Pollinia and massulae, Biology

Assignment Help:

Pollinia and Massulae

In most cases the pollen grains of each tetrad become separated from one another and they lie freely in the pollen sac. In some plants, mostly members of Ericaceae, the pollen grains remain in tetrads even when mature. In certain plants, such as Acacia, the tetrads are stuck together as groups, which may contain as many as 64 pollen grains. In some other plants, such as members of the Asclepiadaceae, all the pollen grains of a sac are united in a single compact mass such a mass is termed a pollinium. In some members of the family Orchidaceae the anthers produce groups of pollen grains which are loosely jointed among themselves, usually by means of viscin threads. These groups are called as massulae.


Related Discussions:- Pollinia and massulae

Define prevention of idd - double fortified salt, Define prevention of idd ...

Define prevention of idd - Double Fortified salt? iron deficiency anaemia and iodine deficiency disorders often co-exist, the most effective approach to control these public he

Cell wall, Cell wall is the structure produced by some of the cells outsid...

Cell wall is the structure produced by some of the cells outside their cell membrane; variously composed of the chitin, peptidoglycan, or cellulose.

How do birds reproduce, Q. How do birds reproduce? Birds like every ver...

Q. How do birds reproduce? Birds like every vertebrate have sexual reproduction. Their embryos develop within shelled eggs containing extraembryonic membranes and exterior the

Explain spray-drying method, Spray-drying method Spray-drying is the co...

Spray-drying method Spray-drying is the common drying method in the production of ISP. The primary physical form of ISP in commerce, is that of fine powders. Structured form

Describe st segment depression, Q. Describe ST Segment Depression? The ...

Q. Describe ST Segment Depression? The development of ST-segment depression with exercise is probably the most reliable sign if myocardial ischaemia and appears to be the most

Interspecific sterility, In interspecific sterility, the failure in mating ...

In interspecific sterility, the failure in mating occurs because of inability of the sperm to reach the egg in animals and the pollen to reach ovules in plants. In plailts interspe

Pollen tube structure, Pollen Tube Structure The pollen tube in the s...

Pollen Tube Structure The pollen tube in the stigma is filled with cytoplasm containing numerous mitochondria and dictyosomes. The number of dictyosome cisternae is reduced i

Overall senescence - senescence, Overall senescence - Senescence Only ...

Overall senescence - Senescence Only the parts above the ground level i.e.  The aerial parts die whereas the underground parts survive For example, potato.

Colonial theory - metazoa, Colonial Theory - Metazoa  This is the most...

Colonial Theory - Metazoa  This is the most popular theory on the origin of Metazoa. The idea was conceived by Haeckel (1874) modified by Metschnikoff (1886) and revived by Hy

What is lipoproteins, A lipoprotein is a biochemical assembly which haves b...

A lipoprotein is a biochemical assembly which haves both lipids and proteins, bound to the proteins that allow fats to move by the water outside and inside cells. The proteins serv

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