Consider the following : 1. Butterflies 2. Fish 3. Frogs How many of the above have poisonous species among them ?
- A.Only one
- B.Only two
- C.All three
- D.None
Correct answer
Explanation
The correct answer is C, All three. Each of the three groups includes species that carry toxins in their bodies to deter predators.
Butterflies: the Monarch butterfly feeds as a caterpillar on milkweed and stores its bitter cardiac glycosides, so birds that eat it fall sick; its bright orange colour is a warning. Fish: pufferfish carry tetrodotoxin, one of the strongest natural poisons, and the stonefish has venomous spines. Frogs: the poison dart frogs of Central and South American rainforests secrete alkaloid toxins such as batrachotoxin through their skin, which forest tribes once used on hunting darts.
A is wrong because more than one group has such species.
B is wrong because it leaves out one group that clearly has poisonous members.
D is wrong because well-known poisonous species exist in all three groups.
Warning colours that advertise poison are called aposematism, and harmless species that copy them show Batesian mimicry.
Exam tip: Monarch butterfly, pufferfish and poison dart frog are the standard examples of poisonous animals.
Practice Questions
View allConsider the following statements :
Statement-I : Giant stars live much longer than dwarf stars.
Statement-II : Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.
Which one of the following is correct in respect of the above statements?
- A.Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
- B.Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
- C.Statement-I is correct, but Statement-II is incorrect
- D.Statement-I is incorrect, but Statement-II is correct
Show answer
Massive giant stars burn their fuel so fast that they live much shorter lives than dwarf stars, so Statement I is false and Statement II is true.
Read the full explanation →Which one of the following is a filter feeder?
- A.Catfish
- B.Octopus
- C.Oyster
- D.Pelican
Show answer
The oyster feeds by drawing water over its gills and straining out plankton and organic particles, which is filter feeding.
Read the full explanation →With reference to radioisotope thermoelectric generators (RTGs), consider the following statements :
1. RTGs are miniature fission reactors.
2. RTGs are used for powering the onboard systems of spacecrafts.
3. RTGs can use Plutonium-238, which is a by-product of weapons development.
Which of the statements given above are correct ?
- A.1 and 2 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
RTGs power spacecraft using heat from the natural decay of plutonium-238; they are not reactors and involve no fission. In an RTG, a radioactive isotope gives off heat as it decays on its own.
Read the full explanation →Consider the following :
1. Cashew
2. Papaya
3. Red sanders
How many of the above trees are actually native to India ?
- A.Only one
- B.Only two
- C.All three
- D.None
Show answer
Of the three, only red sanders is native to India; cashew and papaya were brought from the Americas. Red sanders (Pterocarpus santalinus) is endemic to the southern Eastern Ghats, mainly the Seshachalam and nearby hills of Andhra Pradesh.
Read the full explanation →The speed of the wind is measured by
- A.wind vane
- B.wind rose
- C.barometer
- D.anemometer
Show answer
An anemometer measures how fast the wind is blowing; its name comes from the Greek word anemos, meaning wind.
Read the full explanation →