CSS - PMS - CCE - PCS - General Science
Genetics
What does genotype refer to?
A. An organism's genetic constitution for one or more loci
B. Only body mass
C. Only environmental conditions
D. Only visible appearance
Correct Answer: A
Genotype describes genetic information, while phenotype describes observable characteristics.
CSS - PMS - CCE - PCS - General Science
Genetics
What are alternative forms of the same gene called?
A. Alleles
B. Tissues
C. Enzymes only
D. Organelles
Correct Answer: A
Alleles are different versions of a gene at the same genetic locus.
CSS - PMS - CCE - PCS - General Science
Genetics
What molecule carries most hereditary information in cellular organisms?
A. Water
B. ATP
C. DNA
D. Glucose
Correct Answer: C
DNA stores genetic information in almost all cellular life.
CSS - PMS - CCE - PCS - General Science
Genetics
What is a gene?
A. A chromosome with no DNA
B. A functional unit of heredity represented by a DNA sequence that contributes to a product or trait
C. A protein only
D. A whole organism
Correct Answer: B
Genes are DNA sequences whose expression contributes to functional products and traits.
CSS - PMS - CCE - PCS - General Science
Food Chain
Which arrow direction is conventionally used in a food chain?
A. Toward the Sun only
B. Always from predator to prey
C. No arrows are used
D. From the organism being eaten toward the organism that obtains the energy
Correct Answer: D
Food-chain arrows indicate the direction of energy transfer.
CSS - PMS - CCE - PCS - General Science
Food Chain
What is biomagnification?
A. Increase in concentration of certain persistent pollutants at higher trophic levels
B. Conversion of pollutants into nutrients
C. Increase in body size in every food chain
D. Loss of all chemicals at higher levels
Correct Answer: A
Persistent bioaccumulative substances can become more concentrated in predators high in food webs.
CSS - PMS - CCE - PCS - General Science
Food Chain
If grass is eaten by a rabbit and the rabbit by a fox, what trophic role does the rabbit have?
A. Decomposer
B. Primary consumer
C. Secondary consumer
D. Producer
Correct Answer: B
The rabbit feeds directly on the producer grass.
CSS - PMS - CCE - PCS - General Science
Food Chain
What role do decomposers play in food chains and webs?
A. They eliminate all consumers
B. They stop nutrient cycling
C. They manufacture sunlight
D. They break down dead matter and recycle nutrients
Correct Answer: D
Decomposers return nutrients from dead organisms and wastes to the environment.
CSS - PMS - CCE - PCS - General Science
Food Chain
What is a food web?
A. A network of interconnected food chains
B. A plant root system
C. A single linear feeding pathway only
D. A spider web only
Correct Answer: A
Food webs show multiple feeding interactions in a community.
CSS - PMS - CCE - PCS - General Science
Food Chain
Why are food chains usually limited in length?
A. Energy increases at every level
B. Only a fraction of energy is transferred to each higher trophic level
C. Predators have no energy needs
D. Producers contain no energy
Correct Answer: B
Large energy losses between trophic levels constrain the number of levels that can be supported.
CSS - PMS - CCE - PCS - General Science
Food Chain
Which organisms occupy the first trophic level?
A. Top predators
B. Primary consumers
C. Producers
D. Secondary consumers
Correct Answer: C
Primary producers form trophic level one.
CSS - PMS - CCE - PCS - General Science
Food Chain
What is a primary consumer?
A. An organism that feeds directly on producers
B. A decomposer only
C. An organism that makes its own food
D. An organism that eats only top predators
Correct Answer: A
Herbivores are typical primary consumers.
CSS - PMS - CCE - PCS - General Science
Food Chain
At the base of most food chains are what organisms?
A. Decomposers only
B. Primary producers
C. Parasites only
D. Top predators
Correct Answer: B
Plants, algae and other autotrophs capture energy and form the base of most food chains.
CSS - PMS - CCE - PCS - General Science
Food Chain
What does a food chain show?
A. Only water movement
B. A list of animal names with no relation
C. A linear pathway of energy and nutrient transfer through feeding relationships
D. Only mineral formation
Correct Answer: C
Food chains represent who eats whom and the direction of energy transfer.
CSS - PMS - CCE - PCS - General Science
Ecosystem
What is ecological succession?
A. Instant extinction of all species
B. A gradual change in community composition over time
C. Movement of one animal
D. Daily weather change
Correct Answer: B
Succession describes directional ecological change following formation or disturbance of habitats.
CSS - PMS - CCE - PCS - General Science
Ecosystem
Which process returns carbon dioxide to the atmosphere from living organisms?
A. Transpiration only
B. Respiration
C. Nitrogen fixation
D. Photosynthesis only
Correct Answer: B
Cellular respiration releases CO2 as organic molecules are oxidized.
CSS - PMS - CCE - PCS - General Science
Ecosystem
What generally happens to available energy as one moves to higher trophic levels?
A. It increases without limit
B. It decreases
C. It remains exactly constant
D. It becomes matter only
Correct Answer: B
Energy is lost as heat and through metabolism at each trophic transfer.
CSS - PMS - CCE - PCS - General Science
Ecosystem
What is an ecological niche?
A. Only its body size
B. The functional role and resource use of a species in its environment
C. Only its color
D. Only its geographic address
Correct Answer: B
A niche includes how a species uses resources and interacts with biotic and abiotic factors.
CSS - PMS - CCE - PCS - General Science
Ecosystem
What is a habitat?
A. The physical place where an organism lives
B. The total number of species on Earth
C. The organism's genetic code
D. A food chain only
Correct Answer: A
Habitat describes the environment in which an organism lives.
CSS - PMS - CCE - PCS - General Science
Ecosystem
What is the role of decomposers?
A. Break down dead organic matter and recycle nutrients
B. Prevent all predation
C. Create sunlight
D. Make atmospheric oxygen disappear
Correct Answer: A
Decomposers such as fungi and bacteria return nutrients to ecosystems.