Hydrophily - cross-pollination, Biology

Assignment Help:

Hydrophily - Cross-pollination

All hydrophytes are not necessarily pollinated by water. In fact most of the aquatic plant are anemophilous, e.g. Alisma, Nymphaea. Like anemophilous plants floral envelops are highly reduced or absent in hydrophilous plants. Hydrophily may involve underwater pollination referred to as hyphydrophily, e.g., Ceratophyllum, Majus, and Zostera. A unique example of this type is Zostera mariana (a submerged marine perennial) in which pollen grains are long (up to 250pm) and needle-like resembling pollen tubes. Because of the specific gravity of this pollen they freely float at any depth, and when they come in contact with the stigma they coil around it. In some taxa ephydrophily operates. In these plants pollination is brought about at the surface of water.

The classical example is the submerged dioecious plant, Vallisneria. The male and female flowers are produced under water but on maturity the males get detached from the stalk and float on the surface while the female flowers attached to thin, spirally coiled, long, slender stalks are brought to the surface at the time of pollination. Pollination is achieved through water currents when male flowers come in contact with pistillate flowers. After pollination the flowers are dragged down to the bottom by the recoiling of the stalk. The fruits thus develop under water.


Related Discussions:- Hydrophily - cross-pollination

Portion of double-stranded dna, Suppose that a portion of double-stranded D...

Suppose that a portion of double-stranded DNA in the middle of a large gene is being transcribed by an RNA polymerase. As the polymerase moves through the sequence of six bases sho

External auditors reports, External Auditors Reports The audit report...

External Auditors Reports The audit report is the final stage in the process of an audit.  The terms 'true and fair'  'present fairly' have special significance in the audit

Pericardiocentesis, Pericardiocentesis It is removal of fluid form the...

Pericardiocentesis It is removal of fluid form the pericardial sac. It is a specialized procedure done n ICU or cardiac cath lab or OT. A 16 or 18 gauge needle is inserted

Define the enumeration of food microbiota, Define the Enumeration of Food M...

Define the Enumeration of Food Microbiota? Quality of food depends on its physical, chemical, microbiological and sensory quality. The examination of food for the type and numb

Important herbaria, Q. Important Herbaria? The herbarium is a place whe...

Q. Important Herbaria? The herbarium is a place where dried and mounted specimens are stored according to any recognised system of classification. Special attention is paid tow

Explain the elimination of dna helicase activity in a cell, Which of the fo...

Which of the following results from the elimination of DNA helicase activity in a cell? A. The melting of the DNA double helix at the site of replication initiation will fail t

How many meters long is the molecule, E. coli DNA has a MW of about 2.7 x 1...

E. coli DNA has a MW of about 2.7 x 10^9 Daltons. How many meters long is this molecule and what does this tell you about the state of the intracellular DNA? ( The lenght of a sing

Define left posterior hemiblock, Q. Define Left Posterior Hemiblock? Bo...

Q. Define Left Posterior Hemiblock? Bobbna and associated reported four cases in which they proposed that the left posterior hemi block was initiated by exercise. In their pa

Coelomoducts of molluscs, Coelomoducts of Molluscs In Molluscs, like ...

Coelomoducts of Molluscs In Molluscs, like in Crustacea nephridia are absent. But certain of the larval pulmonates do possess protonephridia suggesting that they have been se

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