Sterility in angiosperms, Biology

Assignment Help:

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.


Related Discussions:- Sterility in angiosperms

Determine the functions of vitamin c, Determine the Functions of Vitamin C?...

Determine the Functions of Vitamin C? The vitamin C is involved in several physiological and biochemical functions in the body. Ascorbate is the biochemically active form of t

Explain about the tray and tunnel dryers, Explain about the Tray and Tunnel...

Explain about the Tray and Tunnel Dryers? Tray and tunnel dryers are widely used in the food industry. In both cases the material being dried is supported on multiple trays, wi

Explain the food intolerance, Explain the Food Intolerance? What is foo...

Explain the Food Intolerance? What is food intolerance? How does it differ from food allergy? Food intolerance like food allergy is an adverse reaction to food. Food intoleranc

Concerning their permeability how are membranes classified, Q. Concerning t...

Q. Concerning their permeability how are membranes classified? Membranes can be classified as permeable, impermeable, selectively permeable or semipermeable. An impermeable

What is the second polar body, Q. What is the second polar body? After ...

Q. What is the second polar body? After termination of the second meiotic division of the oocyte II two cells are generated: the second polar body and the egg cell proper. The

Define the first step to envision the pattern of deformation, Define the fi...

Define the first step to envision the pattern of deformation. The first step in the analysis is to envision the pattern of deformation that would accompany such a failure. In t

What is the function of the plant cell wall, Q. What is the function of the...

Q. What is the function of the plant cell wall? The plant cell wall has protective and structural functions. It plays an significant role in the constraint of the cell size, pr

Psychological disorders, PSYCHOLOGICAL DISORDERS - 1 .       Anxiety ...

PSYCHOLOGICAL DISORDERS - 1 .       Anxiety Disorders 2 .       Obsessive compulsive disorders 3.       Attention deficit disorder 4 .       Mood disorders

Explain the term brown-sequard syndrome, Explain the term Brown-Sequard Syn...

Explain the term Brown-Sequard Syndrome Brown-Sequard syndrome is a rare spinal disorder that results from an injury to one side of the spinal cord in which the spinal cord is

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd