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

Relate the oxide layer and biocompatibility of titanium, Q. Relate the oxid...

Q. Relate the oxide layer and biocompatibility of titanium? The compatibility of a metal with its host environment depends on its resistance to biodegradation and on the degree

The effect of light on the growth of stems, The effect of light on the grow...

The effect of light on the growth of stems (a)  Plant some seeds that grow rapidly like as oats, radish, bean or mustard seeds in two flower pots. When the seedlings are about

Explain the protein energy malnutrition (pem), Explain the Protein Energy M...

Explain the Protein Energy Malnutrition (PEM)? Protein Energy Malnutrition (PEM) is the deficiency of macronutrients or energy and protein in the diet and forms the most import

Where would expect to see its growth, If you inoculate an organism know to ...

If you inoculate an organism know to chemically reduce sulfur (as done by organisms capable of anaerobic respiration), where would you expect to see its growth in the test medium u

Show the efficient contraceptive method, Q. Why is the use of condoms not j...

Q. Why is the use of condoms not just a contraceptive method but also a health protection behavior? The use of condoms besides being an efficient contraceptive method also help

Determine the nutritious meals to the elderly, Determine the nutritious mea...

Determine the nutritious meals to the elderly? The various considerations to be kept in mind for providing nutritious meals to the  elderly are highlighted herewith. Due

#titleclasses of fish.., what are the two main classes into which fish are ...

what are the two main classes into which fish are divided

Define the assessment of copper status in humans, Define the Assessment of ...

Define the Assessment of Copper Status in Humans? A reliable index to assess marginal copper status is currently not available. However, severe copper deficiency may be detecte

Explain human cells that produce proteins for exportation, What are some ex...

What are some examples of human cells that produce proteins for exportation? Which cytoplasmic organelle is expected to be well-developed and abundant in those cells? Specializ

What is the life cycle of the hookworms, What is the life cycle of the hook...

What is the life cycle of the hookworms? Adult hookworms within the human intestine release eggs that are eliminated with the human feces. Under adequate conditions of moisture

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