MDCAT Biology — Homeostasis
Homeostasis is a core Biology topic in the PMDC MDCAT syllabus, covering 9 subtopics. Below are the subtopics to revise, how often the topic appears in past papers, and real past-paper MCQs to try.
Subtopics (9)
- Excretion (Nitrogenous Compounds)
- Glomerular Filtration and Reabsorption
- Human Physiology - Excretion
- Kidney Stones and Failure
- Kidney Structure and Function
- Liver Functions
- Osmoregulation
- Regulation
- Thermoregulation
How Homeostasis is tested
Across the 16 MDCAT past papers on ParhaiKrlo, Homeostasis accounts for 61 questions. It appears in 14 of them, about 4.4 questions a paper. The heaviest was MDCAT 2015, with 7 questions, and the most recent is MDCAT 2025, with 5.
| Paper | Questions |
|---|---|
| MDCAT 2025 | 5 |
| MDCAT 2023 | 2 |
| MDCAT 2019 | 3 |
| MDCAT 2018 | 2 |
| MDCAT 2017 | 5 |
| MDCAT 2016 | 5 |
| MDCAT 2015 | 7 |
| MDCAT 2014 | 5 |
| MDCAT 2013 | 5 |
| MDCAT 2012 | 5 |
| MDCAT 2011 | 5 |
| MDCAT 2010 | 3 |
| MDCAT 2009 | 3 |
| MDCAT 2008 | 6 |
Homeostasis MCQs from the MDCAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · MDCAT 2025 · Homeostasis
Kidneys perform their osmoregulatory role under the effect of Antidiuretic Hormone. Which type of urine is produced in this situation?
- A.Hypotonic urine with decreased volume
- B.Hypotonic urine with increased volume
- C.Hypertonic urine with decreased volume
- D.Hypertonic urine with increased volume
Show answer
Answer: C. Hypertonic urine with decreased volume — ADH makes the kidney produce hypertonic urine of decreased volume.
- Q2 · MDCAT 2023 · Homeostasis
Excretion in Planaria takes place by:
- A.Malpighian tubules
- B.Protonephridia
- C.Metanephridia
- D.Nephron
Show answer
Answer: B. Protonephridia — Planaria (a flatworm) excretes waste using protonephridia, built from specialized flame cells.
- Q3 · MDCAT 2019 · Homeostasis
The route of urine excretion from kidney to outside of body is:
- A.Kidney→ureter→urinary bladder→urethra
- B.Urinary bladder→ kidney→ureter→urethra
- C.Kidney→ureter→urethra→urinary bladder
- D.Kidney→urethra→urinary bladder→ureter
Show answer
Answer: A. Kidney→ureter→urinary bladder→urethra — Urine flows kidney → ureter → urinary bladder → urethra → outside the body.