HSC Biology. Year 2014 Mark Pages 28 Published Jan 12, Biology: Blueprint Of Life Notes. By Leah (97.7 ATAR)

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1 HSC Biology Year 2014 Mark Pages 28 Published Jan 12, 2017 Biology: Blueprint Of Life Notes By Leah (97.7 ATAR)

2 Powered by TCPDF ( Your notes author, Leah. Leah achieved an ATAR of 97.7 in 2014 while attending Tara Anglican School For Girls Currently studying Bachelor of Primary Education at The University of Sydney Achievements: 2nd in State HSC Geography 2014 Caltex All Rounder Award 2014 Geography Teacher's Association Arthur Phillip Award 2011 and 2012 Band 6 HSC Biology Band 6 HSC General Mathematics Band 6 HSC Geography (mark of 97) Band 6 HSC Food Technology Band 6 Studies of Religion I Leah says: Hi all, I achieved an ATAR of 97.7 in the 2014 HSC ranking 2nd in the State in Geography. I'm currently studying a Bachelor of Primary Education at the University of Sydney and am super passionate about educating young people to achieve incredible things. I have over 2 years of tutoring experience and my notes comprehensively cover all HSC syllabus dot points. My advice is work hard and play hard- after all, this is your last year of school! Enjoy your last sports carnivals, muck up days and all the extra curricular activities you do whilst studying diligently and thoroughly to enjoy the all important balance of year 12.

3 Definitions- Theory- scientists explanation of a principle, it is the accepted thinking- but new theories can disprove it- thus the science is tentative Evolution- a change in living things over millions of years Natural Selection- the mechanisation by which evolution occurs- Charles Darwin and Alfred Wallace Genotype- the alleles an organism posses Phenotype- the physical appearance of an organism Process of natural selection- (also include selection pressure) 1. Variation- naturally resistant 2. Advantage- over selection pressures 3. Survival- of resistant species 4. Reproduction- pass on helpful trait 5. Change- majority of population resistant 1.1 Impact of evolution- physical conditions, chemical conditions and competition for resources- Evolution- a change in living organisms over a long period of time Characteristics of evolutiono Arise from common ancestor and change over time o Differences are due to change over time o Similarities suggest a common ancestry Environmental Changeso Temperature, water availability, wind, slop, sea levels, tides o Natural selection- those suited to environmental change survive, others go extinct o E.g. Darwin s finches- beak change according to food available Chemical conditionso Presence or absence of oxygen, carbon dioxide, ph salt, chemicals o Natural selection- those suited to chemical conditions survive, others go extinct o E.g. peppered moth- soot levels industrialisation of England Competition for resourceso Striving for the same resources in limited supply- mates, shelter, prey o Natural selection- those who get the resources survive, others go extinct o E.g. Tasmanian tiger- humans shared same resources Selective pressure- a change that causes some organism with a particular variation to survive and reproduce whilst others without it decrease in number and eventually die out Adaptation- an alteration in structure, function or behaviour that is hereditary (already possess random variation) BLUEPRINT OF LIFE HSC BIOLOGY NOTES Leah Nye Band Macro-evolution- takes place over millions of years, such as new species of families evolving Micro-environment- takes place over short periods of time, such as breeds of dog Australian example- environmental change e.g. rainforest into sclerophyll as rainfall amounts reduced over time 1.a Model Natural Selection- AIM- To stimulate the process of natural selection METHOD- 1. Scatter toothpicks over a large grassy area. Colours: blue, purple, green, yellow, pink, orange- 200 scattered of each colour

4 2. In 30 seconds, pick up as many toothpicks as possible- record how many are collected RESULTSo Less green were picked up (survived) due to being able to camouflage with the grass o Yellow was collected most (spotted easily) and survived the least o Thus, in time, due to natural selection the population would be made up of more green and less yellow RELIABILITYo Repeat 5 times to make the test more reliable VALIDITY- Dispersal bias- toothpicks were in clumps Not starting with 200 sticks Picking up sticks is not indicative of what happens in nature 1.b Case Study- environmental change leads to changes in a species- English peppered moth- perfectly camouflaged to light coloured lichens on trees- black moth stood out (didn t survive) 1800 s industrial revolutions sooty smoke caused trees to turn black- black moths become camouflaged and the light stood out Clean Air Act- reduce soot- trees turned white again Black colour- variation occurs from mutation and meiosis in sexual reproductions Selective agent- birds eating moths Environmental change- pollution/soot from factors 1.2 Evolution supported by: palaeontology, biogeography, comparative embryology, comparative anatomy, biochemistry- PalaeontologyBLUEPRINT OF LIFE HSC BIOLOGY NOTES Leah Nye Band The pressured remains of organic material from the remote past, either mineralised remains in rock or actual remains in rock, ice, amber, tar, peat Layers reflect age- oldest at the bottom Fossils show a similar sequence- showing things arose in a particular evolutionary sequence Transitional forms- Darwin s prediction similar to current species e.g. archaeopteryx- 150 million years old, reptile like- teeth, bones, tail and 3 digits on forelimbs, bird like- wish bone, feather impressions, keel bone for flight- show birds and reptiles arose from one common ancestor Biased towards organisms suited to fossilisation lack of soft organisms Some have well represented lines of descent- others are not in fossil record at all Fossils only date back to years ago Biogeography-

5 Powered by TCPDF ( Examination of physical environment and how it affects species and distribution Show how isolated species have developed and split Evolution caused by natural selection- driven by environmental pressures Isolated areas are subject to individual selection pressures- evolve to survive- rules out interbreeding e.g. Darwin s finches Studies limited to isolated species Comparative embryology- Comparing sages of embryonic development across species- similarities show a common ancestor Vertebrates- fish, reptiles, amphibians, mammals, birds- all have gill slits, tails with muscle blocks as embryos Homologous parts = divergent evolution Ethical issues- studying human embryos Despite homologous structures- not the same genetically Comparative anatomy- Study of similarities and differences in the structure (anatomy) of living organisms Compare living animals to fossils- give all living things arose from one common ancestor Homologous structures show divergent evolution e.g. pentadactyl limb Analogous structures show convergent evolution e.g. wings Vestigial structure show former use e.g. appendix Fossil record incomplete Bias in animals represented Hard to compare living to extinct Superficial structures e.g. wings- may have similar structure- different origin Biochemistry- Study of chemicals found in cells- molecular biology and genetics