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BIOL1130 Exam Revision Notes Nicolie McCluskey Molecules of Life: Requirement of Organisms Biomolecules: are chemical constituents of life. They are carbon based 4 main types of biomolecules are sugars, fatty acids, amino acids and nucleotides. Building blocks of large macromolecules (if macromolecu...

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BIOL1130 Exam Revision Notes Nicolie McCluskey

Molecules of Life: Requirement of Organisms Biomolecules: are chemical constituents of life. They are carbon based  4 main types of biomolecules ‘building blocks’ are sugars, fatty acids, amino acids and nucleotides.  Building blocks of large molecules= macromolecules (if macromolecules are built up of repeating units = polymer)  Polymer example included polysaccharides (from sugars), proteins (from amino acids), nucleic acids (from nucleotides)  Sugar polymers = carbohydrates Organic compounds Carbohydrates

Example

Elements present

Glucose, starch

C, H, O

Lipids

Fats and oils

Proteins – are functional products of genes Nucleic acid

Enzymes and collagen

Source of energy and support for cell structure C, H, O as well as N, Stores Energy P for complex lipids C, H, O, N, S, P Controls rate of reactions in cells

DNA, RNA

C, H, O, N, P

Function

Are storage forms of heritable information

Requirement for living things:   

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Energy Requirements: - Photosynthetic organism require light - Heterotrophs require energy-rich foods Gas Requirements: - Photosynthesis- CO2 - Respiration- O2 Water: - Water is used as a medium in which all the essential metabolic reactions take place. - Also essential to dilute nitrogenous waste in land animals. - Requirement in photosynthesis. Nutrients: - A nutrient is any substance used as food by an organism. Nutrient Source Function Amino acids Animal and plant Structural proteins proteins. Are building and enzymes blocks of protein Simple sugars Starch and other Source of energy carbohydrates Fatty acids Fats and oils Structural lipids eg

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BIOL1130 Exam Revision Notes Nicolie McCluskey cell membrane and hormones. Food stores

Classification:    

Biological classification is the arrangement of organisms into groups that have common characteristics. It also shows structural relationships between groups of organisms eg skin covering of hair and or feeding relationships eg autotrophs. Classification allows people to communicate effectively. Biologist use internationally recognised system to classify organisms.

7 levels of classification: 1. Domain 2. Kingdom 3. Phylum 4. Class 5. Order 6. Family 7. Genus 8. Species-> A species is a consistently similar group of organisms which are capable of producing fertile offspring in their natural environment. Each succession level uses different criteria and contains organisms with more structural features in common. 3 ‘SUPER KINGDOMS’ (domains) 1. Bacteria 2. Archae 3. Eukarya 5 kingdoms: 1. Plants:  Eukaryotic  Multicellular  Photosynthesis  Non motile  Asexual/ sexual 2. Animal:  Eukaryotic  Multicellular  Ingest  Motile  Sexual 3. Fungi:  Eukaryotic

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BIOL1130 Exam Revision Notes Nicolie McCluskey    

Multicellular Absorbs food (parasitic) Non motile Sexual

4. Protista:  Eukaryotic  Single celled  Feeding varies  Asexual/ sexual  Mixed bag of organisms  Most microscopic 5. Monera:  Unicellular  Prokaryotic  Absorbs or photosynthesis  Asexual  

Biological classification is considered as a hierarchical system since it starts off with a large general groups and break into smaller more specific groups. As you go down the levels of classification, organisms in the same group share similar characteristics eg, organisms in the same class share more characteristics than organisms in the same phylum.

Binominal Nomenclature:  Binominal nomenclature is the system of naming an organism where the species is given two names (the Genus and species name) eg Homo sapiens  Genus names can be shared across kingdoms  Scientist use this method of naming organisms because common names may be confusing. However using the Latin are universal and allow for efficient communication between biologists.  The animal family ends with the suffix ‘idae’  Writing scientific names- italics, capitalised and lower case letters.  Naming of an organism is called a taxonomy  Taxonomic keys one of the most common tool used to identify and classify an organism. - The most common type is the dichotomous key: - Dichotomous means there are two choices at each step  Hierarchical classification reflects phylogeny  Each named group should be monophyletic - Containing all descendants of a common ancestor - Non- monophyletic groups: paraphyletic, polyphyletic a. Monophyletic taxon: Includes all descendants from a common ancestor

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BIOL1130 Exam Revision Notes Nicolie McCluskey

b. Paraphyletic taxon: excludes some of the descendants of a common ancestor

c. Polyphyletic taxon: unrelated organisms have been grouped together based on superficial, no homologous resemblance due to convergent evolution

Communities: Ecology The study of interrelationships among organisms and between organisms and their environment  Bioshpere: A narrow belt around the earth consisting all the earths living organism .  Ecosystem: An area where all organisms are present and their interactions with the abiotic environment.  Community: A set of interactig organisms of a different species within an area (biotic environment).  Population: Members of the same species in a particular place at a particular time.  Autotrophs/ producers: Organisms capable of synthesising their own energy amd food. They use external energy source to convert inorganic matter to organic matter. Includes green plants and algae.  Hetertrophs/ consumers: Organisms that lack the ability to synthesis their own energy and food therefor reley directily or indirectly on atotrphs as a spurce of energy and food. When consuming organic matter they convert in to other forms of organic matter.  Detrivores: Include organisms such as crayfish and earth worms consume dead organic matter and animal waste that accumilate as detrius.  Decomposers: Include special types of heterotrophs organisms such as fungi and bacteria. They are responiable break down dead plant matter and animal matter and returen the nutrients back in to the ground, turning

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BIOL1130 Exam Revision Notes Nicolie McCluskey

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organic material back into inorganic material to be directly used by synthesising organisms. They enable the cycling of matter. Photosynthesis: Photosynthesis is the cellular process in which light energy is trapped by the chlorophyll and used to combine carbon dioxide and water to make glucose. Carbon dioxide+water->Oxygen+Glucose+water Chemosynthesis: The proceess by which some bacteria are able to make organic materical from inorganic compunds using energy from chemical reactions.

Organisms Interrelations: - Symbiosis occurs when 2 organisms live in close contact and at least one benefits - Symbionts organisms involved in a symbiosis - Symbioses are common within ecological communities, especially complex ones  Competition- occurs when two organisms fight for the same resource (shelter, food, mate etc.) There will only be one winner Interspecific competition- occurs between organisms of a different species e.g. lion and cheetah Intraspecific competition- occurs between members of the same species  Mutualism- an interaction between two organisms where both obtain a benefit in some way e.g. bacteria lives in the lure of an anglerfish, its gets a stable environment, while the anglerfish is a more efficient predator  Commensalism- one member of the interaction benefits, while the other is harmed nor benefited e.g. anemone fish are immune to the stings but it keeps predators away. The sea anemone gains no benefit with or without the fish. Without it it would have the same quality of life  Collaboration- when two organisms work together to obtain a resource  Amensalism- refers to a relationship between two species in which one of the partners is inhibited while the other is not affected in any significant way  Parasite host- (is a form of predator prey) One organism lives in or one a host organism and causes harm to it. The parasite benefits while the host is harmed in some way Ectoparasite- live on the host e.g. tick Endoparasite- lives inside the host e.g. tapeworm Vectors carry/ transport parasites to host organism e.g. mosquito Parasitoids- different version of parasitism- 1st stage of life cycle is parasitic, 2nd stage of life is not parasitic e.g. insects that are only parasitic in their larval stage and free living as adults- wasp larvae Hemiparatites- plants that are parasitic to neighbouring plants, can exploit multiple hosts at the same time e.g. Australian mistletoe  Predator- prey- One organism feeds up on the other Keystone predators- the presence or absence of the predator has a major effect on the community structure e.g. Seastar Pisaster ochiraceus controls diversity of rock shore communities by controlling mussel abundance. The removal of Pisaster  mussels outcompete other species for space, with

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BIOL1130 Exam Revision Notes Nicolie McCluskey

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Pisaster present weaker competitors survive, increase biodiversity of ecosystem Herbivore- plant- some plants are able to prevent being eaten - Tasting or smelling terrible - Having a poisoned structure - Having thorns or spikes - Stinging nettles

Food Chains and Webs: Food chains: Are a simplified view of a feeding relationship within a community. - Energy flows along a food chain with arrows indicating the direction of energy flow. Sun-> Autotroph-> Consumer-> 2nd order consumer-> Carnivore, tertiary consumer 

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Only 10% of energy is passed on from one trophic level to the next. Food chains are not realistic views of a communities feeding relationship as an organism eats and gets eaten by more organisms. Consumers (heterotrophs) Primary consumers consume autotrophs Secondary consumers consume primary consumers Tertiary consumers consume secondary consumers Omnivores consume organism from more than one trophic level Decomposers- organism that cause chemical decay of organic matter, cycle valuable nutrients from dead organism back into the ecosystem. Usually overlay several trophic levels Detritovers- Organism that consume organic litter (detritus) Scavengers- Organism that eat dead organism Grazer chains- consumers depend on living plants for food e.g. rock shores, grasslands Detritus chains- consumers eat decaying matter (detritus) and debris e.g. mangrove, forests

Food Webs: Food webs show all possible feeding relationships within a community. - The more complex a food web is the more stable. This is because the removal of one species from a simple food web has a disastrous affect on other organism within that food web. But in a complex food web if one species is remove the affect is not so disastrous as there are alternative food sources for the other organisms.

Evolution: Evolution: The gradual change in a species which occurs over thousands of years due to increasing effects of mutations and natural selection. - gradual change in gene or allele frequency over time

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BIOL1130 Exam Revision Notes Nicolie McCluskey -

Refers to biological change over time Evolution occurs within populations Genetic change is inherited change which occurs over generations Evolution allows organisms to evolve to better suit their changing environment Large scale evolution can lead to the diverge of 2 populations in to separate species= divergent evolution= speciation event Evolution requires vairiation to occur Evolution changes frequencies within a gene pool

Gene pools: The gene pool is the sum total of all alleles of all the genes possessed by all the individuals in a population. Factors that cause a gene pool to change over time: - Selection Pressures (eg changing environments) - Mutations - Sexual selection - Population size - Migration/ gene flow - Genetic drift/ Founders effect/ Population bottlenecks -

Populations: refers to members of the same species at a particular time in a particular place

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Species: refers to a group of organisms that are able to reproduce, producing fertile offspring in their natural environment/ under natural conditions

Natural Selection: The process where by organisms with more favourable genes/ characteristics will have an increase chance of survival and reproduction, resulting in more favourable phenotypes being expressed more readily - More favourable phenotypes will be expressed Principles of Natural Selection: 1. Variation exists within population 2. Variation are inheritable 3. More offsprings are born than will survive to reproduce 4. Survival of the fittest- same organisms will have traits that make them better suited to their environment 5. Best suited organisms survive, reproduce and pass on favourable genes to offsprings

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BIOL1130 Exam Revision Notes Nicolie McCluskey Variation: - Variation exists within species and between species - Variation is necessary for evolution - A lack of variation in a population can explain a rapid decline in a population and can even lead to the eventual extinction of a species eg Tasmanian devils are an example of an Australian organisms which lack genetic variation and thus faces extinction due to inability to adapt and become resistant to the fatal Devil Facial Tumour Disease which has caused a rapid decline in population numbers, further reducing the gene pool - The gene pool is the sum total of all alleles of all the genes possessed by all the individuals in a population - Populations with a wide and varied gene pool living across a wide range f habitats will show considerable variations in: -Size -Colour -Ability to escape predators -Ability to be well camouflaged -Ability to resist disease - Competition- Individuals most likely to compete successfully and survive will be those with favourable characteristics (survival of the fittest) - Creating Variation- Variation can be introduced in to a population in the following ways: 1. Independent assortment of chromosomes during meiosis: -

When homologous chromosomes, one from each parent pairs up along the equator during metaphase I of meiosis, the particular arrangement is determined by chance All the maternal chromosomes may be on 1 side of the equator and all the paternal chromosomes on the other or any combination in between 2. Crossing over:

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Crossing over involves pieces of a chromosome exchanging position with pieces from another chromosome of a homologous pair This occurs when the chromosome pair up during prophase I in the first meiotic division 3. Random mating/ random fusion of gametes:

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Random mating involves individual pairing by chance, not according to their genotypes or phenotypes Fertilisation results during the fusion of the gametes Fertilisation is in itself a random process and ensures a different combination of genes each time depending on which sperm/ pollen combines with the egg

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BIOL1130 Exam Revision Notes Nicolie McCluskey -

Genetic information becomes mixed as gametes from the male and female parents unite to form the fertilised egg cell known as a zygote 4. Mutations:

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A mutation is a sudden, permanent change in a gene or chromosome and may introduce variation in to a population Spontaneous errors in DNA replication Mutations occasionally give rise to variation that are favourable but most mutations are damaging or lethal 5. Environmental impacts: - Environmental pressure can produce variation amongst species eg Darwin’s finches who are all from a common ancestor and are the same species but all have different beak types which depend on the type of food which they eat.

Evolutionary fitness: - ‘ Survival of the fittest’- Herbert spencer 1864 - Fitness= survival + reproductive success - Fitness is the measure of how many offspring you have - Fitness is an outcome of natural selection Adaptations: atomically structure, physiological processes or behavioural traits that have evolved by natural selection which increases an organisms change of survival + reproductive success in a particular environment - Natural selection is a culling process Selection Pressures: Drive change within a population Are environmental factors which may reduce reproductive success in a population and thus contributing to evolutionary change or extinction through the process of natural selection.

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BIOL1130 Exam Revision Notes Nicolie McCluskey Examples include: - Competition - Predation - Disease - Parasitism - Land clearance - Climate change - Pollutants 1. Biotic Factors- other living organisms caused e.g. predation, competition, disease 2. Abiotic factors- environmental factors e.g. climate, topography, weather, habitat - Selection pressures act on phenotypes - Acts on all stages of life - May act for many generations Example- Giraffe - As food source become depleted (competition) in the giraffe environment, selection pressures favoured those individuals in the population with longer legs and longer necks - These taller varieties could reach the higher foliage and would be more likely to survive any struggle for existence and pass on their characteristics to the next generation Types of selection: 1. Natural selection: a. Stabilizing selection- selects against the extreme phenotypes. Over time range of variation is narrowed. e.g. birth weight of new born small babies + large babies don’t have a good survival rate due to there extreme weights

b.

Directional selectionphenotypes character shift in one direction. Natural selection against one extreme. Overtime the range/ average trait shifts

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BIOL1130 Exam Revision Notes Nicolie McCluskey

c. Disruptive selection- against average phenotypes. Those at the extremes have a better fitness. Overtime 2 sub populations can form e.g. light moth population + dark moth population - Selection against intermediates group= polymorphism

2. Artificial selection: The selection by humans of animals or plants which have useful features which humans want to more readily express within that species or deplete from a species - Is the man controlled natural selection: to enhance desirable traits or remove undesirable traits - Eg. Domestic dogs: -All breeds of dogs are considered to have originated from a common ancestor, the grey wolf -Breeders select traits that are desirable -They then use inbreeding as the mechanism to these traits in the dog population eg pugs (squashed faces) Problems: - The limited gene pool caused by continued inbreeding means that undesirable genes, already present in the population, increase in frequency and are expressed more often in the phenotype - Undesirable characteristics may include misaligned jaws or other serious conditions - Eg. Epilepsy in Alsatians have revealed a genetic basis for the conditions as a result of inbreeding - Other examples: Agricultural animals- Sheep bred for meat, sheep bred for wool, Dairy cows, Bulls bred for meat (Belgian Blue) - Selective breeding in plants:

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BIOL1130 Exam Revision Notes Nicolie McCluskey -Breeder of plants and animals strive to produce organisms that will possess desirable characteristics such as high crop yield, resistance to disease, high growth rates and beneficial structural features -Wild Mustard plant- Artificial selection has led to the development of vegetables such as Brussels sprouts, cabbage, cauliflower and broccoli. Each of these vegetables have been developed from only one original species: the mustard plant, which is the common ancestor 3. Sexual selection: - Sexual selection is a form of natural selection that affects an individuals ability to mate - In some species, males compete for a mate and the winn...