Ecology Flashcards
To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from…??
A single individual and the entire biosphere
Observing, experimenting, and modeling all rely on the application of scientific methods to guide??
Ecological inquiry
What is the main source of energy for life on Earth?
Sunlight
Some types of organisms rely on the energy stored in ??
Inorganic chemical compounds
Energy flows through an ecosystem in one direction: ??
From the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers)
Only about how much of the energy available within one tropic level is transferred to organisms at the next trophic level?
10%
Carbon dioxide, methane, water vapor, and a few other atmospheric gases trap heat energy and maintain Earth’s temperature range. These are ?? that allow solar radiation to enter the biosphere but slow down the loss of heat to space.
Greenhouse gases
Together, what two factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives?
Biotic and abiotic factors
What can powerfully affect an ecosystem?
Community interactions
Competition, predation, and various forms of symbiosis are examples of what?
Community interactions
Ecosystems are constantly changing in response to what two disturbances?
Natural and human disturbances
As an ecosystem changes, older inhabitants gradually ? and new organisms ? causing further changes in the community.
Die out; move in
Three important characteristics of a population are ??
It’s geographic distribution, density, and growth rate
Three factors that can affect population size are ?
The number of births, the number of deaths, and the number of individuals that enter or leave the population
What three things help predict why some countries have high growth rates while other countries grow more slowly?
Birth rates, death rates, and the age structure of a population
Under ideal conditions with unlimited resources, a population will grow how?
Exponentially
What occurs as resources become less available causing the population growth rate to slow or stop?
Logistic growth
What is the main cause of logistic growth?
The reaching of a habitat’s carrying capacity
What are four human activities that affect the biosphere?
Hunting/gathering, agriculture, industry, and urban development
What is one of the Earth’s greatest natural resources?
Biodiversity
What are three things that species of many kinds have provided us?
Foods, industrial products, and medicines
Name at least 3 medicines that many species have provided us.
Painkillers, antibiotics, heart drugs, antidepressants, and anticancer drugs
What are four ways that human activity can reduce biodiversity?
Altering habitats, hunting species to extinction, introducing toxic compounds into food webs, and introducing foreign species to new environments
What do conservation efforts focus on today?
Entire ecosystems as well as single species
Protecting an ecosystem will ensure that the natural habitats and the interactions of many different species are preserved A) over time B) gradually C) continuously D) at the same time
D) at the same time
During what process is the concentration of pollutant like DDT multiplied as it passes up the food chain from producers to consumers?
Biomagnification
What are the three basic approaches do scientists use to conduct modern ecological research?
Observing, experimenting, and modeling
