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

Sarcolemma, Normal 0 false false false EN-IN X-NONE ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Describe binding of two amino acid for peptide formation, How can the bindi...

How can the binding of two amino acids for the peptide formation be described? A peptide is formed when a carbon from the carboxyl group of one amino acid is linked to the nitr

Bluetongue, B l u e t on g u e Bluetongue (BT) is a non-contagi...

B l u e t on g u e Bluetongue (BT) is a non-contagious and arboviral disease of both domestic and wild ruminants. The disease is enzootic in areas where reservoirs (cat

Endomyocardial biopsy, Endomyocardial biopsy helps in understanding that ca...

Endomyocardial biopsy helps in understanding that carditis can cause CCF in patients with rheumatic heart disease but frequency of diagnostic features on EMB is found only in 17 pe

How is the ovulation date estimated, How is the ovulation date estimated wi...

How is the ovulation date estimated with the control of the woman's body temperature? One method to estimate the exact ovulation day is daily control of the body temperature ta

Planes of cleavage, Planes of Cleavage The ova of most of the animal ...

Planes of Cleavage The ova of most of the animal groups (except some specific cases like insects) are spherical or nearly spherical having their own actual centre comparable

Explain centrifuge - microbiological apparatus and equipment, Explain the C...

Explain the Centrifuge - Microbiological Apparatus and Equipments? Centrifuge is used for separating the substance in liquid or concentrating the microorganisms on the basis of

Metabolism, The main constituents of food are carbohydrates, lipids, and pr...

The main constituents of food are carbohydrates, lipids, and proteins but they are found in complex forms that cannot be directly utilized by the body. Hence, they are broken down

How plant transporting substances through tissue, How plants solve the prob...

How plants solve the problem of transporting substances throughout their tissues? In the bryophytes the substance transport is done by the diffusion. In the tracheophytes (pter

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