Wednesday, 20 May 2026

7D Interactions with organisms

 interactions

Here are the five main types of interactions with examples:

  • Predation (+/-): One organism (predator) kills and consumes another (prey). Example: A lion hunting a zebra.

  • Competition (-/-): Two or more organisms vie for the same limited resource, such as food, water, or territory, harming both in the process. Example: Lions and hyenas competing for the same prey.

  • Mutualism (+/+): Both species benefit from the interaction. Example: Bees gathering nectar while pollinating flowers.

  • Commensalism (+/0): One organism benefits while the other is neither helped nor harmed. Example: Barnacles attaching to whales for transportation.

  • Parasitism (+/-): One organism (parasite) benefits at the expense of another (host), typically without killing it immediately. Example: Ticks feeding on a dog. 

Part B

Identify the type of biotic interaction being described in each example: predation, interspecific competition, intraspecific competition, mutualism, parasitism, commensalism.

 1. _____Competition____ Two humans fight for the last bag of chips.

 2. ____Commensalism______ Some birds use abandoned nests built by other birds. 

3. ____Parasitism______ Tapeworms can be found in the intestines of animals (such as cats, dogs and humans) absorbing nutrients meant for the animal, making them very skinny. 

4. ____Competition_____ Cows and horses both graze on grass. 

5. ____Mutualism___ Dogs have lived with humans for thousands of years, getting food and shelter. Humans receive companionship, protection and assistance from dogs. 

6. ____Predation______ Foxes hunt and kill rabbits.