The fundamental unit of life
18) Functions of ER :
i) It synthesizes important proteins (RER) and lipids (SER).
ii) It provides a pathway for intracellular transport of materials. iii) SER of liver cells is important for detoxification.
24) Golgi apparatus is a network of stacked, flattened, membrane bound sacs and vesicles.
25) Golgi apparatus carries out the storage, modification and packaging of substances manufactured in the cell and is also involved in lysosome formation.
26) The spherical, sac-like lysosomes contain powerful digestive enzymes and form the waste disposal system of the cell. They are also known as ‘suicide bags’.
27) Mitochondria and plastids are each covered by 2 membranes and possess their own DNA and ribosomes.
28) Mitochondria are the ‘powerhouses of the cell’, providing energy for various metabolic activities.
29) Chromoplasts and leucoplasts are the 2 types of plastids present in plant cells.
30) Chloroplasts are chromoplasts containing chlorophyll and carry out photosynthesis in plants.
31) Leucoplasts store starch, oil and protein granules.
32) The large central vacuole of mature plant cells provides turgidity to the cell and also stores important substances.
33) In unicellular organisms, vacuoles play important roles in nutrition and osmoregulation.
34) Ribososmes are sites of protein synthesis.
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