetic information is stored. they are 2 long strands twisted together - this is known as a double helix
Each single chromosomes contains thuosands of genes
When ill or infected our red blood cells come into action.
To help they:
- Injest microorganisms: Some white blood cells injest pathogens destroying them and preventing them causing desies
- Produce anti-bodies:Sine wgute cells produce special anti-bodies, these target particular bacteria and virus to create immunity towards them
- Produce anti-toxins: These are realeased to conteract the toxins released by the pathogens