Read the passage and answer the questions that follow: Based on molecular…
2023
Read the passage and answer the questions that follow:
Based on molecular evidence, we know life evolved from one common ancestor around three billion years ago. From then, evolution progressed, slowly to begin with—in the last billion years, we see very rapid diversification of life forms on Earth as multiple components clicked into place, including multicellularity or multiple cells coming together to form one organism, etc. Against this backdrop, we find all insects share a relationship with each other—they have a certain body plan, cellular functions, genetically encoded features (many have six legs, for instance) and the information of how these features are formed encoded in their genome. Butterflies share many evolutionary features with insects. Butterflies are also specialised moths, the two separating from their sister group of insects 150 to 200 million years ago. Thereafter, moths themselves evolved significantly before butterflies emerged as a separate group about 85 million years ago, around when dinosaurs went extinct. All the characteristics butterflies have—including much more acute vision compared to moths who rely more on smell—grew thereon. Visual cues are extremely important for butterflies which explains why many are so attractive. Their appealing colours evolved to help them either evade predators or attract mates, dark colours developing to help butterflies maintain body temperature, being cold-blooded. Some species developed fascinating traits. Aposematism is a combination of two features—one is a defence against predators, like a chemical cover, some butterflies being toxic to birds, spiders, etc. These caterpillars feed on toxic plants which are difficult, if not deadly, for predators to digest. Being protected thus is an internal property—but butterflies with toxins then developed bright wing patterns to show predators they are dangerous, signalling the risk they bear.
Aposematism is a combination of
A. Defence against predators by emitting a bad smell
B. Bright wing patterns for camouflage
C. Defence against predators by butterflies with toxins
D. Bright wing patterns to show predators they are dangerous
Choose the correct answer from the options given below:
Answer: C. C and D only — ConceptAposematism is a two-part survival strategy: an organism possesses a real defence, such as toxicity, and advertises that defence through a conspicuous…
- A.
A and D only
- B.
B and C only
- C.
C and D only
- D.
D only
Show answer & explanation
Correct answer: C
Concept
Aposematism is a two-part survival strategy: an organism possesses a real defence, such as toxicity, and advertises that defence through a conspicuous warning signal.
The signal does not conceal the organism; it makes the risk easy for a predator to recognize and learn.
Application
In the passage, the defensive component is toxicity acquired when caterpillars feed on toxic plants. This supports statement C.
The signalling component is the bright wing pattern that warns predators of danger. This supports statement D.
The passage neither describes a bad smell nor treats bright patterns as camouflage, so statements A and B do not supply the two components.
Contrast
The smell-plus-warning combination substitutes an olfactory mechanism for the stated toxin-based defence.
The camouflage-plus-toxin combination treats the bright pattern as concealment rather than a warning.
The warning-pattern-only choice omits the underlying defensive property that the signal advertises.
Result
Therefore, the supported combination is toxin-based defence together with bright warning wing patterns—C and D only.