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

Explain galactose metabolism, Galactose Metabolism Galactose  goes to t...

Galactose Metabolism Galactose  goes to the liver via portal blood and is phosphorylated by galactokinase togalactose-  1  -phosphate (GIP) using ATP as  a phosphate donor as s

The dna revolution, Unprecedental clarity has come to our understanding of ...

Unprecedental clarity has come to our understanding of genetic differences by the analysis of DNA sequences. It is not surprising in which the latest DNA technologies are leading t

Explain the indirect methods of microbial estimation, Explain the Indirect ...

Explain the Indirect Methods of Microbial Estimation? Indirect methods, i.e., methods other than those counting the microbial cells can also be used for quantitation purpose. T

Clinical trials for changing nutrient requirements with age, Define Clinica...

Define Clinical Trials for Changing nutrient requirements with age? Several clinical trials provide evidence of changing nutrient requirements with age. The metabolic demand fo

Bioprosthetic valves, Bioprosthetic Valves :  The risk of thromoboembolism...

Bioprosthetic Valves :  The risk of thromoboembolism is limited to the first three months, until the sewing ring gets endothelialised. The recommendation is to have less intense r

Hypothesis - nursing research, Hypothesis: The  spelling of hypothesis...

Hypothesis: The  spelling of hypothesis when written  as  "hypotheses"  indicate plural. The hypothesis is a statement or declaration of  the expected outcome of a research st

Carrier based gutta percha removal -therma-fill, Carrier Based Gutta percha...

Carrier Based Gutta percha Removal “therma-fill” If the cone the carrier is metal and has cutting flutes that are engaging lateral dentin the instrument retrieval system (IRS)

What is an accommodation, What is an accommodation? Accommodation is th...

What is an accommodation? Accommodation is the ability of the eye to focus on an object situated at variable distances from the eye. Like a camera, even the eye requires to cha

What are the final digestion products of protein, What are the final diges...

What are the final digestion products of (a) protein, (b) fat, (c) starch?   a) Proteins are digested to amino acids, b) fats are digested to fatty acids and glycerol,

Explain isozymes, ISOZYMES Sometimes an  enzyme present  in  the  same ...

ISOZYMES Sometimes an  enzyme present  in  the  same  organism is  found  to  have different molecular forms but  catalyzing the  same  reaction. These are called  isozymes. Th

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