Question 1 of 10
Natural selection can BEST be described as:
AOrganisms changing their DNA intentionally
BOrganisms with favorable traits surviving and reproducing more
COrganisms choosing their mates
DEvery organism in a population has an equal chance of surviving and breeding
Explanation
📌 Natural selection = organisms with favorable traits survive and reproduce more, passing those traits to offspring. 'Survival of the fittest.'
Question 2 of 10
Which of the following is a biotic factor?
ATemperature
BBacteria
CSunlight
DWater
Explanation
📌 Biotic = living things (plants, animals, bacteria).
Abiotic = non-living (temperature, water, sunlight, soil).
Abiotic = non-living (temperature, water, sunlight, soil).
Question 3 of 10
In a food chain, which organism is the primary consumer?
AEagle
BGrass
CFox
DRabbit
Explanation
📌 Primary consumer = herbivore = eats producers (plants).
Producers → Primary consumers → Secondary consumers → Tertiary consumers
Producers → Primary consumers → Secondary consumers → Tertiary consumers
Question 4 of 10
For AA × aa, what is the genotype of all offspring?
AAll AA
BAll aa
C1 AA : 2 Aa : 1 aa
DAll Aa
Explanation
Each parent contributes a different homozygous allele → 100% Aa heterozygous.
Question 5 of 10
The relationship between a bee and a flower is an example of:
Amutualism
Bcommensalism
Cpredation
Dparasitism
Explanation
📌 Mutualism: both benefit. Bee gets nectar (food), flower gets pollinated.
Parasitism: one benefits, other harmed. Commensalism: one benefits, other unaffected.
Parasitism: one benefits, other harmed. Commensalism: one benefits, other unaffected.
Question 6 of 10
In an energy pyramid, which level has the MOST energy?
ATertiary consumers
BPrimary consumers
CSecondary consumers
DProducers
Explanation
📌 Producers (bottom level) have the most energy. Only ~10% transfers to each higher level. This is the 10% rule.
Question 7 of 10
In the food web below, what would happen if all the frogs were removed?
AThe whole food web stays exactly the same and nothing changes at all
BEvery organism in the entire food web quickly dies off completely
CInsect population increases and snake population decreases
DSnake population increases
Explanation
📌 If frogs are removed:
• Insects (grasshoppers) they ate would INCREASE (no predator)
• Snakes that ate frogs would DECREASE (less food)
• This demonstrates how removing one species affects the entire food web. Snakes lose a food source so they cannot increase, the web does not stay unchanged, and it does not wipe out every organism.
• Insects (grasshoppers) they ate would INCREASE (no predator)
• Snakes that ate frogs would DECREASE (less food)
• This demonstrates how removing one species affects the entire food web. Snakes lose a food source so they cannot increase, the web does not stay unchanged, and it does not wipe out every organism.
Question 8 of 10
Use the Punnett square to determine the probability of offspring with the homozygous recessive (aa) genotype.
A3/4 (75%)
B1/4 (25%)
C1/2 (50%)
D0
Explanation
Aa × Aa cross: AA, Aa, Aa, aa. Only one box (aa) shows the homozygous recessive: 1/4 = 25%.
Question 9 of 10
Which process in the water cycle is shown by arrow X?
ARunoff
BPrecipitation
CEvaporation
DCondensation
Explanation
📌 Arrow X shows water rising from the surface to the clouds → Evaporation
Evaporation = liquid water → water vapor (gas) due to heat from the sun.
Complete cycle: Evaporation → Condensation (clouds form) → Precipitation (rain) → Runoff → Collection
Evaporation = liquid water → water vapor (gas) due to heat from the sun.
Complete cycle: Evaporation → Condensation (clouds form) → Precipitation (rain) → Runoff → Collection
Question 10 of 10
In the food chain: Grass → Cricket → Frog → Snake → Hawk, which organism is a tertiary consumer?
ACricket
BHawk
CFrog
DSnake
Explanation
📌 Trophic levels:
Grass = Producer
Cricket = Primary consumer (1°) — eats plants
Frog = Secondary consumer (2°) — eats primary consumer
Snake = Tertiary consumer (3°) — eats secondary consumer
Hawk = Quaternary consumer (4°)
Grass = Producer
Cricket = Primary consumer (1°) — eats plants
Frog = Secondary consumer (2°) — eats primary consumer
Snake = Tertiary consumer (3°) — eats secondary consumer
Hawk = Quaternary consumer (4°)