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प्रश्न
Describe the dispersal of fruit and seeds by animals.
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उत्तर
Birds and mammals, including human beings, play an efficient and important role in the dispersal of fruit and seeds. They have the following devices.
- Hooked fruit: The surface of the fruit or seeds have hooks (Xanthium), barbs (Andropogon), spines (Aristida) by means of which they adhere to the body of animals or clothes of human beings and get dispersed.
- Sticky fruits and seeds:
- Some fruits have sticky glandular hairs by which they adhere to the fur of grazing animals. Example: Boerhaavia and Cleome.
- Some fruits have a viscid layer that adheres to the beak of the bird which eats them and when they rub them onto the branch of the tree, they disperse and germinate.
Example: Cordia and Alangium.
- Fleshy fruits: Some fleshy fruits with conspicuous colours are dispersed by human beings to distant places after consumption.
संबंधित प्रश्न
Read the given statements and select the correct option.
- Hydrophytes possess aerenchyma to support themselves in water.
- Seeds of Viscum are positively photoblastic as they germinate only in presence of light.
- Hygroscopic water is the only soil water available to roots of plants growing in soil as it is present inside the micropores.
- High temperature reduces use of water and solute absorption by roots.
Read the given statements and select the correct option.
- Loamy soil is best suited for plant growth as it contains a mixture of silt, sand, and clay.
- The process of humification is slow in the case of organic remains containing a large amount of lignin and cellulose.
- Capillary water is the only water available to plant roots as it is present inside the micropores.
- Leaves of shade plant have more total chlorophyll per reaction centre, low ratio of chl a and chl b are usually thinner leaves.
Read the given statements and select the correct option.
Statement A: Cattle do not graze on weeds of Calotropis.
Statement B: Calotropis have thorns and spines, as a defense against herbivores.
In soil water available for plants is
Ophrys an orchid resembling the female of an insect so as to able to get pollinated is due to phenomenon of
A free-living nitrogen-fixing cyanobacterium which can also form a symbiotic association with the water fern Azolla
Strong, sharp spines that get attached to animal’s feet are found in the fruits of
Sticky glands of Boerhaavia and Cleome support
Why are some organisms called as eurythermals and some others as stenohaline?
Sandy soil is not suitable for cultivation. Explain why?
What is thermal stratification? Mention their types.
What is myrmecophily?
What is a seed ball?
Explain Raunkiaer classification in the world’s vegetation based on the temperature.
Explain different types of hydrophytes with examples.
What are the advantages of seed dispersal?
What is the soil profile? Explain the characters of different soil horizons.
