Year 9 Yearly Exam 2023 Science Study Document PDF

The Complete Year 9 Study Doc Practice Papers 2023 Year 9 Yearly Exam Y9 Yearly 2022 Summary (Ai) Criteria: Living World Diseases (infectious and non-infectious)-Give it your Best Shot Food chain/web- Ecology Energy/biomass pyramids-Ecology Photosynthesis- Ecology Ecological relationships- Ecology Body Systems - My Canteen Rules Chemical World- Introduction to Chemistry (Term 2) Atomic structure/Subatomic particles and website on atomic structure Atomic symbols Features of the Periodic Table Trends in the Periodic Table Isotopes/radioisotopes and half life Radioactivity Physical World- Coaching and Forces Newton's laws of motion - First Law, Second Law, Third Law Forces acting on an object- All the laws of motion Balanced and unbalanced force -Net forces Force/mass and acceleration Newton's second law Speed/ distance and time - Motion Acceleration/Speed and time-Graphs of motion Earth and Space - Cycles in nature- Global Catastrophes Impacts of natural events on Earth's spheres-Global Catastrophes Plate tectonics-Global Catastrophes Timeline of the Big Bang Theory- Space Odyssey Technology eg telescopes-Space Odyssey Evidence of Big Bang theory-Space Odyssey The life cycle of a star/s-Space Odyssey Working Scientifically (This will be incorporated in the various sections of the examination) Scientific diagrams Analyse graphs Interpret data from tables Contents: Living World ○ Give it Your Best Shot ○ Ecology ○ My Canteen Rules Chemical World ○ Introduction into Chemistry Physical World ○ Coaching & Forces Earth and Space ○ Global Catastrophes ○ Space Odessey Working Scientifically ○ Scientific Skills Living World Give it your best shot: Infectious diseases: Infectious diseases are illnesses caused by the spread of microorganisms (bacteria, viruses, fungi or parasites) or prions to humans from other humans, animals or the environment, including food and water. Microbes: Microbes are organisms that are too small to be seen without using a microscope (microorganisms), including bacteria, archaea, and single-cell eukaryotes — cells which have a nucleus, like an amoeba or a paramecium. Sometimes we call viruses microbes too. Pathogen: an organism causing disease to its host another word for this is germ. Pathogens can be split up into 4 main parts: Bacteria: Bacteria are microscopic living organisms that have only one cell. Bacteria cells carry diseases that can infect people if exposed. ○ Tetanus ○ Gangrene ○ Food Poisoning ○ Pneumonia ○ Tuberculosis ○ Leprosy ○ Cholera ○ Sexually Transmitted Diseases Gonorrhea Syphilis ○ Boils Virus: a submicroscopic infectious agent. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea, with diseases. ○ Common Cold ○ Chicken Pox ○ Rabies ○ Cold Sores ○ Warts ○ Hepatitis ○ Small Pox ○ Influenza ○ Ebola ○ Measles ○ Polio ○ HIV ○ Tonsillitis Fungi: Pathogenic fungi are widespread and cause various diseases in human beings and other organisms. This type of pathogen comes from fungi such as some types of mushrooms. ○ Ringworm ○ Athlete's Foot (Tinea) ○ Thrush Protozoans: microscopic, single-celled organisms. Protozoa can multiply in humans and transmit from one person to another. They can cause parasitic infectious diseases like malaria, giardia, and toxoplasmosis. ○ African Sleeping Sickness ○ Giardia ○ Amoebic Dysentery ○ Malaria Types of infections: Bacterial infections: Bacterial infections can affect your skin, lungs, brain, blood and other parts of your body. You get them from single-celled organisms multiplying or releasing toxins in your body. Bacteria are transmitted to humans through air, water, food, or living vectors. The principal modes of transmission of bacterial infection are contact, airborne, droplet, vectors, and vehicular. Viral infections: Infections that are shorter lasting and classically include symptoms such as fever, chills, sore throat, nasal congestion, runny nose, cough, and a lot of times you can have some body aches. Fungal infections: Fungal infections, are diseases caused by a fungus. Fungal infections are most common on your skin or nails, but fungi can also cause infections in your mouth, throat, lungs, urinary tract and many other parts of your body. Protozoal infections: Protozoal infection results in tissue damage leading to disease. These types of infections are caused by ingesting any food or water contaminated with diseases, or disease which is carried by an organism such as sexual transmission, or through insect vectors (insects that transmit diseases through bites or stings). Protozoa cause some common and some uncommon infections. Infections: Infections spread when the microbe/pathogen is passed from one person to another. Forms of spreading the disease are: Coughing Sneezing Sharing Needles Through Organisms (mosquito) Contamination of food and water Non-infectious diseases: a type of infection that is not caused by a pathogen, but rather a result of long-term health consequences. These diseases are not infectious which means they cannot be transmitted from other organisms. There are 4 main categories which this can be split up into: Genetic diseases: A genetic disease/disorder is the result of a gene (or genes) having a problem with its code, causing health problems. ○ Cystic Fibrosis Being the most common life-threatening genetic disorder in Australia, is a disease that causes cells to secrete sticky mucus that clogs the lungs and digestive system. ○ Down Syndrome A genetic disease that is due to an extra chromosome being present in every cell of the person’s body causing physical, mental, and psychological defects. Each human should contain 46 chromosomes (23 chromosomes & 23 chromosomes), but with Down syndrome, an extra copy of chromosome 21 will be present, giving a total of 47 (24 chromosomes, & 24 chromosomes) Environmental diseases: An environmental disease refers to when you are exposed to toxins or substances in the environment that make you sick. The most common example is asbestos which is a toxic substance that can be sometimes contaminated with certain things such as soil. ○ Asbestos A fatal disease of the lungs ○ Industrial Deafness Exposure to loud noises ○ Cancer, Stroke, & Heart Diseases Exposure to cigarette smoke Exposure to toxic chemicals/radiation Lifestyle diseases: A lifestyle disease is a developmental disease that is acquired as a result of poor lifestyle choices. For example, obesity is a lifestyle disease caused by factors relating to your lifestyle such as how often you exercise and how much food you eat. ○ Autoimmune diseases: A malfunctioning in the immune system which causes the body to attack itself as if it is fighting an infection. An example is type 1 diabetes. Pandemics A pandemic is a global outbreak of a disease. Pandemics have caused significant disruptions to society's economies and healthcare systems. ○ HIV/AIDS Identified in the early 1980s, HIV/AIDS is a viral disease that weakens the immune system, leading to life-threatening infections. It primarily spreads through unprotected sex, contaminated needles, and from mother to child during childbirth or breastfeeding. It remains a global health issue. ○ Spanish Flu (1918–1919): A deadly influenza pandemic that infected about one-third of the world’s population, killing an estimated 50 million people. It spread rapidly due to World War I and had a high mortality rate among healthy adults. ○ Plague of Justinian (541–542 CE): A devastating pandemic that struck the Byzantine Empire, killing millions. It was caused by the same bacterium (Yersinia pestis) that led to the Black Death and significantly weakened the empire. ○ Asian Flu (1957–1958): A global influenza pandemic originating in East Asia, caused by the H2N2 strain of the flu virus. It killed around 1 to 2 million people worldwide, with most deaths occurring in the elderly and those with pre-existing health conditions. ○ The First Cholera Pandemic (1817–1824): The first recorded outbreak of cholera, which originated in India and spread to Asia, the Middle East, and Africa. Cholera is caused by contaminated water or food and can lead to severe dehydration and death. ○ The Black Death (1347–1351): A bubonic plague pandemic caused by Yersinia pestis, killing up to 50 million people in Europe. It spread via fleas on rats and caused widespread societal upheaval. ○ H1N1 (2009–2010): A global influenza pandemic caused by the H1N1 virus, initially referred to as "swine flu." It primarily affected younger populations and resulted in an estimated 151,700 to 575,400 deaths worldwide. Ecology: Trophic Levels: The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. Photosynthesis: Photosynthesis is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabolism. Equation: carbon dioxide + water —> glucose + oxygen + water Definitions: Producer: Organisms that make their own food Consumer: An organism that generally obtains its food from other organic matter Decomposer: The organisms that carry out the process of decay or breakdown dead organisms. Decomposers return nutrients back into the soil. Trophic: The position or level of an organism in a food web or chain. -troph: Energy Autotroph: An organism that produce its own food using photosynthesis Heterotroph: An organism that cannot make its own food Abiotic: Physical or chemical parts of an environment that affect living organisms and their ecosystems. Biotic: A living organism in an environment Herbivore: An organism that mostly feeds on plants Carnivore: An organism that mostly eats meat or the flesh of animals. Omnivore: An organism that eats plants and meat. Detrivore: An organism that feeds on any dead organic material (E.g. Fungi and Bacteria feeding on dead leaves or dead animals). Apex Predator: An organism at the top of the food chain. Primary consumer: Organisms that eat producers (herbivore) Secondary consumer: Organisms that eat primary consumers (carnivore) Tertiary consumer: Organisms that eat secondary consumers (Carnivores and omnivores) Quaternary consumers: Organisms that eat tertiary consumers (Carnivores and omnivores) Environment: Surroundings which life and non living things exist Habitat: A place where an organism makes its home Population: A group of organisms living in the same place Community: A group of interacting organisms in the a common location Ecosystem: A biological community of interacting organisms. Biosphere: Where all life exists Biome: Where all weather happens Biotic Factor Examples: Food, invasive species, predators, consumers, prey, producers infectious diseases Abiotic Factor Examples: Light intensity (photosynthesis), temperature, water, pH, soil minerals (Nitrate), wind, gases (oxygen, carbon dioxide). Food Chains: The Ten Percent Law: The 10 percent law is the main reason that most food chains have five or less links. Because 90 percent of the food chain’s energy is lost at each level, the amount of available energy decreases quickly. Food Webs and Food Chains: Food Chain: The flow of energy from one living thing to another living thing, A food chain also refers to the order of events in an ecosystem. Food Web: A network of food chains by which nutrients and energy are passed on from one species of living organisms to another species. For a food chain/food web to be functional, it must have the following: Producers/Plants, These are autotrophs, meaning they produce their own food through the sun's energy (sunlight), water, carbon dioxide, or any other chemical. Primary Consumers, These are heterotrophs, meaning they need to consume other organisms in order to gain their energy. Primary consumers are herbivores. Secondary Consumers, These are heterotrophs, meaning they need to consume other organisms in order to gain their energy. Secondary consumers are carnivores. Decomposers, These are heterotrophs, meaning they need to consume other organisms in order to gain their energy. Decomposers are detrivores, which means that they feed on dead organic matter in order to gain energy. Ecological Relationships: Competition: when organisms compete over one resource Predation: When a predator hunts its prey Commensalism: When one species benefits from interaction and the other is not affected +/0 Mutualism: When both species benefit from interaction +/+ Parasitism: When the interaction does not benefit one organism but does for the other +/- Interspecific Interaction Effect on Species 1 Effect on Species 2 Competition Negative - Negative - Predation/Herbivory Positive + Negative - Mutualism Positive + Positive + Commensalism Positive + 0 effect (+/0) Parasitism Positive + Negative - Other Stuff: Trophic Levels: A trophic pyramid/energy pyramid/ecological pyramid is a graphical representation that shows the flow of energy at each trophic level in an ecosystem For every level on the energy pyramid, only 10% of the energy from the previous level is passed to the next. The flow of energy goes from bottom to top in an energy pyramid The base of the energy pyramid indicates the energy available within primary producers Primary producers are autotrophs, meaning they produce energy from non-living sources of energy All levels of the energy pyramid (besides primary producers) are heterotrophs, meaning they need to gain nutrients from organic carbon, typically other animals/plants PHOTOSYNTHESIS: Water + Carbon Dioxide with the sun's energy creates glucose + oxygen CELL RESPIRATION: Glucose + Oxygen = Water + Carbon Dioxide + Energy Nevin: Smartie pH Scale: The pH scale measures the amount of acidity or alkalinity (basic) a solution is. It ranges from 0-14, with 7 being neutral. A pH below 6 is considered acidic, whilst a pH level above 8 is considered alkaline. My Canteen Rules: The Levels of Organisation: Complex organisms such as humans are made up of many different types of cells, each with a special job to do. However, these cells do not function independently; they are organised into tissues, organs and systems so that they can work efficiently together. Groups of similar cells that carry out a particular job make up tissues. The walls of the intestine contain smooth muscle tissue, which consists of a type of muscle cell. The heart is made up of cardiac muscle tissue, fat and connective tissue. Different types of tissues form organs. The heart, brain, lungs, liver and eye are all organs. Organs, in turn, are organised into systems. The kidneys, ureters and urethra are all part of the excretory system. The ovaries, fallopian tubes and uterus are organs of the reproductive system. Each body system has a particular role to play in keeping an organism functioning. (Science Core 4) Cells are the most basic building blocks of any living thing and are the most important. They carry out essential functions to keep the body alive such as taking energy, exerting energy (metabolism) and creating a strong structure for the body structures. They also reproduce and multiply, which is what makes living things grow, change and adapt to new environments. The faster cells multiply and reproduce, the faster living things grow! The human body is made up of trillions and trillions of cells, which keep us all alive. When cells group, they form tissues. All cells within tissues have similar or the same functionalities, whether that be infection fighting, metabolism execution or muscular development. Tissues form together to make up organs and muscles such as the heart. These are extremely important in distributing certain substances throughout the body or executing movement of the limbs. These organs make up organ systems such as the circulatory and nervous systems! This is the level of organisation within the human body. Homeostasis: An organising principle to maintain a constant internal environment. Necessary to maintain equilibrium, to allow the functioning of cells. Different organ systems and organs work together, to maintain homeostasis throughout the human body. The process by which the body maintains a stable internal environment, even when the external environment acts to change it. For example, your body always keeps your body temperature between 36.5 and 37.5 degrees Celsius, no matter how warm or cold the air is. Homeostasis is important because it keeps the body’s internal environment healthy and safe. Without homeostasis, the internal environment could change and make the organism sick. This is true for all living things. (Education Perfect) ○ Internal Environment: Everything is made inside the body. Several factors make up the internal environment, including… Body temperature Blood pressure Blood glucose levels Iron concentrations Water levels ○ External Environment: Everything around you. This includes… Atmospheric pressure Atmospheric temperature Humidity The composition of the air (air purity) Presence of chemicals The presence of resources such as food and water Flight or Fight Response: When that part of your brain senses danger, it signals your brain to pump stress hormones, preparing your body to either fight for survival or flee to safety. This is through the sympathetic nervous system. This is how the muscles and nervous system react to an external threat. When sensory organs send messages to the brain, it processes them and then sends messages to the body via the nervous system. The nervous system is attached to muscles, which have ATP (the source of energy for use and storage at the cellular level) ready to go. The sequence of the flight or flight response is below. 1. Hypothalamus: This is a part of the centre of the brain, which sends a signal to the rest of the body (via the nervous system). It sends a nervous signal to the centre of the Adrenal Gland. 2. Adrenal Medulla: The inner part of the adrenal gland in the Kidneys, connected nervously to the brain. Instantly, a message is sent from the brain to the adrenal medulla when danger is present. This organ releases a hormone called adrenaline. Adrenaline: Epinephrine which is a chemical signal that is attached to the circulatory system. As the heart beats faster, more epinephrine is spread throughout the body. 3. Liver: When epinephrine reaches the liver, it converts glycogen (found inside the cells of the liver) into glucose (the body’s energy supply). 4. Lungs: Epinephrine in the respiratory system affects the cells of the lungs. This causes breathing to speed up. 5. Heart: Speeds up the rate of heartbeat. 6. Digestive System: Causes vasoconstriction, where the process of digestion is slowed down. Slows down the blood vessels that feed into the digestive system as digestion is not a priority in the flight or fight response. 7. Muscles: Sends more blood to the muscles (vasodilates). Body Systems: Body systems work together to keep organisms alive. The respiratory system brings oxygen into the lungs, but it is the circulatory system that delivers the oxygen to all cells. Without these two systems working together, cells would not obtain the oxygen they need for respiration. Similarly, while the digestive system breaks down food, once the nutrients in food have been converted to particles that are small enough to enter the bloodstream, these also must be transported to cells via the circulatory system. To move our limbs, muscles need to receive signals from the nervous system. Hormones produced by the endocrine system play an important role in regulating the action of the kidneys, which are part of the excretory system. The body systems must act as members of a team; each has a specific task but they must work collaboratively to keep the body functioning. (Science Core 4) Digestive System/ Tract: Quick Definition: The digestive system is a series of organs that breaks food down so it is useful for the body. Its two main functions are breaking down food for the body to use and getting rid of waste. General Overview: The digestive system is a vital part of the human body. It breaks down food ingested, into smaller macronutrients such as carbohydrates, protein and fibre. These obtain the form of tiny particles and slip through the walls of our intestines, and into our bloodstream. Henceforth, the circulatory system distributes these nutrients all over the body. These nutrients are essential to the body for a number of different reasons. Without nutrients, the body will not be able to generate the energy needed to keep vital organs and body systems functioning. Additionally, nutrients aid in growth & development, chemical process regulation and immunity strength of the body. The digestive system obtains these nutrients through a whole array of organs and chemicals, which gradually break down the food we eat. Function: The role of the digestive system is to break down the food that we eat into particles that are small enough to pass through the walls of the intestines and into our blood. There are two types of digestion, mechanical and chemical digestion. In this way, the nutrients in food can reach our body’s cells. A number of organs make up the digestive system. Some organs break up the food mechanically by cutting, grinding or churning it. Other organs secrete chemicals that can break the chemicals in the food into smaller molecules. (Science Core 4) Form/ Structure: Oral Cavity: This is the start of the digestive system. Break down food so it can be ingested. Tongue: Works the food into a little round ball, called a bolus. It then pushes the ball to the back of the mouth, where it is swallowed. Teeth: Used to bite and chew food into small pieces. Salivary Glands: Make about 1.5 L of saliva a day. ○ Saliva: moistens the food, making it easier to chew and swallow. Saliva also contains chemicals that break down the starch in food. Epiglottis: A flap of tissue that closes off the entry to your lungs so that food does not go down and cause you to choke Oesophagus: Directs the food to the stomach. It is a long muscular tube that moves food by the process of peristalsis. ○ Peristalsis squeezes food down the oesophagus by repeated waves of muscle contractions. Liver: Controls the number of glucose molecules in the blood. When there is too much, the liver stores it as glycogen and releases it when needed. The liver also breaks down toxins in the blood. ○ It also makes bile, which breaks down fat into small droplets in the small intestine. The bile is stored by the gallbladder until it is needed in the small intestine. Gallbladder: Stores bile made in the liver until needed in the small intestine. Stomach: A large muscular organ that churns and mixes the food. The stomach lining releases chemicals that start to break down protein. It also releases hydrochloric acid, which kills unwanted bacteria. The stomach can hold between two and four litres of food and can store it for about four hours. Pancreas: Makes chemicals that are used in the small intestine (such as insulin). It also reduces the effect of the acid from the stomach on the walls of the small intestine. Small Intestine: A long, hollow, coiled tube about 6 metres long. It is the main organ of digestion. Food, which is now like a creamy soup, passes slowly into it. Liquid from the pancreas and bile from the gallbladder enter the small intestine to help with digestion. The small intestine is where the breakdown of starch and protein is finished and fat breakdown occurs. The food particles are then tiny and can pass through the wall of the small intestine into the bloodstream. Large Intestine: Undigested food and water pass into the large intestine from the small intestine. Bacteria in the large intestine help in making some vitamins and are the main source of gas. Water, vitamins and minerals pass into the bloodstream. Appendix: A small projection at the beginning of the large intestine. In humans, it does not help with digestion. Rectum: Faeces is stored in this last part of the large intestine. Faeces contain the waste products of digestion. It consists of about 75 per cent water and 25 per cent solid matter — mainly dead bacteria and fibre. Anus: Releases the faeces as waste (Science Core 4) Circulatory System: Blood: Blood is a substance that flows within the circulatory system. It transports oxygen, waste (carbon dioxide), nutrients and hormones. Blood is made of 4 main structures… 1. Plasma: Carries water, hormones and enzymes. It carries hormones, proteins and nutrients to the rest of the body. 2. Red blood cells: Carries oxygen and carbon dioxide 3. White blood cells: defends against diseases 4. Platelets: Aids in clotting blood Heart: Is a muscle which pumps blood around the circulatory system Pulmonary circulation: The networks of arteries and veins between the heart and lungs Systemic circulation: Delivers oxygenated blood to the body and returns deoxygenated blood back to the heart. Arteries: Large blood vessels that carries oxygenated blood away from the heart Veins: Carries deoxygenated blood to the heart Capillaries: blood vessels that connect small arteries to small veins. It transfers nutrients, oxygen and water between cells. Main veins: Inferior and superior vena cava Main artery: Aorta Coronary artery: Supplies oxygenated blood for the heart’s use Natural pacemaker: Producers electrical impulses to keep your heart beating in sync Septum: Separates the right side of the heart with the left side of it Valves: Separates the atriums from the ventricles. Includes the tricuspid valve, mitral valve, pulmonary valve and aortic valve. Diseases include: Heart failure, blood pressure conditions, high cholesterol and heart valve disease Atherosclerosis: The thickening or hardening of the artery walls Arteriosclerosis: general name for a group of conditions that cause arteries to become thick and stiff How to stop this? Maintain healthy diet, be active and to quit smoking Respiratory System: Role: The role of the respiratory system is to carry out respiration and gas exchange. This includes the intake of oxygen and exhalation of waste (carbon dioxide). Respiration: Respiration is the chemical process by which glucose reacts with oxygen to create carbon dioxide, water and ATP (energy). Respiration occurs in the mitochondria of a cell. Respiration is a series of chemical reactions that cells perform in order to produce energy from nutrients. Breathing: The mechanical process in which gases are drawn and expelled from the lungs and nasal cavity Gas exchange: When oxygen moves into the bloodstream, and carbon dioxide gets passed into the lungs within the alveoli (gas sacks). Inhalation: the expansion of muscles that allows air to enter the lungs. This changes the size of the thorax or chest cavity. Nasal Cavity: Is the starting point of the respiratory system Celia: Found in the nasal cavity, trachea and lungs, they stop dust and fluid from entering the lungs. They also move mucus and debris out of the airways. Pharynx: carries food and air down the nose and mouth Larynx: Prevents food and other unwanted particles from entering the trachea. It also houses the vocal cords Trachea: To carry gases such as carbon dioxide, oxygen and nitrogen in and out of the body. Bronchi: To carry oxygen and other gases in and out between each of the lungs and trachea Bronchioles: To carry oxygen out to the alveoli (air sacks) to be diffused Alveoli: Allows gas exchange and diffusion to take place Diaphragm: A muscle at the bottom of the thorax. When it contracts, it increases the thorax size and pulls air into the lungs (inhalation). When it relaxes, it is domed and air is pushed out. Exhalation. Helps you inhale and exhale. Intercostal muscles: Allows the expansion of the chest. When they contract, the chest expands and air is inhaled. It then relaxes and the chest drops to exhale air. Rib cage: Prote cts the heart and the lungs including the main parts of the respiratory and circulatory system Thorax: Chest cavity Nervous System: Quick Definition: The nervous system regulates body functions through voluntary and involuntary movements. General Overview: The Nervous System is the body’s command centre by taking in information through our senses, processing the information and triggering reactions, such as making your muscles move or causing you to feel pain. The nervous system is made up of neurons (which are nerve cells) that transmit signals around the body to complete certain functions. There are three types of neurons: Sensory, motor and interneurons. Sensory neurons send information from our sensory receptors towards the central nervous system (CNS). The motor neurons carry information information away from the CNS and allow movement. Lastly, the interneurons decide what to do and pass on information from sensory neurons to motor neurons. Neurons are made up of three main components: dendrites, cell body and axon. Neurons bundled together form nerves. The nervous system is extremely important when physically moving, responding or reacting to certain external events. There are two sections to the nervous system: Central Nervous System (CNS): This is made up of the brain and spinal cord. It is responsible for voluntary actions such as thinking, movement, learning, memory and maintaining homeostasis. All nerves branch out from the spinal cord and use it as a message pathway to the brain. Peripheral Nervous System (PNS): Consists of the nerves and neurons of the body. The PNS can be divided into the somatic and automatic nervous system, which refers to voluntary and involuntary actions. Form/ Structure: PNS: Consists of the nerves that connect the brain and spinal cord to the rest of the body, such as muscles. These nerves lie externally to the brain and spinal cord. ○ Nerves: A bundle of neurons/ nerve cells all interconnected. ○ Neurons/ nerve cells: are single nerve cells. Neurons are not in direct contact with each other. When an electrical signal, is sent from one neuron to the next, the signal has to be transmitted across the gap to the next neuron. The gap is called the synaptic cleft. ○ The three main types of neurons include… Sensory Neurons: Send information from our sensory receptors (sensory organs) towards the CNS. They process information from the external environment and send information/ signals to the CNS. Motor Neurons: Carry information away from the CNS and produce movement. They carry out voluntary and involuntary movements throughout the body. Interneurons: decide what to do and pass on information. They connect the sensory neurons to the motor neurons. ○ Sensory organs: Receive information from the external environment and send it to the brain which in turn processes it to produce a voluntary movement, that is a motor response. ○ Somatic Nervous System: Voluntary movement executed consciously by the brain. Activated by external stimuli. The somatic nervous system coordinates messages and movement from the external environment. Sensory and motor neurons are important parts of all divisions of the PNS, but especially the somatic system. Sensory neurons are neurons that are activated by stimuli, such as light, noise and heat. These stimuli are received by the sensory neuron/s and a message about what is being sensed is sent to the CNS (brain and/or spinal cord). Motor neurons connect to structures such as muscles and glands and give instructions from the CNS to these structures to complete an action. ○ Autonomic Nervous System: Involuntary, unconscious movement of the body when it is focused on another stimulus. Activated by internal stimuli. The autonomic system is the body's response to internal stimuli. This is usually coordinated by structures in the brain that sense when internal actions need to be taken, such as sensing a change in internal temperature or changes in oxygen levels or sugar in the blood. Other internal actions include functions such as the movement of the digestive tract and the regulation of the heartbeat. Parasympathetic Nervous System: Sympathetic Nervous System ○ Parts of a Neuron: Dendrites: branch-like extensions found at the top of the neuron and their main function is to receive chemical signals from other neurons and then transmit the electrical information down the axon of the neuron Cell Body: makes up the neuron and contains the nucleus and the organelles that the neuron needs to function. The main function of the cell body is to keep the neuron alive. Axon Terminal: Found at the end of axons to transmit messages to other cells via neurotransmitters. Neurotransmitters: Chemicals called neurotransmitters get released from the axon terminal when the electrical impulse reaches the end of the axon/ neuron. The neuron that releases the neurotransmitters is called the presynaptic neuron. These neurotransmitters then band to receptors found on the dendrites of the receiving neuron. This neuron that receives the neurotransmitters is called the postsynaptic neuron. Nucleus: Contains genetic material Myelin Sheath: Allows electric impulses to travel and transmit quickly throughout the neuron. Is made of protein and fatty substances. Axon: is the long cable line projection of the neuron. The main function of the axon is to carry the electrical impulse down the length of the cell, so it can be transmitted to other neurons and the muscles. Synaptic Cleft: The gap between two neurons where signals are transmitted. CNS: Contains the brain and spinal cord. ○ Brain: The main control centre of the entire body. The skull encloses it. It controls all parts of the body, including thinking, movement, learning, memory and maintaining homeostasis. Cerebrum: This is the longest part of the brain making up 10% of the brain. It is responsible for thinking, memory, speaking, learning, coordination, balance and voluntary movement. Brain Stem: involves involuntary body functions like breathing, constant heartbeat, and homeostasis. Temporal Lobe: Processes auditory information and controls memory. Occipital Lobe: Processes visual stimuli Parietal Lobe: Processes sensory information Frontal Lobe: Voluntary movement ○ Spinal cord: The role is to connect the brain to the PNS. All nerves in the body branch out from the spinal cord, which is connected to the brain through the brain stem. The spinal cord is the pathway that the brain uses to communicate with the rest of the body. Function: PNS: Connects the CNS to the rest of the body. It sends motor signals to the rest of the body and relays messages back to the brain. It carries sensory information from the external environment to the brain. ○ Sending motor commands to the muscles for voluntary movement ○ Sending sensory information from the external environment to the brain (except visual) ○ Regulating atomic functions such as blood pressure and sweating (involuntary functions). CNS: The main control centre of the entire body. The central nervous system sends and receives information from and by the PNS. **Electrical signals are transferred through the axon of a neuron, while chemical signals (synapses) are sent between two neurons (within the synaptic cleft)** Endocrine System: Quick Definition: The endocrine system produces and delivers (regulates) hormones to every part of the body through glands. It releases hormones directly into the bloodstream through organs called glands. General Overview: The endocrine system uses chemical messengers called hormones. They are produced in your endocrine glands. The glands and organs make hormones and release them directly into the blood so they can travel to tissues and organs all over the body. Form/ structure: Pituitary Gland Thyroid Gland Pancreas Overies Hypothalamus Adrenal Gland Testes Thymus gland Pineal Glad Parathyroid Gland Function: Hormone: Hormones are chemical substances that act like messenger molecules in the body. Chemically, hormones may be classified as either proteins or steroids. All of the hormones in the human body, except the sex hormones and those from the adrenal cortex, are proteins or protein derivatives. ○ Human Growth Hormone (HGH): Found in the pituitary gland. Influences height, and helps build bone and muscle. ○ Adrenaline: Epinephrine which is a chemical signal that is attached to the circulatory system. As the heart beats faster, more epinephrine is spread throughout the body. Produced in the adrenal glands ○ Insulin: This is produced in the pancreas. Lowers blood sugar and makes energy by administering glucose from blood to cells. Insulin helps blood sugar enter the body's cells so it can be used for energy. Gland: Glands are special tissues in your body that create and release substances. Its An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk. Pituitary Gland: Releases hormones that stimulate other endocrine glands to release their own hormones. The thyroid gland, ovaries and testes are all controlled by hormones released from the pituitary gland. It also releases hormones that control growth and development (especially during adolescence), regulate water balance and contractions during childbirth, and stimulate the release of breast milk. Thyroid Gland: Releases the hormone thyroxine, which regulates cell growth and activity Pancreas: Biggest gland. Releases the hormones insulin and glucagon. These hormones work together to regulate glucose levels in the blood. ○ Insulin allows cells throughout the body to take glucose from the blood. ○ Glucagon controls the amount of glucose released from the liver into the blood. Overies: Release the hormones oestrogen and progesterone. During puberty, these hormones control the development of breasts and the reproductive system. The hormones also work together to regulate the menstrual cycle and control pregnancy. Hypothalamus: Links with the nervous system to coordinate and control reflex actions such as breathing and heartbeat. Releases hormones that, among other things, control body temperature, hunger, thirst, sex drive and emotions. Sends hormones to the pituitary gland to control its release of hormones to other endocrine glands. Adrenal Gland: Release hormones, including adrenaline, that increase heart rate and blood pressure in times of fright. This increases the amount of energy available to muscles. Testes: Release the hormone testosterone, which controls the development of the male reproductive system. It also controls changes during puberty such as growth of body hair and deepening of the voice. Thymus gland: Releases the hormone thymosin, which stimulates the production of white blood cells to help fight infection. Pineal Glad: Releases the hormone melatonin, which controls sleeping and waking pattern Parathyroid Gland: Release the hormone parathormone, which regulates calcium levels in the blood. Therefore, this hormone controls bone development. Role of the endocrine system in maintaining humans as functioning organisms: The endocrine system has many different roles within maintaining humans as functioning organisms. The endocrine system regulates all body systems. For example, it controls your sleep cycle, heart beat abd growth. The endocrine system is made up of various glands that produce specific hormones for a specific task. Hormones are released into the circulatory system (bloodstream) to find target cells. Millions of hormones influences millions of target cells, hence bringing enormous changes over the body. Excretory System: Function: Waste products must be removed from cells to ensure that they do not reach dangerous levels and interfere with normal cell functions. The excretory system makes up 3 separate body systems. Respiratory System: Carbon dioxide is a waste product of respiration. It is excreted in the lungs. Unitary system: There is also another type of waste called nitrogenous waste that needs to be removed from cells. It results from protein metabolism. The liver is involved. It processes the nitrogenous waste and converts it to a substance called urea. Urea is transported in the bloodstream. When it reaches the kidneys it is filtered out of the blood. The kidneys produce urine, a solution of urea and other substances including salts. In addition to excreting urea, the kidneys are also involved in salt and water balance. Integumentary System: The skin also plays a part in excretion. Excess water and salts and small amounts of urea and uric acid are removed from the body via the skin. Chemical World Introduction to Chemistry: Definitions: Chemistry: Chemistry is the study of matter, analysing its structure, properties and behaviour to see what happens when they change in chemical reactions. Matter: Matter is anything that takes up space and can be weighed. Half-life: The half-life of a radioactive isotope is the amount of time it takes for one-half of the radioactive isotope to decay. Nucleus (Atom): A nucleus is the positively charged centre of the atom consisting of protons and neutrons. The nucleus is positively charged in both atoms & ions Atom: An atom is the smallest unit of any chemical element, consisting of a positive nucleus surrounded by negative electrons. Has a neutral net charge Ion: an atom or molecule with a net electrical charge. The net charge is either positive or negative. The charge is based on how many electrons and protons the atom has. More protons mean a positive charge more electrons mean a negative charge. Element: A chemical element is a substance consisting of only one type of atom and cannot be broken down into simpler substances Molecule: A molecule is a group of two or more atoms that bond together. Not all molecules are compounds. Compound: A compound is a substance made up of two or more different chemical elements combined in a fixed ratio. All compounds are molecules Mixture: A mixture is a physical combination of two or more substances that aren't chemically joined. Proton: A proton is a positively charged subatomic particle found in the nucleus of an atom. Biggest subatomic particle of an atom. Neutron: A neutron is a neutral subatomic particle found in the nucleus of an atom. Electron: An electron is a negatively charged subatomic particle found in shells of an atom. Smallest subatomic particle of an atom. Reactivity: Reactivity is a measure of how easily an element will combine with other elements to form compounds. Isotope: Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons. Radioisotope: Radioisotopes are radioactive isotopes of an element Radiation: Radiation is the emission of energy in the form of electromagnetic waves or subatomic particles. Atomic Mass: An atomic mass is the mass of a single atom of a chemical element. Atomic Number: The atomic number is the number of protons in an atom. Electron Shell: The shells are at certain distances from the nucleus. The orbit that an electron follows around a nucleus. Developing The Atomic Theory: Democritus-400BC: Theroised that the world was made of tiny particles called atoms. John Dalton (1786-1844): John Dalton published his ideas about atoms in 1803. He thought that all matter was made of tiny particles called atoms, which he imagined as tiny spheres that could not be divided. That the particles had their own masses and structures. He also discovered that elements had different ratios of different particles. (1803) J.J. Thompson (1856-1940): Nearly 100 years later, J J Thompson carried out experiments and discovered the electron. This led him to suggest the plum pudding model of the atom. In this model, the atom is a ball of positive charge with negative electrons embedded in it - like currants in a Christmas pudding. He proposed the structure of the atom and discovered the electron. He discovered that atoms were made of smaller particles. (April 30 1897) (Cathode Ray) Ernest Rutherford (1871-1937): In 1909 Ernest Rutherford designed an experiment to test the plum pudding model. In the experiment, positively charged alpha particles were fired at thin gold foil. Most alpha particles went straight through the foil. But a few were scattered in different directions. Discovered alpha and beta particles. He discovered that the atom was mostly in space and had a nucleus. (1911) ○ Nuclear model: This evidence led Rutherford to suggest a new model for the atom, called the nuclear model. In the nuclear model…The mass of an atom is concentrated at its centre, the nucleus. The nucleus is positively charged Developing The Atomic Model: Neils Bohr 1885 - 1962: Niels Bohr adapted Ernest Rutherford's nuclear model. Bohr did calculations that led him to suggest that electrons orbit the nucleus in shells. The shells are at certain distances from the nucleus. The calculations agreed with observations from experiments. Further experiments led to the idea that the nucleus contained small particles, called protons. Each proton has a small amount of positive charge. James Chadwick: In 1932 James Chadwick found evidence for the existence of particles in the nucleus with mass but no charge. These particles are called neutrons. This led to another development of the atomic model, which is still used today. Atomic Structure: Subatomic Particles: The nuclei of all atoms contain subatomic particles called protons. The nuclei of most atoms also contain neutrons. The masses of subatomic particles are very tiny. Instead of writing their actual masses in kilograms, we often use their relative masses. The relative mass of a proton is 1, and a particle with a relative mass smaller than 1 has less mass. Subatomic particle Relative mass Relative charge Proton 1 +1 Neutron 1 0 Electron Very small -1 The mass of an electron is very small compared to a proton or a neutron. Since the nucleus contains protons and neutrons, most of the mass of an atom is concentrated in its nucleus. Protons and electrons have electrical charges that are equal and opposite. ○ The amount of protons determines which element an atom belongs to Charge: ○ The net charge is positive (+1) when there are more protons than electrons. This charge makes up an ion. ○ The net charge is negative (-1) when there are more electrons than protons. This charge makes up an ion too. ○ The net charge is neutral (0) with equal protons and electrons. This makes up an atom. ○ Atomic net charge = no. of protons - no. of electrons Electron Configuration: 1. 1st (K) shell: 2 electrons 2. 2nd (L) shell: 8 electrons 3. 3rd (M) shell: 18 electrons 4. 4th (N) shell: 32 electrons Nucleon: A subatomic particle present within the nucleus of an atom or ion. Atomic Mass: The amount of nucleons (protons and neutrons) within an atomic nucleus. ○ Atomic Mass = No. of protons + No. of neutrons Atomic Number: The amount of protons in the atomic nucleus. ○ No. of protons = Atomic No. Electron count: ○ In an atom, no. of electrons = no. of protons ○ In an ion, no. of electrons = atomic no. - charge Summary of Equations: Atomic net charge = no. of protons - no. of electrons Atomic Mass = No. of protons + No. of neutrons No. of protons = Atomic no. No. of neutrons = Mass no. - Atomic no. Electron count in an atom = no. of protons Electron count in an ion = atomic no. - charge Symbol: Valance Electrons: Electrons of the outermost shell of an atom Isotopes: All atoms of a particular element have the same number of protons and so they have the same atomic number. However, they can have different numbers of neutrons and so they they have different mass numbers. The name of an isotope includes its mass number, e.g. Carbon-12 is an isotope of Carbon with a mass of 12. Atoms of the same element must have the same number of protons, but they can have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Isotopes of an element have: the same atomic number different mass numbers Unstable isotopes: Isotopes of Carbon Isotopes of Uranium Radioactivity: A stable atom describes the nucleus of an atom in which the protons and neutrons are held strongly together. An unstable atom is when there is an imbalance in the internal energy of an atom. When there is a excess in neutrons or protons in an atom. Nuclear Radiation: Alpha Radiation/ Decay: Beta Radiation/ Decay ○ Gamma Radiation Radiation Protection: The denser the material, the more protective it is from high-energy radiation. Half Life: The rate at which radioactive atoms decay is measured by a term called the half-life. The half-life is the time it takes for half of the atoms in a radioactive sample to decay. Each radioactive isotope has its own specific half-life, which can range from fractions of a second to billions of years. During the first half-life, half of the atoms will decay, leaving the other half unchanged. In the second half-life, half of the remaining atoms will decay, leaving one-fourth of the original sample. This process continues, with each half-life reducing the number of radioactive atoms by half. The half-life is a crucial concept because it allows scientists to estimate the age of rocks, fossils, or other artefacts containing radioactive isotopes. By measuring the remaining amount of a radioactive isotope and knowing its half-life, scientists can calculate how much time has passed since the material was formed. a) 1600 ➗2 = 800 ∴Half life = 1 min b) 100 ➗2 = 50 particles (@5 minutes) 50 ➗2 = 25 particles (@6 minutes) Element Structure and Trends: Groups are vertical and periods run horizontally on the periodic table of elements Opposite charges cause an attraction/ bond between elements and atoms Atomic radius: the total distance from the centre of the nucleus to the outermost electron shell (valance shell) Electronegativity: the ability of an atom to attract to itself an electron pair, shared with another atom in a chemical bond. The ability to attract valance electrons. Ionisation energy: The amount of energy required to remove an electron from an isolated atom or molecule. Global Catastrophes: Weather & Climate: Weather: The state of the atmosphere and its components over a short period (or at a particular time). Small variations in conditions cause big weather changes. Climate: The general weather and atmospheric conditions over a prolonged period. Shaped by global forces that alter the energy balance in the atmosphere, such as the tilt of the Earth’s axis. Climate Change: A change in the Earth’s overall atmosphere and atmospheric conditions over a long period. ○ Global warming and climate change can affect weather patterns. This is through an effect called the greenhouse effect. As solar radiation emitted by the Sun, enters the Earth’s atmosphere, some of the rays are absorbed by greenhouse gases, such as water vapour, methane, nitrous oxide and carbon dioxide. These particles absorb the radiation and re-emit them in another direction. Some rays penetrate the atmosphere and bounce off the Earth’s surface. It becomes infrared radiation, and as it rises, they are also absorbed by greenhouse gases. This may cause more rainy days or hotter days. El Nino: describes the unusual warming of the surface waters in the Eastern Equatorial Pacific Ocean. Results in more dry weather. La Nina: refers to the cooling of sea-surface temperatures across the east-central equatorial Pacific, increasing rain. Theory of plate tectonics: Theorised by Alfred Wegener. The earth is divided into various plates. These plates are located in the lithosphere, on top of the asthenosphere, they contain a vast array of minerals and are made up of dense rock. Leftover heat from the earth's core from its creation, alongside additional radiation heat up the asthenosphere in a process known as convection, which transforms the asthenosphere into a semi-liquid state. This allows the tectonic plates above to move and drift. This is known as continental drift. Convection currents: Convection describes heat transfer within fluids. Mantle convection describes this phenomenon, within the asthenosphere. The asthenosphere contains the lower mantle, which is semi-molten rock. The liquid closer to the core is hotter and less dense, as its particles’ bonds are looser, so it rises to the surface. It then drags slowly, horizontally across the tectonic plates, creating a convection current, and then cools. Henceforth the liquid becomes more dense and sinks. This continuous cycle of convection currents in the Asthenosphere, drives Plate Tectonics, as it slowly drags the tectonic plates too. Formation of new landforms due to plate movement: The motions of the plates have a tremendous ability to shape and deform rocks through a variety of processes that include folding, faulting, extension, and on a massive scale, mountain building. Technological developments: Seismometer: A seismometer, also known as a seismograph, is the best tool for measuring and detecting earth tremors, especially those induced by earthquakes. It comprises a mass hanging within a frame that remains reasonably steady during seismic activity. When earthquakes pass through the Earth, the ground shifts which causes the seismometer's mass to change, resulting in an electrical signal appropriate to the ground motion. This signal is captured on paper or electronically, allowing scientists to study the earthquake's size, duration, and frequency content. Researchers may use seismic waves to detect the epicentre and magnitude of an earthquake and acquire insights into the Earth's internal structure, which aids in preparedness for earthquakes, hazard assessment, and scientific knowledge of seismic activity GPS: GPS tracking can be utilised to track the movement of earthquakes. The most commonly used method is placing GPS trackers on the surface of earthquake-prone regions, to track any movement. These GPS trackers will be situated in a vast area and will be located close to a fault line. This is because the highest frequencies of seismic waves generated by earthquakes will be located near this region. These GPS locators constantly track their precise location many times per minute. As the tectonic plates shift and move during an earthquake, these GPS trackers will be able to record their position during the movement. Signals will be sent to seismologists, who study the seismic waves of earthquakes. By calculating how far the GPS trackers have moved from their original position (whether that be vertically or horizontally) they can determine the severity of the earthquake. Tsunami detection buoys: work through sensors that are attached to the seafloor. Multiple buoys are installed to detect the progress of the tsunami, as it moves through the ocean. They detect tsunamis through the change in water pressure. Types of plate boundaries: Convergent: A convergent plate boundary is where two or more plates collide with each other. When the plates collide they create volcanoes and mountain ranges. When the plates collide the denser plate passes underneath, forming what's known as a subduction zone. In this zone, the plate that is being subducted into the mantle is melted into magma which rises, forming volcanoes. Typically oceanic plates are denser than continental plates which is why convergent boundaries on land create mountains and convergent boundaries in water create volcanoes. The creation of mountains (Orogeny) is seen most evidently between the Indian and Eurasian plates. Due to continental drift, the Indian plate collided with the Eurasian plate. Because these plates are both continental they both want to pass over each other this collision causes mountain ranges such as the Himalayan mountains to be made. Divergent: A divergent plate boundary is where two or more plates separate from each other. The most well-known example is the separation of the South American and African continents. When the plates separate they create deep valleys, oceanic ridges and in some cases trenches. When the plates separate molten rock (magma) erupts from the opening forming a new crust. When the plates separate they cause earthquakes along the new crust called spreading centres, which are relatively small in magnitude but in some cases can lead to a rise in sea levels. Transform: A divergent plate boundary is where two or more plates pass/slide beside each other. The San Andreas boundary is the best example of lateral plate motion. In this example where San Andreas, as part of the Pacific Plate, slides north-northwestward past the rest of North America. This sliding can cause large lateral displacement of rock, as when the plate slides, rock formations are put on tonnes of stress leading to shallow earthquakes, and a broad zone of crustal deformation. Structure of the earth: The inner core: This solid metal ball has a radius of 1,220 kilometres (758 miles), or about three-quarters that of the moon. It’s located some 6,400 to 5,180 kilometres (4,000 to 3,220 miles) beneath Earth’s surface. Extremely dense, it’s made mostly of iron and nickel. The inner core spins a bit faster than the rest of the planet. It’s also intensely hot: Temperatures sizzle at 5,400° Celsius (9,800° Fahrenheit). That’s almost as hot as the surface of the sun. Pressures here are immense: well over 3 million times greater than on Earth’s surface. Some research suggests there may also be an inner, inner core. It would likely consist almost entirely of iron. The outer core: This part of the core is also made from iron and nickel, just in liquid form. It sits some 5,180 to 2,880 kilometres (3,220 to 1,790 miles) below the surface. Heated largely by the radioactive decay of the elements uranium and thorium, this liquid churns in huge, turbulent currents. That motion generates electrical currents. They, in turn, generate Earth’s magnetic field. For reasons somehow related to the outer core, Earth’s magnetic field reverses about every 200,000 to 300,000 years. Scientists are still working to understand how that happens. The mantle: At close to 3,000 kilometres (1,865 miles) thick, this is Earth’s thickest layer. It starts a mere 30 kilometres (18.6 miles) beneath the surface. Made mostly of iron, magnesium and silicon, it is dense, hot and semi-solid (think caramel candy). Like the layer below it, this one also circulates. It just does so far more slowly. How heat moves: Near its upper edges, somewhere between about 100 and 200 kilometres (62 to 124 miles) underground, the mantle’s temperature reaches the melting point of rock. Indeed, it forms a layer of partially melted rock known as the asthenosphere (As-THEEN-oh-sfeer). Geologists believe this weak, hot, slippery part of the mantle is what Earth’s tectonic plates ride upon and slide across. Diamonds are tiny pieces of the mantle we can touch. Most form at depths above 200 kilometres (124 miles). But rare “super-deep” diamonds may have formed as far down as 700 kilometres (435 miles) below the surface. These crystals are then brought to the surface in volcanic rock known as kimberlite. The mantle’s outermost zone is relatively cool and rigid. It behaves more like the crust above it. Together, this uppermost part of the mantle layer and the crust are known as the lithosphere. The thickest part of Earth’s crust is about 70 kilometres (43 miles) and lies under the Himalayan Mountains, as seen here. The crust: Earth’s crust is like the shell of a hard-boiled egg. It is extremely thin, cold and brittle compared to what lies below it. The crust is made of relatively light elements, especially silica, aluminium and oxygen. It’s also highly variable in its thickness. Under the oceans (and the Hawaiian Islands), it may be as little as 5 kilometres (3.1 miles) thick. Beneath the continents, the crust may be 30 to 70 kilometers (18.6 to 43.5 miles) thick. Along with the upper zone of the mantle, the crust is broken into big pieces, like a gigantic jigsaw puzzle. These are known as tectonic plates. These move slowly — at 3 to 5 centimetres (1.2 to 2 inches) per year. What drives the motion of tectonic plates is still not fully understood. It may be related to heat-driven convection currents in the mantle below. Some scientists think it’s caused by the tug from slabs of crust of different densities, something called “slab pull.” In time, these plates will converge, pull apart or slide past each other. Those actions cause most earthquakes and volcanoes. It’s a slow ride, but it makes for exciting times here on Earth’s surface. Interaction of spheres: Geosphere: the portion of the earth that includes rocks and minerals. It starts at the ground and extends down to Earth’s core. We rely on the geosphere to provide natural resources and a place to grow food. Volcanos, mountain ranges, and deserts are all part of the geosphere. Put simply, without the geosphere, there would be no Earth! Hydrosphere: includes the oceans, rivers, lakes, groundwater, and water frozen in glaciers. 97% of water on Earth is found in the oceans. Water is one of the most important substances needed for life and makes up about 90% of living things. Without water, life would not be possible. Atmosphere: includes all the gases surrounding the Earth. We often call the atmosphere “air.” All planets have an atmosphere, but Earth is the only planet with the correct combination of gases to support life. The atmosphere consists of five layers and is responsible for Earth’s weather. Even though it seems like air is made of nothing, it consists of particles too small to be seen. All these particles have a weight that pushes down on Earth. The weight of air above us is called air pressure. Biosphere: The biosphere is made up of all the living things on Earth and it includes fish, birds, plants, and even people. The living portion of the Earth interacts with all the other spheres. Living things need water (hydrosphere), chemicals from the atmosphere, and nutrients gained by eating things in the biosphere. The spheres interact to affect Earth’s systems and processes, and they are constantly changing each other. For example, ocean currents (hydrosphere) affect air temperature (atmosphere): The Gulf Stream is a powerful water current in the Atlantic Ocean. It’s warm water moderates the temperatures on the east coast of the USA. Another example of how the spheres affect each other is through erosion. Erosion happens in the desert when wind (atmosphere) shapes the sand in the geosphere. Water (hydrosphere) can also shape land, such as in the formation of the Grand Canyon. Cycles in nature: The carbon cycle: the process of how carbon is exchanged between the different spheres of the earth. There are two parts to the carbon cycle: the fast and slow cycle. The fast cycle is carbon dioxide (carbon as a gas form in the atmosphere), being inhaled by plants. These plants utilise carbon dioxide to carry out a process called photosynthesis, where carbon dioxide is used to make air and energy. This is when animals eat plants, they eat the stored carbon too and exhale it during respiration. This returns the carbon back into the atmosphere. The slow cycle takes longer. As plants and animals die, they decompose into the soil, leaving carbon remnants. These remnants get layered and through pressure, from fossil fuels such as coal and natural gas. When these elements are burned, they release carbon back into the atmosphere. Term Definition Example Sentence carbon cycle the process by which carbon The carbon cycle is important for (noun) moves between the atmosphere, maintaining the balance of plants, animals, and the Earth's carbon on Earth. surface. fossil fuels fuels formed from the remains of Most of our energy comes from (noun) ancient plants and animals, such burning fossil fuels like coal and as coal, oil, and natural gas. oil. greenhouse a gas that traps heat in the Earth's Carbon dioxide is a greenhouse gas (noun) atmosphere, contributing to the gas that contributes to climate greenhouse effect and global change. warming. acidic having a pH value less than 7, The ocean has become more (adjective) indicating a higher concentration acidic due to increased carbon of hydrogen ions and a sour taste. dioxide levels. reduce (verb) to make smaller or decrease in We can reduce our carbon size, amount, or intensity. footprint by using public transportation instead of driving. Hydrocarbons Organic Chemical compounds The overuse of hydrocarbons as that consists only of carbon and an energy source has impacted hydrogen atoms the world’s climate in a negative way. The water cycle: This cycle demonstrates how water is being transferred and transformed on the Earth. Bodies of water evaporate with the Sun’s heat, as the particles become more energised. These water particles then cool and condense forming clouds. These clouds grow until they cannot hold any more water, and release it in the form of precipitation (rain or hail). Once the water hits the Earth’s surface, it moves underground to the nearest body of water, or lowest elevation point. As the water travels, it can be absorbed by plants and released once again back into the environment, via transpiration. The Nitrogen Cycle: It describes how Nitrogen moves through the different living and non-living aspects of the world, whether that be through animals or the atmosphere. Nitrogen fixation describes how nitrogen moves into the soil. This could be through lightning strikes. The third part of the cycle is called nitrification, which is a chemical process where nitrogen gets converted into a form that animals and plants can consume. Immobilisation is the form of regulating nitrogen in the soil, by microorganisms consuming it. As nitrogen is exhaled by living organisms, it gets converted into atmospheric nitrogen through denitrification. This releases nitrogen back into the air, back where it started. Greenhouse Effect: Physical World Coaching forces: Acceleration -Acceleration is how quickly something changes its velocity. Acceleration is the change in velocity over time. Constant - to stay the same; not changing. Deduce - to work out; to find a pattern or answer. Directly proportional - when two factors change together; either both increase or both decrease; for example, when one-factor doubles, another factor also doubles. Force- A force is a push or pull upon an object resulting from the object's interaction with another object. Friction - when objects rub together; sometimes used in place of the term, frictional force. Gravity- the force by which a planet or other body draws objects toward its centre. The force of gravity keeps all of the planets in orbit around the sun Inversely proportional - when one factor increases as another factor decreases; for example, when one-factor doubles, another factor is halved. Mass - Mass is a measurement of how much matter is in an object. Mass is a combination of the total number of atoms, the density of the atoms, and the type of atoms in an object. Net force - A net force can accelerate an object causing it to move. The net force is the combined force applied when two or more forces act on an object at the same time. Newton’s 1st Law of Motion - An object will remain at rest or in motion (with constant speed in a straight line) unless it is acted upon by an unbalanced external force. Newton’s 2nd law of Motion - When a force is applied to an object the object will accelerate. The acceleration will depend on the size of the applied force and the mass of the object. Newton’s 3rd Law of Motion - For every action, there is an equal but opposite reaction. (The action force and reaction force act on different objects) Proportional - in the same ratio; when one-factor increases by the same fraction as another factor increases. Speed - Distance covered in a certain time. Uniform - constant; unchanging. Weight- The weight of an object is the force of gravity on the object and may be defined as the mass times the acceleration of gravity Net force: The total amount of force being applied to an object. If more than one force is applied in the same direction, the sizes of the forces add together to make a larger net force. The net force acts in the same direction as the applied force. Balanced force: Sometimes two forces can oppose each other but there is no net force. When this happens we say that the opposite forces are balanced. Peter and Michael are pushing the box in opposite directions with the same amount of force. The force they each apply to the box balances. The box will remain stationary as the forces are balanced. It is as if they cancel each other out. Even though Peter and Michael are both pushing on the box it remains stationary so it seems as if there is no force on the Box. When two equal forces act on an object in opposite directions, the net force is zero. The forces are balanced. To calculate net force when there are opposing forces first determine which force is bigger, in this case, Peter's force is bigger than Michael's force. Next, determine the size of the difference between the forces. 250N - 200N = 50N. Next, determine the direction of the net force. Peter's force is bigger so the net force will be in the direction that he is pushing so the net force will be to the right. Unbalanced forces: If more than one force is applied in different directions, the net force is less. Newton's 1st Law of Motion: An object will remain at rest or in motion (with constant speed in a straight line) unless it is acted upon by an unbalanced (net) external force. Unbalanced is another word for "net". Another way of saying this Law is that anything at rest or moving at constant speed will stay that way unless pushed or pulled by a force. This Law is sometimes called the Law of Inertia. You have experienced this Law when a car brakes. You keep moving forward when the brakes are applied. The force is applied to the car to stop but your body keeps moving forward at the speed you were travelling. This is Inertia. Seat belts slow our motion down. Physics of Motion: Acceleration: The rate at which velocity changes. Anytime you change the velocity or direction you are accelerating which can be either speeding up or slowing down. To calculate the acceleration is distance over time squared. Speed: The rate at which an object changes position. Speed is calculated as distance over time for example kph or km per hour. Velocity: The rate at which an object changes position in a certain direction e.g 80 kph east. It must have a direction attached to it. Speed + direction = velocity Mass: All objects have mass. Mass is the amount of substance in an object. So when you push an object, your force is trying to move the mass of the object. A box doesn't usually start to move when you first push on it. You have to apply enough force to overcome the friction between the box and the floor. Newton's 2nd Law of Motion: When a force is applied to an object the object will accelerate, the acceleration will depend on the size of the applied force and the mass of the object. This can be written mathematically as below: F = m×a or Force = mass x acceleration F is the force measured in Newtons (N), m is the mass of the object measured in kilograms (kg), a is the acceleration measured in metres per second squared (m/s) The relationship between mass and force: The force needed to get a box to the same speed is larger when the mass of the box is larger. The force needed and the mass of the box are proportional to each other. This means that when mass gets bigger, the force needs to get bigger. If the mass is smaller, the force is smaller. Force is directly proportional to mass. The relationship between force and acceleration: A small force leads to a small acceleration, and A large force leads to a large acceleration. The relationship between force and acceleration is that force is directly proportional to acceleration The relationship between mass and acceleration: Acceleration is INVERSELY proportional to the mass. A small mass leads to a larger acceleration, A large mass leads to a smaller acceleration. A large NFL player with a large mass takes a lot more force to accelerate from standing than a player with less mass. Reaction forces: The upward force of the ground on the car. The forces are balanced so there is no movement upwards or downwards. In pairs of balanced forces, the applied force is called the action force. The reaction is the same size but opposite in direction to the action force. Newton’s 3rd law of motion: For every action, there is an equal but opposite reaction. (The action force and reaction force act on different objects) Newton's third law explains the generation of thrust by a rocket engine. In a rocket engine, hot exhaust gas is produced through the burning of a fuel. Gas is expelled out of its engine. The rocket pushes on the gas, and the gas in turn pushes on the rocket. With rockets, the action force is the expelling of gas out of the engine. The reaction force is the force on the rocket from the gas causing upward movement of the rocket. To enable a rocket to lift off from the launch pad, the action, or thrust, from the engine, must be greater than the mass of the rocket. Aristotle vs Galileo: Constant speed is when an object is travelling the same distance each time interval in a straight line. Average speed is found mathematically using this formula: Average speed = total distance travelled/time taken Distance-time graphs Measurements of distance travelled and time taken can be plotted on a distance-time graph. The factor you are measuring goes on the y-axis, which is the vertical axis. In this case, we are measuring distance. The time intervals at which the distance is measured goes on the x-axis. Gradient= Rise/run The gradient of a distance-time graph determines the speed The shape of a distance-time graph tells us about the object's motion. A straight line sloping upwards on a distance-time graph represents motion at a constant speed. A steeper line means a faster speed. A horizontal line on a distance-time graph represents a stationary object with no motion. (That is - there is zero speed). https://www.youtube.com/watch?v=jme_vSj5wRo https://www.youtube.com/watch?v=E43-CfukEgs Measuring motion Graphing distance time and speed Graphing speed and time: Earth and Space Space Odyssey: Big Bang timeline: 1. Planck Epoch (or Planck Era), from zero to approximately 10-43 seconds (1 Planck Time): This is the closest that current physics can get to the absolute beginning of time, and very little can be known about this period. General relativity proposes a gravitational singularity before this time (although even that may break down due to quantum effects), and it is hypothesized that the four fundamental forces (electromagnetism, weak nuclear force, strong nuclear force and gravity) all have the same strength, and are possibly even unified into one fundamental force, held together by a perfect symmetry which some have likened to a sharpened pencil standing on its point (i.e. too symmetrical to last). At this point, the universe spans a region of only 10-35 meters (1 Planck Length), and has a temperature of over 1032°C (the Planck Temperature). 2. Grand Unification Epoch, from 10–43 seconds to 10–36 seconds: The force of gravity separates from the other fundamental forces (which remain unified), and the earliest elementary particles (and antiparticles) begin to be created. 3. Inflationary Epoch, from 10–36 seconds to 10–32 seconds: Triggered by the separation of the strong nuclear force, the universe undergoes an extremely rapid exponential expansion, known as cosmic inflation. The linear dimensions of the early universe increased during this period by a tiny fraction of a second by a factor of at least 1026 to around 10 centimetres (about the size of a grapefruit). The elementary particles remaining from the Grand Unification Epoch (a hot, dense quark-gluon plasma, sometimes known as “quark soup”) become distributed very thinly across the universe. 4. Electroweak Epoch, from 10–36 seconds to 10–12 seconds: As the strong nuclear force separates from the other two, particle interactions create large numbers of exotic particles, including W and Z bosons and Higgs bosons (the Higgs field slows particles down and confers mass on them, allowing a universe made entirely out of radiation to support things that have mass). 5. Quark Epoch, from 10–12 seconds to 10–6 seconds: Quarks, electrons and neutrinos form in large numbers as the universe cools off to below 10 quadrillion degrees, and the four fundamental forces assume their present forms. Quarks and antiquarks annihilate each other upon contact, but, in a process known as baryogenesis, a surplus of quarks (about one for every billion pairs) survives, which will ultimately combine to form matter. 6. Hadron Epoch, from 10–6 seconds to 1 second: The temperature of the universe cools to about a trillion degrees, cool enough to allow quarks to combine to form hadrons (like protons and neutrons). Electrons colliding with protons in the extreme conditions of the Hadron Epoch fuse to form neutrons and give off massless neutrinos, which continue to travel freely through space today, at or near the speed of light. Some neutrons and neutrinos re-combine into new proton-electron pairs. The only rules governing all this random combining and re-combining are that the overall charge and energy (including mass energy) be conserved. 7. Lepton Epoch, from 1 second to 3 minutes: After the majority (but not all) of hadrons and antihadrons annihilate each other at the end of the Hadron Epoch, leptons (such as electrons) and antileptons (such as positrons) dominate the mass of the universe. As electrons and positrons collide and annihilate each other, energy in the form of photons is freed up, and colliding photons in turn create more electron-positron pairs. 8. Nucleosynthesis, from 3 minutes to 20 minutes: The temperature of the universe falls to the point (about a billion degrees) where atomic nuclei can begin to form as protons and neutrons combine through nuclear fusion to form the nuclei of the simple elements of hydrogen, helium and lithium. After about 20 minutes, the temperature and density of the universe have fallen to the point where nuclear fusion cannot continue. 9. Photon Epoch (or Radiation Domination), from 3 minutes to 240,000 years: During this long period of gradual cooling, the universe is filled with plasma, a hot, opaque soup of atomic nuclei and electrons. After most of the leptons and antileptons had annihilated each other at the end of the Lepton Epoch, the energy of the universe is dominated by photons, which continue to interact frequently with the charged protons, electrons and nuclei. 10. Recombination/Decoupling, from 240,000 to 300,000 years: As the temperature of the universe falls to around 3,000 degrees (about the same heat as the surface of the Sun) and its density also continues to fall, ionized hydrogen and helium atoms capture electrons (known as “recombination”), thus neutralizing their electric charge. With the electrons now bound to atoms, the universe finally becomes transparent to light, making this the earliest epoch observable today. It also releases the photons in the universe that have up till this time been interacting with electrons and protons in an opaque photon-baryon fluid (known as “decoupling”), and these photons (the same ones we see in today’s cosmic background radiation) can now travel freely. By the end of this period, the universe consists of a fog of about 75% hydrogen and 25% helium, with just traces of lithium. 11. Dark Age (or Dark Era), from 300,000 to 150 million years: The period after the formation of the first atoms and before the first stars is sometimes referred to as the Dark Age. Although photons exist, the universe at this time is dark, with no stars having formed to give off light. With only very diffuse matter remaining, activity in the universe has tailed off dramatically, with very low energy levels and very large time scales. Little of note happens during this period, and the universe is dominated by mysterious “dark matter”. 12. Reionization, 150 million to 1 billion years: The first quasars form from gravitational collapse, and the intense radiation they emit reionizes the surrounding universe, the second of two major phase changes of hydrogen gas in the universe (the first being the Recombination period). From this point on, most of the universe goes from being neutral back to being composed of ionized plasma. 13. Star and Galaxy Formation, 300 - 500 million years onwards: Gravity amplifies slight irregularities in the density of the primordial gas and pockets of gas become more and more dense, even as the universe continues to expand rapidly. These small, dense clouds of cosmic gas start to collapse under their gravity, becoming hot enough to trigger nuclear fusion reactions between hydrogen atoms, creating the very first stars. The first stars are short-lived supermassive stars, a hundred or so times the mass of our Sun, known as Population III (or “metal-free”) stars. Eventually Population II and then Population I stars also begin to form from the material from previous rounds of star-making. Larger stars burn out quickly and explode in massive supernova events, their ashes going to form subsequent generations of stars. Large volumes of matter collapse to form galaxies and gravitational attraction pulls galaxies towards each other to form groups, clusters and superclusters. 14. Solar System Formation, 8.5 - 9 billion years: Our Sun is a late-generation star, incorporating the debris from many generations of earlier stars, and it and the Solar System around it form roughly 4.5 to 5 billion years ago (8.5 to 9 billion years after the Big Bang). 15. Today, 13.7 billion years: The expansion of the universe and recycling of star materials into new stars continues. Facts vs Theories vs Hypotheses vs Laws Fact: Observations of the world around us. Theory: A well-substantiated explanation acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation. They are based on predictions. Hypothesis: a proposed explanation for a phenomenon made. Is a starting point for further experimentation. Law: A statement based on repeated experimental observations that describes some phenomenon of nature. Evidence for the Big Bang: The Expansion of the Universe and the RedShift: The existence of cosmic microwave background radiation (CMBR): The relative abundance of small elements: Technology & Advancements: The life cycle of a star/s: Working Scientifically Scientific Diagrams: Rules: ○ Must be a sharp, lead pencil. Not coloured. ○ Lines should be 2D, not 3D. ○ Clean, singular lines. Not sketching. ○ Glassware should be open. Do not close off the tops. ○ Always use a ruler ○ Do not shade or colour in ○ Must be around ¼ of the page ○ Objects which touch each other in ‘real life’ should be touching in the diagram. ○ Draw a label with a straight line. No arrowhead and make sure to keep it neat, with no lines crossing each other. Laboratory Equipment: ○ ○ ○ ○ ○ ○ ○ ○ ○ Drawing and Analysing Graphs: Drawing Graphs ○ Label the x and y axis ○ Equal spacings between columns ○ Do not write x and y ○ Have a title ○ Dependent variable is on the y-axis What is measured during the experiment ○ The Independent variable is on the X-axis Changes ○ The line graph should not intersect with the y-axis ○ Do not use arrows Interpreting data from a table: Variables: Dependent: What is measured during the experiment Independent: Changes Controlled: Stays the same The Scientific Method: There are seven steps to the scientific method: Question, Research, Hypothesis, Experiment, Data Analysis, Conclusion, and Communication. Scientific Report Writing: 1. Aim 2. Hypothesis 3. Equipment ○ Scientific Diagram 4. Method 5. Results ○ Table ○ Graph 6. Discussion ○ Accuracy: How close the experiment’s results reached the true or accepted value. ○ Validity: If the experiment measures the intended values ○ Reliability: The extent to which the findings of repeated experiments, conducted under identical or similar conditions, agree with each other. An extent to which repeated observations and/or measurements taken under identical circumstances will yield similar results. I could repeat the experiment 10 times and get totally different results. This means my experiment is invalid. 7. Conclusion ○ From this experiment, it was found that… ○ Restate findings and link it to the hypothesis

Year 9 Yearly Exam 2023 Science Study Document PDF

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