SC Online Learning (24/05/11)

2) How has/will human activity in the Amazon regions affect the Allomerus decemarticulatus ants?

Human activities like cutting down of trees, or deforestation would destroy their natural habitat, as they inhabit in the stem of a plant. This would also prevent them from catching their prey, as the way they catch their prey is to “cut hairs from the stem of the plant, and use the tiny fibres to build a spongy platform.” Without the plants, these ants would not be able to set up these traps, and might prevent them from catching their prey successfully, and the population might die because of hunger.

3a) From this extract, identify the different symbiotic relationships and site the organisms involved.

(i) Exploitative relationshipà Between the Allomerus decemarticulatus ants (predator) and the insect they eat (prey). In this case the ants get food, which benefits them, while the insect they prey on dies, which harms them.

(ii) Commensalism: Between the Allomerus decemarticulatus ants and the plants, which the ants get the hairs from. In this case, the ants would get the hairs from the stem they need to build their trap to get their prey, which benefits them. And, the plant would not be affected, as only the hair of the plant is taken away by the ants.

(iii) Competition: Between the Allomerus decemarticulatus ants as well as another carnivorous species who also feed on insects, in the Amazon region. In this case, the ants and the carnivorous predator would compete for food, and both of the species would have a negative impact.

3b) For each type of relationship you have identified in (a), name another example of a pair of organisms depicting that relationship in nature.

(i) Exploitative relationship: Between the rabbit (predator) and the grass (prey) in a forest community. In this case, the rabbit feeds on the grass, and benefits as it fills its stomach. While the grass on the other hand, dies, and thus is harmed.

(ii) Commensalism: Between the remora and the shark. In this case the remora fish hides under the shark and get protection as well as food, from the bits of food that fallout from the shark’s teeth, from the shark. While the shark does not get affected as the remora fish is small and unnoticeable.

(iii) Competition: Between the lion and the tiger. In this case, both animals are fighting for food as they are both carnivorous and feed on meat. Both animals would be harmed by the injuries they inflicted on the opposite party and would be negatively affected.

Done by: Chua Zhong Zhi (08)