Interactions in the Environment
What is an Ecosystem?
Check Your Learning: Answer the following questions:
1. Define the followings:
Organism: A single living thing
Population: Is the number of organisms of the same species living in one place at the same time.
Community: A community is made up of all the populations that live in the same area. (All organisms within an area)
Ecosystem: The network of interactions that link the living and non-living parts of an environment.
Biome: Is a collection of related ecosystems.
Biosphere: Is all of the biomes and all of the ecosystems on Earth.
Species: A group of living things that look similar and can mate and produce similar offspring.
Micro-organism: A living thing that is small and must be viewed with the help of a microscope.
Ecology: The study of relationships between organisms, and between organisms and their environment.
2. Explain how a rotting log can be an ecosystem.
An ecosystem is a system of interactions between biotic and abiotic parts of an environment. That system can be large or small. In a rotting log, abiotic elements such as water, temperature, and light are interacting with fungi, insects, micro-organisms (living things) and the rotting log itself (which began as a biotic living tree and is being decomposed into abiotic nutrients).
3. Give an example of a smaller ecosystem existing within a larger ecosystem.
Forest is an example of a large ecosystem that contains many smaller ecosystems. For example, animals in the savannah ecosystem drink water from the marsh ecosystem, which gets some water that runs off from the savannah and swamp forest ecosystems when it rains.
4. Define biotic and abiotic. List thee biotic and three abiotic components (examples):
Biotic: Living things that live in the same ecosystem. / 3 examples: plants (grass, carrots, apples), animals (dogs, lions, etc), others (humans, bacteria)Abiotic: Non-living things that live in the same ecosystem / 3 examples: water, temperature, light, oxygen, nutrients, soil, etc.
The Needs of Living Things
Check Your Learning: Answer the following questions:
1. a) List the basic needs of all living things.
Living things need energy (from sunlight), gases in the air, water, nutrients, and ideal temperature.
b) Explain why organisms need these factors to survive.
Organisms need water, oxygen or carbon dioxide from the air, and nutrients from food to grow, to maintain their bodies, and to carry out their life processes. These activities also require energy. Without a ideal temperature range, organisms will either freeze to death or overheat.
2. Explain why sunlight is a basic need for both plants and animals.
Plants need light energy to make their own food. The Sun's energy is passed along to animals when they eat plants or other animals that have eaten plants. Animals and plants also need the Sun to keep Earth at a ideal temperature.
3. Describe the different (3) ways that different organisms need water to survive.
a) Plants need water, CO2, and sunlight to grow up and to make food. b) Animals need water to digest food and to form bodily fluids, such as blood. C) Water animals also get their oxygen from water.
4. Name two ways that plants affect human survival.
Plants help humans survive by a) producing oxygen, which we need to breathe, and by b) providing us with food.
Interactions Among Living Things
Check Your Learning: Answer the following questions:
1. In your words, explain competition.
Competition is an interaction between organisms that use the same resources available in an area. Competition can occur within a population (that is, between members of the same species) and between populations of different species.
2. Explain how competition affects the number of organisms that can live in a habitat.
Competition limits the number of organisms that can live in a habitat because some resources are limited. When there is not enough of a resource for all the organisms in an area, the organisms that lose the competition for that resource either die or move somewhere else in search of that resource.
3.
a) What is a predator animal? Give an example of a predator.
A predator is an animal that hunts and kills another animal for food. Examples include cats, which hunt mice.
b) What is a prey animal? Give an example of a prey animal.
A prey animal is an animal that is hunted and eaten. Examples include rabbits, which are hunted by foxes.
c) What is mutualism? Give an example of a mutualism.
Mutualism is an interaction between individuals of different species that benefits both individuals. An example of mutualism can be seen when a bee visits a flower. Another example occurs between plants of legume family and bacteria in the soil.
Chapter Review
1. For each of the followings, explain the difference between the two terms:
a) Biotic and abiotic
Biotic / Biotic means living. Biotic elements of the environment are living things or things produced by living thingsAbiotic / Abiotic means non-living and not produced by living things. Abiotic elements of the environment are non-living things and conditions.
b) Individual and population
Individual / An individual is one living thing.Population / A population is the sum of all the individuals of the same species in an area.
c) Predator and prey
Predator / A predator is an animal that hunts and kills its food.Prey / A prey is the animal hunted by the predator.
2. Give two examples of biotic-abiotic interactions
a) The giving off oxygen into the air by plants as they photosynthesize.
b) The taking of oxygen from water by fish as they breathe.
3. a) What is an ecosystem?
An ecosystem is a system of interactions among and between the biotic (living) and abiotic (non-living) elements of an environment.
b) How is an ecosystem different from a habitat? Give and example of each.
A habitat is the place in an environment where an organism lives. For example, when a frog lives in and around a pond, the pond area is frog’s habitat.
The pond ecosystem is the system of interactions between and among the frog, water, pond plants and algae, other animals in the pond, air, sunlight, temperature range over the year, and other biotic and abiotic elements in the area.
4. Imagine you are a gardener. You are having trouble growing a certain species of plant in the area where you live (Fig 2).
a) Suggest possible (3) reasons why this type of plant will not grow in your area.
1. The plant may have too little or too much water.
2. 1. The plant may have too little or too much sunlight.
3. It may need nutrients that are not in the soil.
4. It may not be able to grow in the temperature range in the region.
5. A pest that might not be easy to see may be damaging the plant.
b) What steps (name 3) could you take to solve the problem?
1. Move the plant to a well-drained slope for less water or to low spot for more water.
2. Remove other plants that are shading the plant, or add plants to provide shade if the temperature is too hot.
3. Add nutrients to the soil.
4. Move the plant indoor or into a greenhouse, if it needs to be warmer.
5. Examine the plant closely and attempt to remove any pests.
6. Key Question: What are the essential elements of a healthy ecosystem?
A healthy ecosystem needs living and non-living elements, including sunlight, that interact to provide organisms with water, oxygen or carbon dioxide, nutrients, and a ideal temperature range to survive.
What is an Ecosystem?
1. Organisms are biotic because they are living things.
2. An ecosystem is the interactions of biotic and abiotic parts of the environment. A marsh is one ecosystem in Point Pelee National Park.
3. A population is made of members of the same species.
A community is made of many different species.
4. Elements in an ecosystem are biotic and abiotic. These elements constantly affect each other. For example, when the Sun melts snow, two biotic elements interact.
Analyze Parts of an Ecosystem
1. a) Two abiotic elements b) a biotic an abiotic element. C) Two biotic elements.
The Needs of Living Things
1. Sunlight, air, water, food, and an ideal temperature.
2. Organisms can only live in habitats where their basic needs are met.
3. Water has dissolved gases. Most plants and animals that live in water absorb these gases from the water.
4. Some animals eats plants, which have already used sunlight to make food. Meat-eaters then get energy by eating plant-eaters.
5. Organisms need: Sunlight to grow and reproduce. Air to get important gases. Water and food to grow and stay healthy. An ideal temperature…
Identify the basic needs of living things:
1)
a) food b) sunlight c) water d) air e) ideal temp range
2)
a) The air in the environment has oxygen for me to breathe.
b) The food that grows in the area gives me nutrients.
3) Only organisms that need a small supply of water could live in a desert. Organisms that need a large supply of water could not survive.
Interactions among living things
1. Competition happens when organisms that live in the same place try to use the same resources.
2. The owl is the predator because it hunts. The mouse is the prey because it is hunted by the owl.
3. The owls do not have enough to eat. They become weaker and some die.
Symbiosis is the relationship between organisms of different species that show an intimate association with each other. Symbiotic relationships provide at least one of the participating species with a nutritional advantage. It is 3 types:
1. Mutualism is an interaction between organisms of different species. This interaction benefits both organisms.
2. The number of organisms that can live in a habitat depends on the amount of resources in the area. Organisms have to compete for the same resources. When the resources are limited, some organisms die or move to another area.
3. Commensalism is an interaction between organisms of different species. One benefits while the other neither benefited nor harmed.
4. Parasitism is a biotic interaction that is beneficial to one species (the parasite) and detrimental to the other (the host). The parasite lives on or in the host and obtains its nutrition from the host.
Analyze changes in populations (activity sheet)
1. This chart shows predation. You can see how predator and prey populations affect each other.
2.
a) The wolf population decreased, and the moose population increased.
b) As the wolf population decreased, there were fewer predators to eat the moose. As a result, the moose population increased.
How do humans fit into ecosystems?
1. Humans need the same resources that another organisms need, such as soil and water.
2. Pesticides and fertilizers can pollute the soil. Pesticides may take away food from birds. Farming machines pollute the air.
3. Mining gives humans important metals. Humans can also harm ecosystems. Toxic substances harm organisms in the environment.
4. Humans change ecosystem by adding or taking away things. Shelters in Ontario cut down forests to build farms and towns.
Interactions Within Ecosystems
Check Your Learning: Answer the following questions:
1. Explain the differences between producers and consumers.
Producers: get energy from food they make themselves. Most producers make food using CO2, water, and energy from sun.
Consumers: They get energy by eating other organisms.
2.
a) What are the raw materials of photosynthesis?
The raw materials of photosynthesis are CO2 and water (H2O). Plants also need sunlight to perform photosynthesis.
b) What are the products of photosynthesis?
The products of photosynthesis are oxygen and sugars.
c) What happens to the products of photosynthesis?
The sugars made in photosynthesis are used by the producer for energy and to build up its body. Oxygen that the plant does not use itself is released into the atmosphere. The food and oxygen may be used by animals when they consume plants and breathe in oxygen.
3. What is the difference between detrivores and decomposers?
Detrivores get their energy by feeding on large parts of decaying animals and plants.
Decomposers feed on decayed matter left behind by consumers and detrivores.
4.
a) What are the similarities between omnivores and carnivores?
Omnivores and carnivores are both types of consumers, and both eat animals.
b) What the differences between omnivores and carnivores?
Omnivores eat plants, but carnivores do not.
5. What role do scavengers play in ecosystems?
Scavengers eat the remains of dead organisms.
6. Define the followings:
a) Producer: an organism that makes its own food from non-living materials.
b) Consumer: an organism that eats other living things for energy.
c) Herbivore: an organism that eats plants only.
d) Carnivore: an organism that eats other animals only.
e) Omnivore: an organism that eats both plants and animals.
f) Scavenger: an organism that eats already dead animals.
g) Detrivore: an organism that feeds on large parts of decaying plant and animal matter and on waste material.
h) Decomposer: an organism that consumes and breaks down dead organisms or waste matter into simple substances.
7.
a) Define the process of photosynthesis.
Photosynthesis is a process by which plants use water, carbon dioxide, and sunlight to produce sugars (food).
b) What is the equation for the stages of the photosynthesis?
Sun’s energy + water + Carbon dioxide à food (sugar) + oxygen
H2O + CO2 + light energy à sugar (C6 H12 O6 ) + O2
Food Chains and Food Webs
Check Your Learning: Read Pages 125-128. Answer the following questions:
1. Define food chain and food web.
Food Chain: a sequence that shows how energy and nutrients are transferred from one organism to another in an ecosystem.
Food Web: a model that shows how food chains in an ecosystem are connected.
2. Create two food chains from the following list. Use Figure 4 to help you.