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 the penicillium - fungi, Explain the Penicillium - Fungi? Class...

Explain the Penicillium - Fungi? Classification Kingdom - Mycetae Division - Amastigomycota Class - Ascomycetes Subclass - Plectomycetidae Order - Eurotiales

Determine the various neurobehavioural characteristics, Determine the vario...

Determine the various neurobehavioural characteristics Contemporary views of brain function tend to conceptualise localisation in interaction with a number of developmental and

Describe pathophysiology of tetralogy of fallots, Describe Pathophysiology ...

Describe Pathophysiology of tetralogy of fallots ? The PS causes concentric hypertrophy of right ventricle without enlargement. The right ventricular pressure are equal to or h

Define precautions for preparation of bacterial smear, Define Precautions f...

Define Precautions for preparation of bacterial smear 1. The slide should not be greasy. 2. Hold the slide by their edges only. 3. Label should not come in contact with s

Steps of initiation , The entire mechanism of protein synthesis i...

The entire mechanism of protein synthesis in eukaryotes is generally the same as in prokaryotes, with three phases explained as termination, elongation and initiation. Furthermore,

Define procedure for determination of fungal and yeast count, Define Proced...

Define Procedure for Determination of Fungal and Yeast Count? Now carry out the exercise following the steps enumerated herewith: 1. Shake the food sample and aseptically tr

State the phases of soil genesis, State the phases of soil genesis Soil...

State the phases of soil genesis Soil genesis embodies two distinct phases. One is weathering that involves disintegration and decomposition of rocks and minerals, the other is

Pisciculture, Pisciculture: This is the culturing of fishes. There is a pri...

Pisciculture: This is the culturing of fishes. There is a principal form of aquaculture called Fish farming, while other methods can come under mariculture. Fish farming main aim i

What is the monohybridism, What is the monohybridism? The Monohybridism...

What is the monohybridism? The Monohybridism is the study of only one characteristic in the crossing of two pure individuals (hybridization) for that characteristic.

How can the immune memory lead to the efficacy of vaccines, How can the imm...

How can the immune memory lead to the efficacy of vaccines and also produce allergies? Vaccines are controlled inoculations of fragments of infectious agents or of inactive inf

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