Download Interactions and Ecosystems Study Guide 1. Describe the difference

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Science 7
Unit A: Interactions and Ecosystems Study Guide
1. Describe the difference between biotic and abiotic parts of an ecosystems? Give examples…
Biotic factors are things that are living in an ecosystem, i.e. plants, animals etc.…
Abiotic factors are Non-Living factors in an ecosystem, i.e. soil, sun, water, rocks, etc.…
2. Explain the following terms, and provide examples?
a. Species
Are organisms that are similar, can reproduce and their offspring can reproduce with one
another i.e. humans, horses, etc.
b. Population
A number of individuals of the same species living together in the same area
c. Community
All the populations of different species living and interacting in the same area make up a
community
3. What are the basic needs of living objects for survival?
Water,
food (nutrients),
Energy,
Suitable Habitat (living conditions)
4. Describe the three types of Symbiotic relationships, and provide an example for each one?
Mutualism: Is a relationship between organisms where both species benefits, and neither one is harmed
i.e. bumble bees/flowers, bumble bees get food, the flowers are cross pollinated
Commensalism: is a relationship between organisms where one species benefits, and the other is
neither harmed nor benefits. i.e. orchids/trees, orchids grow on the trees to access sunlight that they
would otherwise struggle to get. The tree in the mean time is unharmed
Parasitism: Is a relationship between organisms where one organism benefits, and the other is harmed.
i.e. tapeworm and host (animal/human)
5. What is the difference between a behavioral adaptation, and a structural adaptation?
Adaptation is a way in which an organism responds to changes in its environment
They can be structural which means the organism develops a physical change that allow it to survive
better in the new conditions. i.e. changing colour of skin to suit the change in season like the Artic Hare
Or Behavioral adaptations, which is a change in the way they live that allows them to survive. i.e. birds
migrate south to avoid cold winter conditions, animals hibernate
6. What is the difference between a ‘dump’ or landfill- and a sanitary landfill?
Dump/landfill were just big holes where people dumped their garbage, no thought or concern was given
to runoff, attractiveness or potential problems of an open pit
Sanitary Landfill, are designed to have proper drainage that controls the polluted runoff, also you
section off the different types of garbage (wood, steel, appliances) that allows for proper disposal of the
garbage.
7. Compare the following consumers:
a. Carnivores
Consume only meat, meaning that they are usually a high level consumer on the food chain
b. Herbivores
Eat only plants/producers, meaning they are a first level consumer
c. Omnivores
Eat both plants and animals, and therefore can appear just about anywhere on the food
pyramid
8. What is the word equation (reactants & products) for photosynthesis?
Carbon Dioxide + Water + Energy (sun) → Oxygen + Food (starches & sugars)
9. What is the word equation (reactants & products) for Cellular Respiration?
Food Energy + Oxygen → Carbon Dioxide + Water + Energy (used for living things)
10. What is the difference between scavengers and decomposers?
Scavenger: is an organism that feed off of the remains of living things (don’t usually kill their
own food) i.e. ravens, housefly larvae
11. What are two ways that we represent the flow of energy in an ecosystem? Which one is a more
accurate portrayal?
Food Webs
Food Chains
Food Webs, because they include multiple food chains all at once, providing a better
descriptions of how energy actually flows through an ecosystem
12. What are the three main parts to the water cycle?
Precipitation (rain, snow, hail), Evaporation (liquid turns to gas, heads up into the atmosphere),
Condensation (gas turns back into a liquid up in the atmosphere)
13. What are two sources of carbon dioxide in the atmosphere?
Pollution either from industries (factories) or vehicles
Cellular respiration performed by living organisms
14. What is the process that removes carbon dioxide from the atmosphere?
Photosynthesis uses the suns energy and Carbon Dioxide to produce oxygen, water, and food
energy
15. Explain the following ways that Ecosystems can change?
a. Bioinvasion
New species is introduced to an ecosystem that is stronger than the native species
(original) with less enemies, therefore they quickly multiply and take over an ecosystem
b. Resource Competition
Competition occurs due to the limited amount of any one resource in an ecosystem at
any given time. The competition over factors such as food, habitat, etc… Control not
only the populations of species, but can play a major role in the survival of others
c. Predation
Involves the predator/prey relationship and the cycle that is exists between the two. So
when the population of prey is high (ideal conditions), the number of predators will rise,
which will lead to a drop in the population of prey due to hunting, and therefore the
population of predators will drop accordingly in response to this change. See p. 60 of
your text book
d. Weather
Changes in weather or climate can alter an ecosystem dramatically. Dry periods can
cause a wetland area to dry up, Natural disasters can alter the existing ecosystem as
well (floods kill some plants and animals, lightning can start forest fires)
16. What is the difference between Primary Succession and Secondary Succession?
Primary succession occurs in areas where no life exists due to the absence of soil (i.e. volcanic
island
Secondary Succession occurs when a community has been destroyed or disturbed by natural
occurrences or human activities. It is different because these habitats previously supported life
(i.e. a farmers field, parking lot, a strip mine)
17. What is a pioneer species, what role does it play in developing a climax community?
Is the first species to arrive to an ecosystem that was devoid of life before it arrived. These species
tend to be plants that can survive in harsh conditions and have adaptations that allow to grow when
little soil is present
18. Explain how things like pesticides can have ‘unintended consequences’ (use DDT example)?
Often choices are made in life without considering the larger picture. Pesticides are one of these
choices that have been used to control pest insects for many different reasons, but they end up
altering the ecosystems where their used with many unwanted results.
DDT was used in the early 1950’s to help kill mosquitoes causing an outbreak of malaria. This solved
the malaria problem, but then bioaccumulation (build up) of DDT was altering other organisms
especially cats that were starting to die after eating too many poisoned geckos. Thus leading to an
increase and infestation of rats that were normally prey for the cats.
Farmers have used DDT and other pesticides in North America, the effect on migrating birds has
been detrimental. It causes the thickness of their shells to weaken often causing the eggs to break
before the offspring inside can become viable.
19. What is the difference between threatened, endangered, extirpated, and extinct?
Threatened: Species whose numbers are declining
Endangered: Serious risk of becoming extinct
Extinct: Species no longer exists anywhere on earth
20. What is an ecological footprint? What are some ways you can reduce your ecological footprint?
Is a term we use to help us understand the effect our way of life has on the earth
It involves a measurement between the amount of resources we use vs. the amount of resource
waste that the earth can handle without interference.
Ways that you can reduce ecological footprints involve any process that lessens the amount of
resources you consume. i.e. better water consumption, better transportation uses (car pooling,
walking), Recycling and reusing items, cutting down on energy consumption
21. What is meant by sustainable lifestyle?
Sustainable lifestyle is living within the means of your current ecosystem, so that it can continue
to support your needs for future years, and generations to come.
This primarily refers to resource consumption such as non-renewable resources, food, water,
etc.