Population Changes
A population increases when this number is greater than the number of deaths
What is the number of births?
Organisms need these molecules for energy to live, grow, and reproduce.
What are energy storage molecules (ESM)?
What is an organism called when it is eaten by another organism?
A resource.
What is it called when two populations use the same resource?
Competition.
Which population increased dramatically in Glacier Sea?
The moon jelly population.
A population decreases when the number of deaths exceeds the number of births.
What is the number of deaths?
Animals usually obtain energy storage molecules by doing this.
What is eating food/resources?
What is an organism called when it eats another organism?
A consumer.
If one competitor population decreases, what happens to the amount of the shared resource available to the other competitor?
More of the resource may become available.
What population do moon jellies eat to get energy storage molecules?
Zooplankton.
If births increase while deaths stay the same, what happens to population size?
The population increases.
When an organism reproduces, its stored energy generally does this.
It decreases because reproduction requires energy.
If a resource population increases, what may happen to its consumer population?
The consumer population may increase because more food and energy storage molecules are available.
What is an indirect effect in an ecosystem?
When a change in one population causes a change in another population through one or more populations in between.
If the zooplankton population increases, how could this affect moon jelly births?
Moon jelly births could increase because more zooplankton provides more energy storage molecules for reproduction.
If deaths decrease while births stay the same, what happens to population size?
The population increases.
If a population has more food available, individuals may obtain more ESM. How can this affect births?
Births may increase because more organisms have enough stored energy to reproduce.
If a consumer population decreases, what may happen to its resource population?
The resource population may increase because fewer organisms are eating it.
Population A and Population B both eat Population C. If Population A decreases, what may happen to Population B?
Population B may increase because there is less competition for Population C.
If the sea turtle population decreases, how could this affect moon jelly deaths?
affect moon jelly deaths?Moon jelly deaths could decrease because fewer sea turtles would be eating them.
A jelly population had 120 births and 80 deaths during the same period. Explain the expected population change.
The population should increase because births are greater than deaths.
Explain the chain: more resource organisms → more ESM for consumers → ______.
More reproduction/births in the consumer population, which can cause its population to increase.
Sea turtles eat moon jellies. How could a decrease in sea turtles affect moon jellies?
Fewer sea turtles would eat moon jellies, so jelly deaths would decrease, and the jelly population could increase.
How could a population that does not directly eat moon jellies or get eaten by moon jellies still affect the moon jelly population?
moon jellies or get eaten by moon jellies still affect the moon jelly population?It could change another population in the food web, which could change the amount of food or the number of consumers affecting moon jellies.
A population that competes with moon jellies for zooplankton decreases. How could this cause the moon jelly population to increase?
With fewer competitors, more zooplankton is available to moon jellies. Moon jellies get more energy storage molecules, reproduce more, and births can increase.