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1. By
asghar khan lecturer in Botany
Govt: Degree College Totakan

2.  are membrane bounded, mostly pigment containing
bodies present in plants cells only
 They are not found in fungal or animal cells
 Plastids are classified into three types
 i) Chloroplast
 ii) Chromoplasts
 iii ) Leucoplasts

4.  Large ,green, round or oval cytoplasmic organelle
 Contain green pigments called chlorophyll
 Chlorophyll is a complex organic compound
containing central Mg atom resembles
hemoglobin
 Present in all photosynthetic eukaryotes
 Most obvious in leaf cells
 Vary in size from 4 um to 6um in diameter
 Number may be from one to one hundred per cell

5.  A chloroplast consist of three components
 i ) an outer most covering (envelop)
 ii ) Grana
 iii) Stroma
 Outermost covering is formed of double membrane
structure encloses the grana and stroma

6.  Grana (singular granum meaning seed)
 Consists of many flattened fluid filled sacs called thylakoids
 Many thylakoides grouped together forming a stacks or pile
of coins called Granum
 The grana are interconnected by layer called inter grana
 Photosynthetic pigments are present within the membranes of
the thylakoides
 Light reaction of photosynthesis are taking place within the
membranes of thlakoids of granum.

7.  Stroma
 Stroma is a large central space within the chloroplast
surrounded by double membrane envelope
 Home to grana,site of dark reaction of photosynthesis
 Covers most of the volume of chloroplast
 Contain enzymes, some ribosome's and small Circular
DNA in gel like solution called matrix
 Fix Carbon dioxide to manufacture sugar

9.  CHROMOPLAST
 They Lack chlorophyll and are other than green
 may be red, orange or yellow in colour
 Mostly present in ripened fruits, petals of flowers and
autumn leaves
 They help in pollination and seed dispersal
 LEUCOPLAST
 These are colorless plastids, triangular or tubular in
shape
 Present in underground food storage parts such as potato
tubers, radish root.
 Concerned with storage of food

10.  Chloroplast absorbs light energy and store it in chemical form
(ATP),all living organism use this chemical energy for their
functions
 Chloroplasts are involved in phtosynthesis,besides synthesis of
food material oxygen is formed as a by product
 Chromoplast present in petals & ripened fruits are involved in
dispersal of seeds & also attract insects for pollination
 Leucoplast are concerned with the storage of food in
underground parts