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

Explain control function of organic molecules, What are some examples of th...

What are some examples of the control and informative function of organic molecules? Based on genetic information, organic molecules control the whole work of the cell. The nuc

.ecology, describe between native and non-native species from the Otay rive...

describe between native and non-native species from the Otay river valley

Define hexokinase, Hexokinase, that catalyzes the first irreversible step o...

Hexokinase, that catalyzes the first irreversible step of glycolysis, is inhibited by glucose 6-phosphate.   Thus  when  PFK  is  inhibited and  fructose  6-phosphate builds  up an

Define the dietary management for underweight, Define the Dietary Managemen...

Define the Dietary Management for Underweight? We just read about the etiological factors that may lead to undernutritioin and weight loss. Whatever may be the cause, all under

Sickle cell, Sickle cell anaemia in man is caused by a defective chain of h...

Sickle cell anaemia in man is caused by a defective chain of haemoglobin. The abnormal haemoglobin known as MbS differs from natural haemoglobin (HhA) in one amino acid. A substitu

What are the uses of construction of a retaining wall, What are the uses of...

What are the uses of construction of a retaining wall? The retaining wall is constructed whenever space requirement do not allow the natural slope to be formed for an excavatio

Parenchymal inflammation, Parenchymal Inflammation Parenchymal inflamm...

Parenchymal Inflammation Parenchymal inflammation can be due to infectious diseases or acute bronchitis or pneumonia discussion will be mainly on pneumania in the following t

Define absorption of calcium from dietary calcium supplement, Define Absorp...

Define Absorption of Calcium from dietary calcium supplements? Absorption from dietary calcium supplements is important to know, since they are almost universally recommended f

Explain about homo neanderthalensis, Homo neanderthalensis successfully liv...

Homo neanderthalensis successfully lived in the cold, harsh ice-age conditions of Europe until becoming extinct approximately 30 000 years ago. Adaptations which enabled them to s

Differences between electron acceptors and electron carriers, What are the ...

What are the differences between electron acceptors and electron carriers? Give an example of each.

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