Skip to main content
Sign in Create a free account
Varsity Tutors
Sign in Sign up

Practice Test 3 - Middle School Life Science

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

  1. A population of snails includes banded shells and unbanded shells. Evolutionary change can be measured by shifts in trait frequency (proportions) across generations. A student wrote: "The snails evolved because banded shells increased from 10 to 40." Here are the counts from the same population: Generation 1: 10 banded, 90 unbanded Generation 2: 20 banded, 180 unbanded Generation 3: 30 banded, 270 unbanded Generation 4: 40 banded, 360 unbanded Which claim about evolution is incorrect based on the evidence?
  2. Two ecosystem models are described below. Interaction patterns can be compared across ecosystems using evidence from the models. Ecosystem Model 1 (Forest floor): mushrooms break down dead leaves; worms eat some of the decaying material; birds eat worms. Ecosystem Model 2 (Desert wash): bacteria break down dead plants; insects eat some of the decaying material; lizards eat insects. Which statement compares the ecosystems correctly using evidence about interactions?
  3. A student looks at embryo images from four species at the same early stage (Stage 1): turtle, chicken, rabbit, and fish. The student claims: "Turtle is most closely related to chicken." The images show turtle and chicken embryos share a very similar head shape and limb bud placement at Stage 1, while rabbit is somewhat similar and fish is most different. Because embryology provides evidence for relatedness, which claim is least supported by the embryological evidence shown?
  4. A wetland ecosystem food web model is shown. Arrows show energy transfer (from food to eater). Producers and consumers are labeled, and food webs show interconnected feeding relationships. Food web: - cattails (producer) → insect (consumer) - cattails (producer) → muskrat (consumer) - algae (producer) → snail (consumer) - insect (consumer) → frog (consumer) - snail (consumer) → duck (consumer) - frog (consumer) → heron (consumer) - duck (consumer) → heron (consumer) - muskrat (consumer) → fox (consumer) Error-checking: A student redraws one arrow as heron → duck and says, "This shows the heron gives energy to the duck when it eats it." Which claim about the model is incorrect? (Choose ONE.)
  5. Two ecosystem models are described below. Interaction patterns can be compared across ecosystems using evidence from the models. Ecosystem Model 1 (Stream): mayfly larvae are eaten by trout; trout are eaten by otters. Ecosystem Model 2 (Prairie): mice are eaten by snakes; snakes are eaten by hawks. Which statement compares the ecosystems correctly using evidence about interactions?
  6. A model shows: Gene C (instructions) → (arrow labeled "used to make") → Protein C. A change happens in Gene C so the instructions are different. Which prediction about protein production is supported by the model? (Statement reminder: genes provide instructions for proteins.)
  7. Fossils of an ancient reptile-like animal show a jaw joint and ear bones that are intermediate between those in modern reptiles and modern mammals. The fossils are found in older rock layers than the earliest fossils of modern mammals. Which evidence-based conclusion about common ancestry is supported?
  8. Use the model to trace matter through digestion and respiration. Which path shows matter moving during digestion (not respiration) according to the model? Model (arrows show matter movement): Food → mouth → stomach → small intestine → blood → body cells; Oxygen → lungs → blood → body cells; Outputs: carbon dioxide leaves lungs; solid waste leaves anus; liquid waste leaves bladder.
  9. Which model best shows the nucleus sending protein instructions to ribosomes?
  10. A population of snails lives on the same shoreline. Shell shape can be round or pointed. Evolutionary change can be measured by shifts in trait frequency (proportions) across generations. Trait frequency data: - Generation 1: 90 out of 100 are round - Generation 2: 60 out of 100 are round - Generation 3: 30 out of 100 are round Which statement about evolutionary change is supported by the data?
  11. Students tested how light affects growth of the same species of algae in identical containers for 10 days. All containers had the same water, nutrients, and temperature. The line graph shows algae concentration over time. Which claim about resources and growth is incorrect based on the data and evidence? Students state that resources can limit or support growth.
  12. Two groups of bean plants have different inherited traits: Group P has purple stems and Group G has green stems (genetic factors). They are grown in two environments: full sun and shade (environmental factors). Evidence (average height after 5 weeks): - Purple-stem plants: 25 cm in full sun; 15 cm in shade - Green-stem plants: 23 cm in full sun; 14 cm in shade A student makes the claim: "Stem color causes plants to grow taller." Which claim about growth is incorrect based on the evidence and the idea that growth results from interactions between genes and environment?
  13. A pond ecosystem is shown in the model below. The arrows show energy flow (not matter movement). Sunlight is the main energy source for most ecosystems. If the pond receives much less sunlight for several weeks (for example, due to heavy cloud cover), which prediction about energy availability is supported by the model?
  14. Fossil layers show changes in life forms over time. A stratigraphic model lists layers from older (bottom) to younger (top): - Layer 1 (oldest): fern leaf fossils - Layer 2: fern leaf fossils + insect wing fossils - Layer 3: insect wing fossils + small reptile footprints - Layer 4 (youngest): small reptile footprints only Which statement about the fossil layers is correct based on the evidence and the rule that lower layers are older?
  15. Cells are the basis for determining whether something is living. Two simplified microscope diagrams are shown side by side. Sample X (Yogurt): many small round units; each has a clear boundary; some units are grouped but still separate. Sample Y (Salt water after drying): scattered grains and irregular patches; no clear repeating units with boundaries. Which conclusion about life is incorrect based on the observed models?
  16. A forest has an outbreak of an invasive insect that kills ash trees. Evidence shows: the insect spreads fastest when people move firewood; removing and replacing ash trees in parks reduces hazard from falling trees but does not stop spread; a public rule that firewood must be bought locally reduced new infestations in nearby counties by about 50%; releasing a parasite wasp that attacks the invasive insect can reduce insect numbers over time but requires ongoing monitoring. Conservation choices: Option 1: Remove ash trees in city parks and replant different species. Option 2: Restrict movement of firewood and run inspections at campgrounds. Option 3: Release parasite wasps and monitor populations. Criteria: scientific effectiveness (slowing spread and reducing tree loss), economic cost, and social feasibility. Constraints: the city can enforce rules at its campgrounds but cannot control private wood transport everywhere; monitoring funds are limited to 2 years. Which conservation choice is best justified by the evidence and constraints?
  17. Use the cell model: labels identify Cell membrane (outer boundary with gate icons and arrows showing exchange), Nucleus (inner circle with instruction icon), and Cytoplasm (interior fluid with arrows showing movement). The model shows that each part contributes to the cell's overall function and that structure relates to function. Which claim is NOT supported by the model?
  18. Two populations of the same lizard species lived on the same rocky hillside during the same summer. Population M has longer legs; Population N has shorter legs. Data collected: - Population M: 25 females; 60 hatchlings survived to 1 month - Population N: 25 females; 45 hatchlings survived to 1 month Traits can influence reproductive success. Which argument best links the leg-length trait to reproductive success using the evidence?
  19. A simplified cell model shows a boundary labeled cell membrane. Inside is pink; outside is white. Arrows show water entering and waste leaving. A second substance, "dye," is shown outside but the arrow pointing toward the cell stops at the boundary (blocked). The model states: "The membrane regulates exchange." Which supported statement best describes what the membrane is doing in this model?
  20. Two simplified models show that reproduction type affects genetic outcomes. Model 1 (asexual reproduction): Parent count: [1] Parent: ⬤(striped) Offspring: ⬤(striped) ⬤(striped) ⬤(striped) Similarity/variation shown: offspring look the same as the parent. Model 2 (sexual reproduction): Parent count: [2] Parents: ⬤(striped) + ⬤(spotted) Offspring: ⬤(striped) ⬤(mixed) ⬤(spotted) Similarity/variation shown: offspring show differences. Which comparison of offspring is supported by the models, using evidence from both models?

Practice tests