3.5 Population size and ecosystems 1 Flashcards
What is an ecosystem?
A balanced biological system made up of biotic and abiotic elements
What is a habitat?
A particular area occupied by a population
What is a community?
The different populations of species that live in a habitat
What is a niche?
An organism’s role in the ecosystem
What is ecology?
A branch of Biology that studies the relationship between living organisms and their environment
What is an environment?
The complex of physical, chemical, and biotic factors that act upon an organism or an ecological community and ultimately determines its form and survival
What is a population?
The number of organisms of the same species in a certain place, at a certain time, which can reproduce
Which factors increase a population?
Immigration and birth rate/ rate of cellular division
Which factors decrease a population?
Emigration and death rate/ rate of cellular death
What is the equation for a stable population?
Immigration + birth rate = Emigration + death rate
What is the equation for a growing population?
Immigration + birth rate> Emigration + death rate
What is the equation for a decreasing population?
Immigration + birth rate < Emigration + death rate
What are the two strategies for population growth?
- Fugitive species (r)
-Equilibrium species (k)
Describe a fugitive species (r)
-Rapid reproduction rate and dispersal
-Can invade new habitats rapidly
-Can’t tolerate competition
-i.e. sea palm and dandelion
Describe an equilibrium species (k)
-Balance population numbers with competition in a stable habitat
-Growth pattern is sigmoidal (one-step growth)
-i.e. elephant and fox