Practice Test 39 - High School Biology

20 questions. Answer them in any order, then submit to see your score and every explanation.

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1. A conservation team must choose a strategy for a large mammal whose main threat is habitat fragmentation from new roads that split the forest into small patches. Options include: (1) build wildlife corridors (connected strips of habitat) between patches, (2) start captive breeding with no habitat changes, or (3) increase hunting permits to reduce human-wildlife conflict. Which option most directly targets the primary cause of biodiversity loss for this species?
2. After eating a meal, a person's blood glucose level rises above its usual range. The body detects the rise and triggers responses that help bring glucose back toward the usual range. This is an example of homeostasis maintained by a feedback loop. Which option best describes the role of feedback here?
3. Two genotypes of a plant differ in drought survival. In a dry year, genotype $AA$ has a 92% survival probability and genotype $aa$ has an 88% survival probability. Compared with a situation where $AA$ survives at 92% and $aa$ survives at 12%, which statement best describes how fast allele frequencies will change in the dry year?
4. A grassland prairie experienced a severe wildfire in Year 0. Ecologists tracked three indicators at the same site over time. Data (same 1-hectare plot): - Native plant species richness (number of native plant species) - Aboveground plant biomass (g/m²) - Soil nitrate (mg/kg) Which conclusion is best supported by the data about ecosystem recovery? Pre-fire (Year -1): richness 42, biomass 610, nitrate 9 Year 0 (1 month after fire): richness 14, biomass 120, nitrate 22 Year 2: richness 31, biomass 480, nitrate 12 Year 5: richness 39, biomass 590, nitrate 10
5. In the carbon cycle diagram, which labeled process moves carbon from plants back to the atmosphere as $CO_2$?
6. Which option is an example of a tissue (a group of similar cells working together for a function)?
7. Before photosynthesis, a plant has carbon dioxide ($\mathrm{CO_2}$) and water ($\mathrm{H_2O}$), which are relatively low-energy, stable molecules. During photosynthesis, sunlight is used to make glucose. What happens to the energy from sunlight in this process?
8. Photosynthesis can be summarized as an energy conversion process. Which statement best describes the energy transformation that occurs when a plant makes glucose from CO2 and H2O in sunlight?
9. A student makes a combined model for a forest ecosystem over a full day. They want to show that plants do photosynthesis and respiration, while animals do only respiration. Which model description best matches this and correctly shows matter cycling and energy flow?
10. A student traces matter through a simple chain: grass → grasshopper → frog → snake. Which statement is correct about what happens to the atoms from the grass as they move through the chain?
11. A student is building a model of what happens when they run up stairs and then stop. Their breathing is heavy, their heart is pounding, and after resting both slow down. Which additional connection would best show coordination (signal flow) in a model that already includes respiratory → circulatory → muscular material flow?
12. A pond ecosystem includes algae, aquatic plants, snails, small fish, large fish, and decomposer bacteria. Algae and aquatic plants use sunlight, CO2, and water to build sugars. Snails eat algae, small fish eat snails, and large fish eat small fish. Which option correctly matches each role to how it gets energy and matter?
13. An energy pyramid is shown below: Top: Tertiary consumers (10 units) Middle: Secondary consumers (100 units) Lower: Primary consumers (1,000 units) Bottom: Producers (10,000 units) Arrows point upward from producers to consumers, and heat-loss arrows leave each level. Based on the diagram, which statement best explains why there are fewer tertiary consumers than primary consumers?
14. Complete the photosynthesis equation by choosing the correct products: $6CO_2 + 6H_2O +$ light energy $\rightarrow$ ________​
15. Fossil measurements of a horse ancestor lineage show average shoulder height at different times. 50 million years ago: 0.45 m 40 million years ago: 0.62 m 30 million years ago: 0.88 m 20 million years ago: 1.15 m 10 million years ago: 1.38 m Present: 1.50 m Which statement best describes the evolutionary pattern in body size?
16. A student claims: "If two organisms have the same genotype, their traits will always be identical." Which response best corrects the claim using genotype–environment interaction?
17. On an island, most bird species resemble birds from the nearest mainland but differ in beak size and shape. Which type of evidence for evolution does this pattern best represent?
18. In a population of giraffes, neck length varies and the variation is heritable. During a long dry period lasting many generations, most leaves near the ground are eaten quickly, but leaves high in trees remain available. At first, only a small fraction of giraffes have slightly longer necks. Which statement best explains how long necks can become an adaptation in this population through natural selection over many generations?
19. Cellular respiration can be summarized by the equation: $\mathrm{C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP\ energy}$. Which substances are the reactants (inputs) in this process?
20. In early development, embryos of fish, chickens, and humans look more similar to one another than the adults do (for example, they share a tail-like structure and pharyngeal pouches early on). Which type of evidence for evolution does this describe?

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