Question 1 of 10
Use the Punnett square to determine the probability of offspring with the homozygous recessive (aa) genotype.
A1/4 (25%)
B0
C3/4 (75%)
D1/2 (50%)
Explanation
Aa × Aa cross: AA, Aa, Aa, aa. Only one box (aa) shows the homozygous recessive: 1/4 = 25%.
Question 2 of 10
Which process in the water cycle is shown by arrow X?
ACondensation
BRunoff
CPrecipitation
DEvaporation
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 3 of 10
Natural selection can BEST be described as:
AOrganisms with favorable traits surviving and reproducing more
BOrganisms choosing their mates
COrganisms changing their DNA intentionally
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 4 of 10
Which of the following is a biotic factor?
ABacteria
BWater
CSunlight
DTemperature
Explanation
📌 Biotic = living things (plants, animals, bacteria).
Abiotic = non-living (temperature, water, sunlight, soil).
Abiotic = non-living (temperature, water, sunlight, soil).
Question 5 of 10
In a food chain, which organism is the primary consumer?
AGrass
BRabbit
CEagle
DFox
Explanation
📌 Primary consumer = herbivore = eats producers (plants).
Producers → Primary consumers → Secondary consumers → Tertiary consumers
Producers → Primary consumers → Secondary consumers → Tertiary consumers
Question 6 of 10
In an energy pyramid, which level has the MOST energy?
APrimary consumers
BSecondary consumers
CTertiary 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
The relationship between a bee and a flower is an example of:
Acommensalism
Bparasitism
Cmutualism
Dpredation
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 8 of 10
For AA × aa, what is the genotype of all offspring?
AAll AA
BAll aa
CAll Aa
D1 AA : 2 Aa : 1 aa
Explanation
Each parent contributes a different homozygous allele → 100% Aa heterozygous.
Question 9 of 10
In the food chain: Grass → Cricket → Frog → Snake → Hawk, which organism is a tertiary consumer?
AHawk
BFrog
CSnake
DCricket
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°)
Question 10 of 10
In the food web below, what would happen if all the frogs were removed?
AInsect population increases and snake population decreases
BSnake population increases
CEvery organism in the entire food web quickly dies off completely
DThe whole food web stays exactly the same and nothing changes at all
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.