Question

In hydrochory, small fruits and seeds are carried over the surface of water through
A)Surface tension
B)Lightweight of fruit
C)Buoyancy mechanism
D)All of the above

Answer 1

Dispersal of seeds, spores, or fruits by water is known as hydrochory. All these can be dispersed by rain, ice, or being directly submerged in the water. The primary dispersal of freshly deposited seeds and secondary dispersal of previously dispersed seeds is mainly done by the water. The hydrochory generally occurs in the swamps, rivers, and the coastal forest species.

Complete answer:
-The hydrochory is used by many aquatic and some terrestrial species for the dispersal of seed through the water. The dispersed seeds travel long distances depending on the specific mode of water dispersal.
-The dispersal mechanism is especially applied to the fruits which are generally waterproof and float on water.
-The denser object is able to float or run along the water surface due to the surface tension and it is a very important property of water.
-When there is an upward force exerted by the water on an object which is less dense than itself is known as buoyancy and it is also the very important characteristic of water.
-The lightweight of fruit and seed has the same characteristics as the buoyancy of water.
-Therefore surface tension of water, buoyancy, and lightweightness of the fruit or seed, all three permit them to float on the surface of the water.

Additional Information: -Water lily is a very good example of hydrochory. They make fruits that flow in the water and then drop down to the bottom of the pond to take root on the floor of the pond.
-The seeds of the palm are also dispersed by the water. The palm tree is mainly grown near the oceans and the seeds transported by the ocean currents over a very long distance. This allowed the seeds to be dispersed in other continents.
-The seeds of mangrove trees are also carried far away with the help of water currents when they fall on the surface of the water.

So, the correct answer is,” All of the above”.

Note: -The fruits and seeds which are specialized for the dispersal with the help of water generally developed some kind of floating devices and a protective covering which makes them water-resistant. For example, coconut has a fibrous Mesocarp, and Lotus have spongy thalamus.
-The dispersal mechanism also provides an opportunity for the seedling to establish themselves away from the parent plant and helps to occupy more favorable habitats.
-The dispersal also allows genetic mixing in a population.