Day: June 16, 2019

Plastids - Introduction: Plastids are membrane bound organelle found in all plant cells and some protists (euglina). Dr Ernst Haeckel discovered plastid. Plastid Classification: Plastids are classified into two types, they are: 1. Leucoplast 2. Chromoplast Plastid Classification Leucoplasts: These are colourless plastids (non pigmented). Leucoplasts do not have grana. Leucoplasts are found in Roots, Rhizomes, Tubers, etc. ,parts of the plants which are not exposed to sunlight. Main function of Leucoplasts are storage of food. Based on their function Leucoplasts are further classified into 3 Types: a. Amyloplasts - Stores carbohydrates. Location: Potato Tuber, Wheat, Rice, etc b. Allueronplasts - They are also known as proteoplasts. They stores aluerone protein. Location: Maize, Pulses. c. Elaioplasts - Stores Fat. These can be found in castor seed, ground nut, etc. Chromoplasts: These are coloured plastids (Colored due to presence of Pigments). Chromoplasts have grana / Thylakoid Chromoplasts are found in Leaf, Petals, Fruits, etc. , parts of the plants exposed to sunlight. Main function of chromoplasts are photosynthesis, attraction of pollinating agents. Chromoplasts are further classified based on the type of pigment present: a. Chloroplasts - Green Pigmented plastid, found in Green leaves, green stem,etc b. Pheoplast - contains Xantophyll & Fucoxanthin. These are found in brown algae. - c. Rhodoplast - contains red pigment called to phycoerythrin. these are found in red algae. Some of the other pigments present in plants are: 1. Lycopin - Red pigment found in Tomato. 2. Capsanthin - Red pigment found in Red Pepper. 3. Carotenes - Orange / Red pigment found in carrots. Leucoplasts and Chromoplasts are interchangable, means that when lecuoplasts attains pigments it becomes chromoplasts and when the chromoplasts lose pigments it can become leucoplasts. Got something to say about this post? Leave a comment...your comments are valuable for improving the posts.