Which set of vegetables is underground stem or modified stem of a plant?
- A.Potato, artichoke, round gourd
- B.Onion, garlic, carrot
- C.Potato, onion, garlic
- D.Potato, garlic, turnip
Correct answer
Explanation
The correct answer is C, Potato, onion, garlic. All three are underground modified stems: the potato is a stem tuber, and onion and garlic are bulbs.
A stem can be told from a root by its nodes and buds. The eyes of a potato are nodes with buds, which is why a piece of potato with an eye grows into a new plant; the tuber stores starch. In onion and garlic the true stem is a small flat disc at the base, and the fleshy layers or cloves around it are leaves full of stored food, so the whole bulb is a modified shoot. Other underground stems are ginger and turmeric (rhizomes) and colocasia (corm).
A is wrong because round gourd (tinda) is a fruit, and the artichoke eaten is a flower bud.
B is wrong because carrot is a modified tap root, not a stem.
D is wrong because turnip is a modified tap root.
Exam tip: potato tuber, ginger rhizome, onion bulb and colocasia corm are stems; carrot, radish, turnip, beetroot and sweet potato are roots.
Practice Questions
View allConsider 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
Show answer
An accelerometer measures acceleration, including the pull of gravity, and each of the three actions depends on reading it. An accelerometer is a small sensor, today usually a MEMS (micro-electro-mechanical system) chip, that senses changes in speed and the direction of gravity.
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
Show answer
Carbon fibre is widely used in cars and aircraft for its strength and low weight, and it can be recovered and recycled.
Read the full explanation →Which one of the following cell organelles contains DNA?
- A.Golgi apparatus
- B.Mitochondrion
- C.Lysosome
- D.Endoplasmic reticulum
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Mitochondria carry their own small, circular DNA and their own ribosomes. Mitochondria are the powerhouses of the cell, where aerobic respiration makes ATP.
Read the full explanation →A sound wave having frequency of 300 Hz is travelling in an unknown medium. Its wavelength is not known. It travels a distance equal to 150 times its wavelength in time t. The value of t is :
- A.0.5 s
- B.1 s
- C.1.5 s
- D.2 s
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A wave moves forward by one wavelength in each cycle, so 150 wavelengths take 150 cycles, and 150 cycles at 300 per second take half a second.
Read the full explanation →A body floats in a liquid if the buoyant force is :
- A.equal to its weight.
- B.less than its weight.
- C.greater than its weight.
- D.zero.
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A floating body is in equilibrium, so the upward buoyant force exactly balances its weight. By Archimedes' principle, a body in a liquid is pushed up by a force equal to the weight of the liquid it displaces.
Read the full explanation →