B.4 Ecology

Which sequence correctly describes the flow of energy between organisms in the marine food web?

• from seals to penguins to krill
• from whales to krill to small fish
• from sea birds to seals to penguins
• from small fish to penguins to seals

A student wrote several observations in a field notebook. Which term best classifies all of the student’s observations?

• population
• food chain
• ecosystem
• community

What is the process by which bacteria living on the roots of legumes covert nitrogen gas into nitrates in the soil?

• nitrogen fixation
• excretion
• decomposition
• denitrification

Carbon cycles through the biosphere through ALL processes EXCEPT:

• photosynthesis
• respiration
• transpiration
• decomposition

There are 150 Saguaro cacti plants per square kilometer in a certain area of the desert. Which population characteristic does this information best refer to?

• exponential growth chart
• geographic range
• population density
• emigration

Emigration is to ________________________, as immigration is to_________________________.

• organisms leaving a territory; organisms entering a territory
• organisms entering a territory; organisms leaving a territory
• organisms dying; the birth of new organisms
• the birth of new organisms; organisms dying

When individuals in a population reproduce at a constant rate under ideal conditions without any limitations, this behavior produces a growth pattern called:

• logistic growth
• demographic transition
• growth density
• exponential growth

A student listed characteristics of a classroom aquarium ecosystem. Which characteristic is a BIOTIC component of the aquarium ecosystem?

• The water temperature is 23°C.
• The pH of the water is usually between 6.5 and 6.8.
• Two types of bacteria help to control the ammonia levels.
• The lighting is supplied by natural sunlight and a fluorescent light bulb.

Tadpoles grown in ponds with high densities of tadpoles have lower survival and growth rates than tadpoles grown in ponds with lower densities of tadpoles. Which interaction between tadpoles grown in high-tadpole-density ponds would most likely cause the decreased survival and growth rates?

• symbiosis
• mutualism
• competition
• commensalism

Which population description is most likely represented by the graph?

• A population of birds quickly increases but then becomes stable due to limiting factors in the environment.
• A population of mice slowly increases but then fluctuates seasonally as predators raise their young and limit prey populations.
• A population of fish quickly increases in the spring when there is plenty of food but then decreases quickly in the fall when food is limited.
• A population of wolves slowly increases because of limiting factors in the environment but then increases constantly when additional prey migrate into the environment.