In this article we will discuss about the structure of pistil, explained with the help of suitable diagram. The pistil is the female part of the flower, which is divisible into stigma, style, and ovary. It is adapted to receive the pollen, aid its germination, and subsequently entry of the pollen tube into the ovary, ovule and finally into the [...]
Morphological characteristics of pollen grains have been categorised into different groups: 1. Pollen Units 2. Polarity 3. Symmetry 4. Shape 5. Size 6. Apertures 7. Sub-Divisions of the Pollen Surface 8. Sporoderm Stratification 9. Exine Ornamentation 10. 'LO' Analysis. Characteristic # 1. Pollen Units: The pollen grains are produced within the anther of the flower. Pollen mother cells originate from [...]
The following points highlight the four main methods of air sampling. The methods are: 1. Gravity Sedimentation Methods 2. Inertial Methods 3. Filtration 4. Precipitation. 1. Gravity Sedimentation Methods: a. Sedimentation from still air: Alvarez and Castro (1952) constructed a simple box for the study of airborne fungi, has two hinged slides and a covered tray at the bottom for [...]