Sterility in angiosperms, Biology

Sterility in Angiosperms

Sterility in angiosperms may arise due to several causes. Either the anther may not be formed, or anthers are formed but meiosis may be abnormal.

A. In situations where anthers are not formed, they may take abortive forms and appear like petals or sepals. These conditions are referred to as petaloid and phyllody respectively. There are even cases where anther formation may be suppressed altogether. These cases of pollen sterility have premeiotic determination.

B. There are other examples in which anthers are produced but meiosis is abnormal resulting in the formation of non-viable pollen.

C. Sometimes normal pollen grains are formed but they are not released. This results from failure of anther dehiscence. Such a situation is also described by the term contabiscent anther.

D. Sometimes meiosis is normal but abortion can take place due to premature dissolution of callose. This can occur at any stage during microsporogenesis.

Posted Date: 1/23/2013 1:33:28 AM | Location : United States







Related Discussions:- Sterility in angiosperms, Assignment Help, Ask Question on Sterility in angiosperms, Get Answer, Expert's Help, Sterility in angiosperms Discussions

Write discussion on Sterility in angiosperms
Your posts are moderated
Related Questions
Explain about the term- Chroma Chroma is the relative purity or strength of the spectral colour and its numerical value extend from (/0) for neutral colours to (/8) for the stro

MONOSACCHARIDES Simple carbohydrate monomers, which cannot be hydrolysed further into simpler or smaller subunits. Monosaccharides are generally colourless, crystallin

Q. Differentiate between sterilization and disinfection? 1) Sterilization is defined as freeing the object or substance from all life of any kind. It is the process by which a

PHYLUM  PROTOZOA Definition  and  Introduction  All  unicellular ( or  acellular )  eukaryotic  animals. Most  primitive (Gr. Protos = first=zoon= animals ) organisms

Explain Fungi - Nutritional Types of Microorganisms? Fungi are filamentous, eukaryotic microorganisms, ubiquitous in nature. These grow best in dark and moist habitats. Their h

Which of the following serves as an actuating signal, or as part of an actuating signal, in a negative feedback system? A. Action potentials in diaphragm skeletal muscle fibers

Skeleton - Animal Kingdom You all know that the skeleton forms the framework of the body of different organisms in the animal kingdom. Besides giving shape to the animal, it a

Q. How are gametes formed in the pteridophyte life cycle, by mitosis or meiosis? What is the type of meiosis that occurs in pteridophytes? In pteridophytes gametes are made by

Types of Blood Vessel Arteries Arteries carry blood away form the heart via the pulmonary artery and aorta. Arterioles As major arteries begin to branch , th

Eucaryotic Cell Organelles A eucaryotic cell has excessive foldings of intrace!:u:;ir cembrane as compared to procaryotic cell. The eucaryotic cell has a number of'organelles s