Formation of tropical forests needs mean annual temperature and mean annual precipitation as:
1. 18 – 25 °C and 150 – 400 cm
2. 5 – 15 °C and 50 – 100 cm
3. 30 - 50°C and 100 – 150 cm
4. 5 – 15 °C and 100 – 200 cm
Assertion (A): | Organisms living in oceans do not face any water-related problems. |
Reason (R): | Life on Earth originated in water and is not sustainable without water. |
1. | Both (A) and (R) are true but (R) does not explain (A). |
2. | (A) is true but (R) is false. |
3. | (A) is false but (R) is true. |
4. | Both (A) and (R) are true and (R) explains (A). |
The salt concentration [measured as salinity in parts per thousand] for inland waters is:
1. Less than 5
2. Between 5 and 15
3. 30 – 35
4. More than 100
Organisms that are tolerant for a wide range of salinity are called:
1. | Stenohalines | 2. | Euryhalines |
3. | Halophytes | 4. | Stenothermals |
Many freshwater animals cannot live for long in sea water and vice versa because of:
1. Buoyancy related problems
2. Lack of impermeable skins
3. Thermolabile enzymes
4. Osmotic considerations
Small plants [herbs and shrubs], growing in forests, are usually adapted to photosynthesize optimally under:
1.Very high light conditions
2.Very low water conditions
3.Very high water conditions
4.Very low light conditions
Photoperiod affects:
1. Plants only
2. Animals only
3. Both plants and animals
4. Neither plants nor animals
Assertion (A): | The availability of light on land is closely linked with that of temperature. |
Reason (R): | Sun is the source for both – light and temperature. |
1. | (A) is true but (R) is false. |
2. | Both (A) and (R) are true and (R) explains (A). |
3. | Both (A) and (R) are true but (R) does not explain (A). |
4. | (A) is false but (R) is true. |
Which of the following forest plants controls the light conditions at the ground?
1. Lianas and climbers
2. Shrubs
3. Tall trees
4. Herbs
Statement I: | Many plants depend on sunlight to meet their photoperiodic requirement for flowering. |
Statement II: | Many animals use photoperiod cues for timing their foraging, reproductive and migratory activities. |
Statement III: | The spectral quality of solar radiation is not important for life. |