Biology 1

• root hairs cells have cell walls
• cell walls define the shape of the cell and strengthens the cell
• Meristem contain undifferentiated cells
• Meristem cells can divide by mitosis
• Root hair cells are considered specialised become tehy have a specific function and they have undergone differentiation
• 3 ways in which communicable diseases are transmitted are through the air, dirty water and contaminated surfaces.
• An antibody destroys pathogens and is made by the immune system
• fungal infections are spread through spores spread by wind and enters the leave through the stomata
• Monoclonal antibodies can be used in diagnosis
• Monoclonal antibodies can be used to measure the levels of hormone in the blood.
• Vaccines contain dead or weakened microorganisms
• A vaccine contains an antigen that stimulates the production of antibodies without causing disease
• Mice are injected with an antigen to stimulate the production of lymphocytes that make specific antibodies. Tumour cells are then cultured as they can divide and grow endlessly. The lymphocytes are fused with the tumour cells to create hybridoma cells. A single hybridoma cell can divide to make a large number of identical cells called clones. All cloned cells can now make the antibody. After the monoclonal antibodies are produced they are collected and purified.
• An advantage of monoclonal antibodies is that they are specific to what we are looking for.
• Monoclonal antibodies detect pathogens in the blood.
• Monoclonal bodies can treat diseases.
• The antibody delivers the substance specifically to cancer cells without harming other cells in the body.
• Monoclonal antibody trials have very harmful side effects.
• If pregnant the woman produces the hormone HCG
• Memory cells destroy the pathogen before it can cause illness.
• Bacteria reproduce using asexual reproduction.
• Asexual reproduction is fast and only involves one parent.
• Mitosis takes place during asexual reproduction.
• Mitosis produces 2 genetically identical cells while meiosis produces 4 genetically different cells.
• The thick layers of muscle in arteries allow them to withstand high pressures.
• The elastic fibres in artery walls allow them to stretch and recoil as the blood is pumped.
• Lungs have a good blood supply to maintain a steep concentration gradient.
• Lungs have a large surface area to volume ratio.
• Rate of transpiration can be measured using a potometer.
• As humidity increases, the rate of transpiration decreases.
• The liver produces bile
• Urea is produced in the breaking down of amino acids.
• Palisade mesophyll is the site of photosynthesis
• When there is a lot of water in a leaf, the guard cella become turgid and they open to allow more CO2 in
• Guard cells close at night as there is no light energy for photosynthesis
• Lower level of the leaf is more shaded and cooler so less water evaporates
• Meristem cells are stem cells found in the roots and shoots of a plant
• Bacteria cells produce rapidly when it is warm and moist
• To prevent new strains of antibiotic resistant bacteria doctors should only prescribe antibiotics when necessary and patients should complete their full course of antibiotics.
• The first stage of drug testing is pre-clinical trials