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MIX PAPERS :AQA GCSE REVISIONS QUESTIONS AND ANSWERS HIGHLY PASSED

AQA A-Level Changing atomic model: Atomic structure and the periodic table Chemistry Revision Questions and Answers

AQA A level Biology Revision Questions with certified Answers

Ecosystem - The interaction of a community of living organisms with the non-living parts of their environment What is a community made up of? - The populations of different species or organisms that are all interdependent in a habitat Habitat - The environment in which an organism lives Population - The total number of organisms of the same species living in the same geographical area Interdependence - The way in which each species within a community depends on other species for food, sh...

What are the two types of microscopes? - Light Microscope Electron Microscope What is the magnifying power of a light microscope? - x 2,000 What is the magnifying power of an electron microscope? - x 2,000,000 What is the resolving power? - The ability to distinguish between two separate points What is the resolving power of light microscopes? - 200 nm What is the resolving power of electron microscopes? - 0.2 nm What are the advantages of light microscopes? - 1. living samples 2. can vi...

What are chromosomes? - They are really long molecules of DNA What does DNA stand for - DeoxyribonNucleicAcid. It is a complex chemical in a thread-like chain. It contains coded information and genetic information Where is DNA found - It is found in the nucleus of animal and plant cells in long structures called chromosomes. Chromosomes normally come in pairs What is DNA structure called - It is a polymer. It is made up of two strands coiled together in the shape of a double helix. What i...

Describe how you would use a biochemical test to show that a solution contained a non-reducing sugar, such as sucrose. [3] - ,first reducing sugars test; boil with dilute HCl acid then Neutralise with NaHCǑ, add benedict and heat to 95 degrees C brick red ppt forms if reducing sugar is present Describe a chemical test you could carry out to show that a piece of coconut contains lipids. [3] - (Crush in) ethanol / alcohol; Add (to) water (Order of adding is critical for this point); Emulsion...

large molecules often contain carbon. why? - they can readily form bonds with other carbon atoms. this forms a 'backbone'. other atoms can then attach. describe benedicts test for reducing sugars - add equal volumes of the sugar sample and benedicts reagent. heat the mixture in a water bath for 5 minutes. brick red precipitate will form. what is a reducing sugar? - a sugar that can reduce (give electrons to) another chemical. describe the benedicts test for non reducing sugars - with fo...

describe and explain the steps in the light dependent reaction of photosynthesis - 1. photoionisation: light reaches chlorophyll in PSII, which is absorbed by an electron, which becomes excited and moves to a higher energy level. 2. the electron passes to a carrier protein in the thylakoid membrane, and is passed down a series of carrier molecules called an electron transfer chain. 3. as the electron moves down, energy is lost from the electron and is released as ATP. 4. the loss of electr...

Buffer stock - A stock of raw materials held in reserve to protect the production process from unforeseen shortages. Customer loyalty - The likelihood that past customers will continue to buy from the business, enhanced by high quality customer service and/or reward programmes. Customer satisfaction - Whether customers are pleased with the goods/services they receive; whether they would purchase again. Flow production - Using a production line to make goods continuously and in large number...

What are cells? - The building blocks of organisms Define eukaryotic cell - Cells that have a true nucleus Define prokaryotic cell - Cells that do not have a true nucleus What is in an animal cell? - Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes What is in a plant cell? - Same as animal plus: vacuole, chloroplasts, chlorophyll, cell wall What is in a yeast cell? - Same as animal plus: temporary vacuole, cell wall What is in a bacterial cell? - Cytoplasm, cell membrane, cell wa...

How is the real size of a magnified image calculated? - Real size = Image size ÷ Total magnification. What is a eukaryotic cell? - A cell with DNA inside a membrane bound nucleus. Prokaryotic cells do not have a nucleus. Name two differences between a plant cell and a bacterial cell? - Plant cells have a nucleus / plant cells have mitochondria / plant cells have chloroplasts / plant cells have a cellulose cell wall whereas bacteria do not contain any of these structures. Bacteria have chr...

How is the real size of a magnified image calculated? - Real size = Image size ÷ Total magnification. What is a eukaryotic cell? - A cell with DNA inside a membrane bound nucleus. Prokaryotic cells do not have a nucleus. Name two differences between a plant cell and a bacterial cell? - Plant cells have a nucleus / plant cells have mitochondria / plant cells have chloroplasts / plant cells have a cellulose cell wall whereas bacteria do not contain any of these structures. Bacteria have chr...

What is homeostasis? - The maintenance of a constant internal environment. What is a stimulus? - A change in your environment than requires a response. e.g Light, sound, touch, pressure, pain, chemical or temperature. What do the receptors do? - Detect the stimulus or change in environment. What happens after the receptors? - Receptors send messages to the CNS via the sensory neurone. What makes up the central nervous system? - The brain or spinal cord What is an effector? - Muscles or gl...

What does a nucleus do? - It contains genetic material and controls the activities of the cell What does cytoplasm do? - It's a gel-like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions What does a cell membrane do? - It holds the cell together and controls what goes in and out What do mitochondria do? - These are where most of the reactions for aerobic respiration occur. Respiration transfers energy that the cell needs to wor...

What is the charge of a proton? - +1 What is the charge of a neutron? - 0 What is the charge of an electron? - -1 What is the relative mass of a proton? - 1 What is the relative mass of a neutron? - 1 What is the relative mass of an electron? - Very small How many types of atoms do elements contain? - Only one type What are compounds? - Substances containing two or more different elements that are chemically bonded together What are mixtures? - Substances containing two or more differen...

This type of surface is a good absorber and emitter of thermal radiation - Dark, rough (matt) surface This type of surface is a bad absorber and emitter of thermal radiation - Light, shiny surface In this process particles vibrate colliding with each other passing energy along. Solids are best at it, then liquids, then gases. - Conduction In this process particles move around carrying energy with them. Gases are best at it, then liquids then solids - Convection This process doesn't requi...

Weight - Mass x Gravitational Field Strength Work Done - Force x Distance Force Applied to a Spring - Spring Constant x Extension Moment of a Force - Force x Distance Pressure - Force / Area

Energy Stores - 1) Elastic potential 2) Gravitational potential 3) Thermal 4) Electrostatic 5) Nuclear 6) Chemical 7) Kinetic 8) Magnetic 9) Light 10) Sound How is energy transferred? - 1) Mechanically - force doing work 2) Electrically - work done by moving charges 3) Heating/Radiation - light, sound How can work be done? - When a current flows or by a force moving an object Kinetic energy formula - E=1/2mv² Kinetic energy(J) = 0.5 x mass(kg) x speed²(m/s) Gravitational potent...

What are eukaryotic cells? - Cells that are more complex and have a nucleus (animal and plant cells) What are prokaryotic cells? - Cells that are smaller and simpler, and don't have a nucleus but still have genetic information (bacteria) What are eukaryotes? - Organisms made of eukaryotic cells What is a prokaryote? - A prokaryotic cell (it's a single celled organism) What is cytoplasm? - A liquid gel in which most of the chemical reactions needed for life take place. It contains enzymes...