Which one of the following shows a unique relationship with an insect that has coevolved with it and that is the only insect that can pollinate this tree ?

Defines symbiotic/mutualistic relationships where two species depend on each other and may occupy a niche neither could alone.

A student could apply this pattern to ask whether fig and wasp traits show reciprocal dependence (e.g., wasp life cycle inside figs, fig requiring wasp for pollination) by checking species-specific natural history.

Gives pollination as a canonical example of mutualism: a pollinator gets food and the plant gets pollinated.

Use this rule to investigate whether a particular Ficus provides exclusive rewards and whether only one insect species visits and pollinates it in field reports or species accounts.

Explains that insects are among the main agents of pollination, moving pollen between flowers.

Combine this with observation that figs have enclosed inflorescences (basic outside knowledge) to hypothesize that specialized insect pollinators (like wasps) might be required and then search for species-specific associations.

Shows how particular pollinator presence/absence can strongly affect plant seed production, implying tight dependence in some plant–insect systems.

Use this logic to predict that if a fig depends on a single wasp species, removing that wasp would reduce seed/fruit set — a testable implication via ecological studies or published experiments.

Notes high plant and insect endemism and biodiversity, implying many regionally restricted, specialized interactions can exist.

A student could combine this with geographic maps of Ficus and local insect fauna to assess whether co-occurring endemic wasp species might match particular fig species geographically (supporting species-specific coevolution).

Gives the general rule that many kinds of agents (wind, water, insects, bats, birds) act as pollinators, implying pollination is commonly shared among multiple groups rather than by a single exclusive insect.

A student could check the silk-cotton tree's flower traits (e.g., nocturnal/large/nectar) and known ranges of bats/birds/insects on a map to see if multiple pollinator types are plausible.

Shows an example (lac insect Kerria lacca) of an insect that feeds on saps of many different host trees, illustrating that insect–tree interactions are often generalist rather than strictly one-to-one.

Use this pattern to ask whether known silk-cotton pollinators are specialists or generalists by comparing records of insect visitors across tree species in the same regions.

Explains a clear plant–insect relationship (silkworms and mulberry) where the insect depends on a host for feeding but is not claimed to be the sole agent for a plant function like pollination — illustrating that close associations need not imply unique pollination roles.

Compare the documented specialist relationships (like silkworm–mulberry) with the ecology of Bombax/Ceiba to judge whether a similarly exclusive pollinator is likely.

Describes insects (silkworms) feeding on multiple tree species (mulberry, mahua, sal, ber, kusum), again showing insect herbivores often use several hosts rather than a single tree species.

A student could survey whether insects associated with silk-cotton are recorded on other plants; if so, exclusivity is less likely.

Lists silk-cotton trees among dominant species in Himalayan foothill flora, implying geographical overlap with diverse pollinator communities (birds, bats, insects) in such habitats.

Using a map of the tree's range and known pollinator distributions, test whether a single insect species' range exactly matches the tree's range (required for an exclusive coevolved pollinator).