Ecosystems, Habitats, and Symbiotic Relationships

Ecosystem

• An ecosystem consists of organisms living together and interacting with each other and their environment.

• Definition is simple to memorize but important for exams.

Habitat

• A habitat is the place where an organism lives, with an environment made of physical and living features.

Abiotic vs. Biotic

• Abiotic: Non-living (physical) features.

• Biotic: Living features.

Abiotic Environment (Non-Living Features)

• Important for survival:

  • Temperature: Maintained by the sun.

  • Light: Essential for photosynthesis.

  • Water

  • Air

  • Soil

Biotic Environment (Living Features)

• Consists of all the organisms living in a habitat.

• Organisms interact and form relationships.

  • Competition

  • Predator and Prey

  • Symbiosis

Relationships

Competition

• Plants compete for sunlight (growing taller) and water/minerals (roots going deeper).

• Animals compete for food, especially with predators.

• Humans compete for jobs, grades, etc.

Predator and Prey

• Predators hunt prey for food and survival.

Symbiosis

• Classified into three subcategories:

  • Parasitism

  • Commensalism

  • Mutualism

Parasitism

• One side (parasite) benefits at the expense of the other (host).

• Example: Mosquito biting a person.

  • Mosquito benefits (gets blood).

  • Person is harmed (itchy bite, potential diseases like dengue).

Commensalism

• One side benefits, the other is not significantly helped or harmed.

• Example: Climber plants (orchids, money plants) climbing on a tree.

  • Climber plant benefits (gains sunlight).

  • Tree is not affected.

Mutualism

• Both sides benefit.

• Example: Teacher and students.

  • Students gain knowledge.

  • Teacher improves teaching through student feedback.

Symbiosis Examples in Nature

Parasitism

• Wasps lay larvae on a caterpillar. The larvae benefit, and the caterpillar dies after serving its purpose.

Commensalism

• Remora fish attaches to a larger fish. The remora fish benefits because it has the free ride so it gets to eat.

Mutualism

• Sea anemone cannot move to catch prey. Clownfish acts as a lure to attract sea creatures to the sea anemone which poisons the fish so that it can eat them. Clownfish is protected and eats the remains of the dead fish.