Practice Test 86 - 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 desert food chain follows the 10% rule. If tertiary consumers have 25 units of energy, about how much energy was available at the producer level? (Producer → 1° → 2° → 3°)​
2. A large area of tropical rainforest is cleared and replaced with cattle pasture. Within a few years, local bird and insect species are much less common, and the remaining forest exists as small, isolated patches separated by fields. Which ecosystem impact is most directly caused by this land-use change?
3. A student says, "When leaves fall and rot, the matter in them is gone." Which response best describes the role of decomposers in matter recycling?
4. A coastal fish species has declined due to overharvesting. Managers propose two options: Option A creates a no-fishing marine protected area (MPA) covering 30% of breeding habitat. Option B keeps all areas open but sets a catch limit that aims to remove no more than the population's annual growth. Which statement best evaluates these options in terms of effectiveness and trade-offs?
5. A section of DNA unwinds and only one strand is used as the template during transcription. Which statement best describes the relationship between the DNA template strand and the mRNA produced?
6. A farming region applies large amounts of fertilizer. A cause-effect diagram is proposed to model biodiversity impacts in a nearby lake. Which option best represents a correct pollution-to-biodiversity pathway (including a mechanism) rather than just listing events?
7. A plant makes glucose during the day and can still grow at night when there is no sunlight. What best explains how photosynthesis makes this possible?
8. A plant makes glucose during photosynthesis by taking carbon from atmospheric CO2 and hydrogen/oxygen from H2O. Later, the plant builds proteins in its leaves. Which statement best traces where the atoms in the protein come from and what happens to them during synthesis?
9. A DNA comparison shows that species X and Y share 99% of their DNA sequences, while species X and Z share 85%. What is the best conclusion based on this molecular evidence?
10. A food chain in a desert ecosystem is: Cactus → Mouse → Snake → Hawk → Decomposers. Which statement correctly describes how energy moves through this chain?
11. During a 5-minute sprint, a student's breathing rate increases and their leg muscles begin to feel tired. They also notice they are exhaling more forcefully. Which flowchart model best represents how body systems interact to support the working muscles during the sprint?
12. Identical twins share the same genotype. One twin had good nutrition throughout childhood and is 180 cm tall. The other twin experienced long-term poor nutrition and is 168 cm tall. Which statement best describes why their heights differ?
13. Which option correctly matches each substance to its role in the overall photosynthesis equation ($6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$)?
14. A simplified quantitative model shows energy changes during photosynthesis: 100 units light energy → Photosynthesis in chloroplast → 4 units chemical energy stored in glucose + 96 units released as heat What does the model indicate about energy capture in photosynthesis?
15. A runner breathes faster during exercise. This helps deliver more oxygen to cells for cellular respiration. What is a main reason cells need this oxygen during aerobic respiration?
16. Independent assortment is one way meiosis creates genetic diversity. What does independent assortment describe?
17. Claim: A bacterial population evolved resistance to Antibiotic Q. A student collected these results: 1) After 20 generations with Antibiotic Q present, 92% of cells in the population can grow on plates containing Antibiotic Q. 2) A control population grown for 20 generations without Antibiotic Q has 4% of cells that can grow on plates containing Antibiotic Q. 3) Sequencing shows a resistance mutation $m$ increased in frequency from 0.02 to 0.85 in the antibiotic-exposed population. 4) When an individual bacterial cell is exposed to Antibiotic Q, it sometimes turns on stress-response genes within minutes. Which choice best evaluates whether the evidence supports the claim that the population evolved resistance?
18. A student is building a simple flowchart model of dehydration after playing outside on a hot day. They want to show how the body responds using 23 systems. Which model best represents system interactions that help restore water balance?
19. When a blood vessel is damaged, platelets stick to the site and release signals that attract and activate more platelets. This causes even more platelets to gather until a clot forms. Which type of feedback loop is described?
20. A student measures leaf length (cm) for 10 plants in the same population: Plant IDs 1–10 leaf lengths (cm): 6.2, 5.9, 7.1, 6.8, 6.0, 7.4, 6.5, 5.7, 6.9, 6.1 What is the range of leaf length in this population?

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