Word Definition Topic active transport the process by which dissolved molecules (solutes) move across a cell membrane from a lower to a higher concentration Life processes and cells Aerobic respiration respiration that requires oxygen Life processes and cells Anaerobic respiration respiration that occurs in the absence of oxygen Life processes and cells antibodies proteins produced by the body's immune system that attack foreign invaders (antigens) Life processes and cells bacteria single-celled micro-organisms, some of which are pathogenic in humans, animals and plants. Singular is bacterium Life processes and cells bivalent Having two chromosomes - one from the male gamete and one from the female gamete. Life processes and cells cell Basic unit of life. Unicellular organisms only have one cell. Multicellular organisms have many cells. Life processes and cells chloroplasts microscopic structures containing chlorophyl found in green plant cells where photosynthesis takes place Life processes and cells chloroplasts tiny bodies found in plant cells which are green because they contain chlorophyll Life processes and cells chromatid One of two daughter strands of a replicated chromosome Life processes and cells chromatids Two daughter strands of a replicated chromosome Life processes and cells concentration gradient a difference in concentration between two adjacent areas. Particles will move down the concentration gradient from an area of high concentration to an area of low concentration. Life processes and cells cytoplasm the living substance inside a cell (not including the nucleus) Life processes and cells dendrites branch-like extensions of a neurone or nerve cell which receive impulses from other neurones Life processes and cells diffusion The movement of particles (molecules or ions) from an area of higher concentration to an area of lower concentration Life processes and cells epidermis the outer protective layer of the skin Life processes and cells genes basic units of genetic material that are inherited from our parents. Life processes and cells haemoglobin the red protein found in red blood cells that transports oxygen round the body Life processes and cells ileum the longest part of the small intestine, where food is completely digested. Life processes and cells invaginates during cell division, the squeezing-in of the cell membrane at the equator to separate daughter nuclei Life processes and cells invagination a stage in cell division, in which the cell membrane pushes in at the equator to separate the two daughter nuclei Life processes and cells kinetic energy energy produced through motion Life processes and cells membrane a very thin layer of tissue Life processes and cells microscopic extremely small; something which can only be seen through a microscope Life processes and cells mitochondria structures in the cytoplasm of all cells where respiration takes place. Singular is mitochondrion Life processes and cells mitosis A type of cell division which produces daughter cells identical to the parent. Life processes and cells molecules a collection of two or more atoms held together by chemical bonds. The fundamental unit of compounds Life processes and cells multicellular having more than one cell Life processes and cells nucleus the center of a cell where genetic information is usually stored. Life processes and cells offspring A new human, animal or plant that is created as a result of reproduction. Life processes and cells organ Group of tissues doing a particular job between them, eg the heart. Life processes and cells organ system Group of organs doing a particular job between them, eg the circulatory system. Life processes and cells organelle Microscopic structure which does a particular job in a cell, eg the nucleus Life processes and cells organism a living being - plant, animal, fungus or bacterium. Life processes and cells osmosis the movement of water molecules across a semi permeable membrane down a concentration gradient Life processes and cells partially permeable allowing some particles to pass through but not others Life processes and cells photosynthesis the chemical change that occurs in the leaves of green plants that uses light energy to convert carbon dioxide and water into glucose. Oxygen is produced as a by product of photosynthesis. Life processes and cells recombinant DNA which has been exchanged between chromosomes during meiosis - part paternal genetic material, part maternal. Life processes and cells replication Production of an identical copy. Life processes and cells spindle fibres Fibres produced during cell division. They contract to drag chromatids to the poles of the cell. Life processes and cells tissue Group of cells of the same type doing a particular job, eg the blood (a liquid tissue) Life processes and cells unicellular having only one cell Life processes and cells vacuoles a space within the cytoplasm of plant cells that contains cell sap Life processes and cells valves structures containing a flap or flaps to ensure one-way flow of liquid Life processes and cells villi minute hair-like projections which cover the lining of the small intestine. They aid digestion by greatly enlarging the gut's surface area Life processes and cells