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

What is exudative diarrhoea, Q. What is Exudative diarrhoea? Exudative ...

Q. What is Exudative diarrhoea? Exudative diarrhoea: It is associated with the mucosal damage leading to out pouring of mucus, blood and plasma proteins with a net accumulation

Define the term - peroxisomes and glyoxisomes, Peroxisomes and Glyoxisomes ...

Peroxisomes and Glyoxisomes A number of metabolic reactions, such as, the oxidation of amino acids and lipids result in the production of hydrogen peroxide. As hydrogen peroxid

Explain the function of muscular tissue, How can the presence, localization...

How can the presence, localization and function of muscular tissue in beings of the phylum Annelida be explained? In these beings there are a longitudinal muscular layer under

Explain control of oedema in nutritional care, Explain Control of Oedema in...

Explain Control of Oedema in Nutritional Care? Low levels of circulating proteins lead to oedema due to loss of colloidal osmotic pressure to maintain the normal fluid shift me

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

Differences between axon and dendrite, DIFFERENCE S BETWEEN AXON AND DENDR...

DIFFERENCE S BETWEEN AXON AND DENDRITE (DENDRON)     AXON   DENDRIT E (DENDRON) 1. It is single per neur

Explain the universality of the genetic code, How does the universality of ...

How does the universality of the genetic code make the recombinant DNA technology possible? The universality of the genetic code refers to the fact that all living beings have

How to create organisms with traits, Do a bit of research on gene splicing,...

Do a bit of research on gene splicing, a DNA technology that bioengineers can use to create organisms with traits that never before seen in nature (herbicide-resistant crops, mice

Phylum protozoa, how conjugation takes place in paramecium

how conjugation takes place in paramecium

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