Chapter 1 Flashcards
Where does the word Ecology come from?
A Greek word that means house or home
What was the term Ecology used to describe?
The observations made and the work done by scientists who studied nature and history of plants and animals
What is the definition of Ecology?
The study of relationships between living things (organisms), and their non-living surroundings, the environment
What is a name for living things?
Organisms
What is a system?
An object or a group of objects that a scientist chooses to study
What is everything other than the system referred to?
The surroundings
What is the Biosphere?
All of the areas on Earth that are inhabited by and that support life
What is the atmosphere?
The gaseous part of Earth, concentrated mainly within 10 km of Earth’s surface, but also extending hundreds of kilometers higher
What is the Geosphere?
The solid, mainly rocky part of Earth (also called the lithosphere)
What is the geosphere?
All of the water (solid as well as liquid) that exists and moves through the geosphere
What are the two types of systems?
An open system and a closed system
What is an open system?
A system that allows energy and matter to cross the system’s boundary—to enter and leave it.
What is a closed system?
A system that allows only energy (but not matter) to cross the boundary
What type of system is earth?
An open system
What do all organisms use energy for?
They use this energy to grow, maintain body processes, and reproduce
How is energy released into organisms?
From carbohydrates and other energy-rich organic molecules
What is the process that releases energy into the body called?
Cellular Respiration
For species that do not live in oxygen rich environments what is the process of releasing energy into the body called?
Fermentation
How is energy stored in molecules to begin with?
Through the process of photosynthesis
What is photosynthesis?
Using the sun’s energy to convert carbon into carbohydrates such as sugars and starches
How are carbohydrates stored?
Using sugars and starches
What is the word equation for Cellular Respiration?
C6H12O6(s) + 6O2(g) → 6CO2(g) + 6H2O() + energy
Carbohydrates + Oxygen → Carbon Dioxide + Water + Energy
What is the word equation for Photosynthesis?
6CO2(g) + 6H2O() + light energy → C6H12O6(s) + 6O2(g)
Carbon Dioxide + Water + Sun’s Energy → Carbohydrates + Oxygen
What are producers?
Organisms that are able to use the Sun’s energy to produce food for themselves using photosynthesis
What producers also known as?
Autotrophs, which means “self-feeders.”
What are heterotrophs or other-feeders?
Organisms that obtain molecules by consuming other organisms or absorbing nutrients from them
What are ” Heterotrophs that consume other heterotrophs or autotrophs called?
Consumers
What is the source of energy for all producers that grow on Earth’s surface or that float on or near the surface of the ocean and other bodies of water?
The Sun
How much of the sun’s radiant energy reaches earth each day?
About 1022 J (joules)
What are the 3 outcomes for radiant energy coming to earth?
- Will be reflected back to space
- Will be absorbed by atmosphere and clouds
- Will be absorbed by Earth’s surface
How much energy is reflected by clouds or particles in the atmosphere?
30%
What is albedo?
A term used to describe the amount of reflected energy. Average albedo is 30%
How are albedos affected by the surfaces?
- Light-coloured, reflective surfaces and thick cloud cover have high albedos of 80 percent to 90 percent.
- Dark surfaces such as forest canopies (treetops) and water have lower albedos of 25 percent or less
What percentage of sun energy is absorbed by gases such as water vapour and carbon dioxide in the atmosphere?
19%
What is the energy absorbed by absorbed by gases such as water vapour and carbon dioxide used for?
Some of this energy will heat the atmosphere, and some will radiate back into space
What percentage of the suns energy reaches earths surface?
51% Energy absorbed by the land and oceans warms the planet’s surface.
How much of the sun’s energy is used for producers?
Only a small fraction
What type of environment do chemosynthetic producers live in?
Scalding hot acidic water heated by geothermal energy with no light
Why can’t chemosynthetic producers rely on light for photosynthesis?
Because the light does not penetrate that deep
How are organisms able to survive without light?
Through chemosynthesis
How does the process of chemosynthesis work?
Micro-organisms are able to split hydrogen sulfide molecules spewing from deep sea vents. The bacteria then capture the energy stored in chemical bonds
What is a byproduct of chemosynthesis?
Sulfuric Acid
What are herbivores?
Organisms that eat plants
Why are herbivores termed primary consumers?
Because they are the first (primary) eaters of plants and other producers
What are the most common primary consumers?
On land, insects, snails, grazing mammals, and birds and mammals that eat seeds and fruits
In water, some species of fish, small invertebrate animals such as clams, and some aquatic insects
In the deep-ocean vents, tubeworms and mussels are common primary consumers
What are carnivores?
Animals that eat other animals
What are secondary consumers?
Organisms that eat primary consumers
What are examples of secondary consumers?
Spiders, frogs, and insect-eating birds are examples of secondary consumers
What are tertiary consumers?
Consumers that eat secondary consumers
How do decomposers obtain their energy?
By eating or absorbing leftover or waste matter. This waste matter includes the feces of living organisms, dead bodies, or body parts of other organisms.
What are examples of decomposers?
Decomposers include certain kinds of fungi, bacteria, earthworms, and insects.
Why are decomposers important?
Because they return organic and inorganic matter to the soil, air, and water. These materials can then be used again by producers to make new energy rich organic molecules
What type of system is earth to matter?
A closed system (except meteorites and satellites) No matter enters or leaves the biosphere
What type of path does energy flow in the biosphere?
It can not be cycled, it has a one way path unlike matter
What is the first law of thermodynamics?
Energy cannot be created or destroyed. It can only be converted from one form to another or transferred from one object to another
What is the second law of thermodynamics?
No process of energy conversion is 100 percent efficient, however. With each conversion of energy, there is less energy available to do useful work
Why are producers necessary?
Because a constant supply of energy is needed by producers
How does energy enter organisms in extreme environments?
Chemosythesis
How do chemosynthetic producers work?
Chemosynthetic producers capture the chemical energy stored in chemical bonds and convert it to chemical energy in the form of high-energy carbohydrate molecules
In a biosphere what is an ecological system made up of?
-All the organisms that live in an area and
-The physical environment of that area.
The physical environment includes non-living things
What interacting living and nonliving components form?
A self-regulating system through which energy and matter are transferred
What are the Trophic levels to describe feeding relationships in ecosystems?
- Producers
- Primary consumers (Herbivores)
- Secondary consumers (Carnivores)
- Tertiary Consumers (Carnivores ex. Lion, Polar Bear, Orca)
- Decomposers
What is a Trophic level?
A feeding level through which energy and matter are transferred.
What does the first Trophic levels provide to all other trophic levels?
The first trophic level in any ecosystem provides all the chemical energy required to fuel the other trophic levels.
Which Trophic levels are considered producers?
The First trophic level
Who created Food Chains?
Chales Elton
What is a Food Chain?
A model that shows the linear pathways where food is transferred from producers to primary consumers and to higher trophic levels
What is a Food Web?
A model of food (energy) transfer in an ecosystem that shows the connections among food chains
How many Trophic levels do food chains have?
Usually somewhere between three and six
Why does the length of a food chain have its limits?
Because the laws of thermodynamics limit the amount of energy that can be transferred from one trophic level to another
How do thermodynamics limit food chains?
As energy is transferred from producers and consumers, only some of that energy is passed along at each step.
Some energy is transferred as unusable heat
What percent of energy is not transferred to the next Tropic level?
About 80 percent to 95 percent of the chemical energy that is available at one trophic level is not transferred to the next one
How much energy do we assume is transferred?
10%
What are ecological pyramids?
Feeding relationships between organisms
What are 3 types of ecological pyramids?
Pyramids of Numbers
Pyramids of Biomass
Pyramids of energy
How are the numbers of organisms affected by trophic levels?
Animals at higher trophic levels are fewer in number than organisms at lower trophic levels
What does a Pyramid of Numbers represent?
The amount of organisms at each trophic level.
Each bar represents a different trophic level and its width represents the numbers of organisms at that level.
What shape can pyramids of numbers be?
They do not always go smallest to largest because there may be less producers than primary of secondary consumers
What is a limitation of pyramids of numbers?
It does not take into account the size of individual organisms
Why have scientists turned to using biomass as a way to measure energy transferred?
Because organisms do not always consume other organisms that are smaller than them. ex. A cougar eating a caribou
What is Biomass?
The dry mass of living, or once-living, organisms per unit area
What does each level of a pyramid of biomass represent?
Each trophic level
What does a pyramid of biomass represent?
How the amount of biomass changes as energy is transferred from one trophic level to the next
What is a complication with a pyramid of biomass?
Scientists define biomass in different ways. Some include only living materials. Others also include
once-living materials.
There are also exceptions to the upright pyramid shape, as there is with pyramids of numbers. The amount of producers may be much less than the consumers
How can there be fewer producers than consumers in an ocean ecosystem
The phytoplankton producers grow and
reproduce at a rate that exceeds that
of the consumer. The number of producers doubles in size every few days, but this is not reflected in their biomass because they are eaten as quickly as they reproduce
What does a pyramid of energy depict?
The total amount of energy that is transferred through each trophic level
What shape can a pyramid of energy be?
A pyramid of energy is always upright, because there can never be less energy in a lower trophic level than in a higher one
How is stability of a feeding relationship related to number of species?
The stability of feeding relationships in ecosystems decreases with a decrease in the number of species (that is, biodiversity)—especially the number and variety of producers
What are food chains and food webs based on?
Trophic levels
What are ecological pyramids used to describe?
Quantitative relationships between trophic levels
What is a pyramid of numbers based on?
The number of organisms in each trophic level
What is a pyramid of biomass based on?
Based on the biomass of organisms in each trophic level
What is a pyramid of energy based on?
The total amount of energy in each trophic level and cannot be inverted.
