Bachelor’s Degree Programme (BSCG) – Plant Anatomy and Embryology Assig. Answer | BBYCT – 135 (Q-9)
9. Differentiate between:
a) storied and non-storied cambium
b) amoeboid and glandular tapetum
c) self and cross pollination
d) psychophily and hymenophily
e) open and closed style
a) Storied or Stratified Cambium: In TLS the initials are arranged in horizontal regular file having a stratified structure. The initials are usually short and all of about the same length. The ends of the initials occur approximately at the same level.
Non-Storied or Non-Stratified Cambium : In longitudinal tangential view the tapered end of fusiform initials overlap each other in a random arrangement. For example – Rhus. Non-storied Cambium is more common and longer than the storied type.
b) Secretory or glandular tapetum: These cells secrete sporopollenin, pollenkitt and compatibility proteins. These cells provide Ubisch bodies which help in the ornamentation of exine as they have a chemical called sporopollenin which is deposited on them.
Amoeboid tapetum: Cells undergo breakdown and their entire protoplast move towards centre to nourish microspores.
c) Self-pollination – Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant.
Cross-pollination – Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower on a different individual of the same species.
d) psychophily – Butterfly-pollinated(psychophily) flowers tend to be large and showy, pink or lavender in colour, frequently have a landing area, and are usually scented. Since butterflies do not digest pollen (with one exception), more nectar is offered than pollen.
hdrophily – Water-pollinated(hdrophily) plants are aquatic and pollen is released into the water. Water currents therefore act as a pollen vector in a similar way to wind currents. Their flowers tend to be small and inconspicuous with many pollen grains and large, feathery stigmas to catch the pollen.