In this article we will discuss about the evolutionary trends among pollen grains based on palynotaxonomical works. Primarily the aperture is proximal in position in all the taxa of plants, and a change from proximal to distal has been conditioned by physiological and ecological needs that arose in the wake of the origin of new plant taxa. The bryophytes and [...]
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 [...]
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 [...]