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

What is anabolism, Q. What is Anabolism? Anabolism Anabolism is a pr...

Q. What is Anabolism? Anabolism Anabolism is a process of synthesis or making of larger or complex molecules from smaller molecules. These molecules are of different kinds l

Explain risk management, Explain Risk Management Risk Management :  ...

Explain Risk Management Risk Management :  The  process  of weighing  policy  alternatives  to accept, minimize or reduce assessed risks and  to select and  implement approp

Pox diseases, P o x diseases Small-pox in human beings and pox in a f...

P o x diseases Small-pox in human beings and pox in a few animal species are closely related to each other. It is shown by the fact that the vaccine for the prevention of sma

Standard titration - estimation of vitamin c in lemon juice, Explain Standa...

Explain Standard titration - Estimation of Vitamin C in Lemon Juice? Pipette 5 ml of standard ascorbic acid solution into a 100 ml conical flask. Fill the burette with the dye s

Particulate theory - pre-mendelian theory, Particulate Theory (i)      ...

Particulate Theory (i)         Maupertuis (1689-1759) proposed that the body of each parent give rise to minute particles. (ii)         In sexual reproduction, these particl

Blood protozoan and ricketsial diseases - trypanosomiasis, B l oo d Prot...

B l oo d Protozoan and Ricketsial Diseases T r y p a n o s o m i a si s It is also known as surra in equines and tibarsa in camel and results in intermitte

Hygroscopic coeflicient-retention of soil moisture, Hygroscopic Coeflicient...

Hygroscopic Coeflicient To have a more complete picture of soil moisture relations, let us take a soil sample and oven dry it for 24 hours at 11 o C. Now if this soil is kept i

Explain the basic concept of adulteration, Explain the Basic Concept of Adu...

Explain the Basic Concept of Adulteration? Food adulteration is the change in original composition and quality of food by adding, removing or substituting some ingredients of f

Invertebrates, Are chaetopterus species coelomate?

Are chaetopterus species coelomate?

Adverse effect to intestinal mucosa, Q. Adverse effect to intestinal mucosa...

Q. Adverse effect to intestinal mucosa? Alcohol: Alcohol is known to cause damage to intestinal mucosa independent of gastric acid content. Thus high amounts are not advised.

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