What is the structure of anther?
➢ A typical anther is a tetrasporangiate, bilobed structure with two microsporangia in each lobe. The two sporangia in each lobe become confluent at maturity due to the lysis of the septum. ➢ The well-differentiated anther wall comprises an epidermis, an endothecium, 1-3 middle layers and the tapetum.
What is the structure of pollen grain?
Pollen grains are microscopic structures that vary in size and shape. A mature pollen grain has a two-layered wall—the outer exine and inner intine. mitotically to produce two functional male gametes. to fold onto itself to prevent further desiccation.
How are pollen grains formed in the anther?
Pollen grains are produced by meiosis of microspore mother cells that are located along the inner edge of the anther sacs (microsporangia). The outer part of the pollen is the exine, which is composed of a complex polysaccharide, sporopollenin. The germ cell divides by mitosis to produce two sperm cells.
What is anther and pollen grain?
Difference between anther and pollen is that anther is the pollen-bearing part of the stamen in the flower. While pollen is the granular substance that is produced in the flower. This is produced in the anthers of the flowering plants.
What is anther and its types?
Standard anther attachment types are basifixed, anther attached at its base to apex of the filament; dorsifixed, anther attached dorsally and medially to the apex of the filament; and subbasifixed, anther attached near its base to the apex of the filament.
What are the two types of anther?
(1) Dithecous : These have two lobes with four microsporangia or pollen sacs. (2) Monothecous : They have only one lobe with two microsporangia or pollen sacs.
What is pollen grains short answer?
Pollen, a mass of microspores in a seed plant appearing usually as a fine dust. Each pollen grain is a minute body, of varying shape and structure, formed in the male structures of seed-bearing plants and transported by various means (wind, water, insects, etc.) to the female structures, where fertilization occurs.
What are pollen grains in easy words?
Pollen grains are microscopic structures that carry the male reproductive cell of plants. The inside of the grain contains cytoplasm along with the tube cell (which becomes the pollen tube) and the generative cell (which releases the sperm nuclei). The outer shell is made of two layers.
How many pollen grains are formed?
So each microspore forms 4 pollen grains in a single division.
What is the function of pollen grains?
Pollen grains carry male reproductive cells (gametes) in a plant and are haploid microgametophytes. Their main function is in the transferring of the male gametes to their female counterparts (ovules – female reproductive cells) in the embryo sac. It thereby facilitates sexual reproduction to occur in the plant.
What is anther flower?
Anther: The part of the stamen where pollen is produced. Pistil: The ovule producing part of a flower. The ovary often supports a long style, topped by a stigma. The mature ovary is a fruit, and the mature ovule is a seed. Stigma: The part of the pistil where pollen germinates.
How is the pollen grain formed in the anther?
The Formation of a Pollen Grain STEP 1: CHAMBER DEVELOPMENT As the anther begins to develop, four patches of tissue grow and become four chambers or “pollen sacs.” These chambers are where the pollen grains will eventually develop.
What kind of structure is the anther in a flower?
Definition of Anther. The anther is a structure found in the male reproductory part of the flower refers to as “ Stamen ” or “ Androecium ”. It has a knob-like structure, which usually consists of two lobes joined together by the connective tissue. It carry the pollen grains within the microsporangia, which further develops into a pollen sac.
How is the structure of a pollen sac formed?
The structure formed is called an embryo sac When the pollen grain lands on the stigma, fertilisation is initiated. Sucrose solution secreted by the stigma stimulates the pollen grain to germinate and form a pollen tube. The pollen tube grows down the style towards the ovule.
Where are the anther and stigma located on the pollen?
A diagram illustrating the location of the anther and stigma is shown below. Pollen grains vary in size, shape, and surface characteristics depending on the plant species (shown below).