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

An mrna molecule codifies only one type of protein, An mRNA molecule codifi...

An mRNA molecule codifies only one type of protein? Eukaryotic cells have monocistronic mRNA, i.e., every mRNA codifies only one polypeptide chain. Prokaryotes can present poly

taxonomy, what are the phase of alpha taxonomy

what are the phase of alpha taxonomy?

Determine the food source for magnesium, Determine the food source for Magn...

Determine the food source for Magnesium? Magnesium is widely distributed in variety of foods and beverages. In plants it is associated with chlorophyll. Thus, green leafy veget

Coral reefs, Coral reefs form in clear warm tropical seas and are particula...

Coral reefs form in clear warm tropical seas and are particularly well developed in the South Pacific. They are formed by accumulation in calcarious skeletons of tiny colonial anim

Reasons for increasing popularity of dental implants, Q. Reasons for increa...

Q. Reasons for increasing popularity of dental implants? There are various reasons for increased popularity of dental implants. With the rapid development and evolution of impl

Define interaction of vitamin k with vitamins a and e, Define Interaction o...

Define Interaction of Vitamin K with Vitamins A and E? Excess vitamin A interferes with vitamin K absorption while the a-tocopherol or vitamin E, as we have already studied ear

Explain lyme disease, Explain Lyme disease The disease - About 70-80% o...

Explain Lyme disease The disease - About 70-80% of patients infected by B. burgdorferi develop the characteristic skin lesion, erythema migrans, which occurs at the site of the

Zonation in the lake biome, Q. Zonation in the lake biome? Precipitatio...

Q. Zonation in the lake biome? Precipitation that does not evaporate or penetrate the soil remains on the soil surface resulting in run off which flows down from the mountains

Classification of coal by rank, Coal can be classified into following categ...

Coal can be classified into following categories in the order of rank. Peat:  peat is a brown and fibrous mass. It is the first stage of coalification. It is not used as

Explain false left ventricular aneurysm, Explain False Left Ventricular Ane...

Explain False Left Ventricular Aneurysm? False Left Ventricular Aneurysm :  False aneurysm develops after acute rupture of an infarct. It is usually fatal, but a few survive

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