Life Science & Scientific Inquiry — Midterm exam worked answers
Student exam paperCourse-authored study paper with accessible keys. Use two flexible 45-minute blocks for the midterm, three for the cumulative final, and one for the optional sample. The questions revisit taught ideas and cases; these are not secure official school tests. Feedback has a separate session.
20 questions · 60 points · suggested 90 minutes
Student instructions
- Use the supplied records; a glossary, notes, and calculator are permitted.
- Explain briefly and show calculation steps with units; a labeled diagram or supported oral response can be accepted where appropriate.
- Attempt responses before opening the worked key.
- The suggested timing can be extended for reading and writing needs; mark reasoning rather than speed or exact model wording.
Science inquiry and calculation notes
| Task | Method |
|---|---|
| Change | Final value minus initial value, with units. |
| Mean | Sum all values and divide by the number of values. |
| Percentage | Part divided by total, multiplied by 100. |
| Percentage points | Subtract two percentage values; distinguish from relative percent change. |
| Model | Label quantities, relationships, assumptions, and omissions. |
| Explanation | Claim + relevant evidence + biological reasoning + a limitation. |
Coverage and marks
| Chapter | Questions | Points |
|---|---|---|
| Scientific Inquiry & Diversity of Life | 1, 2, 3, 4, 5 | 15 |
| Cells, Transport & Cellular Energy | 6, 7, 8, 9, 10 | 15 |
| Body Organization, Transport & Movement | 11, 12, 13, 14, 15 | 15 |
| Coordination, Defense & Reproduction | 16, 17, 18, 19, 20 | 15 |
Parent / teacher marking guide
- A person awards each of the three criteria separately; written responses are not automatically graded.
- Accept scientifically accurate alternatives and accessible response forms.
- Discuss errors and revise a response. A score does not certify district mastery or homeschool credit.
Question 1 · 3 points
A class repeats this same light-confounded comparison ten times. Can it now identify water’s separate effect?
Worked answer
No. Repetition does not remove the linked light difference. Redesign the comparison so light is comparable, and use independent seedlings with recorded starting sizes.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 2 · 3 points
A drawing is enlarged while its copied scale bar is left unchanged. Can that bar still calibrate the enlarged cell?
Worked answer
No. The bar no longer has the same image-to-specimen relationship. Resize it with the image or provide a new valid calibration.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 3 · 3 points
A graph shows an association between rainfall and plant height. Does the association alone prove rainfall caused every difference?
Worked answer
No. Other conditions such as soil, species, light, and initial size may differ. A causal explanation needs a plausible mechanism and comparisons addressing alternatives.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 4 · 3 points
A student changes a model after repeated contradictory observations. Is this automatically dishonest?
Worked answer
No. Revising a model in response to accurately recorded evidence is part of science. Concealing or inventing observations would be a different problem.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 5 · 3 points
A fungus has walls but no chloroplasts. Must it be an animal or a plant?
Worked answer
No. Those two categories do not exhaust biological diversity. Fungi have their own characteristics; combine cell features, nutrition, and relationship evidence rather than forcing a two-category choice.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 6 · 3 points
A newly observed unicellular organism has no tissue. Does that contradict cell theory?
Worked answer
No. Unicellular organisms consist of one cell that carries out life processes. Tissues are not required in every organism.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 7 · 3 points
A bacterium has DNA and ribosomes but no nucleus. Can it still make proteins?
Worked answer
Yes. Ribosomes can use cellular instructions without an enclosed nucleus; the arrangement differs from the typical eukaryotic-cell model.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 8 · 3 points
A bulb cell has a wall and nucleus but no visible chloroplasts. Must the observation be wrong?
Worked answer
No. Many plant tissues lack chloroplasts, and visible detail also depends on the instrument. Use tissue context and additional features.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 9 · 3 points
A membrane is freely permeable to the solute in a second model. Can the previous nonpenetrating-solute prediction be copied unchanged?
Worked answer
No. Solute redistribution changes the relevant conditions. Determine permeability and concentrations before predicting water movement.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 10 · 3 points
A student says plants use respiration only at night. Correct the claim.
Worked answer
Plants respire in light and darkness. Photosynthesis can occur in suitable light at the same time, so a net gas change must account for both processes.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 11 · 3 points
A diagram includes the heart but no vessels. What important relationship is missing?
Worked answer
The transport network connecting the heart with tissues is missing. Pumping must be connected to pathways and exchanges to explain delivery and return.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 12 · 3 points
A diagram says food energy is created in the stomach. Correct it.
Worked answer
Food already contains chemical energy. Digestion processes molecules and absorption makes products available; cellular processes transfer energy into usable forms rather than create it.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 13 · 3 points
A vessel carries blood from the heart toward the lungs. Is it an artery or vein under the directional definition?
Worked answer
It is an artery because it carries blood away from the heart, regardless of its oxygen content before lung exchange.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 14 · 3 points
A diagram says one muscle contracts to bend and then pushes to straighten a joint. What needs correction?
Worked answer
Skeletal muscle contraction produces a pull. Opposing muscle action or another force can restore the movement; relaxation is not an active push along the same attachment.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 15 · 3 points
A draft calls kidney processing a digestive absorption step. Correct the system relationship.
Worked answer
Kidneys process materials from blood and regulate excretion and balance. Digestive absorption moves food-related materials across the intestinal lining; circulation connects the systems but the steps differ.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 16 · 3 points
Why could different task instructions change a response-time comparison?
Worked answer
They can change what must be detected, interpreted, or done. Comparable instructions and timing methods are needed before comparing outcomes.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 17 · 3 points
A student says “negative feedback is bad feedback.” Correct the terminology.
Worked answer
Negative describes opposition to a deviation. It does not label the process morally or medically harmful.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 18 · 3 points
Why should a decomposition bacterium not automatically be labeled a harmful pathogen?
Worked answer
Its role depends on organism and context. Decomposition can recycle matter; being microscopic or bacterial does not by itself establish disease-causing activity.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 19 · 3 points
Two sexual offspring share parents but differ in traits. Does that by itself contradict inheritance?
Worked answer
No. They can receive different combinations of inherited material and experience different environments. Sexual inheritance is not an exact visual blend.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.
Question 20 · 3 points
Why is the same germination treatment not automatically best for every plant species?
Worked answer
Species can have different requirements and tolerances. Evidence from one species and interval needs qualification before generalizing.
Identify the relevant organism, process, or model.
Connect supplied evidence with the explanation, using calculation steps and units where needed.
State a correct assumption, distinction, or evidence limitation.
Marking criteria
- Accurate biological concept or distinction.
- Evidence, calculation, or model connected with an explained claim.
- A correct limitation, assumption, or needed additional observation.