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

Succession, why succession more likely to occur on valley floor than steep ...

why succession more likely to occur on valley floor than steep slopes

Why vegetable and fruit are important for human body, Why Vegetable and Fru...

Why Vegetable and Fruit are important for human body? The vegetables and fruits add colour and variety to our diets in addition to providing a host of essential nutrients and p

Describe protocol that are used for endotracheal intubation, Describe Proto...

Describe Protocol that are used for Endotracheal Intubation in ICU Intubation is a three person procedure; skilled assistance is mandatory: • "Top end" intubator who coordi

Show the impressions at first - Transitional Restorations, Q. Show the Impr...

Q. Show the Impressions at first - Transitional Restorations? The dental technique will have modified the abutment to the desired shape and will now be able to fabricate the tr

Explain the gram staining technique, Explain the Gram Staining technique? ...

Explain the Gram Staining technique? Gram staining is a differential staining procedure which divides bacteria into two groups: Gram positive and Gram negative, based on staini

What is gymnosperms explain its dividions, What is Gymnosperms explain its ...

What is Gymnosperms explain its dividions? Gymnosperms are one of the two major groups of plants that bear seeds. The other group, the Angiosperms (flowering plants), differ in

Categories of phloem transport, Categories of Phloem Transport Essenti...

Categories of Phloem Transport Essentially, the phloem transport can be subdivided into the following: The "loading" of the organic nutrients from the mesophyll c

Explain the oligosaccharides (dp: 3-9) - carbohydrates, Explain the Oligosa...

Explain the Oligosaccharides (DP: 3-9) - carbohydrates? Oligosaccharides consists of short chains of monosaccharide units joined by covalent bonds. The glycosidic bond may be α

Explain indications for surgery of total anomalous, Explain Indications for...

Explain Indications for Surgery of Total Anomalous pulmonary Venous Connection ? Once TAPVC is diagnosed in a neonate with symptoms, operation should be undertaken immediately.

Closed heart surgery, Closed Heart Surgery Blind operations and access...

Closed Heart Surgery Blind operations and access is obtained into the heart through incision on the ventricular or atrial wall. Commonest closed heart surgery done is m

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