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Grade 10: Science subject test

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1. RNA codons guide a ribosome while the DNA template stays unchanged. What is supported? Which inference or prediction is best supported?All genes must code for proteins.Translation can build an amino-acid sequence without changing DNA.Every translated codon edits the DNA template.Protein production is always DNA replication.

2. The supplied sequence GTACT becomes GACT. Which immediate effect is established? Which inference or prediction is best supported?One base was deleted; downstream coding effects need the reading-frame context.One extra base was inserted.The unchanged length proves a substitution only.The deletion guarantees one specific disease.

3. Supplied case 6: coding-segment RNA bases=45, using the explicitly named quantities. Complete codon count equals coding-segment bases divided by three for these divisible-by-three cases. What result follows?135 codons16 codons14 codons15 codons

4. Deleting the first A from AAAGCU changes groups from AAA GCU to AAG CU in the same frame. What follows? Which inference or prediction is best supported?Only one entire codon was removed.The frame effect predicts a specific real-person diagnosis.Downstream triplet grouping shifts, with an incomplete ending in this supplied segment.Every original codon grouping stays fixed.

5. Migrants enter a population, breed and contribute alleles. What population pathway is established? Which inference or prediction is best supported?Gene flow can change allele frequencies through reproductive contribution.Movement without breeding always transfers alleles.Every migrant creates a new species immediately.Alleles cannot move between populations.

6. Supplied case 6: focal allele copies=36; diploid individuals=45, using the explicitly named quantities. Allele percentage equals 100 times focal copies divided by twice individual count. What result follows?80 %41 %39 %40 %

7. Separated groups later reunite and exchange genes readily. What does this limit? Which inference or prediction is best supported?Gene exchange proves identical traits in every detail.Every species definition is resolved by one observation.Separation alone was insufficient to establish reproductive isolation.Their former separation must never have occurred.

8. Small populations with no measured trait advantage show different random-sample frequency shifts. What fits? Which inference or prediction is best supported?Chance is incompatible with inheritance.Drift predicts sampling variation without requiring a selective advantage.Every random shift proves purposeful selection.All small samples must preserve exact frequencies.

9. Water molecules remain intact while attractions between molecules change during melting. What distinction fits? Which inference or prediction is best supported?Every melting event decomposes each molecule.Between-molecule attraction is the same as every internal bond.Liquid phase proves no interactions remain.Intermolecular rearrangement does not require breaking water’s internal covalent bonds.

10. Solid metal conducts, while a supplied ionic solid does not until dissolved. What difference fits? Which inference or prediction is best supported?Ions cannot ever carry charge.Dissolving necessarily removes every ion charge.Mobile electrons in the metal contrast with ions fixed in the ionic solid.Every solid conducts because it is solid.

11. A supplied analysis confirms new molecules and rearranged internal covalent connections. What conclusion fits? Which inference or prediction is best supported?New bonds require creation of new atoms.A chemical reaction is supported beyond a phase-only description.Only intermolecular spacing changed.All melting always yields these new molecules.

12. Supplied case 6: higher softening temperature (°C)=300; lower softening temperature (°C)=220, using the explicitly named quantities. Temperature gap equals higher supplied softening temperature minus lower temperature. What result follows?80 °C520 °C81 °C79 °C

13. Supplied case 6: solute amount (mol)=3.5; solution volume (L)=7, using the explicitly named quantities. Molarity equals solute moles divided by solution liters. What result follows?1.5 mol/L-0.5 mol/L0.5 mol/L24.5 mol/L

14. Supplied case 6: initial concentration (mol/L)=5; initial volume (L)=2; final volume (L)=20, using the explicitly named quantities. Final concentration equals initial concentration times initial liters divided by final liters. What result follows?-0.5 mol/L0.5 mol/L200 mol/L1.5 mol/L

15. Supplied case 6: positive exponent a in hydronium 10^(-a) mol/L=8, using the explicitly named quantities. If hydronium concentration is 10 raised to negative a mol/L, model pH equals a. What result follows?8 pH units80 pH units9 pH units7 pH units

16. Supplied case 6: pH at 25°C=11, using the explicitly named quantities. At stated 25°C, pOH equals 14 minus pH. What result follows?25 pOH units4 pOH units2 pOH units3 pOH units

17. Respiration returns supplied organic carbon to CO₂. What follows? Which inference or prediction is best supported?CO₂ formation necessarily creates a new element.The same carbon can reenter the gas pool without being used up as energy.Respiration destroys every carbon atom.Carbon cycling proves usable energy is perfectly recycled.

18. Supplied case 6: initial carbon stock (model units)=180; annual inflow (same units)=24; annual outflow (same units)=30, using the explicitly named quantities. Final carbon stock equals starting stock plus inflow minus outflow. What result follows?174 model carbon units234 model carbon units175 model carbon units173 model carbon units

19. Warming reduces reflective ice and raises absorbed sunlight in the supplied loop. What follows? Which inference or prediction is best supported?The loop necessarily cools the system.Less reflection means less absorption under fixed input.Positive feedback means a morally desirable result.That loop amplifies the initial warming.

20. A building redesign lowers susceptibility under unchanged modeled storm conditions. What is supported? Which inference or prediction is best supported?Lower vulnerability proves no exposed people remain.One model certifies all climate outcomes.Vulnerability reduction can lower modeled impact without changing the storm hazard.The redesign stops every storm.

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