Biology- cell division, differentiation, and organisation 4.0 / 5 based on 1 rating ? BiologyCells, tissues and organsChapter 2IGCSEAQA Created by: Splash HeslinCreated on: 18-12-14 12:06 Mitosis Asexual cell division where two identical cells are formed. 1 of 26 Meiosis The 2- stage process of cell division which reduces the chromosome number of the daughter cells. It forms 4 gametes. 2 of 26 Chromosome A thread of DNA made up of strings of genes. 3 of 26 Allele An alternative form of the same gene. 4 of 26 Haploid nucleus A nucleus containing a single set of unpaired chromosomes (sperm and egg) 5 of 26 Diploid nucleus A nucleus containing 2 sets of chromosomes ( a body cell) 6 of 26 Differentition A cell that is specialized for a particular function. 7 of 26 Stem cells An undifferentiated cell that can turn into any type cell. 8 of 26 Problems with stem cell research (embryonic) Ethical issues (human rights, killing a child), progress is slow/ expensive, could cause cancer. 9 of 26 Benign tumours A tumor only affecting one area, but can still be life threatening. 10 of 26 Malignant tumors (cancer) Tumors that spread (travels through the bloodstream) 11 of 26 Causes of cancer Carcinogens, ionising radiation, virus infections. 12 of 26 Tissue A group of cells with similar structure and function working together. 13 of 26 Organ A group of tissues working together to carry out a specific function. 14 of 26 Organ system A group of organs working together to carry out a specific function. 15 of 26 Plant organs Leaf, stem, root, flower. 16 of 26 Organisation Cell, tissue, organ, organ system, organism. 17 of 26 What does digestion do? It breaks down food's molecules so the body can absorb the now soluble food molecuels. 18 of 26 Digestion glands Pancreas, salivary gland (in stomach producing digestive enzymes), liver producing bile. 19 of 26 Xylem Transports water (plants) 20 of 26 Phloem Transports sucrose (plants) 21 of 26 Stem Provides support in plants. 22 of 26 Root Anchors plants and obtains water and minerals. 23 of 26 Palisade mesophyll Upper layer of mesophyll in plant leaves that contains many chloroplasts for photosynthesis. 24 of 26 Spongy mesophyll Lower layer of mesophyll tissue in leaves that contains some chloroplasts and air spaces to give a large surface area for diffusion of gasses. 25 of 26 Stoma Openings in leaves of plants which allow gasses to enter/ exit leaf. They are opened/closed by guard cells. 26 of 26
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