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Organisms and Populations — BIOLOGY STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceBIOLOGYOrganisms and Populations4 Marks
Question
Explain Mutualism as a population interaction with suitable examples.###Explain Mutualism with examples
✓

Answer

→ This interaction confers benefits on both the interacting species.
→ Lichen : It is a mutualistic relationship between a fungus & photosynthesizing algae or cyanobacteria.
→ Mycorrhizae : Associations between fungi & the roots of higher plants. The fungi help the plant in the absorption of essential nutrients from the soil while the plant provides the fungi with carbohydrates.
→ Mutualism between plant & animal through pollination and seed dispersion :
Examples :
(1) Fig trees & wasps : The fig species is pollinated only by its 'partner' wasp species.
→ Female wasp pollinates the fig inflorescence  while searching for suitable egg-laying sites in fruits.
→ The fig offers the wasp some developing seeds, as food for the wasp larvae.
(2) Orchids : show diversity of floral patterns. They can attract the right pollinator insect (bees & bumblebees) to ensure pollination. Not all orchids offer rewards.
(3) 'Sexual deceit of Ophrys :  (Mediterranean orchid). One petal of its flower resembles female bee in size, colour & markings.
→ So male bee 'pseudocopulates' with the flower and is dusted with pollen. When this bee 'pseudocopulates' with another flower, it transfers pollen to it.
→ If the female bee's colour patterns change. slightly during evolution, pollination success will be reduced unless the orchid flower co- evolves to maintain the resemblance of its petal to the female bee.

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