Phreatophytes are the plants adapted to grow in
- A.moist shaded places
- B.rocky environments
- C.arid environments
- D.active volcanic lava
Correct answer
Explanation
The correct answer is C, arid environments. Phreatophytes are deep-rooted plants that survive in dry regions by drawing water from the water table.
The name comes from the Greek for 'well plant'. These plants send their roots far down, sometimes tens of metres, to reach the groundwater or the moist zone just above it. They are common in deserts and semi-arid lands, especially along dry river beds. Mesquite (Prosopis), the date palm, tamarisk and some acacias are examples. Because they draw on groundwater all year, phreatophytes can lower the water table in arid regions.
A is wrong: plants of moist shaded places are called sciophytes or shade plants.
B is wrong: plants of rocky surfaces are called lithophytes.
D is wrong: fresh lava is colonised first by lichens and mosses, not by phreatophytes.
Exam tip: phreatophyte = deep roots to the water table in deserts; lithophyte = rock; hydrophyte = water.
Practice Questions
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- A.nickel
- B.iron
- C.tin
- D.aluminium
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Bronze is an alloy of copper and tin, usually about 88 parts copper to 12 parts tin. Adding tin makes copper harder, stronger and easier to cast, and bronze also resists corrosion well.
Read the full explanation →Which one of the following instruments is used for measuring moisture content of air?
- A.Hydrometer
- B.Hygrometer
- C.Hypsometer
- D.Pycnometer
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A hygrometer measures humidity, that is, the amount of water vapour or moisture in the air. The name comes from the Greek "hygros", meaning wet.
Read the full explanation →Which one of the following elements is present in the green pigment of leaves?
- A.Magnesium
- B.Iron
- C.Calcium
- D.Copper
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The green pigment of leaves is chlorophyll, and a magnesium atom sits at the centre of every chlorophyll molecule.
Read the full explanation →Consider the following actions :
1. Detection of car crash/collision which results in the deployment of airbags almost instantaneously
2. Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive
3. Detection of the tilt of the smartphone which results in the rotation of display between portrait and landscape mode
In how many of the above actions is the function of accelerometer required?
- A.Only one
- B.Only two
- C.All three
- D.None
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Read the full explanation →Consider the following statements :
1. Carbon fibres are used in the manufacture of components used in automobiles and aircrafts.
2. Carbon fibres once used cannot be recycled.
Which of the statements given above is/are correct?
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
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Carbon fibre is widely used in cars and aircraft for its strength and low weight, and it can be recovered and recycled.
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