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

Relationship between whales and hippos, In the evolution of whales, there i...

In the evolution of whales, there is evidence that whales and hippo form a monophyletic group. Show all the evidence that supports the close relationship between whales and hippos

State the replication of dna strands, Which of the following statement is t...

Which of the following statement is true regarding the replication of DNA strands? A. The products of replication include one double helix made exclusively of parental DNA and

Define about the concept of sports nutrition, Define about the concept of s...

Define about the concept of sports nutrition? The concept of sports nutrition was evolved fundamentally with integration of different disciplines in order to collectively striv

Zoonotic diseases-kyasanur forest disease, Kyasanur forest disease Kya...

Kyasanur forest disease Kyasanur forest disease (KFD) was first recognized in 1957 as a new disease entity affecting man and monkeys in Karnataka, India. The disease is named

Explain the metabolic pathways in the cornea, Explain the metabolic pathway...

Explain the metabolic pathways in the cornea. Metabolic Pathways: a. 88 per cent of glucose is utilized through glycolysis. b. Only 12 per cent of glucose utilized by

Define the streak plate method - pure culture techniques, Define the Streak...

Define the Streak Plate Method - Pure Culture Techniques? The method was developed by Loeffler and Gaffkey in the laboratory of Robert Koch. The streak plate method depends on

What is the plant hormone remarkable for stimulating, What is the plant hor...

What is the plant hormone remarkable for stimulating flowering and fruit ripening? What are the uses and practical inconveniences of that hormone? The plant hormone notable for

Write the meaning of hyperglycemia, Q. Write the meaning of Hyperglycemia? ...

Q. Write the meaning of Hyperglycemia? Hyperglycemia is a Greek term: hyper -meaning excessive; glyc - meaning sweet; and emia- means "of the blood". It is a condition in whic

Surgical treatment of infective endocarditis, Cardiac surgical intervention...

Cardiac surgical intervention has an increasingly important role in the treatment of intracardiac complications of endocarditis. Retrospective data suggest that mortality is unacce

Visualize patient ductus arteriosus, Q. Visualize Patient Ductus Arteriosus...

Q. Visualize Patient Ductus Arteriosus? Best view to visualize a patient ductus arteriosus is high parasternal or ductal view. A patient ductus arteriosus in this view is see

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