Chapter 3 - Ecology Flashcards
What is ecology?
Ecology is the scientific study of interactions among organisms and between organisms and their physical environment.
What does the biosphere consist of?
The biosphere consists of all life on Earth and all places on Earth that contain life.
How are economics and ecology connected?
Economy can affect the biosphere that humans live in. Humans depend on the biosphere for ecological possessions such as water. These possessions can be sold or traded.
What is a species?
A species is a group of similar organisms who can breed and produce fertile offspring.
What is a population?
A population is a group of individuals that belong to the same species and live in a set area.
What is a community?
A community is an assemblage of different populations that live together in a defined area.
What is an ecosystem?
An ecosystem is all the organisms that live in a place, together with their physical environment.
What is a biome?
A biome is a group of ecosystems that share similar climate and typical organisms.
What is a biotic factor?
A biotic factor is any living part of an environment that organisms might interact with.
What is an abiotic factor?
An abiotic factor is any nonliving part of the environment such as water, precipitation, and sunlight.
What are the three ecological methods?
The three ecological methods are observation, experimentation, and modeling.
What are primary producers?
Primary producers, also known as autotrophs, are the first producers of energy-rich compounds that are later used by other organisms. Nutrient limitation will cause primary producers to function less than adequate.
What do organisms need energy for?
Organisms need energy for growth, reproduction, and metabolic processes.
Can energy be created?
Energy cannot be created. It can only be used from another source and transferred.
For most organisms, what is the ultimate energy source?
Sunlight is the ultimate energy source for most organisms.
What do primary producers/autotrophs do?
Primary producers/autotrophs take energy from the sun and convert it into forms that living cells can use.
What happens during photosynthesis?
In photosynthesis, primary producers capture light energy and use it to power chemical reactions. The primary producers take in carbon dioxide, water, and light energy to produce carbohydrates and oxygen. The oxygen is then released to the atmosphere.
How do organisms that live in dark ecosystems void of sunlight produce carbohydrates?
These organisms harness chemical energy from inorganic molecules, like hydrogen sulfide, to produce carbohydrates. This process is called chemosynthesis. Carbon dioxide, hydrogen sulfide, and oxygen is taken in and carbohydrates and sulfur compounds are produced.
How do consumers/heterotrophs obtain energy and nutrients?
Consumers depend on other organisms for energy and nutrients.
What are carnivores?
Carnivores kill and eat other organisms.
Ex. - Cats, dogs, snakes
What are scavengers?
Scavengers consume the carcasses of organisms killed by other animals or by other causes.
Ex. - Vultures, hyenas
What are decomposers?
Decomposers feed by chemically breaking down organic matter. The decay that they cause is part of a process that produces detritus.
Ex. - Bacteria, fungi
What are herbivores?
Herbivores obtain energy and nutrients from plants.
Ex. - Cows, deer
What are omnivores?
Omnivores obtain energy and nutrients from both plants and animals.
Ex. - Humans, bears
What are detrivores?
Detrivores obtain energy by grinding down detritus particles.
Ex. - Giant earthworms, shrimp
What is a food chain?
A food chain is a series of steps in which organisms transfer energy by eating and being eaten.
What is a food web?
A food web is comprised of many different food chains. It shows multiple interactions among organisms.
What are zooplankton?
Zooplankton are small, swimming herbivores.
Ex. - Krill
What are phytoplankton?
Phytoplankton are floating algae that are the primary producers in certain aquatic food chains.
What does the pyramid of energy display?
The pyramid of energy displays the relative amount of energy available at each trophic level.
What does the pyramid of biomass display?
The pyramid of biomass displays the relative amount of living organic matter on each trophic level.
What does the pyramid of numbers display?
The pyramid of numbers displays the number of individuals at each trophic level.
What is an ecological pyramid?
An ecological pyramid shows the relative amount of energy and matter on each trophic level.
What is a trophic level?
Each step in a food chain or web is called a trophic level.
How many trophic levels are there?
There are 4 trophic levels.
What group of organisms always takes up the first trophic level?
Primary producers are always located on the first trophic level.
Organisms spend most of their energy on life processes. What happens with the remaining energy?
The remaining energy is released as heat.
What percent of energy available within one trophic level is transferred to the next?
10% of energy is transferred to the next trophic level.
What is biomass?
Biomass is the total amount of living tissue within a given trophic level.
What are biogeochemical cycles?
Elements pass from one organism to another and among parts of the biosphere through closed loops called biogeochemical cycles.
What are biological processes?
Biological processes consist of any and all activities performed by living organisms.
What are some examples of geological processes?
Some example of geological processes are volcanic eruptions, the formation and breakdown of rock, and major movement of matter within and below the surface of the Earth.
What is transpiration?
Transpiration is the process of water entering the atmosphere by being evaporated off of a plant’s leaves.
What is evaporation?
Evaporation is when water enters the atmosphere from a body of water.
Why do organisms need nutrients?
Organisms need nutrients to build tissue and carry out life functions.
What is runoff?
Runoff is precipitation that returns back to a larger body of water.
How do decomposers release carbon to the environment?
Decomposers release carbon to the environment when they break down dead organisms.
How is carbon dioxide released to the atmosphere?
Carbon dioxide is released to the environment by volcanic activity of by human activities such as factory emissions.
Why do organisms need nitrogen?
Organisms require nitrogen to make amino acids, which are used to build proteins and nucleic acids.
What is the most abundant gas in our atmosphere?
Nitrogen (N2) is the most abundant gas in our atmosphere.
How is nitrogen found in bodies of water?
Nitrogen is dissolved in bodies of water.
What is nitrogen fixation and why does it need to happen?
Nitrogen fixation is the process of soil bacteria converting nitrogen gas into ammonia (NH3) because plants cannot take in nitrogen in its gas form.
What form of nitrogen can plants use and how is it made?
Plants use nitrates (NO2) and nitrites (NO3) that is made from fixed nitrogen after being converted by other soil bacteria.
How do consumers receive nitrogen?
Consumers get nitrogen from eating producers.
How do decomposers release nitrogen?
Decomposers release nitrogen from waste and dead organisms.
What is denitrification?
Soil bacteria convert nitrates (NO2) into nitrogen gas which is released into the atmosphere in a process called denitrification.
How does nitrogen get into the atmosphere?
Fertilizers are one way nitrogen gets into the atmosphere.
What is a major source of phosphorus on land?
A major source of phosphorus on land is the compounds released from the weathering of rocks.
When do plants bind phosphate into organic compounds?
Plants bind phosphate into organic compounds when they absorb it from soil or water.
What is a limiting nutrient?
A limiting nutrient is a nutrient whose supply limits its productivity.
Why do scientists use models?
Scientists use models to illustrate processes that are too complex or take place over a long period of time.
How does phosphate get into the ocean?
Geological activity washes phosphates from rock into the ocean.
