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

Eukaryotic chromosomes, The vast amount  of genomic  DNA in a eukaryotic  c...

The vast amount  of genomic  DNA in a eukaryotic  cell is strongly  packaged  in chromosomes  having  within  a specialized  organelle and  the nucleus.  This very vast amount of e

Mitral valve replacement with allograft , Mitral Valve replacement with All...

Mitral Valve replacement with Allograft (Mitral homograft) :  C. Acar and colleagues used mitral allograft for mitral valvc replacement using a new technique of fixation of p

Basic principles of planning diets for diabetes, Q. Basic principles of pla...

Q. Basic principles of planning diets for diabetes? The above objectives can be met by adhering to some of the basic principles of planning diets which include the consideratio

What is the binding between two amino acids called, What is the binding bet...

What is the binding between two amino acids called? The chemical bond among two amino acids is called a peptide bond. Protein Structure Review - Image Diversity: peptide bo

Zoonotic diseases, Zoonotic Diseases The term zoonosis (zoonoses, plura...

Zoonotic Diseases The term zoonosis (zoonoses, plural) was coined by Rudolf Virchow to describe the disease transmitted from animal to man and vice versa. Zoonoses have been de

Explain the infraorbital nerve and vessels, Infraorbital nerve and vessels ...

Infraorbital nerve and vessels The infraorbital nerve exits through the infraorbital foramen. This foramen and the neurovascular contents are within 5 to10mm of extremely resor

Explain development of excretory system, Explain Development of excretory s...

Explain Development of excretory system? The filtration rate of kidney is low and infants find it difficult to eliminate high concentration of solutes. However, by the end of t

Define reagents required for osazone test, Define Reagents Required for Osa...

Define Reagents Required for Osazone Test? - Solutions of glucose, galactose,fructose, lactose, maltose, sucrose. - Phenyl hydrazine mixture (2 parts of Phenylhydrazine hydr

Show overall management of diabetes, Q. Show overall management of diabetes...

Q. Show overall management of diabetes? Diabetes as we all know is a disease with ever increasing prevalence in' our country. It can be described as a disease characterized by

Define the miscellaneous applications of sugar, Define the Miscellaneous Ap...

Define the Miscellaneous Applications of Sugar? Sugars are used in 1. Custards, 2. puddings, 3. pie fillings and meringues Depending on the sugar to perform vital c

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