Biology Definitions

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Magnification - is the degree to which the size of the image is larger than the object itself. Numerically, it is the size of an image size divided by the actual size of the object measured using the same units. It is usually expressed as for example x10.

Resolution - Is the degree to which it is possible to distinguish between two objects that are very close together. The higher the resolution the greater detail you can see. Micrometre - A micrometre is equal to one millionth (10-6) of a metre. It is the standard unit for measuring cell dimensions. Nanometre – Is one thousandth (10-3) of a micrometre. It is therefore one thousand millionth (10-9) of a metre. It is a useful unit for measuring the sizes of organelles within cells and for measuring the sizes of large molecules. Staining – staining in microscopy refers to any process that helps to reveal or distinguish different features. In light microscopy, stains may be colours or fluorescent dyes. In electron microscopy, they are metal particles or metal salts. Cytoskeleton – refers to the network of protein fibres found within cells that gives structure and shape to the cell, and also moves organelles inside cells. Organelle – refers to a particular structure of a cell that has a specialised function. Some organelles are membrane-bound, others are not. All preform a particular role in the life processes of the cell. Phospholipid bilayer – is the basic structural component of plasma membranes. It consists of two layers of phospholipid molecules. Proteins are embedded in this layer. Fluid mosaic – refers to the model of cell membrane structure. The lipid molecules give fluidity and proteins in the membrane give it a mosaic appearance. The molecules can move about. Cell signalling – is when cells communicate with one another by signals. Many molecules act as a signals – some signal during processes taking place inside cells; others signal from one cell to others. Cytokines are an example of cell signals. Diffusion – is the movement of molecules from a region of high concentration of that molecule to region of lower concentration of that molecule down a concentration gradient. Active transport – refers to the movement of molecules or ions across membranes, which uses ATP to drive protein ‘pumps’ within the membrane. Solute – a substance that dissolves in a liquid.

Solvent – a liquid that dissolves substances.
Solution – a liquid containing dissolved substances.
Cell cycle – describes the events that take place as one parent cell divides to produce two new daughter cells which then each grow to full size. For some organisms, the cell cycle is the life cycle, and each daughter is a new single-celled organism.

Magnification - is the degree to which the size of the image is larger than the object itself. Numerically, it is the size of an image size divided by the actual size of the object measured using the same units. It is usually expressed as for example x10.

Resolution - Is the degree to which it is possible to distinguish between two objects that are very close together. The higher the resolution the greater detail you can see. Micrometre - A micrometre is equal to one millionth (10-6) of a metre. It is the standard unit for measuring cell dimensions. Nanometre – Is one thousandth (10-3) of a micrometre. It is therefore one thousand millionth (10-9) of a metre. It is a useful unit for measuring the sizes of organelles within cells and for measuring the sizes of large molecules. Staining – staining in microscopy refers to any process that helps to reveal or distinguish different features. In light microscopy, stains may be colours or fluorescent dyes. In electron microscopy, they are metal particles or metal salts. Cytoskeleton – refers to the network of protein fibres found within cells that gives structure and shape to the cell, and also moves organelles inside cells. Organelle – refers to a particular structure of a cell that has a specialised...
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