Biologys Unit 3
The air surrounding our planet
Atmosphere
What is the function of nitrifying bacteria?
. the conversion of ammonium into nitrates
A food chain is represented below. Phytoplankton ⟶ Krill ⟶ Mackerel ⟶ Sea gull Which of the following organisms is correctly paired with its role in the food chain? Select one: a. Phytoplankton - secondary consumer b. Krill - producer c. Sea gull - tertiary consumer d. Mackerel - primary consumer
.Sea gull - tertiary consumer
The efficiency of energy transfer from a lower trophic level to the next highest level is roughly
10%
The transfer efficiency of energy between trophic levels is usually about
10%
Which number on the diagram below shows the location of the secondary consumers? Select one: a. 1 b. 2 c. 3
3
Of all the energy striking the Earth, how much is used by living things?
< 1%
Phosphate ions in the soil would be described as
Abiotic Factors
Air, oxygen levels, wind currents, temperature, dirt, light and humidity are all examples of
Abiotic factors
Which type of pyramid shows the amount of living tissue at each trophic level in an ecosystem?
Biomass pyramid
A group of ecosystems that have the same climate and similar species.
Biome
This sphere is composed of all the living things
Biosphere
Phosphorus is important to living organisms because it forms the important life-sustaining molecule(s) (check all that apply) Select one or more: a. Carbohydrates b. NO2 c. DNA and RNA d. ATP
DNA and RNA; ATP
Which one of the following has the largest population in a food chain? Select one: a. Decomposers b. Producers c. Secondary consumers d. Primary consumers
Decomposers
In urban areas, water can contain high levels of phosphorous due to use of agents such as fertilizers. What is a possible negative effect of excess phosphorus in the water?
Development of "dead zones"
Plants can use nitrogen directly from the atmosphere.
False
Which of the following is a difference between food chains and food webs? Select one: a. Food chains show energy flow in an ecosystem, and food webs do not. b. Food webs separate organisms by trophic level, but food chains do not. c. Food webs contain both plants and animals, but food chains contain only plants. d. Food chains are linear, while food webs are complex.
Food chains are linear, while food webs are complex
Which of the following statements is true?
Humans help recycle phosphorus when they eat plants
Composed of all the water on or near the earth
Hydrosphere
This sphere includes the continents, the ocean floor, all the rocks on the surface and below to the mantle.
Lithosphere
Which form is nitrogen primarily in while it's in our atmosphere (atmospheric N)?
N2
The rate at which energy is stored as biomass by plants and made available to the consumers in the ecosystem.
Net primary productivity
The correct sequence of increasing biological complexity is
Organism, population, community, ecosystem, biome, biosphere
Most phosphorus found in the biosphere is stored in
Rock and soil minerals and ocean sediment
A finch that feeds on a grasshopper, which eats plants, is a
Secondary consumer
Which of the following carbon reservoirs holds the most carbon?
Sediments and sedimentary rock
What is an energy pyramid used to show?
The amount of energy at each trophic level
Ecologists divide the species in an ecosystem into trophic levels on the basis of what?
Their main source of nutrition
The arrows in a food chain or web represents what?
They show what direction the energy is flowing between organisms.
How does carbon leave the atmosphere and become part of the food chain?
Through photosynthesis
Water can enter the atmosphere by evaporating from the leaves of plants in the process of
Transpiration
Which of the following correctly pairs a step of the water cycle with its events?
Transpiration - water enters through a plant's roots, travels through its vascular system, and escapes through its leaves
Ecologists divide the species in an ecosystem into these on the basis of their main source of nutrition.
Trophic levels
When an aquatic ecosystem receives a large input of a limiting nutrient, the result is
algal bloom
Process in which decomposers break down amino acids and nucleic acids back into ammonia.
ammonification
Phosphorus does NOT travel through which of the following spheres?
atmosphere
Which of the following pathways is available in the carbon cycle? Select one: a. atmosphere >> land plants b. land plants >> marine life c. soil >> primary consumers d. deep ocean >> soil
atmosphere >> land plants
Matter can recycle through the biosphere because
biological systems do not use up matter, they transform it
The total amount of living tissue within a given trophic level is called the
biomass
The combined portions of the planet in which life exists, including land, water, and the atmosphere, form the
biosphere
What do plants do with the nitrogen they absorb?
build proteins
In the nitrogen cycle, bacteria that live on the roots of plants
change nitrogen gas back into ammonium
Autotrophs convert solar energy into ________ energy.
chemical
When organisms use chemical energy to produce carbohydrates, the process is called
chemosynthesis
Decomposers are important to ecosystems because they
return vital nutrients to the ecosystem
Process in which soil bacteria convert nitrogen compounds in soil back into nitrogen gas:
denitrification
Organisms that feed on plant and animal remains and other dead matter with their mouths
detritivores
A mathematical formula designed to predict population fluctuations in a community could be called a(n)
ecological observation
The lowest level of environmental complexity that includes biotic and abiotic factors is
ecosystem
Both energy and matter are recycled within an ecosystem.
false
T/F All pyramids are shaped like a typical pyramid.
false
Which of the following reservoirs in the carbon cycle is biotic? Select one: a. atmosphere b. surface ocean c. land plants d. both a and b
land plants
An ecological method that uses mathematical formulas based on data collected is
modeling
What is the process where ammonium is converted to nitrite (NO2-) and then to nitrate (NO3-) to be used directly by plants called?
nitrification
Process in which nitrogen gas from the atmosphere is converted into ammonia by bacteria:
nitrogen fixation
What is the process of combining atmospheric nitrogen with other elements to make nitrogen into usable compounds
nitrogen fixation
Which ecological inquiry method is an ecologist using when he or she enters an area periodically to count the population numbers of a certain species?
observing
Which is the most common limiting nutrient in fresh water ecosystems?
p
Which biogeochemical cycle does NOT involve a stage where the chemical enters the atmosphere
phosphorus
A group of organisms of the same species that inhabit a specific area and interbreed is called a(n)
population
These organisms eat plants
primary consumers
What are processes that remove carbon from the atmosphere called?
sinks
A group of organisms that can breed and produce fertile offspring is known as a
species
Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of the remaining energy, some is used for the organism's life processes, and the rest is
stored as fat
A snake that eats a frog that has eaten an insect that fed on a plant is a
tertiary consumer
Finches feed on grasshoppers that eat plants. If a hawk eats a finch it is a
tertiary consumer
When is ammonia released?
the breaking down of dead animals and plants
