In this article we will discuss about the transverse sections of petiole of some flowers:- 1. Cucurbita 2. Sunflower 3. Piper Betle 4. Waterlily. 1. Cucurbita: A transverse section through the petiole of Cucurbita shows the following anatomical features (Fig. 5.124): It is wavy in outline having distinct ridges and furrows and a large cavity at the centre. (i) Epidermis: [...]
Polarity is defined as the condition of having distinct poles in a pollen grain. Jackson in 1928 assumed that a pollen grain points to the poles like Silphium. Silphium laciniatum, also known as compass plant, has leaves that 'turn their edges north and south and avoid the mid-day radiation' —Willis. Pollen mother cell after meiosis forms four pollen grains that [...]
The following points highlight the four common types of spore found in embryophytes. The types are: 1. Isospore (n., pl. -s, syn. Homospore) 2. Heterospore (n., pl. -s; hetero- a Greek Prefix Meaning 'different', 'not normal') 3. Meiospore (n., pl. -s) 4. Miospore (n., pl. -s; in Greek Meion means 'less', 'smaller'). Type # 1. Isospore (n., pl. -s, syn. [...]