Biology

• nucleus 


  controls the cells activities and contains genetic material
• cell membrane


  controls the movement of substances into and out of the cell
• cytoplasm 


  jelly-like substance where chemical reactions take place
• mitochondria 


  the site of respiration
• ribosome


  site of protein-synthesis (proteins are made)
• cell wall


  strengths the cell, made of cellulose
• chloroplast 


  sit of photosynthesis (contains chlorophyll, a green pigment which absorbs light)
• vacuole


  Filled with cell sap to help keep the cell turgid (stiff) to provide support
• Mitosis- cell division

  1. cell grows, number of sub-cellular structures (e.g. ribosomes and mitochondria) increases and DNA replicates to form two copies of each chromosome. 2- Nucleus divides and one set of chromosomes is pulled to each end of the cell. 3. cytoplasm and cell membranes divide to form two identical cells
• transport across membranes: - Diffusion 


  The net movement of particles from an area of higher concentration to an area of lower concentration. Occurs in solutions and gases. USES: MOVEMENT OF OXYGEN AND CARBON DIOXIDE IN GAS EXCHANGE (LUNGS-ALVEOL; LEAVES-SPONGY MESOPHYLL AND STOMATA) AND OF THE WASTE PRODUCT UREA FROM CELLS INTO THE BLOOD PLASMA FOR EXCRETION IN THE KIDNEY
• Transport across membranes: Osmosis


  The diffusion of water from a dilute to a concentrated solution, across a partially permeable membrane. USES: MOVEMENT OF WATER ACROSS CELL MEMBRANES INTO AND OUT OF THE CELLS.
• Transport across membranes: -Active Transport 


  The movement of particles from a low concentration to a high concentration, using energy from respiration. USES: ABSORPTION OF MINERAL IONS INTO PLANT ROOT HAIRS FROM VERY DILUTE SOLUTIONS IN THE SOIL. ABSORPTION OF SUGAR MOLECULES FROM LOWER CONCENTRATIONS IN THE GUT INTO THE BLOOD WHICH HAS A HIGHER SUGAR CONCENTRATION.
• levels of organisation: CELL


  The smallest unit for building all organisms e.g. muscle cell
• levels of organisation: TISSUE

  A group of cells with a similar structure and function, which work together to do a particular job e.g. muscle tissue
• level of organisation: ORGAN


  A group of different tissues, which all work together to do a particular job e.g. heart
• level of organisation: ORGAN SYSTEM


  A group of different organs, which all work together to do a particular job e.g. circulatory system
• level of organisation: ORGANISM


  A living thing (capable of the 7 life processes)
• Organisation in plants: WAXY CUTICLE


  physical barrier to infection that prevents water loss
• Organisation in plants: EPIDERMIS


  Type of plant tissue that covers the surface of a plant allowing light through
• Organisation in plants: PALISADE MESOPHYLL


  Tightly packed cells in leaf where photosynthesis takes place. Contains many chloroplasts
• Organisation in plants: SPONGY MESOPHYLL


  Tissue in the leaf with air spaces between cells- specialised for gas exchange
• Organisations in plants: STOMATA 


  Opening the allows Co2 water vapour and Oxygen to diffuse in and out of the leaf
• Organisation in plants: GUARD CELLS 


  Cells that open and close stomata to allow gas exchange to enter the leaf for photosynthesis
• Transport in plants: TRANSPORTATION 


  The loss of water vapour from the leaves by evaporation from cells and then out through the stomata
• Transport in plants: TRANSLOCATION


  The movement of dissolved sugar around the plant
• Factors affecting transpiration: TEMPERATURE

  Increasing temperature increases the rate as water evaporates quickly
• Factors affecting transpiration: HUMIDITY

  Increasing humidity decreases the rate as water evaporates slowly
• Factors affecting transpiration: WIND SPEED

  Increasing wind speed increases the rate as water evaporates quickly
• Factors affecting transpiration: LIGHT


  Increasing light increases the rate as stomata open
• key terms: COMMUNICABLE


  A disease spread from person to person caused by a pathogen
• key terms: PATHOGEN


  Micro-organism that causes disease. The four types of pathogen are bacteria,virus,fungus and protist.
• key terms: BACTERIA


  Causes disease by reproducing rapidly inside the body and releasing toxins which damage tissues and makes us feel ill
• key terms: VIRUS


  Causes disease by living and reproducing inside cells, causing cell damage
• key terms: VECTOR


  An organism which carries something e.g. a disease but didn’t affected by it such as a mosquito
• Measles


  VIRUS. SYMPTOMS: fever,red skin rash. TRANSMISSION: inhalation of infected droplets from sneezes and coughs. METHODS OF REDUCING TRANSMISSION: vaccination
• HIV


  VIRUS. SYMPTOMS: Flu-like symptoms. Develops into AIDs over time which damages the body’s immune system. TRANSMISSION: sexual contact,exchange of bodily fluids, sharing needles. METHODS OF REDUCING TRANSMISSION: condoms, don’t share needles
• TMV


  VIRUS. SYMPTOMS: Distinctive mosaic pattern of discolouration on leaves, affects growth of plant by reducing photosynthesis. TRANSMISSION: Spread through the use of infected tools on healthy plants (direct contact). METHOD OF REDUCING TRANSMISSION: Removing infected areas of the plant, sterilising gardening tools
• Gonorrhoea


  Bacteria. SYMPTOMS thick yellow or green discharge from the penis or vagina , pain when urinating. TRANSMISSION: Sexual contact. METHOD OF REDUCING TRANSMISSION : Treatment with antibiotics, use of barrier method of contraception e.g. condom
• Rose black spot 


  Fungus. SYMPTOMS: Purple or black spots on leaves. Effects growth of plant due to reduction of photosynthesis. TRANSMISSION: Air,water or direct contact. METHOD OF REDUCING TRANSMISSION: use of fungicides and/ or removing and destroying the affected leaves
• Malaria


  Protist.SYMPTOMS: Recurrent episodes of fever. TRANSMISSION: Mosquito (vector). METHOD OF REDUCING: Preventing mosquitoes breeding: mosquito nets and insect repellent