Unit #1 – Topic 4 – How Organisms Interact
1. Define biotic & abiotic. Please give an example of each. p.38
- Biotic: the living parts of an ecosystem
- Ex. Animals, plants, insects, microorganisms
- Abiotic: the non-living parts of an ecosystem
- Ex. Air, sun, soil, water
2. What is a niche? P.40 What are examples of your different niches?
- Niche: the role or characteristic activity that is undertaken by an organism
in an ecosystem; one organism may fill several niches
- Examples of your niches: student, sports, music, son/daughter,
brother/sister, etc.
3. Define each of the following and include examples.
Producers: plants and algae that use the energy from the Sun to make
food for themselves. They make life possible for all other organisms on Earth.
Ex. Plants (trees, sunflowers, crops, vegetables, etc.)
Consumers: organisms that eat the food made by producers or they will
eat other consumers. Consumers can be either herbivores (plants), carnivores
(meat), omnivores (both).
Ex. Cows, falcons, deer, raccoons, tadpoles, etc.
Herbivores: animals that eat producers (Ex. Beaver, cow, deer)
Carnivores: animals that eat other consumers (Ex. Tiger, bear, falcons)
Omnivores: animals that eat both producers and consumers (Ex. Humans,
raccoons)
4. How are Predators and Prey related? Give examples.
- Predators catch and kill organisms of another species (prey)
- Prey get caught and eaten by another organisms of a different species
(predator)
- Predators can also be prey to another species. Prey can also be predators to
another species.
5. Please copy the diagram of the Food Chain from p. 42 into your notes and
label all parts using vocab from above.
Producer – Grass
Consumer – mouse, snake, hawk
Herbivore – mouse
Carnivore – hawk, snake
Predator – hawk, snake
Prey – mouse, snake
6. A Food Chain is: a sequence of feeding relationships among living
organisms as they pass on food energy
*Shows how energy stored in food passes from organism to organism*
7. Copy the Food Web on p.43 into your notes. How is it different than a
food chain?
A food web is different from a food chain because it is a network of
interconnected food chains.
8. What does the term energy flow mean? Give an example
Energy flow is the movement of energy, starting from the Sun, and passing
from one organism to the next.
Ex. Sun -> grass -> cow
9. A Pyramid of Numbers represents the number of organisms consumed at
each level. In a Pyramid of numbers, there are always more animals being
eaten than there are animals eating. This supports the visual of a Pyramid.
Energy is consumed at each level. Producers form the bottom level.
10. Biomass is the total mass of all organisms in an ecosystem. The most
biomass is in the base of a pyramid formed by producers.
11. What is the difference between a scavenger and a decomposer? P.44
Scavengers: organisms that feed on dead or decaying plant or animal matter
Ex. Magpie, crows, wolverines, etc.
Decomposers: grow on or in dead or waste material, absorbing some of the
nutrients into their own cells. The remaining nutrients recycle back into the
ecosystem.
Ex. Fungi, bacteria, mushrooms, etc.
Topic 4 Review: page 48 #1-4