3591818
Description
Flashcards by Ben Goetze, updated more than 1 year ago
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Created by Ben Goetze
over 8 years ago
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| Question | Answer |
| Multicellular | Consists of many cells (e.g. animals, plants) |
| Unicellular | Consists of One Cell (e.g. bacteria) |
| Tissue | A tissue consisting of only one type of cell e.g. muscle tissue |
| Organ | Consist of two or more tissues forming a structure with a particular function e.g. muscle tissue |
| Organ Systems | Organs working together e.g. cardiovascular system |
| Organism | Individual Creature |
| Differentiation | The activation of particular genes in stem cells so they develop particular structures to carry out particular functions |
| Organ systems that constitute the body | Circulatory Respiratory Excretory Nervous Digestive Reproductive |
| MRSGREN | Movement Respiration Sensetivity Growth Reproduction Excretion Nutrition |
| Cell Theory | All living things consist of cells and the products of cells. All cells arise from pre-existing cells |
| Implications of SA/V ratio in cells | As cells increase in size, it becomes more difficult for them to provide nutrients and to remove wastes by diffusion. This means surface exchange becomes less efficient, limiting the effective size of cells |
| Prokaryotes | Small, 10micrometers, no true nucleus, no membrane bound organelles e.g. bacteria |
| Eukaryotes | Larger - 50-100 micrometers, true membrane bound nucleus, membrane bound organelles. May form multicellular organisms e.g. plants, animals |
| Nucleus | Double Membrane bound structure within which is the DNA in the form of chromosomes. The nuclear membrane has pores through which RNA can pass |
| Mitochondria | Double membrane structure within which aerobic respiration takes place. Also contains a small level of DNA. Large internal surface area |
| Chloroplast | Double Membrane structure that contains DNA. It is mainly found in plants and is the site for photosynthesis. |
| Vacuole | Single membrane sac like structure that stores materials. Large sap vacuole in plant cells. |
| Golgi Body | Stack of membranes where proteins are packaged for export from cell Vesicles (small vacuoles) break off containing proteins to be exported from cell |
| Ribosomes | Don't contain membranes, rather made from RNA. Where proteins are synthesized. |
| Endoplasmic Reticulum | A system of membrane pathways through the cytoplasm of a cell. Provides surface area for cellular reactions and a transport pathway. Some sections have ribosomes on the surface so called Rough Endoplasmic Reticulum, other sections lack ribosomes so called smooth |
| Gene | Section of the DNA code that determines the structure of a particular protein |
| Evolution | The change in organisms over generations |
| Endosymbiotic | Once Cell living within another, both gaining benefit Small cell engulfed by a larger cell. Gains protection from from larger cell and gives it some benefit. |
| Cytoskeleton | Network of proteins through cytoplasm connecting cellular components. Can cause membrane to move |
| Fluid Mosaic Model | Fluid - Membrane is a dynamic structure, components can move. Mosaic - Membrane consists of different components e.g. Phospholipids and proteins |
| Polar Head | Charged so attracts water molecules |
| Hydrocarbon Tail | Hydrophobic - repels water |
| Endocytosis | Membrane invaginates forming a vacuole with materials from outside the cell e.g. Nutrients |
| Exocytosis | Vacuole fuses with cell membrane and contents are expelled out of cell |
| State 3 Functions of the cytoskeleton | Control cell shape, Move Organelles, Enable Cell movement, Enable endo/exocytosis |
| Intracellular: Extracellular: | Inside Cell Outside Cell |
| Cells Take in: | Nutrients: Glucose, Amino Acids and Oxygen |
| Cells expel | Wastes e.g. Urea and Carbon Dioxide |
| Cells regulate | Water balance by controlling water molecules and ions |
| The internal composition of the cell is regulated to: | Provide the ideal conditions for the metabolism (biochemical reactions) of the cell. e.g. pH, water balance, oxygen, glucose |
| Bilipid Layer | Barrier to H20, only allows lipid soluble substances through e.g. O2 |
| Proteins: | Some provide pathways for water molecules and those dissolve in water.Others provide specific pathways for particular molecules e.g. Glucose, ions |
| Passive Transport | No energy input required. Substances move from a higher concentration to a lower concentration along a concentration gradient. e.g. Diffusion, Facilitated Diffusion, Osmosis |
| Active Transport | Requires input of energy. Substances moved against a concentration e.g. active transport, endocytosis, exocytosis |
| Diffusion | Molecules move randomly causing collisions with each other. These collisions will tend to spread molecules apart unless confined. Given time, in a sealed container, molecules will spread out evenly. |
| Osmosis | The passive movement of water molecules across a semi-permeable membrane Solvent - e.g. Water Solute dissolves in water e.g. Na+ and Cl- ions from NaCl |
| Facilitated Diffusion | This is where a protein provides a specific pathway across the membrane - called a carrier protein e.g. for glucose |
| ATP | Short term energy storage compound in cells that can provide energy when and where it is required |
| Macromolecules | Large Molecules |
| Polysaccharides | Complex sugars consisting of simple sugar (monosaccharide) subunits. |
| Polymer: Polysaccharide Protein Nucleic Acid | Monomer: Monosaccharide Amino Acid Nucleotide |
| Lipids | Fats and oils. Not polymers. Made of glycerol and fatty acids. |
| Protein Structures | Cytoskeleton, Muscle |
| Cellulose exists in | Cell Walls in plants |
| Chitin exists in | Exoskeleton of arthropods e.g. insects and cell walls of fungi |
| Phospholipids | Bilayer backbone of membranes |
| Polysaccharides energy storage | In plants: Starch In Animals: Glycogen |
| Lipid energy storage | Plants: Oils Animals: Fat layers |
| Chromosome | Main component DNA: carries code on DNA |
| Gene | A segment of DNA that codes for a particular polypeptide |
| Enzyme | A protein that is a biological catalyst. Speeds up reaction rate. |
| Induced Fit Model | Enzyme and substrate bond. Enzyme clamps around substrate, putting pressure on the chemical bonds. This reduces the activation energy. |
| DNA | a polymer consisting of monomers called nucleotides. Each nucleotide consists of a phosphate, a sugar and a base. |
| The 4 Bases in DNA | Adenine (complementary to) Thymine Cytosine (complementary to) Guanine |
| To form DNA | nucleotides bond to form two polynucleotide strands which are bonded together by complementary bases. Then the molecule twists to form a helix. |
| Process of Semi Conservative Replication | The polynucleotide strands are separated by DNA polymerase. New nucleotides are introduced and since A always bonds with T and C always bonds with G, a new complementary strand is formed. Hence 2 new DNA molecules exist, each containing one newly synthesised and one original strand. |
| Mutations | Change in the base sequence |
| Mutation Rate can be increased by | Radiation e.g UV from sun Mutagenic Chemicals e.g. Dioxins Heat (as temp increases mutation rate increases) |
| Enzymes are | Biological Catalysts Reusable Specific for a particular reaction Globular Proteins |
| Enzymes are specific to their substrate because: | All enzymes are globular proteins with a specific 3D shape, and part of this shape is termed the active site. This is where a particular substrate molecule can lock onto the enzyme resulting in its catalysis to product. Because of this one enzyme can only bond with one substrate, making it specific. |
| Denaturation of Enzymes | the shape of an enzyme changing. Caused by extremes of pH and high temperatures |
| Competitive Inhibitors | molecules that bind to the active site of enzymes blocking their function. They are not the intended substrate. e.g Hydrogen Cyanide blocks a particular enzyme in the aerobic respiration pathway therefore starving the body of energy |
| Activation Energy | The initial input of energy required by substrates to react to become products. |
| The amount of DNA in a cell doubles before cell division because... | Semi-conservative DNA replication occurs before cell division so both daughter cells carry the full genetic code |
| Binary Fission occurs in | Prokaryotes |
| Binary Fission | The DNA loop replicates and then the cell splits in two. Each resulting cell containing a loop of DNA |
| Order the phases of Mitosis | 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase |
| Prophase | Nuclear Membrane breaks down, chromosomes condense and become visible under a microscope, spindle fibres form |
| Metaphase | Spindle Fibres arrange chromosomes along equator of cell |
| Anaphase | Spindle Fibres cause chromosomes to split at centromere and migrate to poles of cell |
| Telophase | Chromosomes clustered in two sets, one at each pole. Nuclear membrane reforms at each pole. |
| Internal Factors regulating division | Proteins produced by the cell which stimulate mitosis. Often set off by the cell detecting hormones e.g. Human Growth Hormone |
| External Factors regulating division | Nutrients, Cell/Cell Contact, Cell/Environment contact. These stimuli can either inhibit or stimulate cell division depending on factor. e.g High nutrients - Stimulate Low Nutrients - Inhibit |
| Gene Product | A polypeptide - Protein. Examples are MPFs (Mitosis Promoting Factors) that initiate the onset of mitosis. |
| Reasons for growing cells in a laboratory | Research - A supply of cells to experiment on to discover more about cell functioning. Medical - Growing Cells for medical purposes e.g. skin grafting Commercial - Growing plants from tissue samples get ,amy plants with required feature e.g. Flower Colour |
| Dissection | Removal of cells from organism. Enzymes often used to isolate cells in sample |
| Suspension | Placement of Cells in culture medium with required nutrients |
| Cell Culture | Suspension placed in cell culture flask in ideal temperature conditions to stimulate growth and division |
| Uses of Cell Culture | Research - Chemical and Drug testing on cells, using cells instead of animal testing Medicine - Skin Tissue, Anti-body production, Vaccine Production, Tissue for Transplant Agriculture - Rapid production of plants for sale, development of more productive crops |
| The functional Unit of information on the chromosome: | The gene |
| A gene consists of | A unique sequence of bases that code for a polypeptide or an RNA molecule |
| Amino Acids are coded for by | a sequence of 3 bases or a codon. In fact it is a degenerate code as there is more than one codon for each amino acid |
| The flow of information from DNA to protein | DNA --> RNA --> Protein (Unidirectional in most organisms) |
| Transcription | DNA is unzipped by DNA Helicase, A complimentary strand of mRNA is created from DNA template strand |
| Translation | the mRNA molecule migrates to the ribosome. tRNA anti-codons attached to specific amino acids bond to complimentary mRNA codons and peptide bonds form between adjacent amino acids, forming a Protein. |
| DNA can be extracted from Cells by | disrupting cell and nuclear membranes with detergent and then centrifuging so that DNA settles in a distinct layer |
| Probes | usually a segment of DNA or DNA that carry a code complimentary to a segment of the DESIRED GENE. The probes have a marker attached e.g. Flourescent that show up the location they attach |
| Particular Genes can be selected and removed using probes and restriction enzymes: | DNA is heated, strands part and probes can then bind to a specific gene. Once the gene is located in can be cut from its chromosome using a restriction enzyme. This cuts at a particular base sequence. |
| Bacterial Plasmids | small loops of DNA in the cytoplasm of prokaryotes in addition to their main DNA loop. They can be removed, manipulated and then returned to bacteria. |
| Micro-Injection | A very fine glass tube is used to introduce genes into a cell's nucleus e.g. Transgenic Animals Genes are introduced at the zygote to add genetic features |
| Social Consequences of DNA manipulation: | - Possibility of harm to organism - New gene combinations may have unexpected consequences - Genetically engineered crops can genetically pollute organically grown crops - Herbicide resistant plants have an increased weed potential - Monopolies of biotechnology companies BUT - Increased food production potential - Ability to alleviate genetic disease impacts |
| Sequencing | Working out the order and number of bases on a DNA segment |
| PCR | An artificial form of DNA replication where DNA is heated splitting the hydrogen bonds between bases. This separates the polysaccharide strands so that new ones can form along old, therefore duplicating the DNA. Many cycles of this forms copies of the original sample. |
| Mitosis | The splitting of two chromatid chromosomes into one chromatid chromosomes |
| Asexual reproduction produces genetically identical organisms since: | Offspring only get DNA from one parent, and are such clones of that parent. Mutation must occur to change the base sequence |
| Meiosis | Two cycles of cell division. The first halves the chromosome number. The second splits the two chromatid chromosomes into one chromatid chromosomes. This produces gametes |
| Gamete | Sperm + Ova Haploid Cells |
| Fertilisation | When a sperm and Ova fuse |
| Diploid Cells | Normal body cells. Have paired chromosomes. One of each pair is paternal and one maternal |
| Homologous Chromosomes | Chromosomes of the same size, shape and genes |
| Gametes are Haploid so: | When they fuse they produce a zygote with the normal number of chromosomes (diploid) |
| Crossing Over | Occurs late in prophase 1 when Homologous chromosomes associate. Adjacent chromatids associate, mixing genes of maternal and paternal origin |
| Independant Assortment | Also occurs in prophase 1: It is random whether a paternal or maternal origin gene is on the left/right for each pair. So resulting in a mixing of genes in the gametes. |
| Offspring of sexual reproduction are usually not genetically identical because: | Meiosis and random fusion of gametes results in a high degree of genetic diversity |
| Variation of Offspring is affected by meiosis and fertilisation by: | meiosis: random assortment of homologous chromosomes and crossing over fertilisation: random fusion of gametes |
| prophase I | Nuclear membrane breaks down, random assortment of homologous chromosomes, crossing over occurs. Cell in diploid form. |
| metaphase I | Spindle fibres align homologous pairs along the centre of the cell |
| Anaphase I | Homologous pairs separate towards poles |
| telophase I and cytokinesis | Cells split. two haploid cells. |
| Meiosis II | Same as mitosis. Results in 4 Haploid gametes (sperm or ova) |
| Not all organisms will survive to reproduce because: | Due to the high degree of variation in sexually reproducing populations, some individuals will be better suited to the environment and so are more likely to survive and reproduce |
| Natural Selection | The process by which the variants in a population most suited to the environment have a higher chance of survival and reproduction. Hence a higher proportion of their genetic features will be in the next generation |
| Exchange taking place at: Lungs, Intestine, Skin, Kidneys | Lungs: CO2 + H2O out. O2 in Intestine: Nutrients in Skin: Water + Salts out Kidneys: Urea out |
| Features of exchange surfaces: | Thin- Short distance for exchange (rapid) Moist - Water is solvent for many substances (facilitating exchange) Large Surface Area - Larger available surface area, larger capacity for substance exchange |
| Blood Capillaries | Have thin, moist, permeable walls allowing diffusion of oxygen and nutrients from blood to extracellular fluid and wastes in the opposite direction |
| Lymph Capillaries | Collect excess water from extracellular fluid returning it to the venous system. Also transports lipids. |
| Nephrons are effective at removing toxins since: | They filter out everything from the blood except cells and proteins. Then they selectively reabsorb what is required |
| Nephron | The functional units of kidneys where the blood is initially filtered and then required materials are reabsorbed. They are thin, moist and numerous hence a large surface area. |
| Urine contains | Excess water Excess ions (salts) Urea Toxins Any molecules not required by body |
| Alveolus | Exchange surface in lungs. Alveolus in thin, moist, and there are many alveoli, hence large surface area. |
| Concentration gradient is maintained in alveoli through | ventilation of lungs and blood flow. Ensures oxygen diffuses in and carbon dioxide diffuses out |
| Small Intestine responsible for: | absorption of nutrients, resulting from digestion of food, into the blood. |
| Structure of Small Intestine:A long convoluted tube where the inner surface has many inward pointing fingerlike projections called villi. These structures provide a large surface area for absorption | A long convoluted tube where the inner surface has many inward pointing fingerlike projections called villi. These structures provide a large surface area for absorption |
| Structure of Villi: | Fingerlike projections. Epithelial cells of villus have small projections called microvilli (increase surface area). Contain capillary network and lacteal. Thin, moist, large surface area |
| Nutrients are absorbed through villi: | Glucose: Active transport, facilitated diffusion Amino Acids: Diffusion and Active transport Fatty acids and Glycerol: Active transport and Pinocytosis (fat reformed) |
| Organisms detect and respond to changes in internal and external environment such as: | Internal: Conc of CO2, Blood Pressure, Osmolarity, pH, temperature External: Light, Sound, Heat, Pressure |
| Importance of sensory receptors | Sight (eyes) avoid predators, find food Sound (ears) Avoid predators, understand language Pain receptors in skin avoid dangers and protective responses They enable us to successfully interact with our environment |
| Nervous vs Hormonal Communication | Key: N - Nervous, H - Hormonal Transmission: N impulses along nerves, H chemicals in blood, detected by receptors on cell Speed: N very rapid, H slower as transported in blood Duration: N Short lived, H longer lasting Action: N Specific e.g. sensory nerves, H more general over body e.g. adrenalin |
| Reflex Arc: Hot Surface | Stimulus: Hot Surface Receptor: temperature receptor in skin Sensory Nerve Part of Central Nervous System Motor Nerve Effector muscles of arm Response: pull hand away from hot surface |
| Stimulus Response Model: High temperature | Stimulus: elevated body temperature Receptor: Temperature receptors in hypothalamus of brain Sensory Nerves Processing hypothalamus of brain Motor Nerves Effectors: Arterioles in skin, vasodilation, sweat glands - sweating Response: Body temp drops back to normal Negative feedback: Response counteracts stimulus |
| Stimulus Response Model for Low Temperature | Stimulus: Low Body Temperature Receptors: Temperature receptors in hypothalamus Sensory Nerves Processing hypothalamus of brain Motor Nerves Effectors: Arterioles - vasoconstriction, adrenal glands increase metabolism (short term), thyroid glands increase metabolism (long term) Negative Feedback |
| Chemicals that interfere with metabolism: | e.g. cyanide inhibits an enzyme in the mitochondria, halting cellular respiration and causing death. Stimulus such as Caffeine tend to increase general metabolism |
| Issues associated with drug use: | Physical or psychological dependence, resistance of bacteria to antibiotics, sensitivity during pregnancy |
| Exercise | Benefits general health e.g. heart function, muscle tone, lung function, blood flow, mental wellbeing |
| Smoking | Higher chance of cancer, stroke, cardiovascular disease, emphysema (breakdown of alveolar walls), addictive |
| Alcohol | Addictive, liver damage, reckless behaviour |
| Gene Pool | The sum of all the genes of all the individuals in a population. This includes breeding and non-breeding individuals. |
| Population | All the members of a particular species in a particular area |
| Genetic Variability in Sexually Reproducing Organisms stems from | Crossing Over, Random Assortment of Homologous Chromosomes (both in meiosis) and random fusion of gametes (during fertilization) |
| Biotic Factors that contribute to natural selection | Predators, Competitors, Disease, Food all impact on survival |
| Abiotic factors contribute to natural selection | Shelter, Water, Temperature, Climate also impact on survival |
| Describe the process through which strains of bacteria evolve by natural selection: | Bacteria with natural resistance to an antibiotic (that arose by mutation) experience an antibiotic selecting agent. Most non resistant bacteria are killed. Next generation the % of resistant forms increase. If the bacteria is re-exposed, the resistant bacteria are selected for, and then the population is now dominantly resistant. |
| Geographical Isolation | One population of a species is split into two or more by a geographical feature e.g. Lava flow, river, fire |
| Speciation | Different populations of the same species develop enough genetic differences so that they no longer naturally reproduce so that they produce fertile offspring |
| When a population is separated each group may be exposed to different conditions, such as | Different selective pressures Different types selected for Different gene proportions in successive generations Gene Pools diverge |
| Differences between early and current organisms | Earliest forms of life, according to the fossil record were simple prokaryotic cells. Progressively organisms have diversified, with greater complexity developing over time |
| The greater the similarity between sequences of nucleotides the more likely it is that their separation was recent since: | The shorter the time, the less time for mutation, and hence DNA more similar. |
| All cells require: | Energy |
| Energy can be obtained in physical or chemical forms such as: | Light - photosynthesis Carbohydrates - Respiration |
| The main source of energy for life is: | The Sun |
| Plants that contain __________ can undertake photosynthesis when exposed to light | chloroplasts |
| Glucose is broken down in cellular respiration, releasing ____________ | energy |
| Energy Pathways involve many small regulated steps because: | Each step requires specific enzymes, Multiple stages to control pathway, Energy released in smaller more manageable levels. |
| A metabolic pathway is controlled by | A specific enzyme |
| Products for each step of the process are called | Intermediate compounds |
| Body temperature is maintained through | Heat produced from biochemical reactions |
| Autotrophs | Produce organic compounds e.g. Plants by photosynthesis (converting to chemical energy) |
| Heterotrophs | Consume organic compounds from organisms. Herbivores - consume plants Carnivores - consume animals |
| Equation for photosynthesis | \(\ 6CO_2 + 6H_2O \xrightarrow {Light} C_6H_{12}O_6 + 6O_2\) |
| Equation for Aerobic Respiration | \(\ C_6H_{12}O_6 + 6O_2 \xrightarrow\ 6CO_2 + 6H_2O + Energy\) |
| Fermentation is: | an anaerobic alternative to aerobic alternative to aerobic respiration. |
| Equation for Fermentation: | In plants/yeast \(\ C_6H_{12}O_6 \xrightarrow\ 2C_2H_5OH + 2CO_2 + Energy\) Glucose --> Ethanol + Carbon Dioxide + Energy In Animals - \(\ C_6H_{12}O_6 \xrightarrow\ 2C_3H_6O_3 + Energy\) Glucose --> Lactic Acid + Energy |
| More energy through Aerobic respiration than anaerobic respiration because: | Aerobic respiration is a much more complete breakdown. More chemical bonds broken therefore more energy released |
| Energy is required for: | Growth, Movement, Repair and Reproduction |
| Species | A group of organisms that can naturally reproduce giving rise to fertile offspring |
| Trophic Levels | Feeding levels in a community |
| Decomposers | Recycle Nutrients |
| Producers: | Form organic compounds from inorganic ones |
| 1st Order Consumers | Gain organic molecules from plants |
| 2nd Order Consumers | Gain organic molecules from other animals |
| Environmental Conditions that determine characteristics of communities | Temperature Water Wind Shelter Daily and Seasonal Variation |
| Describe how environmental factors may determine the type of community | Humid Tropics - Warm, humid, constant daylength, therefore rapid photosynthesis, therefore tropical rainforest - grows all year Temperate Regions - Seasonal, therefore summer growth, therefore winter more dormant e.g. deciduous trees |
| Nutrients need to be recycled because: | They are a finite resource |
| On average ___% of energy is passed from one trophic level to the next. Much is lost as _______. | 10%, Heat |
| Energy can be contained in molecules such as _________, _________ and ______ in the form of _________ ___________ | glucose, lipids and ATP, chemical bonds |
| The productivity of a community can be affected by: | The level of energy available e.g high/low light exposure, or length of light exposure |
| If the total output of energy from earth > total input on the Earth | Ice age (or cooling) |
| If the total output of energy from earth < total input on the Earth | Global Warming (warming cycle) |
| If the total output of energy from earth = total input on the Earth | Stable conditions |
| Succession Defenition (with example) | The progressive change in a community. e.g. Basalt Lava Flow - initially barren, no plants able to grow -weathering and erosion -seeds germinate -organic matter accumulates -soil improves -herbivores feed on plants -carnivores live on herbivores |
| Biodiversity | the variety of life present in a particular habitat |
| Biodiversity is essential for the perpetuation of communities because: | The greater a communities biodiversity the more resilient it is to environmental change |
| R- selected species | Species with a high reproductive effort, short life and many offspring. More emphasis on reproduction than long term survival They are more common in early succession or disturbed communities e.g. grasshoppers/locusts/mice |
| K - Selected species | Species with low reproductive effort, long life, and few offspring. More emphasis on survival rather than reproduction. High level of parental care. More common in stable communities. e.g. Human/Whale/Elephant |
| Human practices that can lead to major changes in communities include: | Land clearing Building dams Using fire to burn vegetation War Hunting Agriculture Introduced Species |
| Extinctions brought about by human activities include: | The Tasmanian Tiger - competition with Dingo, hunting from aboriginals Toolache Wallaby - land clearing, pelt hunting Pig footed Bandicoot - Predation by Cats/Foxes, Land clearing, Loss of traditional land management by fire of aboriginals |
| The best way to preserve species is to _______ __________ because: | Preserve habitat, Populations of species evolve to suit a particular habitat. They are well suited to survive and reproduce under these conditions |
| Examples of Biological and Ethical issues involved with the level of human population: | Biological - Each human requires resources. Pressure on ecosystems Ethical - Is it right that one species dominates ecosystems to the detriment of many others? |
| Biosphere | Total range of where life is formed on the planet |
| Stages of the Sigmoid Curve | Lag, Log, Transition, Equilibrium |
| The human population has a prolonged __________ phase due to: | log phase, Due to our advances in medicine, sanitation and technology |
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