Chapter 1: Interactions Between Living Things and Their Environment Lesson 1: Interdependence of Plants and Animals

The student will:  recognize how animals and plants are interdependent.  distinguish between commensalism, parasitism, and mutualism.  predict whether an organism can survive in a particular ecosystem.

Getting the Idea  When a tree falls down in the woods, many other living things in that forest are affected.  Birds that might have made their homes in the tree have to find a new place to live. Plants that were living in the shade under that tree are now in the bright sun.

Getting the Idea  Animals that might have eaten fruit or leaves from that tree must find other food.  An ecosystem is all the living and non-living things that can be found in a particular area.

Getting the Idea  The plants and animals in any ecosystem are connected to each other in different ways. When something happens to one part of an ecosystem, other parts of the ecosystem are affected, too.

The Nonliving Parts of an Ecosystem  An ecosystem is made up of many plants and animals. But there are important parts of an ecosystem that are not alive.  The sun, water, soil, and air are all parts of the ecosystem that give that area certain characteristics. These are abiotic characteristics.

The Nonliving Parts of an Ecosystem  One ecosystem might be rocky and dry.

The Nonliving Parts of an Ecosystem  Another ecosystem might be marshy and cold.

The Nonliving Parts of an Ecosystem  These nonliving factors determine the kinds of plants and animals will be able to live in an ecosystem.

The Nonliving Parts of an Ecosystem  Plants and animals that need warm, moist conditions will be found in tropical ecosystems but not in the Arctic tundra.

The Nonliving Parts of an Ecosystem  Polar bears will be found in the Arctic tundra but not in the tropical ecosystems because their thick fur and layer of fat would make it hard to handle the heat of the tropics.

The Nonliving Parts of an Ecosystem

The Living Parts of an Ecosystem  The nonliving parts of an ecosystem create an area, or habitat, for all the living organisms in that ecosystem.  The living things include plants, animals, bacteria, and fungi. The things are the biotic characters. They couldn’t live without the abiotic resources in the area, such as water, soil, and sunlight.

The Living Parts of an Ecosystem

 In many ways, the living organisms depend on each other, too. Animals depend on plants for things such as food and shelter. Plants give off oxygen and take in carbon dioxide. Animals need the oxygen that plants are breathing out. In return, animals breathe out the carbon dioxide that plants need.

The Living Parts of an Ecosystem  Plants depend on animals to deposit waste in the soil that can return nutrients to the soil.  Plants also depend on fungi to break down dead plants and animals to return nutrients to the soil.

The Living Parts of an Ecosystem  Each living organism must find a way to live and survive in its habitat.  All of the activities that an organism does, along with its actual habitat, form an organism’s niche.

The Living Parts of an Ecosystem  A niche is the role of an organism in its habitat, including where and what it eats and all the other interactions it has in the habitat.

The Living Parts of an Ecosystem

 So a beaver’s niche would be the pond it lives in, the forest around the pond where it chews on trees, the tree bark it eats, the predators that it must hide from, the air it breathes, and the sun that warms its home.

1. Which of the following is a way that plants depend on animals?  A. Animals get energy by eating plants.  B. Plants are homes to birds and other animals.  C. Plants get carbon dioxide from animals.  D. Plants get oxygen from animals.

2. Which of the following is a living part of a pond ecosystem?  A. Water  B. Sun  C. Bacteria  D. soil

3. There are many ways that plants and animals depend on each other for survival. All of the following are examples of interdependence in ecosystems except that  A. plants provide food for animals  B. animal waste gives nutrients to the soil  C. Insects pollinate the flowers of plants  D. Plants get their energy from animals

1.A harbor seal lives in the ocean, eats fish, and is eaten by polar bears. The ocean, the fish, and the polar bears are all part of the harbor seal’s  A. Niche  B. Predators  C. Nonliving environment  D. prey

1. Which of the following is a way that plants depend on animals?  C. Plants get carbon dioxide from animals.

2. Which of the following is a living part of a pond ecosystem?  C. bacteria

3. There are many ways that plants and animals depend on each other for survival. All of the following are examples of interdependence in ecosystems except that  D. Plants get their energy from animals

A harbor seal lives in the ocean, eats fish, and is eaten by polar bears. The ocean, the fish, and the polar bears are all part of the harbor seal’s  A. niche

Homework:  An ecosystem contains blueberry bushes, deer, mice, snakes, and a river. Give FOUR examples of how living and nonliving parts of this ecosystem depend on each other to survive.