Question

How many of the following shows “+ :“ interaction?
i. Fig and wasp
ii. Convolvulus and wheat
iii. Sparrow and seeds
iv. Tiger and deer
v. Epiphytes on mango tree
vi. Plasmodium and human

A) 5
B) 2
C) 4
D) 3

Answer 1

The organisms under natural conditions influence each other directly or indirectly. The members of that particular community are dependent upon each other. This interdependence is reflected in their interactions, mainly for food, space, reproduction, and protection. These interactions are important for the survival of different species and groups as a whole.

Complete answer:
The interactions between members of an ecological community can be classified within two broad categories. These are:
• Direct effect
• Indirect effect

The interactions having a direct effect between populations of species in a community are broadly categorized into:
• Positive: Both participating species get benefits and neither is harmed.
• Negative: An interaction in which both species or one of the species gets harmed.
• Neutral interaction: interacting species have no effect on each other.
Predation involves negative interaction. The sign ‘+’ and ‘:‘is used to denote their interaction.
The positive sign is for the species that is getting benefitted and the negative sign is for the species which is being consumed or is being harmed.

- Sparrow and seeds: It is an example of seed predation. It is also termed as Granivory. It is a type of plant interaction and in this, the granivores feed on fruits and so damage the fruit.
- Tiger and Deer: Tiger is a carnivore and it predates upon Deer for food requirements. Tiger acts as a predator and is unharmed while Deer acts as prey and is harmed.
- Fig and Wasp:The relationship between Fig and wasp is that of mutualism. Wasp gets a place for reproduction as fig serves a womb and in turn, wasp helps Fig by pollinating the seeds.
- Convolvulus and wheat: The Convolvulus is a weed and it uses the nutrients stored in place for wheat and hence acts as a parasite.
- Epiphytes on mango trees: Epiphytes are the Orchids grown on the mango tree and share Commensalism as only one is benefited and the other remains unaffected.
- Plasmodium and Humans: The plasmodium acts as a parasite on the human body that acts as a host. It is an example of a Parasitic relationship.

Hence, the correct answer is option (B).

Note: Effective predation requires structural, functional and behavioural adaptations, the nature of which depends on the predator's general body organisation and size, the type of predatory strategy adopted, the general environmental conditions in which predation is practiced, and the predators' defensive strategies. The environmental structural complexity of the landscape, habitat, and microhabitat scale, and its seasonality affect the behaviour and efficiency of the predator.