Search results
Results from the WOW.Com Content Network
Pollen itself is not the male gamete. [4] It is a gametophyte, something that could be considered an entire organism, which then produces the male gamete.Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell.
Bees in four tribes of the family Apidae, subfamily Apinae have corbiculae: the honey bees, bumblebees, stingless bees, and orchid bees. [14] [15] The corbicula is a polished cavity surrounded by a fringe of hairs, into which the bee collects the pollen; most other bees possess a structure called the scopa, which is similar in function, but is a dense mass of branched hairs into which pollen ...
Development of pollen sacs begins with the differentiation of archesporial cells in the hypodermal region below epidermis at four corners of the young anther. The archesporial cells divide by periclinal division to give a subepidermal primary parietal layer and a primary sporogenous layer. The cells of the primary parietal layer divide by ...
Pollen sac may refer to: Structures in plants that hold pollen; Bee pollen, sacs or balls of pollen packed by bees This page was last edited on 29 ...
Diagram of an anther in cross section. 1: Filament; 2: Theca; 3: Connective (the conducting vessels in red); 4: Pollen sac (also called sporangium) The androecium is one of the fertile cycles of flowers. The parts that make up the androecium are called stamens whose function is the generation of male gametophytes or pollen grains.
The parts of a flower Double fertilization. Double fertilization or double fertilisation (see spelling differences) is a complex fertilization mechanism of angiosperms.This process involves the fusion of a female gametophyte or megagametophyte, also called the embryonic sac, with two male gametes (sperm).
Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms.
Each of the microsporocytes in the microsporangia undergoes meiosis, producing four haploid microspores. These develop into pollen grains, each consisting of four cells and, in conifers, a pair of external air sacs. The air sacs give the pollen grains added buoyancy that helps with wind dispersal. [3] Types of Gymnosperms: Conifers. Pines ...