Error notes

Paper: ILTS practice — Zoology, merged set (Evolution + Human Health and Disease) | 45 questions | Aamirah Fathima

160out of 180

41correct

4incorrect

0blank

Evolution was a clean sweep — 22 out of 22, including all four assertion–reason items and both Hardy–Weinberg questions. Every error sits in Human Health and Disease, and all four are single-word or single-clause decisions rather than missing content. There is nothing to re-teach here; there are four reading habits to tighten.

The four errors

One card each. The fix line is the drill to run, not a summary.

Q24 Drug effect vs absence of drug Withdrawal syndrome

MarkedA

CorrectB — nausea, sweating, shakiness

What happened Option A read "anxiety, depression, sleep". Anxiety is genuinely on the NCERT list, so the option felt familiar and got marked on a partial match. But withdrawal disturbs sleep — it does not produce it, and depression is not in the NCERT set. Option B contains three of the four listed symptoms and nothing wrong. NCERT's list is anxiety, shakiness, nausea, sweating.

The discriminator When two options share a correct word, the winner is the one with no incorrect word in it. A familiar first word is not evidence.

Fix On any symptom-list question, tick each listed item against the textbook set and reject the whole option on the first bad item — do not score options by how many items match. Ask of every symptom: is this the body on the drug, or off it? Euphoria, hallucination and sleep are on-drug effects.

Q32 Assertion–reason instability Vaccination — two-statement judgement

MarkedB — Statement I true, Statement II false

CorrectD — both statements true

What happened Statement II said vaccination is an example of artificially acquired active immunity. That is correct, and she rejected it. This is the error worth the most attention on the paper, because the same concept appeared three times and she got the other two right:

Q	What it asked	Her answer
Q30	Pulse polio vaccination falls under which category of immunity	Active immunity — correct
Q31	Assertion–reason: does vaccination introduce memory cells into the body	A true, R false — correct
Q32	Is vaccination artificially acquired active immunity	Rejected a true statement

The pattern underneath Q31's reason was genuinely false, and the suspicion carried forward one question. She arrived at Q32 already primed to find a false clause about vaccination and found one that wasn't there. So the instability is not a knowledge gap in immunity — she demonstrably holds active-vs-passive and antigen-in-vs-memory-cells-out. It is contamination between consecutive questions on the same topic.

Fix The three-step written defence has to be re-run from scratch on each question, never adjusted from the one before. Concretely: when two or more questions in a row cover the same topic, cover the previous answer with her hand before reading the next stem. A verdict of "false" on one statement is evidence about that statement only.

Q36 Near-miss vocabulary CT vs MRI

MarkedA — MRI

CorrectD — CT

What happened Both CT and MRI produce three-dimensional images of internal organs, so the shared part of the description cannot decide the answer. The stem named X-rays. CT uses X-rays; MRI uses strong magnetic fields and non-ionising radiation.

The discriminator The physics named in the stem, not the output described in the stem. C in CT stands for computed — X-ray sections. M in MRI stands for magnetic.

Fix Underline the mechanism word in the stem (X-rays, magnetic field, antibody, enzyme, electrical) before looking at the options. Add to the cancer-detection sheet as a two-line pair so they are learned against each other rather than separately.

Q45 Grid transcription — to confirm Vector of chikungunya and dengue

MarkedD — house fly

CorrectB — female Aedes

What happened House fly is not a plausible near-miss the way Culex or Anopheles would be — those are the options a genuine content gap would produce. Two things point to a slip rather than a gap: this is the last question on the paper, and the cell directly above it (Q44) is also D.

Before logging this Ask her what she intended. If she says Aedes, this is a transcription error into the wrong cell and does not belong with the content errors at all. If she says house fly, it becomes an attribution error and the three mosquito genera need a fresh pass.

Fix Add one line to the end-of-paper routine: read the last three grid cells back against the last three questions before handing over. Costs fifteen seconds and protects four marks.

What this paper says about the tracked families

Two families held under test conditions. One resurfaced in a new form.

Holding Ratio and direction reversal

Q17 gave the homozygous recessive frequency as 0.09 and asked for the allele frequency. Her margin working reads 0.09 = q², q = 0.3 — she took the root instead of squaring, and wrote the step down rather than doing it in her head. Q43 (low haematocrit means fewer red cells, not more) also went the right way. Both are direction decisions she has previously reversed under time pressure.

New form Assertion–reason instability as carry-over

In earlier papers this family showed as errors going in both directions across a paper, which read as an unsettled procedure. Here the procedure worked — all four assertion–reason items in Evolution were correct, and Q31 was correct. What failed was insulation between neighbouring questions on one topic. That is a narrower and more fixable thing than the original diagnosis, and the hand-over-the-previous-answer habit is the whole remedy.

Full response record

For the tracking sheet. Sections I and II scored separately.

Section	Questions	Correct	Wrong	Marks
I — Evolution	1–22	22	0	88 / 88
II — Human Health and Disease	23–45	19	4	72 / 92
Total	45	41	4	160 / 180

Errors at Q24, Q32, Q36, Q45. All four in Section II, none in Evolution. Attempt rate 45 / 45 — attempt discipline intact on the whole paper, including the sections that have carried blanks before.

Carry into the next paper

Underline the mechanism word in every diagnostic-technique stem before reading options.
On symptom or statement lists, reject an option on its first wrong item rather than scoring it by how much matches.
When consecutive questions share a topic, cover the previous answer before reading the next stem.
Read the last three grid cells back against the last three questions before finishing.
Confirm the Q45 intention, then log it either as transcription or as attribution — not as unresolved.