AQA GCSE Biology

Tough supporting wall of the eye - Sclera Transparent outer layer found at the front of the eye. Refracts (bends) light into the eye - Cornea Contains muscles that allow it to control the diameter of the Pupil (hole in the middle) and therefore how much light enters the eye - Iris Focuses light ...

What are the structures of an animal cell? - Nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. What are the structures of a plant cell? - All structures from animal cells and cell wall, permanent vacuole and chloroplasts. What does the nucleus do? - Stores DNA and directs all cellul...

What are the structures of an animal cell? - Nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. What are the structures of a plant cell? - All structures from animal cells and cell wall, permanent vacuole and chloroplasts. What does the nucleus do? - Stores DNA and directs all cellul...

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 c...

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...

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 ce...

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 ce...

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 an...

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 membra...

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 fo...

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 D...

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 s...

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 ...