Envi-Sci Quiz Prep 10.4
From Energy Flow in Ecosystems Reading Notes
What is the source of energy plants use to grow?
THE SUN
What is the process called whereby the plants convert the sun’s energy into food?
PHOTOSYNTHISIS
Where do animals get their energy to grow, move and reproduce?
They eat the plants or other animals that ate plants
SO, originally, where did the all the energy come from that the animals use?
THE SUN
What is a producer?
PLANTS
What is a consumer?
ANIMALS
What chemical source do some deep ocean producers use for energy?
Thermal Vents
What are decomposers?
Fungus and bacteria that eat dead plants and animals.
Producers are what tropic level?
The bottom
Herbivores are what tropic level?
First level consumers
Carnivores are what tropic level?
Second (+)level consumers
How does your body get the energy out of food?
CELULAR RESPIRATION
What is cellular respiration?
The process cells use to oxidize food to extract it’s energy
For what do you use most of the energy you obtained through cellular respiration?
Most of the energy is used just to keep you alive and growing.
What happens to the excess energy that you don’t use?
It is stored as fat until you need it.
How can we trace the transfer of energy through an ecosystem?
Energy Pyramid
What is a “food chain”?
A simplified model of who eats what.
How is energy lost at each trophic level?
About 90% of the energy taken in is lost to the processes of cellular respiration and just keeping the organism alive
How does energy loss affect the types of organisms at each increasing tropic level?
Fewer individuals can be supported at each increasing level
Drill How do decomposers fit into the ecosystem’s energy flow?
Decomposers can put some energy back into the system when they are eaten
Drill How do decomposers help the environment?
They return nutrients to the soil, and clean up debris that could cause disease or fuel fires
Why do large hunting animals have super large territories?
They are at the top of the food and energy pyramid where the energy density is the lowest
Food/Energy Pyramid
REAL Food/Energy Pyramid 90% energy loss each level
Population Sampling Lab How would the number of samples affect the results?
More Samples = Better accuracy
Population Sampling Lab How would sample size and population size affect these results?
Bigger samples = Better Accuracy
Population Sampling Lab What would cause your results to be off from the actual population?
Random Chance Tags cause increased predation Tags cause disease Hunters don’t report Animal habits not considered
What concerns should biologists have about a species’ habits before they use this method to approximate population size?
If we are looking in the wrong place at the wrong time, our results will be invalid Example: If we are sampling Canadian Geese in the summer in Maryland, while the geese are in Canada
Drill Why is a food web more realistic than a food chain?
Most species eat and are eaten by many different organisms, as depicted in a food web
Drill If a food chain were broken, how could that affect the top level consumers?
All of the consumers above the break would die off.
Keystone Species PPT What does a keystone species do?
A keystone species holds the community together. Without it, everything else falls apart
Keystone Species PPT When the California sea otter was killed off, what happened to the Sea urchin population?
It grew out of control because the otter wasn’t there to eat it.
Keystone Species PPT What do sea urchins eat in that area?
The base of the giant kelp plants
Keystone Species PPT What happened to the kelp plants?
They were all killed by the high sea urchin population.
Keystone Species PPT What happened to the young and small fish?
They were eaten or left because there was no kelp forest to hide in.
Keystone Species PPT What regulates the number of sea otters that can live in an area?
The amount of sea urchins it has for food
Keystone Species PPT What are interdependent species?
Species that depend on each other to survive
Keystone Species PPT What kills the Monterey Pine Forests, and what carries it to the trees?
Pine pitch canker, carried by the pine bark beetle
Keystone Species PPT What regulates the growth of the beetles?
The Woodpeckers eat them so they do not become too numerous and kill all the trees.
Keystone Species PPT What regulates the number of wood peckers?
The number of dead trees for them to nest in.
Keystone Species PPT What fertilizes the milkweed flowers?
Monarch butterflies
Keystone Species PPT What feeds on the sap of the milkweed plant?
Monarch butterfly larva
Keystone Species PPT Why don’t birds eat the larva?
They are poisonous from eating the milkweed sap
Drill What is natural selection?
The process where a species attributes are selected for or against by the natural pressures of the environment. - - Food supply, competition, weather, etc
In general, what sort of species reproduces the most quickly?
Small organisms that are low on the food web and have many predators
What is a territory?
An area defended by one or more individuals against other individuals
What is the primary limiting factor to an area’s carrying capacity?
The most limited resource
. What is a population?
All members of a species in the same area at the same time
What is a population’s density?
# of individuals per unit of space or volume
What is a population’s dispersion?
How they are spread out in that area Clumped Random Even
What is a population’s growth rate?
Births minus deaths
What is a population’s reproductive potential?
The fastest rate at which the population can grow under perfect conditions
What 3 things affect a population’s reproductive potential?
# of offspring in a liter # of liters per year How young they reproduce
Why do physically larger species reproduce so slowly?
They have long generation times. (length of time before reproducing the first time)
What is exponential growth?
Population increases faster and faster
What is necessary for exponential growth to occur?
Lots of food and space Few predators
What is an ecosystem’s carrying capacity?
Maximum population the ecosystem can support
What happens if the carrying capacity is exceeded?
Population crashes – may recover at lower level May die off completely
What is a “limiting resource”?
Resource that limits how many individuals it can support
What is the resource that determines the ecosystem’s carrying capacity?
The resource in lowest supply
Why is there competition within a population?
Limited food, Limited shelter Limited mates
What 4 things does a territory provide?
Space Shelter Food Breeding sites
How is competition within a population part of natural selection?
Only those with the competitive traits to survive and reproduce get to pass on their genes to the next generation