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

Which are the heart chambers, Q. Which are the heart chambers respectively ...

Q. Which are the heart chambers respectively where the entrance and the exit of blood occur? The heart chambers through which blood enters the heart are the atria there are the

Names and uses of the various laboratory tools, What are the names and uses...

What are the names and uses of the various laboratory tools? Tools are beakers, microscopes, tweezers, hot plates, lasers, test tubes, voltmeters, Erlenmeyer flasks, thermomete

What do numeric pyramids represent?, What do numeric pyramids represent? ...

What do numeric pyramids represent? The Numeric pyramids represent the number of individuals in each trophic level of a food chain.

What is the role of plant cells, What is the role of Plant Cells? Plant...

What is the role of Plant Cells? Plant cells function essentially in the same manner as other eukaryotic cells, but there are three unique structures which set them apart. Plas

Can our experiences change our brain, Can our experiences change our brain ...

Can our experiences change our brain A. It is now know by Scientists that brain is remarkably "plastic:" it continues to change during the course of life in accordance with our

Explain ventricular septal defect in details, Explain Ventricular Septal De...

Explain Ventricular Septal Defect in details ? Indications of surgery :  Some VSDs close spontaneously or become smaller in size. This has to be taken into consideratio

Provide communication between the cells, A) Maintain structural integrity o...

A) Maintain structural integrity of the cell B) Regulate the movement of substances into and out of the cell C) Provide communication between the cells D) ALl of the above

How to ensure food safety by haccp, Ensuring  Food  Safety It is now w...

Ensuring  Food  Safety It is now well-known that the end product inspection and  testing does not provide safety of food. It has inherent limitation of mapping the potential ha

What are the cytoplasmic structures present in animal cells, Q. What are th...

Q. What are the main cytoplasmic structures present in animal cells? The main cytoplasmic structures of the cell are the centrioles, the cytoskeleton, mitochondria, peroxisomes

Summary of accident causation, Summary of Accident Causation In the li...

Summary of Accident Causation In the light of above theories it is concluded that the decision of workers to work safe is largely influenced by external factors such as meetin

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