WorksheetsUnit 8 Winter Break Quiz
Total questions: 20
Worksheet time: 10mins
Which statement best distinguishes endotherms from ectotherms?
Ectotherms cannot regulate temperature by behavior at all
Ectotherms generate more metabolic heat than endotherms
Endotherms match body temperature exactly to ambient conditions
Endotherms maintain body heat largely via internal metabolism
A penguin’s flipper uses countercurrent heat exchange. What immediate advantage does this provide at the tissue level?
Eliminates the need for insulation such as fat
Increases total metabolic rate of the whole organism
Raises arterial temperature above core temperature
Reduces heat loss by warming returning venous blood
Two animals of similar shape live in the same climate: a mouse and an elephant. Which prediction about metabolic rate per gram is most accurate, and why?
Elephant equals mouse per gram because of thermoregulation
Elephant is higher per gram due to greater absolute mass
Mouse is lower per gram due to smaller oxygen demand
Mouse is higher per gram due to higher surface-area-to-volume
Which statement best distinguishes autotrophs from heterotrophs?
Autotrophs produce organic food using external energy
Autotrophs consume other organisms for chemical energy
Heterotrophs fix carbon directly from atmospheric CO2
Heterotrophs synthesize glucose from sunlight or chemicals
Primary productivity in an ecosystem is defined as which of the following?
Total biomass of all trophic levels combined annually
Rate at which producers store chemical energy as biomass
Proportion of sunlight reflected by primary producers
Amount of energy consumers assimilate from producers
In a typical energy pyramid, why does biomass decrease from producers to top predators?
Producers pass all energy directly to herbivores
Top predators convert energy with perfect efficiency
Energy is lost as heat and waste at each transfer
Decomposers recycle energy without any losses
A grassland supports 15,200 kg of grasses, 1,520 kg of grasshoppers, and 152 kg of mice. Which principle is illustrated by these values?
Consumers contain more energy than producers
Biomass increases at higher trophic positions
Energy is conserved fully across trophic transfers
About ten percent of energy moves to the next level
If drought reduces producer biomass by half, which outcome is most likely across the food web?
Complete energy retention through decomposer action
Higher predator abundance due to less competition
Lower consumer numbers due to reduced energy base
Unchanged herbivore biomass despite fewer plants
Which statement best defines genetic diversity within the context of biodiversity levels?
Functional roles of producers within food webs
Variation of genes within a single species population
Number of species present across multiple habitats
Range of ecosystems across a geographic landscape
A keystone species is best described as a species that
reproduces faster than any competing species
has a disproportionately large effect on community structure
is the most abundant organism by total biomass
occupies the highest trophic level in all food webs
Examine the graph comparing communities with and without a keystone species. What inference is most supported by the trends shown?
Species richness is unaffected by functional roles within ecosystems
Adding producers always decreases the number of species gradually
Removing a keystone species rapidly reduces species richness over time
Predators consistently increase when keystone species are absent
Which best defines an invasive species?
Any species introduced by natural currents
A native organism with stable population
Any non-native organism with low impact
A non-native organism causing ecological harm
What process explains increasing toxin concentration at higher trophic levels?
Genetic drift within small populations
Biogeochemical cycling of nutrients
Primary succession after disturbance
Biological magnification across food chains
Which nutrient pair most commonly drives eutrophication in aquatic systems?
Iron and silica inputs
Calcium and magnesium inputs
Nitrogen and phosphorus inputs
Sodium and chloride inputs
During eutrophication, what sequence most likely leads to a dead zone?
Nutrient surge, algal bloom, decomposition, oxygen drop
Sediment loss, plant decline, herbivore boom, clarity rise
Warm water, ice formation, fish migration, oxygen rise
Storm mixing, nutrient dilution, fish spawning, oxygen rise
Which statement about greenhouse gases is most accurate?
They reflect ultraviolet radiation to space
They convert heat energy directly into ozone
They trap outgoing infrared radiation near Earth
They block incoming visible radiation entirely
Which population outcome occurs when death rate exceeds birth rate for multiple generations?
Population size declines over time
Population size stabilizes at carrying capacity
Population size cycles without trend
Population size grows exponentially
Which process is primarily responsible for the loss of energy between trophic levels in an ecosystem?
Direct transfer of all energy to top predators
Respiration and heat loss by organisms
Photosynthesis by producers
Complete recycling of nutrients by decomposers
What is the main ecological consequence of introducing a non-native predator to a stable ecosystem?
Increase in native prey populations
Disruption of existing food webs and possible decline of native species
Immediate extinction of all producers
Stabilization of ecosystem biodiversity
Which adaptation helps ectotherms survive in fluctuating environmental temperatures?
Maintaining a fixed body temperature regardless of environment
Behavioral thermoregulation such as basking or seeking shade
Constant internal metabolic heat production
Exclusive reliance on insulation like fur or feathers
