Practice Test 12 - High School Biology

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

Which statement best defines homeostasis?
A forest region contains the last large patch of habitat for an endangered bird. Two plans are proposed: Plan A: Protect the remaining intact forest from logging through a conservation easement. Plan B: Allow logging to continue, but require companies to plant new tree seedlings after each harvest. Which plan more directly addresses the root cause of the bird's decline, and why?
Himalayan rabbits all have the same genotype for a temperature-sensitive coat color trait. A student raises one rabbit in a warm room and another rabbit (same genotype) in a much cooler room. The warm-room rabbit grows mostly white fur, while the cool-room rabbit develops darker fur on cooler body parts (ears, nose, feet). Which statement best explains these results?
A class compares two flowchart models for urban development near a wetland. Model 1: [Urban development] → [Wetland filled in] → [Biodiversity declines] Model 2: [Urban development] → [Habitat loss + fragmentation] → [Fewer nesting sites + reduced food] → [Population decline] → [Local extinctions] → [Reduced biodiversity] Which statement best evaluates the models?
In a coastal ecosystem, phytoplankton (tiny photosynthetic organisms) are eaten by zooplankton. Zooplankton are eaten by small fish, and small fish are eaten by tuna. Which option correctly compares primary, secondary, and tertiary consumers in this chain?
Identical twins have the same genotype. One twin had a balanced diet throughout childhood, while the other experienced long-term malnutrition. As adults, the well-nourished twin is taller. Which idea best explains why the twins can differ in height?
Claim: Decomposers recycle nutrients back into the soil, making them available for plants. A class compares two pots with the same amount of dead leaves mixed into soil: - Pot A: normal soil (microbes and fungi present) - Pot B: sterilized soil (microbes killed) Results after 6 weeks: 1) Pot A has much less visible leaf material than Pot B. 2) Soil nitrate (NO $_3^-$ ) in Pot A increases from 5 mg/kg to 18 mg/kg; Pot B stays near 5 mg/kg. 3) Bean seedlings planted afterward grow taller in Pot A than in Pot B. 4) Both pots receive the same amount of water and light. Which evidence is most relevant and sufficient to support the claim?
Two forests experience the same windstorm. Forest A shows little change in tree cover during the storm. Forest B loses many trees, but within several years its tree cover and animal populations return to near pre-storm levels. Which statement correctly compares resistance and resilience in these forests?
A cell replaces damaged molecules over time (turnover). If the cell stopped synthesizing macromolecules, which outcome best explains why it would eventually fail to function?
A student stands up quickly after sitting and feels briefly dizzy, then feels normal again. A simple model is being made to show system interactions that help maintain steady blood flow to the brain. Which addition best improves the model?
A scientist compared beak depth (mm) in two finch populations using the summary below. - Island X: minimum 7 mm, maximum 13 mm - Island Y: minimum 9 mm, maximum 11 mm Based on these ranges, which statement is correct?
After eating a large meal, a person's blood glucose rises from 90 mg/dL to 135 mg/dL. Cells in the pancreas detect the increase and release insulin. Over the next 2 hours, body cells take up more glucose and the blood glucose level returns to about 95 mg/dL, after which insulin release decreases. What best explains why the glucose level returns to its normal range?
Which situation best describes an unstable ecosystem (low stability)?
When a person becomes dehydrated, the body must conserve water. How do the circulatory and excretory systems interact to help regulate water balance?
A grassland produces about 12,000 kg of edible grass each year that can be used by a herd of antelope. On average, one antelope needs about 300 kg of edible grass per year to survive and reproduce. Using $K = \frac{\text{total resource}}{\text{resource needed per individual}}$ , what is the carrying capacity (K) for antelope in this grassland (assuming grass is the limiting resource)?
A student is interpreting a simple ecosystem model. The model shows: - Photosynthesis box: inputs CO2, H2O, and light; outputs glucose and O2. - Cellular respiration box: inputs glucose and O2; outputs CO2 and H2O. - A separate arrow shows light entering the system and another arrow shows heat leaving. What is the best interpretation of what the arrows represent?
A person holds their breath underwater. After a short time, their muscles feel weaker and they must surface. Which interaction best explains why both the respiratory and circulatory systems are needed for sustained muscle activity?
Claim: Decomposition helps complete nutrient cycles by moving matter from dead organisms back into forms plants can use. Forest floor observations over 6 months: 1) Leaf litter layer became thinner over time. 2) Soil tests showed an increase in available nitrogen in the topsoil. 3) The average daily sunlight in the forest stayed about the same. 4) Many insects were seen near rotting logs. Which evidence best supports the claim about decomposition and nutrient cycling?
A gene has the coding DNA triplet GAA at one position. A substitution changes it to GAG. In this case, the protein produced is unchanged. Which term best describes this type of mutation outcome?
A small island produces about 5,000 kg of edible vegetation per year that rabbits can eat. A rabbit needs about 50 kg of this vegetation per year to survive and reproduce. Using $K = \frac{\text{total food per year}}{\text{food needed per rabbit per year}}$ , what is the island's carrying capacity (K) for rabbits?

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