UAT-UK SPEC CODE: B9 (Animal physiology)ASSUMED MATHS 1 PREREQUISITE: M4.14FREQUENCY: MEDIUM
Renal Vessels, Nephron Ultrafiltration, Selective PCT Reabsorption & ADH Osmoregulation
Deconstructed from 5 past UAT-UK questions (2.15% of all historical Biology papers). Students using standard A-Level classroom methods spend an average of 135s on this archetype—blowing past the 90s ESAT budget. Using the 2-line Sub-90 heuristic below compresses solve time to 35s (saving 100s per question).
Historical Frequency
5 Past Qs
2.15% of Biology
Classroom Trap Time
135s
+45s over 90s budget
Sub-90 Target Time
35s
Banks +100s on the clock
Dominant UI Format
Table Matching
Maths 1 Skill: M4.14
Card 1 & Card 2 Preview: The Classroom Time Trap vs. Sub-90 2-Line Rule
Excerpted from our interactive 6-Step Topic Lesson for ARCH-B-10.
CARD 1 OF 6 • THE CLASSROOM TIME TRAP (135s)
Why Students Bleed Time:
Trace each solute through the nephron:
- Plasma proteins: ; blocked by the glomerular basement membrane in filtrate and in urine.
- Glucose: small molecule (); filtered freely into Bowman's capsule , then ** selectively reabsorbed in the PCT** in final urine.
- Urea: small molecule; filtered freely and concentrated as water is reabsorbed in final urine.
- Plasma proteins: ; blocked by the glomerular basement membrane in filtrate and in urine.
- Glucose: small molecule (); filtered freely into Bowman's capsule , then ** selectively reabsorbed in the PCT** in final urine.
- Urea: small molecule; filtered freely and concentrated as water is reabsorbed in final urine.
In 5 past UAT-UK questions (2.15% of Biology), candidates lose 100s by proteins and blood cells are too large for ultrafiltration; glucose is filtered and then completely reabsorbed in the proximal convoluted tubule. Instead, apply B9 with Maths 1 skill M4.14.
CARD 2 OF 6 • THE 2-LINE SUB-90 HEURISTIC (<35s)
Bowman's capsule has **glucose () & urea (), no protein ()**; PCT reabsorbs of glucose Urine has **only urea ()**.
Bowman's capsule has **glucose () & urea (), no protein ()**; PCT reabsorbs of glucose Urine has **only urea ()**.
Sanity & Limit Check: Verify units/signs against
multi_statement_linchpin_foil (Claiming glucose is too large to be filtered at the glomerulus (it IS filtered into Bowman's capsule, then 100% selectively reabsorbed by active transport in the PCT)) and sign_or_direction_flip (Saying high blood water potential (dilute blood) triggers MORE ADH release and concentrated urine).Examiner Distractor Blueprint for ARCH-B-10
FOIL #1multi_statement_linchpin_foil
Claiming glucose is too large to be filtered at the glomerulus (it IS filtered into Bowman's capsule, then 100% selectively reabsorbed by active transport in the PCT)
Proteins and blood cells are too large for ultrafiltration; glucose is filtered and then completely reabsorbed in the proximal convoluted tubule.
FOIL #2sign_or_direction_flip
Saying high blood water potential (dilute blood) triggers MORE ADH release and concentrated urine
Dehydration (low blood water potential) -> pituitary releases MORE ADH -> collecting duct MORE permeable -> MORE water reabsorbed -> small volume of concentrated urine.
FOIL #3table_column_pruning_trap
Reading urea/ion numbers before pruning nephron fluid tables via Protein = 0 (in Bowman's capsule filtrate) and Glucose = 0 (in healthy urine)
Protein is strictly 0 in glomerular filtrate and urine; glucose is strictly 0 in healthy urine—prunes 75% of rows in 5s.
FOIL #4multi_statement_linchpin_foil
Claiming urea concentration is lower in urine than in glomerular filtrate because urea is actively secreted
Urea concentration rises sharply along the nephron because water is reabsorbed into the blood, concentrating the remaining urea.
Try 1 Live Sample Question Under the 90-Second Stopwatch
Press W to open the 2-line dry-wipe scratchpad, select A–E, and lock in to reveal the Dual-View solution.
sub90 ESATARCH-B-10: Renal Vessels, Nephron Ultrafiltration, Selective PCT Reabsorption & ADH Osmoregulation (Sample)Biology
00:00.0
SUB-90 ZONE (<35S)
0.0s35s Sub-9090s ESAT Budget150s Classroom
Right-click any option to cross out • Keys
A–E + EnterQuestion 1 of 1 • 90s Target
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Biology•ARCH-B-10•Standard 5-Option
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