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

Genetics, What is the term for the pattern of base pairing between one DNA ...

What is the term for the pattern of base pairing between one DNA strand and its partner in a duplex?

How does the breathing process correct acidosis, Q. How does the breathing ...

Q. How does the breathing process correct acidosis? The increment of the respiratory frequency makes the body eliminate more carbon dioxide and to shift the equilibrium of the

Name term for white blood cells producing immunoglobulins, Which of the bel...

Which of the below is a term for mononuclear, granulocytic white blood cells which produce immunoglobulins? a) Platelets b) Lymphocytes c) Erythrocytes (pron: eh-rith-reh

Lipoproteins help in transport of lipids, Four major groups of lipoproteins...

Four major groups of lipoproteins help in transport of lipids. These include: 1.  Chylonzicrons-function is to carry dietary triacylglycerols 2.  Very  low  density lipoprot

Explain genetic information that is transmitted hereditarily, Which is the ...

Which is the biological molecule that contains the genetic information that is transmitted hereditarily and controls the cellular functioning? The hereditary molecule that cont

Genomic dna libraries , A genomic DNA library is made from the genomic DNA ...

A genomic DNA library is made from the genomic DNA of an organism. For instance, a mouse genomic library could be made by digesting mouse nuclear DNA with a restriction nuclease to

How does chewing food help to speed up digestion, How does chewing food hel...

How does chewing food help to speed up digestion? Chewing reduces food to portions small sufficient to be swallowed and enhances the surface area of the food for digestive enzy

Are viruses cellular beings, Q Are viruses cellular beings? Viruses are...

Q Are viruses cellular beings? Viruses are considered living beings but they don't have cellular structure. There are few controversies regarding their classification as liv

Define criteria for assessment of vitamin k status, Define Criteria for Ass...

Define Criteria for Assessment of Vitamin K Status? The parameters of blood clotting time and prothrombin time are used as criteria  to assess vitamin K status as this vitamin

Explain virus envelope, Virus envelope is known as: 1.  Capsid 2.  Vi...

Virus envelope is known as: 1.  Capsid 2.  Virion 3.  Nucleoprotein 4.  Core Capsid

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