Grade 9 Finals Review - Biology PDF

Finals review Topic 1 - Biology Lesson 1 - DNA Sequence DNA is an organism's genetic material Stores the genetic information of an organism Genetic information determines how an organism looks, functions, and behaves. DNA stands for Deoxyribonucl...

Finals review Topic 1 - Biology Lesson 1 - DNA Sequence DNA is an organism's genetic material Stores the genetic information of an organism Genetic information determines how an organism looks, functions, and behaves. DNA stands for Deoxyribonucleic acid Functions of DNA Stores the genetic information of an organism An organism's DNA is stored in each of its cell -DNA molecules coil and compact into a condensed form called chromatin -Just before reproduction, DNA condenses further into structures called chromosomes -During Reproduction, copies of chromosomes (and therefore DNA) are transferred to the offspring The Nucleus contains DNA DNA is the molecule that carries the master set of instructions for how cells function, what they will produce, and when they will die  The phosphate and sugar make up the sides (knows as backbones) of each DNA molecule The rungs are made up of four different nitrogen bases organised in a specific pattern -Adenine with Thymine, 2 hydrogen bonds -Cytosine with Guanine, 3 hydrogen bonds Lesson 2 - DNA Replication DNA replication is how the DNA makes an exact copy of itself The 4 Enzymes and Functions Helicase - Unzips the DNA by by breaking the hydrogen bonds between bases Primease - Helps the DNA Polymerase figure out where to go DNA Polymerase - Adds complementary nucleotides to the correct bases on the original DNA strands and connects them Ligase- Connects the lagging strands In the nucleus, DNA is usually in the form of chromatin Chromatin coils into X-Shaped chromosomes during cell division Homologous is having the same relation Humans have 46 chromosomes (23 pairs) -Homologous chromosomes are paired based on similar characteristic Each chromosome can carry thousands of genes Lesson 3 - Mitosis Mitosis is the cell division of two identical daughter cells Mitosis occurs during asexual reproduction Cells divide in order for your body to gown and also replace the old cells, and repair damaged tissues Chromosomes are made from protein and DNA chromosomes are measured by the number of centromeres Interphase: the resting phase, the cell growth, and replicated DNA, takes 90% of the cell cycle Phases of mitosis Prophase :Membrane breaks down, spindle fibres form, DNA condenses into duplicated chromosomes Metaphase: The spindle fibres line up the Chromosomes along the middle (Equaterial) of the cell Anaphase: Chromosomes are being pulled apart and go to each end of the cell Telophase: Two nuclei forms and each contain a complete copy of the cells DNA Cytokinesis: The cytoplasm and organelles are divided, and two separate cells are formed From 46 to 23 chromosomes In total, 2 cells are formed Lesson 4 - Meiosis Meiosis is the cell division in which parent cell divides to produce 4 daughter cells The PMAT happens twice The main features of meiosis: Chromosomes are copied Cell divides twice, forming four gametes Diploid is a type of cell that has two parts of chromosomes, one from each parent Gametes are an organism's reproductive cells. They are also referred to as sex cells. Sperm cells have 23 chromosomes and egg cells have 23 chromosomes The middle part of the chromosome is the chromatids Phases of meiosis Phase 1 Prophase: Membrane breaks down, Spindle fibre forming, Chromosomes pair up (sameheight) and they cross-over Metaphase: Align in pairs in the middle Anaphase: Chromosomes move apart to either end of the cell Telophase: Two nuclei forming Cytokinesis will then split cytoplasm, making 2 new cells Phase 2 Prophase 2: Membrane breaks down, spindle fibre forming, DNA condenses and thickens to chromosome Metaphase 2: Chromosomes align in the middle Anaphase 2: Chromatids gets pulled apart to either end of the cell Telophase 2: Two nuclei forming Cytokinesis will then split the cytoplasm again, making 4 new cells From 92 to 46 to 23 chromosomes In total, 4 new cells Difference between Mitosis and Meiosis Mitosis -Asexual -Cell Growth -Replace old cells and Repair damaged tissues -PMAT happens once -Identical daughter cells -2 new daughter cells -Two Nuclei -4 Stages Meiosis -Sexual -Produce Egg and sperm cells -Four Gametes cells -PMAT happens twice  -Different daughter cells -4 new daughter cells -Four nuclei -8 stages Lesson 5 - Reproduction in a flower Pollination is the transfer of pollen to a stigma, ovule, flower, or plant to allow fertilisation Cross Pollination - Involves two or more different flowers. This occurs when pollen are transferred from one flower to another through wind, insects, mammals or birds Self Pollination - This type of pollination occurs when pollen grains from the anther fall directly onto the stigma of the same flower Keywords: Stamen, Anther, Filament, Pollen tube, Ovary, Ovule, Sepal, Petal Lesson 6 - Reproduction Cell theory is that cells are the basic structural, functional, and organisational units of both single-celled and multicellular organisms Why is the reproduction of the cells important? Ensures that life exists beyond its present generation Transfers genetic information from parents to offspring Kwantlen First Nation (Fort Langley): First Foods Ceremony. A tradition from their ancestors They welcome the return of salmon during the start of the salmon run Honours promise to renew and replenish the spirit and flesh An organism's cells reproduce for 3 reason Growth Replace old cells Repair damaged cells The Cell Theory The cell is the basic unit of life All organisms are composed of one or more cells All cells come from other living cells Sustainability Is an ability of the environment and living things it supports to endure into the future. Sustainability of living things depends on reproduction Reproduction ensures organisms have a source of nutrients and energy to sustain life processes Continuity is how each species of organisms continues to exist overtime Examples of different strategies to reproduce Flowers: Colours and scent attract animals to transfer pollen Animals: Males attempt to attract a mate Bacteria: Reproduce on their own by dividing into two Two types of reproduction Asexual -Requires only one parent -Produces genetically identical offspring  Sexual -Requires two parents -Produces genetically different offspring Both Asexual and Sexual Genetic information is passed onto offspring Information is contained in DNA Topic 2 - Chemistry Lesson 1 - Atoms The atom has a neutral charge The mass of an atom is located in the nucleus Electrons have no mass and are not located in the nucleus The atomic number also tells you how much electrons and protons there are Protons and electrons have the same amount The mass number is the number of protons and neutrons added together We can also find the neutron by subtracting the atomic number and the atomic mass Electrons orbit the nucleus at set distances in certain fixed energy levels (AKA shells). First shell = 2 electrons Second Shell = 8 electrons Third Shell = 8 electrons Fourth Shell = 16 electrons The electrons are at the orbital of an atom, while the proton and neutron are in the nucleus Lesson 2 - Periodic table The chemical elements are arranged in order of increasing atomic number. The horizontal rows are called periods and the vertical columns are called groups. +(number) is the ion charges Groups - vertical line Alkali metals = 1 Alkaline earth metals = 2 Transition metals = 3-12 Chalcogens = 16 Halogens = 17 Noble gases = 18 Periods - horizontal line The period number indicates the principal energy level that is filling as we move from left to right Each periods tells how much shells there is, for example the first group will have 1 shell, so on and so forth Each groups tells how much are in the outer shell, for example the first group will have 1 extra electron, so on and so forth Covalent radius is the effective distance from the center of the nucleus to the outer valence shells Lesson 3 - Ions and ionic bonding An ion is an atom or group of atoms that has an electric charge, either positive or negative Atoms with incomplete outer electron shells are unstable An atom that loses electrons has more protons, making the ion a positive ion An atom that gains electrons has more electrons, making the ion a negative ion An ion is formed when an atom gains or loses electrons and becomes charged Before ionic bonding occurs the atom has an overall neutral charge, because they have an equal amount of proton and electrons Cations are also known as positive ions Anions are also known as negative ions An ion made up of a group of atoms is called a compound ion Compound Ions are usually formed by a reaction between a metal and a non-metal Both metal and non-metal have incomplete outer shells and so are unstable Positive and negative ions are strongly attracted to each other. This electrostatic attraction is called ionic bonding Ionic substances form giant ionic lattices containing oppositely charged ions. They have high melting and boiling points. An ionic lattice is formed when ionic compounds stack up on each other forming a large structure The Ionic lattice will continue to build in this way until there are no more ions left to add Ionic compounds such as sodium ch loride form crystals with a cubic shape. This is due to the structure of the ionic lattice All ionic compounds form lattice and crystals when solid Ionic bonds are strong and a lot of heat is needed to break them down Larger ionic charges produce stronger ionic bonds, which needs more heat to be broken down. Strong ionic bonds hold ions together As solids, Ionic compounds cannot conduct electricity because their ions are bonded together in the lattice As liquids, the ions can break free of the lattice and are able to move freely. Ions can then carry an electric current Ionic compounds are brittle, but also hard. When the lattice is hit, a layer of ions is shifted so that ions with the same charges are lined up together. These like charges repel each other and so split the ionic lattice causing it to shatter. Ionic bonds are strong electrostatic forces between ions Lesson 4 - Alkali metals Alkali metals are metals that are extremely reactive Alkali metals are located in group 1 Alkali metals get their names because they produce alkalies when they interact with water. The reactivity of alkali metals increase as you go down the periodic table, which means that the atom get larger and further from the nucleus They have to be stored in oil to make sure they don't interact with any oxygen in the air They react so strong when they touch water because enough heat is given off during the exothermic reaction to ignite the H2(g) Lesson 5 - Covalent bonding Covalent bonding is the share of atoms Covalent bondings have no charge Covalent bonding can be an element and compound Covalent bonds between the atoms are strong Covalent bonds are between 2 nonmetals Although the covalent bonds holding the atoms together in a simple molecule are strong, the intermolecular forces between simple molecules are weak. REVISION Sodium + Chlorine → Sodium chloride. (NaCl) Lithium + Iodine → Lithium Iodide. (Lil) Potassium + Bromine → Potassium Bromide. (KBr) Example: Complete the word and symbol equation for sodium reacting with water Sodium + Water → Sodium Hydroxide + Hydrogen Na + H2O → NaOH + H2 Example: Difference of Compounds, Elements, Mixtures Element is the simplest substance that cannot be broken down by any chemical methods. Compound is made of two or more elements chemically combined together. Mixture is made from two or more substances physically combined together. Heterogeneous Mixture - A mixture in which the particle cannot be dissolved and is visible to the eye Homogeneous Mixture - A mixture in which the solute is dissolved in the solvent Example: Why are the melting/boiling points of lithium low? Answer: There are weak intermolecular forces, which needs little energy to break Example: Why are the melting/boiling points of lithium high? Answer: There are strong bonds between them (not intermolecular forces) which needs a lot of energy to break Covalent bonds between the atoms are strong Ionic bonds are strong electrostatic forces between ion Metallic bonds are strong electrostatic forces between metal ions Example: Why does lithium not conduct electricity? Answer: There are no free ions or electrons Example: why does lithium conduct electricity? Answer: There are free ions or electrons James Chadwick discovered the neutrons KEY WORDS Electrostatic forces: An attractive as well as repulsive force caused by the electric charge particles Intermolecular forces: forces of attraction between atoms, molecules, and ions when placed close together Delocalised electrons: An electron not connected to a single atom or covalent bond Bohr diagrams show electrons orbiting the nucleus of an atom somewhat like planets orbit around the sun. In the Bohr model, electrons are pictured as travelling in circles at different shells, depending on which element you have. Topic 3 - Physics Lesson 1 - Series and parallel circuit Series circuit is a circuit in which current can only flow along one path Simple Loop Same amount of current One bulb breaks, everything does Parallel circuit is a circuit that has at least one branch point where the current splits into two or more pathways Side by side Different current Not a loop One bulb breaks, nothing else does Current is the flow of electrons Current is measure by amps (ampere) Having Low amps means that electricity is flowing more slowly and delivering less power to your device Higher amps mean that electricity is flowing more quickly and delivering more power to your device. As you add resistors (bulbs) in a series circuit the resistance increases which decreases the current, but in a parallel circuit the voltage is the same so it doesn't matter how many light bulbs you add as long as you have a strong battery. As you add resistors in a parallel circuit the resistance will decrease (because there are more than one branch points, so it doesn't matter) but the current will increase Electrons will go from positive to negative In a series circuit, the current is the same but not for parallel In a parallel circuit, voltage is the same across each component of the parallel circuit Lesson 2 - Circuits and there components  This is an instrument called voltmeter and is used to measure the voltage between two points in an electrical circuit This is an instrument called ammeter and is used to measure the electric current This is the resistor also known as the compounment, it is charged by the flow of electrons This is used to adjust the value of current or voltage This is a device used to convert audio signals into sound signals The cell stores chemical energy and transfers it to electrical energy when a circuit is connected When two or more cells are connected together we call this a Battery The cells chemical energy is used up by pushing a current (electrons) around a circuit The bigger the voltage supplied by the cell, the bigger the current Unlike an ammeter a voltmeter is connected across the components Scientists usually used the term Potential Difference (pd) when they talk about voltage In a series circuit voltage is shared the components In a parallel circuit voltage is the same in all parts Lesson 3 - Ohms Law Ohms Law was made by georg ohm Ohm's law is the law stating that electrical potential difference between two points in a circuit is equal The Ohm is used to measure the resistance Voltage = Current x Resistance Current = Voltage ÷ Resistance Resistance = Voltage ÷ Current Power = Voltage x Current Resistance is the limit of flow of charge The bigger the resistance is, the less the current will flow Power is the amount of energy consumed or released by a circuit Voltage is the difference in electric potential between two points Lesson 4 - Fossil Fuels Coal Thermal energy is the energy contained within a system that is responsible for its temperature (heat) 1: The coal is shipped and transported near the power station 2: The coal is moved to the power station by the conveyor belts 3: The coal is ground into a fine powder (pulverised, which means to crush something into a powder.) 4: The pulverised coal is transported into the furnace. 5: The coal is burned inside the furnace releasing heat energy (Thermal energy is occurred) 6: The heat energy is used to turn water into steam 7: The steam is making the turbine spin 8: The turbine is making the electromagnet spin 9: The electromagnet is generating the electricity 10: The national grid is sending the electricity to our homes Coal is found in underground formations called “coal seams” or “coal beds” Also known as caves. They mine for it with tools like picaxe. Coal is no longer formed in our planet, it will run out sooner or later Coal is Non-renewable energy, it cannot be replenished (replaced) and will run out. There are many problems using coal as an energy source 1: Carbon dioxide is released causing global warming 2: Sulphur and nitrogen oxides are released causing acid rain 3: Dust from mining is causing the smog (Air pollution that reduces visibility) 4: Eye sore (Extremely ugly and disliked, or disapproved of). Destruction of landscape and habitats 3 types of fossil fuels Coal Oil Gas Concerning features of fossil fuels is that they are non renewable Coal is the fossilised remains of trees Oil and gas are formed from the remains of sea creatures Non renewable - eventually run out Renewable - capable of being used again Most conventional power stations run on coal Topic 4 - Ecology Lesson 1 - Energy level Food chains can be organised into an energy pyramid Trophic level 1 are usually the producers Trophic level 2 are usually the primary consumers Trophic level 3 are usually the secondary consumers Trophic level 4 are usually the tertiary consumers Between the levels, 90 percent of energy is being lost (10 000 kcal will be 1000 kcal) The rest of the energy is lost in heat or undigested Lesson 2 - Food Web Food web is made up of multiple food chains that interact together It shows more interactions among the variety of producers and consumers It also can show biodiversity (All types of organisms living in a given area) Biodiversity can contribute to the sustainability of an ecosystem If an organism runs out, more options are available Lesson 3 - Food Web Food chain is a series of organisms each dependent on the next as a source of food Food chains are inaccurate Food chain starts with a producer Producers are autotroph which means that they can make their own food Example: Grass, plants, algae Consumers are heterotrophs which that they they need to feed on other organisms Example: Bacteria can be both heterotroph and autotroph Secondary consumer are eaten by a tertiary consumer and the food chain keeps going If an organism is removed from the food chain, you can harm the others because they might not have enough to eat If the tertiary consumer runs out, the secondary consumer will gain rapidly making the primary consumer run out Omnivores eat meat and plants Carnivores eat meat Herbivores eat plants Lesson 4 - Bioaccumulation Bioaccumulation is a process of gathering of chemicals in an organisms that takes place if the rate of intake exceeds the rate of excretion As the human population grows, more waste is produced. If it is not handled, the waste can cause pollution How the chemicals spread In water, from sewage, fertiliser, or toxic chemicals  On land from landfill and from toxic chemicals such as pesticides (used for destroying insect and plants) and herbicides (used for harming plants), which may be washed from land into water In air, from smoke and acidic gases Pollution kills plants and animals which can reduce biodiversity (all the different kinds of life you’ll find in one area) Steps on how bioaccumulation works 1. Small amounts of pesticides/pollution from human activity are absorbed by plants. 2. These plants are eaten by primary consumers in low concentrations. 3. The toxin cannot be excreted so when the primary consumers are eaten by secondary consumers all the toxin is absorbed by the secondary consumers. 4. This repeats throughout the food chain. 5. The toxins remain in the tissues of the animals at each trophic level of the food chain, animals at the top of the food chain accumulate the most toxins. Excessive nutrients from fertilisers are flushed into the lakes and rivers from rain storms Eutrophication occurs when the environment becomes filled with nutrients, increasing the amount of plant and algae growth to freshwater rivers and more Bioindicators Pollution levels in water can be measured in many ways (analysing in laboratories) Oxygen and pH levels are measured using instruments The water can be analysed to show levels of polluting chemicals such as pesticides or industrial waste.