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Infection and response
Organisation
Cell biology
Biological molecules
Homeostasis and response
Responding to change (a2 only)
Energy transfers (a2 only)
The control of gene expression (a-level only)
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
Cells
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1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
Britain & the wider world: 1745 -1901
Inter-war germany
World war one
2n revolution and dictatorship: russia, 1917-1953
World war two & the holocaust
1l the quest for political stability: germany, 1871-1991
The cold war
2j america: a nation divided, c1845-1877
Medieval period: 1066 -1509
The fight for female suffrage
2m wars and welfare: britain in transition, 1906-1957
2d religious conflict and the church in england, c1529-c1570
Britain: 1509 -1745
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03/06/2023
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SCIENCE Biology - EoY Revision Photosynthesis: → Plants need water, sunlight, and carbon dioxide to carry out photosynthesis. → Mesophyll is the tissue where most photosynthesis takes place. → Xylem is the tissue which is responsible for carrying water around the plant. → The sugar made in photosynthesis can be used for energy and to make other substances like cellulose and starch. → The main factors affecting the rate of photosynthesis are light intensity, carbon dioxide concentration and temperature. → Reasons for carbon dioxide levels increasing are human activities and natural causes from animals. → Leaves are adapted to absorb sunlight by: · Large surface area. Thin - short diffusion pathway. • Closely packed palisade cells. → At night, without sunlight, photosynthesis stops and the stomata closes. With only respiration taking place, only oxygen diffuses into the leaves and carbon dioxide diffuses out. → How plants contribute to conditions for animal life: . Low levels of carbon dioxide - plants absorb carbon dioxide during photosynthesis. . Oxygen needed for respiration - plants produce oxygen during photosynthesis. Availability of food - plants can be eaten by animals. The larger surface area of the root hairs on a root hair cell allow them to absorb water. Digestion & Nutrition: → 7 nutrients needed for a balanced diet: . Vitamins · Minerals • Water . Fibres . Carbohydrates . Lipids · Protein → Chemical food tests: . Starch - iodine...
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solution, orange brown -> blue black · Sugar - benedict + heat, blue -> brick red Fat - ethanol + water, colourless -> cloudy white · Protein - biuret reagent, blue -> purple → Possible effects of a diet that does not contain enough calcium for a child are rickets (softens the bones and causes bow legs), stunted growth, and sore or weak muscles. → Hydrochloric acid in the stomach chemically breaks down the foot and the digestive enzymes split up the proteins. → Diseases linked to unbalanced energy or fat intake are obesity, diabetes, heart disease, and some cancers. → Enzymes speed up the rate of reaction without being used up. → The amylase enzymes digest starch. → Digestive system diagram: Mouth Liver Gallbladder Small intestine Anus Esophagus Stomach Pancreas Large intestine Rectum Cells: → Cell membrane - controls what enters and exits the cell. → Mitochondria - site of aerobic respiration, produces energy. → Ribosomes - makes proteins for the cell. → Nucleus contains DNA, controls activities of the cell. → DNA found in the nucleus, codes for different characteristics. → Digestive system - breaks down food into nutrients. → Substances such as oxygen, carbon dioxide, and glucose pass into animal cells. → Bacterial cells do not have a nucleus. → Cells with a cell wall - plant, bacteria. ➜ Proc by whic active transport. → The magnification you should start with on a microscope is 4x. → Image size = Actual size x Magnification (I-AM). substances move in and out of cells - diffusion, osmosis, → How to use a microscope to view cells: · Place glass slide onto the stage . Turn the coarse focus knob until you can clearly view cells . Turn the fine focus knob until cells are in focus → Root hair cell diagram: Root hair Cell membrane Cell wall Vacuole Cytoplasm tail (flagellum) Adaptations: •Adapted to take up water and minerals by having a large surface area to increase rate of absorption · Contains lots of mitochondria which release energy during respiration for active transport →Sperm cell diagram: cytoplasm Nucleus cell membrane nucleus mitochondria Adaptations: . A tail to propel them to towards the egg Many mitochondria to produce energy · Nucleus contains fathers DNA for fertilisation →Plant cell diagram: Cytoplasm Nucleus Cell membrane- Cellulose cell wall- Mitochondrion Permanent vacuole Chloroplast- Adaptations: · Cell membrane allows carbon dioxide in and oxygen out for photosynthesis . Chloroplasts produce energy through photosynthesis for the plant → Epithelial cell diagram: Cell Membrane Cell Interior Gap Junctions Nucleus 550 Adaptations: . Epithelial cells that cover each villi increase surface area over which digested food is absorbed