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प्रश्न
Describe the dispersal of fruit and seeds by animals.
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.
In soil water available for plants is
The plant of this group are adapted to live partly in water and partly above substratum and free from water
Why are some organisms called as eurythermals and some others as stenohaline?
The organic horizon is generally absent from agricultural soils because tilling, e.g., plowing, buries organic matter. Why is an organic horizon generally absent in desert soils?
Soil formation can be initiated by biological organisms. Explain how?
Sandy soil is not suitable for cultivation. Explain why?
Describe the mutual relationship between the fig and wasp and comment on the phenomenon that operates in this relationship.
What is myrmecophily?
What is co-evolution?
Explain Raunkiaer classification in the world’s vegetation based on the temperature.
Explain different types of hydrophytes with examples.
Read the following statements and fill up the blanks with the correct option.
- Total soil water content in soil is called ______
- Soil water not available to plants is called ______
- Soil water available to plants is called ______
Identify the A, B, C, and D in the given table
| Interaction | Effects on species X | Effects on species Y |
| Mutualism | A | (+) |
| B | (+) | (-) |
| Competition | (-) | C |
| D | (-) | 0 |
Column I represent the size of the soil particles and Column II represents the type of soil components. Which of the following is the correct match for the Column I and Column IL
| Column - I | Column - II | ||
| I) | 0.2 to 2.00 mm | i) | Slit soil |
| II) | Less than 0.002 mm | ii) | Clayey soil |
| III) | 0.002 to 0.02 mm | iii) | Sandy soil |
| IV) | 0.002 to 0.2 mm | iv) | Loamy soil |
What is the soil profile? Explain the characters of different soil horizons.
