Practice Test 85 - High School Biology

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

Start practice test

1. In a coastal ecosystem, phytoplankton photosynthesize. Clams filter-feed on phytoplankton, and sea stars eat clams. When clams and sea stars die, bacteria decompose their remains. Which option correctly matches each organism to its role?
2. A room has a thermostat set to 20°C. The thermostat measures the room temperature and turns the heater on or off to keep the temperature near 20°C. This is most similar to which idea in biological homeostasis?
3. A cell is in interphase before mitosis begins. Which event happens during interphase that prepares the cell for mitosis?
4. A nature reserve has 2,400 kg of available food for a population of foxes each month. Each fox requires about 80 kg of food per month. If food is the limiting resource, what is the carrying capacity (K) for foxes in the reserve?
5. The heart contains muscle tissue that contracts, connective tissue that supports, nervous tissue that helps control heartbeat, and epithelial tissue lining parts of the heart. What level of biological organization is the heart?
6. A lake receives chemical runoff that kills many fish and reduces water clarity. Ten years later, the lake is still cloudy and is dominated by algae, with few fish compared to before the pollution event. Which conclusion best fits this scenario?
7. A fish pond contains 10,000 liters of water with an average dissolved oxygen level of 7 mg/L. The pond's oxygen is replenished each day (assume the full amount is effectively available daily). Each fish needs about 35 mg of oxygen per day. Using $K = \frac{\text{total oxygen available per day}}{\text{oxygen needed per fish per day}}$, what is the pond's carrying capacity (K) for fish?
8. A sealed bottle ecosystem contains a plant and a small insect. After several days in complete darkness, the insect dies even though the bottle is still sealed (no matter has left). Which model best explains this outcome using photosynthesis and cellular respiration?
9. A complete human is made of many organ systems (like the digestive and circulatory systems) working together. What is the level of biological organization of a complete human?
10. In humans, homologous chromosome pairs have the same genes in the same locations (loci), but may carry different versions (alleles). Which option best describes a homologous pair?
11. A student says, "Homeostasis means your internal conditions never change." Which response best corrects this idea while staying consistent with the concept of homeostasis?​
12. In a certain species, allele R is dominant to allele r. Two heterozygous parents ($Rr \times Rr$) have children. If their first child has genotype $rr$, what is the probability that their second child will also have genotype $rr$?​
13. In a meadow, primary consumers have 2,200 kJ of energy and secondary consumers have 220 kJ. What percentage of energy is transferred from primary consumers to secondary consumers?​
14. Glucose made by plants can be used to build more than just carbohydrates. Which option best describes how glucose can contribute to making different macromolecules in cells?
15. A mosquito population includes a small number of individuals with a heritable gene variant that makes them resistant to an insecticide. After insecticide spraying, many mosquitoes die, but resistant mosquitoes survive and reproduce. After repeated spraying over several seasons, most mosquitoes are resistant. Which statement best describes what evolved?
16. An energy pyramid follows the 10% rule. If producers have 50,000 units, how much energy is available to tertiary consumers (3° consumers)?
17. Food chains rarely have more than 4–5 trophic levels (producer through top predator). Which explanation best matches the 10% rule?
18. Claim: Carbon matter cycles through an ecosystem (carbon moves from the atmosphere into organisms and back to the atmosphere). A student collects the following evidence: 1) In a sealed clear container with a plant, CO$_2$ drops from 420 ppm to 360 ppm during 6 hours of light. 2) In the same container during 6 hours of darkness, CO$_2$ rises from 360 ppm to 410 ppm. 3) When dead leaves are mixed into soil, CO$_2$ above the soil increases over several days. 4) The plant's leaves are green. Which set of evidence is relevant and sufficient to support the claim? ​
19. A farming region converts a diverse grassland into a single-crop (monoculture) field. Which model best includes the key components needed to explain a drop in biodiversity in the area?
20. A runner's muscle cells need more energy during exercise. Which pair of substances must be delivered to the cells to support increased aerobic cellular respiration?

Practice tests