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

Invertebrete zoology, give an example invertebrate phylum/phyla for protopl...

give an example invertebrate phylum/phyla for protoplasmic grade organization

Define protein needs in nutrient requirement, Define Protein needs in Nutri...

Define Protein needs in Nutrient Requirement and Dietary Management? It is one of the most crucial nutrient which determines the ultimate outcome of burns. Amino acid requireme

Explain haploid cells and triploid cells, Q. Can mitosis occur in haploid (...

Q. Can mitosis occur in haploid (n) cells and in triploid cells? The mitotic cell division can occur in haploid (n) cells, diploid (2n) cells, triploid (3n) cells, and so on. M

Explain composition of human milk, Explain Composition of Human Milk? R...

Explain Composition of Human Milk? Research clearly shows that each type of mammalian milk is unique and consists of a highly complex mixture of organic and inorganic compounds

Define advantages of colonies obtained at different dilution, Define Advant...

Define Advantages of Colonies Obtained At Different Dilution 1. As colonies grow both on the surface and beneath the agar surface, so aerobes facultative anaerobes and non-stri

What is the dosage and cost of micafungin, Dosage and cost of micafungin ...

Dosage and cost of micafungin The recommended dosage of micafungin is 50 mg/day for prophylaxis and 150 mg/day for treatment, both given IV as a single dose over 1 hour.

Nutritional management for lactose intolerance, Q. Nutritional Management f...

Q. Nutritional Management for lactose intolerance? Diagnostic tests are available that can give information about the level and activity of the lactase enzyme. Depending on the

Surgical significance of inferior alveolar nerve and artery, Surgical signi...

Surgical significance of Inferior alveolar nerve and artery In an excessively resorbed ridge, the mental foramen with its contents of mental nerve and vessels, can be found o

Define lipoprotein metabolism, Q. Define Lipoprotein Metabolism? Lipopr...

Q. Define Lipoprotein Metabolism? Lipoproteins serve to transport absorbed dietary fat and endogenously synthesized cholesterol and triglyceride. Nevertheless, it is possible t

Ontogeny, Ontogeny: This is the study of history of an individual. Ontogen...

Ontogeny: This is the study of history of an individual. Ontogeny is also known as ontogenesis and morphogenesis. Ontogeny describes the origin or the development of an organism -

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