Ecology Chapter 2: Food Chains

Ecosystems and Food Chains

• A food chain shows how each living organism gets its food and how nutrients are passed from one organism to another.
• Plants and animals depend on each other for survival in an ecosystem.

Predators and Prey

• An animal that hunts and eats other animals for food is called a predator.
• An animal that is hunted by another animal is called prey.

Competition in Ecosystems

• Animals living in the same ecosystem compete with each other for food, water, and space.
• Plants also compete with each other for basic needs like nutrients, sunlight, water, and space.

Balance in Ecosystems

• A change or alteration of any one factor disturbs the balance in the entire ecosystem.
• Natural disasters like storms, floods, famines, and droughts can upset the balance in an ecosystem.

Human Impact on Ecosystems

• Human activities that affect the balance in an ecosystem include deforestation, overgrazing, pollution, overhunting, and overfishing.
• Ways to protect ecosystems include reforestation, treating sewage and waste water, and reducing the use of chemical fertilizers and pesticides.

Key Terms

• A group of individuals of the same type that live together within an ecosystem at a particular time is called a population.
• Areas that receive medium rainfall are called temperate regions.
• Overgrazing, the practice of cattle that destroys grasses, shrubs, and plants.
• Competition between two or more living organisms for the same basic needs is called competition.
• Reforestation is the growing of trees in areas that once had forests.
• Herbivores are animals that eat plants.

Ecosystems and Food Chains

• A food chain shows how each living organism gets its food and how nutrients are passed from one organism to another.
• Plants and animals depend on each other for survival in an ecosystem.

Predators and Prey

• An animal that hunts and eats other animals for food is called a predator.
• An animal that is hunted by another animal is called prey.

Competition in Ecosystems

• Animals living in the same ecosystem compete with each other for food, water, and space.
• Plants also compete with each other for basic needs like nutrients, sunlight, water, and space.

Balance in Ecosystems

• A change or alteration of any one factor disturbs the balance in the entire ecosystem.
• Natural disasters like storms, floods, famines, and droughts can upset the balance in an ecosystem.

Human Impact on Ecosystems

• Human activities that affect the balance in an ecosystem include deforestation, overgrazing, pollution, overhunting, and overfishing.
• Ways to protect ecosystems include reforestation, treating sewage and waste water, and reducing the use of chemical fertilizers and pesticides.

Key Terms

• A group of individuals of the same type that live together within an ecosystem at a particular time is called a population.
• Areas that receive medium rainfall are called temperate regions.
• Overgrazing, the practice of cattle that destroys grasses, shrubs, and plants.
• Competition between two or more living organisms for the same basic needs is called competition.
• Reforestation is the growing of trees in areas that once had forests.
• Herbivores are animals that eat plants.