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PinkMonkey Online Study Guide-Biology

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Figure 15.10

Male cone (Fig. 15.10): The male cone (i.e. male strobilus) is compact, large (up to 50 cms long) and oval. It is produced singly at the apex of the male plant. Further growth of the stem is sympodial and takes place by the activity of a lateral bud.


The male cone consists of a thick central axis on which numerous microsporophylls are arranged in compact spirals. Each microsporophyll is small and flat. It is differentiated into a lower narrow fertile region and a terminal broad, sterile apophysis with a pointed apex. The lower surface (abaxial surface) of the fertile region bears numerous small microsporangia (pollen sacs). They are organized into groups or sori. Each group has 3-6 microsporangia. Each microsporangium contains many diploid microspore mother cells (pollen mother cells). They divide by meiosis and produce haploid microspores (pollen grains). These are liberated from the cone and carried by wind during pollination (wind pollination).

 

Table of Contents

15.0 - Introduction
15.1 Pteridophyta : General Account
15.2 Gymnosperms
15.3 Angiosperms : Dicotyledons
15.4 Angiosperms : Monocotyledons
15.5 Vascularization
15.6 Development of seed habit
15.7 Development of Flower and Fruit

Chapter 16





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