Printable Midterm Form A

1. [Unit 00] A planned investigation has a serious risk that cannot be controlled with available equipment. What should happen first?

1. Revise or replace the method before beginning.
2. Proceed with fewer trials.
3. Ask participants to accept the risk.
4. Continue if the scientific question is important.

2. [Unit 00] Which action is appropriate when an approved activity requires splash goggles?

1. Share one pair while materials are being handled.
2. Wear correctly fitting splash goggles for the entire exposure period.
3. Wear ordinary eyeglasses instead.
4. Remove the goggles whenever they fog.

3. [Unit 00] What is the safest rule for an unlabeled substance?

1. Taste a tiny amount.
2. Mix it with water to see what happens.
3. Do not handle or use it; inform the supervising adult.
4. Smell it closely to identify it.

4. [Unit 00] A liquid splashes into a student’s eye during a supervised laboratory activity. What is the correct immediate response?

1. Finish recording data before responding.
2. Rub the eye with a dry towel.
3. Wait to see whether pain develops.
4. Use the approved eyewash procedure immediately and alert the supervisor.

5. [Unit 00] A result does not match the other trials. What is the most responsible response?

1. Document it, check the method and equipment, and repeat if appropriate.
2. Delete it without explanation.
3. Change it to equal the mean.
4. Conclude that all other trials are wrong.

6. [Unit 00] Which study plan requires informed consent and additional ethical safeguards?

1. Timing a paper helicopter.
2. Collecting identifiable health information from human participants.
3. Measuring the length of classroom pencils.
4. Using a published anonymous dataset.

7. [Unit 00] Which field practice is appropriate?

1. Remove rare specimens for a personal collection.
2. Publish exact locations of vulnerable species.
3. Observe from a permitted stable location and minimize disturbance.
4. Enter a protected nesting area for a closer photograph.

8. [Unit 00] Which notebook entry best supports reproducibility?

1. Only the final conclusion.
2. A copied procedure with no changes recorded.
3. A list of results without units.
4. Date, materials, exact method, measurements, changes, and unexpected events.

9. [Unit 00] A student writes, ‘The liquid is cloudy, so a new substance definitely formed.’ Which statement is most scientifically defensible?

1. Cloudiness is an observation; formation of a new substance is an inference requiring more evidence.
2. Cloudiness proves a chemical reaction occurred.
3. The statement contains only observations.
4. The liquid must be a mixture.

10. [Unit 00] Which question is most testable?

1. Does light help plants?
2. How does 4, 8, or 12 hours of daily light affect mean seedling height after 14 days under otherwise matched conditions?
3. Are plants interesting?
4. Which plant is best?

11. [Unit 01] A student changes light intensity and measures the oxygen production rate of an aquatic plant. What is the independent variable?

1. Light intensity.
2. Oxygen production rate.
3. Plant species.
4. Elapsed measurement time.

12. [Unit 01] Repeated measurements are 12.2 cm, 12.2 cm, 12.3 cm, and 12.2 cm. What can be concluded from these values alone?

1. There is no measurement uncertainty.
2. The measurements are precise.
3. The measurements are accurate.
4. The true value is 12.225 cm.

13. [Unit 01] What is the mean of 4.0, 4.5, 5.0, and 4.5 seconds?

1. 4.75 seconds.
2. 18.0 seconds.
3. 4.5 seconds.
4. 4.0 seconds.

14. [Unit 01] Which graph is generally most suitable for showing the relationship between temperature and reaction rate?

1. A pie chart.
2. A pictogram.
3. A single-category bar chart.
4. A scatter plot or line graph with two numerical axes.

15. [Unit 01] Why are repeated trials useful?

1. They reveal variation and improve confidence in an estimate such as the mean.
2. They prove the hypothesis.
3. They remove all random error.
4. They guarantee accuracy.

16. [Unit 01] An observational study finds an association between screen time and sleep duration. Which conclusion is justified?

1. No confounding variable could exist.
2. The variables were associated in the observed sample, but causation is not established.
3. Screen time caused every sleep difference.
4. Sleep duration caused all screen use.

17. [Unit 01] Which statement is scientific reasoning rather than a claim or a measurement?

1. The reaction lasted 24 seconds.
2. Three trials were completed.
3. Greater surface area increases collision opportunities, explaining the faster measured reaction.
4. The powdered sample reacted faster.

18. [Unit 01] A ruler has millimetre markings. Which report best reflects its resolution for a direct length reading?

1. Report twenty decimal places.
2. Report no units.
3. Claim the length is exact.
4. Report to the nearest millimetre and acknowledge reading uncertainty.

19. [Unit 01] Which question is directly investigable with measurements and a defined comparison?

1. How does wing length in centimeters affect flight distance in meters for airplanes made from the same paper and design?
2. Should everyone enjoy building paper airplanes?
3. Is flight interesting?
4. Which paper airplane looks best?

20. [Unit 01] A student deliberately changes ramp height and measures how far the same toy car travels. Which statement is correct?

1. Ramp height is the dependent variable.
2. Distance traveled is the dependent variable.
3. The toy car is the independent variable.
4. Distance traveled should be controlled.

21. [Unit 02] Which statement is part of modern cell theory?

1. All living organisms consist of one or more cells.
2. Every cell has a nucleus.
3. Viruses are complete cells.
4. Cells arise only from nonliving matter.

22. [Unit 02] Which structures occur in all known cells?

1. A Golgi apparatus and lysosomes.
2. A plasma membrane and ribosomes.
3. A nucleus and mitochondria.
4. Chloroplasts and a cell wall.

23. [Unit 02] Which feature distinguishes a typical eukaryotic cell from a typical prokaryotic cell?

1. It has a plasma membrane.
2. It contains genetic material.
3. Most DNA is enclosed in a membrane-bound nucleus.
4. It has ribosomes.

24. [Unit 02] A specimen is 0.04 mm long and its image is 20 mm long. What is the magnification?

1. 50×.
2. 800×.
3. 0.002×.
4. 500×.

25. [Unit 02] Osmosis is the net movement of:

1. Water across a selectively permeable membrane from higher water potential toward lower water potential.
2. Solute from low concentration to high concentration without energy.
3. All particles through any membrane.
4. Water only from low solute concentration to low solute concentration.

26. [Unit 02] Why does a high surface-area-to-volume ratio support exchange?

1. It prevents all water movement.
2. More membrane area is available relative to the material requiring exchange.
3. It eliminates diffusion distance.
4. It creates energy.

27. [Unit 02] Which statement correctly links photosynthesis and cellular respiration?

1. Respiration occurs only in animals.
2. Photosynthesis destroys carbon atoms.
3. Photosynthesis stores energy in organic molecules, while respiration transfers usable energy from those molecules.
4. Both processes require sunlight at every step.

28. [Unit 02] Which sequence is ordered from smaller to larger biological organization?

1. Organ → cell → tissue → organism.
2. Tissue → organ system → cell → organ.
3. Organ system → organ → tissue → cell.
4. Cell → tissue → organ → organ system.

29. [Unit 02] Which observation most directly supports the conclusion that a specimen is cellular?

1. It is green.
2. Repeated microscope views show membrane-bounded units with internal contents.
3. It moves when pushed.
4. It has a measurable mass.

30. [Unit 02] Which structure is present in both prokaryotic and eukaryotic cells?

1. Mitochondrion
2. Golgi apparatus
3. Ribosome
4. Membrane-bound nucleus

31. [Unit 03] Homeostasis is best described as:

1. Dynamic regulation of internal conditions within functional ranges.
2. Keeping every variable perfectly constant.
3. A process occurring only during illness.
4. The absence of environmental change.

32. [Unit 03] Which sequence represents a negative-feedback system?

1. Stimulus → random action with no information pathway.
2. Change → receptor → coordinating centre → effector → response that reduces the change.
3. Change → amplifier → response that increases the change indefinitely.
4. Effector → receptor → no response.

33. [Unit 03] What is the primary role of red blood cells?

1. Filter urine.
2. Transmit nerve impulses.
3. Transport oxygen using haemoglobin.
4. Produce digestive enzymes.

34. [Unit 03] Which adaptation increases gas-exchange efficiency in alveoli?

1. Thick dry walls.
2. Low blood supply.
3. A small number of sealed chambers.
4. Large surface area and a thin exchange barrier.

35. [Unit 03] Most absorption of digested nutrients occurs in the:

1. Small intestine.
2. Stomach.
3. Large intestine.
4. Oesophagus.

36. [Unit 03] The kidneys help regulate:

1. Only food intake.
2. Water, ions, pH, and removal of nitrogenous wastes.
3. Only body temperature.
4. Only oxygen uptake.

37. [Unit 03] Compared with endocrine signalling, nervous signalling is generally:

1. Carried only in blood.
2. Unable to affect muscles.
3. Faster and more targeted.
4. Always slower and more widespread.

38. [Unit 03] A classroom heart-rate record should be used to:

1. Diagnose heart disease.
2. Publish named student records.
3. Replace professional medical evaluation.
4. Explore physiological patterns without diagnosing a medical condition.

39. [Unit 03] In negative feedback, the response generally:

1. Stops communication
2. Opposes the initial change
3. Amplifies change without limit
4. Removes the receptor

40. [Unit 03] Which is commonly modeled as positive feedback?

1. Sweating
2. Insulin after a meal
3. Water conservation
4. Blood clotting at a damaged vessel

41. [Unit 04] Which sequence is correct?

1. DNA contains genes and is organized into chromosomes.
2. Chromosomes contain cells inside genes.
3. Genes contain organisms.
4. Alleles are made of tissues.

42. [Unit 04] Mitosis usually produces:

1. Gametes only.
2. Two genetically similar daughter cells with the same chromosome number as the parent cell.
3. Four genetically varied haploid cells.
4. One cell with twice the chromosome number.

43. [Unit 04] Meiosis contributes to variation through:

1. Preventing chromosome separation.
2. Eliminating all mutation.
3. Crossing over, independent assortment, and random fertilization.
4. Producing identical diploid cells.

44. [Unit 04] For Aa × Aa, what is the expected probability of genotype aa?

1. 1/2.
2. 3/4.
3. 1.
4. 1/4.

45. [Unit 04] Phenotype is influenced by:

1. Genotype and environmental conditions.
2. Genotype only in every trait.
3. Environment only in every trait.
4. Neither inheritance nor environment.

46. [Unit 04] A mutation is:

1. A change in exercise level.
2. A change in genetic material that may be neutral, harmful, or beneficial depending on context.
3. Always harmful.
4. Always inherited by offspring.

47. [Unit 04] Why is cell-cycle regulation important?

1. It stops all cell replacement.
2. It produces gametes by mitosis.
3. It coordinates division and helps limit uncontrolled proliferation.
4. It guarantees that cancer cannot occur.

48. [Unit 04] Which principle is essential when using identifiable genetic information?

1. Public release without permission.
2. Treating probability as destiny.
3. Using ancestry claims to rank human worth.
4. Consent, privacy, limited access, and recognition of uncertainty.

49. [Unit 04] Which statement correctly relates a gene to DNA?

1. A gene is a segment of DNA involved in a functional product or regulation.
2. A gene is a protein surrounding every chromosome.
3. A gene is the complete genome.
4. A gene is a whole cell.

50. [Unit 04] An allele is:

1. A complete chromosome set
2. A variant form of a gene
3. Any environmental influence
4. A type of cell division

51. [Unit 05] Which term describes all populations of different species living and interacting in an area?

1. Community.
2. Population.
3. Habitat.
4. Organism.

52. [Unit 05] Why is less energy available at higher trophic levels?

1. Matter stops cycling.
2. Organisms use and dissipate much energy through metabolism and heat transfer.
3. Energy atoms are destroyed.
4. Predators cannot digest food.

53. [Unit 05] A population exceeds resource availability and then declines. Which factor most directly explains the decline?

1. Creation of new energy.
2. Removal of all variation.
3. Density-dependent limitation such as competition for food.
4. Unlimited carrying capacity.

54. [Unit 05] Species richness measures:

1. The total biomass only.
2. The genetic sequence of one organism.
3. The age of an ecosystem.
4. The number of species present.

55. [Unit 05] Natural selection requires:

1. Heritable variation and differences in reproductive success.
2. Individuals changing genes because they need to.
3. All organisms surviving equally.
4. No environmental influence.

56. [Unit 05] Which is direct empirical evidence used to reconstruct evolutionary relationships?

1. The assumption that all similarities have one cause.
2. DNA sequence similarities and differences.
3. A philosophical preference.
4. A single unsupported story.

57. [Unit 05] An ecosystem is generally more resilient when it has:

1. No disturbance history.
2. No nutrient cycling.
3. Functional diversity and multiple pathways that can maintain processes.
4. Only one species performing each function.

58. [Unit 05] Which plan is strongest?

1. Move organisms without permits.
2. Publish sensitive nest locations.
3. Choose an action without baseline data.
4. Protect habitat, involve affected communities, monitor outcomes, and revise using evidence.

59. [Unit 05] Which level includes interacting populations and abiotic conditions?

1. Ecosystem
2. Species
3. Organism
4. Population

60. [Unit 05] A niche is best described as:

1. Only the geographic location of an organism
2. The organism’s role, resource use, tolerances, timing, and interactions
3. A permanent population size
4. A fossil classification

61. [Unit 06] The atomic number equals the number of:

1. Protons.
2. Neutrons plus electrons.
3. Neutrons only.
4. Electron shells.

62. [Unit 06] A neutral atom has atomic number 12. How many electrons does it have?

1. 10.
2. 12.
3. 6.
4. 24.

63. [Unit 06] Isotopes of the same element differ in their number of:

1. Valence shells only.
2. Nuclei.
3. Neutrons.
4. Protons.

64. [Unit 06] An atom with 17 protons and 18 electrons has charge:

1. +1.
2. 0.
3. −17.
4. −1.

65. [Unit 06] Why is a periodic-table atomic mass often not a whole number?

1. It is an abundance-weighted average of naturally occurring isotopes.
2. Atoms contain fractional protons.
3. Every isotope has the same abundance.
4. Electrons have no mass.

66. [Unit 06] For elements 1–20, group patterns are strongly related to:

1. The number of compounds already discovered.
2. Outer-electron arrangements.
3. Neutron color.
4. Nuclear size only.

67. [Unit 06] Which broad statement is accurate?

1. Halogens are metals.
2. All elements in a period have identical properties.
3. Group 1 metals generally become more reactive down the group.
4. Noble gases are highly reactive.

68. [Unit 06] Why have atomic models changed over time?

1. Atoms changed their laws.
2. Scientists preferred more complex drawings.
3. No experiments were involved.
4. New evidence required revision of earlier explanations.

69. [Unit 06] Which statement distinguishes an element from a compound?

1. An element contains one type of atom; a compound contains elements chemically combined in fixed proportions
2. Compounds cannot be pure
3. Elements always separate physically
4. An element contains one proton only

70. [Unit 06] Rutherford’s scattering evidence most directly supported:

1. Atoms are indivisible spheres
2. Positive charge and most mass are concentrated in a small nucleus
3. Electrons are positive
4. Atoms contain no empty space