Biology Homeostasis MCQs Chapter 1 Class 12

Biology Homeostasis for Second Year Entry Tests and FSC Board Exams

Homeostasis is a critical topic in Second Year Biology that explains how organisms regulate and maintain a stable internal environment despite external changes. This topic is essential for students preparing for MDCAT, NUMS, AKU, NUST, UET ECAT, and FSC Second Year board exams. Key concepts include thermoregulation, osmoregulation, excretion, hormonal regulation, feedback mechanisms, and homeostatic imbalances, which are frequently tested in MCQs and conceptual questions.

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Created on March 02, 2022 By Ali Durrani

Biology Ch 1 Class 12 Homeostasis

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1 / 65

The only possible treatment in end stage renal failure is:

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Hemodialysis

B) Peritoneal dialysis

C) Lithotripsy

D) Kidney transplantation

2 / 65

In a hot summer after noon, if your body’s Homeostatic machinery keep your internal temperature quite lower than that of external than this is an example of

Positive feed back

Negative feed back

. Feed back

Osmoregulation

3 / 65

In humans, the temperature regulation control center is located in:

PMC 2020
Biology
Homeostasis
Elimination Tool:

A) Kidneys

B) Brain

C) Lungs

D) Liver

4 / 65

Reabsorption of calcium is triggered by:

NUMS 2019 Reconduct
Biology
Homeostasis
Elimination Tool:

A) Aldosterone

B) Parathormone

C) Antidiuretic

D) Vasopressin

5 / 65

Ureter open into the urinary bladder through:

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Pelvis

C) Ureteral orifices

B) Hilus

D) Urethral orifices

6 / 65

Urine leaves the kidney through a duct called:

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Urethra

B) Pelvis

C) Ureter

D) Nephron

7 / 65

Which one is not a nitrogen waste?

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Hypoxanthine

B) Xanthophyll

C) Adenine

E) Citrulline

8 / 65

Urine formation is the result of:

NTS 2015 SMBBMC
Biology
Homeostasis
Elimination Tool:

A) Ultrafiltration

B) Reabsorption

C) Tubular secretion

D) All of the above

9 / 65

Which of the following fish drink large amount of sea water and excrete concentrated urine resulting in maximum salt excretion and minimal water loss?

Hagfish

Fresh water fishes

Bony fishes

None of these

10 / 65

Which one of the following group of animals is homeothermic?

NUMS 2014
Biology
Homeostasis
Elimination Tool:

A) Reptiles

B) Amphibians

C) Birds

D) Fishes

11 / 65

Which part of the brain regulates body temperature?

NTS 2016 SMBBMC
Biology
Homeostasis
Elimination Tool:

A) Cerebellum

B) Cerebrum

C) Hypothalamus

D) Medulla

12 / 65

Which organ is called the body thermostat?

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Pituitary gland

B) Kidneys

C) Hypothalamus

D) Adrenal gland

13 / 65

Humans are:

NUMS 2016
Biology
Homeostasis
Elimination Tool:

A) Ammonotelic

B) Ureotelic

C) Uricotelic

D) None of these

14 / 65

The excretory product that requires minimum water for its elimination compared to others is:

NUMS 2017
Biology
Homeostasis
Elimination Tool:

A) Creatinine

B) Ammonia

C) Urea

D) Uric Acid

15 / 65

Negative feedback mechanism is the characteristic of which class?

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Class Fish

B) Class Amphibia

C) Class Reptilia

D) Class Mammalia

16 / 65

Which of the following fishes excrete large volume of diluted urine?

Bony Marine fishes

Fresh water fishes

Both depending upon the surrounding water

None of these

17 / 65

Deamination in the liver initially produces:

NTS 2010
Biology
Homeostasis
Elimination Tool:

A) Ammonia

B) Arginine

C) Ornithine

D) Urea

18 / 65

Rose is an example of

Hydrophytes

Mesophytes

Xerophytes

Halophytes

19 / 65

The water content of mammalian blood is regulated by antidiuretic hormone(ADH). In which part of the nephron does regulation occur ?

NTS 2015 SMBBMC
Biology
Homeostasis
Elimination Tool:

A) The ascending limb of the loop of gentle

B) The collecting duct

C) The descending limb of the loop of gentle

D) The proximal convoluted tubule

20 / 65

High level of _____ and _____ in the blood and the contributing factors in the formation of kidney stones.

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Calcium, oxalate

B) Calcium, magnesium

C) Calcium, sodium

D) Sodium, sulphate

21 / 65

Which of the following substances helps to concentrate urine?

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Aldosterone

B) ADH

C) Glucosterone

D) Thyroxin

22 / 65

Humans maintain their body temperature within a narrow limit due to their _____ characteristics.

NUMS 2019 Cancelled
Biology
Homeostasis
Elimination Tool:

A) Ectothermic

B) Endothermic

C) Heterothermic

D) Hypothermic

23 / 65

The characteristic which enable animals to tolerate dehydration is called

Osmoconformation

Osmoregulaton

Anhydrobiosis

Anhydrosis

24 / 65

Which excretory product in produced in plants during autotrophic mode of life?

CO2

H2O

Both A and B

25 / 65

In osmosis water molecules move from area of _______ to _______ through semipermeable memberane

Higher solute concentration to lower solute concentration

Lower solute concentration to higher solute concentration

Lower solvent concentration to higher solvent concentration

All of these

26 / 65

The major portion of (NH)2CO is secreted by:

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Sweat

B) Saliva

C) Urine

D) Stool

27 / 65

As an excretory organ, liver:

PMC 2020
Biology
Homeostasis
Elimination Tool:

A) Detoxifies many chemical poisons

B) Produces ammonia for excretion by the kidneys

C) Produces urea and uric acids from the nitrogen of amino acids

D) All of the above

28 / 65

Sunken stomata are found in:

NUMS 2014
Biology
Homeostasis
Elimination Tool:

A) Mesophytes

B) Xerophytes

C) Halophytes

D) Hydrophytes

29 / 65

Excretory system, consisting of protonephridia tubes, are present in phylum:

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Porifera

B) Annelida

C) Platyhelminthes

D) Cnidaria

30 / 65

Most of the marine invertebrates are

Osmoconformers

Osmoregulators

Both depend upon the concentration of sea water

None of these

31 / 65

The mechanism of regulation, generally between organism and its environment, of solutes and the gain and the loss of water is called

Homeostasis

Hemostasis

Osmoregualtion

Thermoregulation

32 / 65

The excretion of hypertonic urine in humans is associated best with the:

PMC 2020
Biology
Homeostasis
Elimination Tool:

A) Glomerular capsule

B) Proximal convoluted tubule

C) Loop of Henle

D) Distal convoluted tubule

33 / 65

________ are animals that do not adjust their internal osmolality and are isotonic with their environment.

NUMS 2019 Cancelled
Biology
Homeostasis
Elimination Tool:

A) Osmoconformers

B) Osmoregulators

C) Thermoregulators

D) Thermoconformers

34 / 65

Ammonia is chief excretory product in:

NUMS 2014
Biology
Homeostasis
Elimination Tool:

A) Reptiles

B) Turtles

C) Mammals

D) Fish

35 / 65

In animals excess of nitrogen is excreted primarily in form of

Creatinine

Trimethyamine oxide

Pyrimidine

Ammonia

36 / 65

Which of the following statement about Homeostasis is incorrect

There is a definite control system that regulates the homeostatic activities

Homeostatic mechanisms keep the internal environment fixed despite of wide changes in external environment

Because of this the fluctuations of internal environment are of extremely narrow range as compared to that of external environment

All are correct

37 / 65

Glomerulus in kidneys is made up of:

NUMS 2019 Reconduct
Biology
Homeostasis
Elimination Tool:

A) Loop of vessels

B) Tubular epithelium

C) Ball of capillaries

D) Cup-shaped swelling

38 / 65

Malpighian tubules are involved in excretion in:

NTS 2011
Biology
Homeostasis
Elimination Tool:

A) Cockroach

B) Earthworm

C) Human

D) Planaria

39 / 65

In comparison to a constantly changing external environment, _____ is when the body maintains the internal processes to work in a narrow range of internal fluctuations.

NUMS 2019 Reconduct
Biology
Homeostasis
Elimination Tool:

A) Regulation

B) Homeostasis

C) Balancing

D) Thermoregulation

40 / 65

Which of the following statement about conifers is correct?

Stored excretory products in vacuoles, at a concentration that leads to crystal formation.

ccumulate waste in leaves, which fall in autumn.

Production of black wood in the center.

Excrete some of the waste materials directly into soil, occasionally using them as a chemical weapon against other competing plants.

41 / 65

The human body maintains all of its cells’ internal concentration _____ to internal body fluid.

NUMS 2019 Cancelled
Biology
Homeostasis
Elimination Tool:

A) Isotonic

B) Hypotonic

C) Hypertonic

D) Hyposmotic

42 / 65

Which of the following occurs in the body in response to the secretion of Glucagon?

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Conversion of glucose to glycogen in liver cells

B) Decrease in blood glucose concentration

C) Increased uptake of glucose by muscle cells

D) Production of cyclic AMP in target cells

43 / 65

The concentration of Na ions in the body fluids is controlled by the ____ hormone.

NTS 2012
Biology
Homeostasis
Elimination Tool:

A) ADH

B) Parathormone

C) Aldosterone

D) Estrogen

44 / 65

Which hormone prepares the body for situations of stress and emergency?

NUMS 2014
Biology
Homeostasis
Elimination Tool:

A) Adrenaline

B) Non adrenaline

C) Thyroxin

D) Insulin

45 / 65

The mechanism by which substances are removed from the blood and are directly added to the tubular fluids is called:

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Glomerular filtration

B) Excretion

C) Tubular secretion

D) Tubular reabsorption

46 / 65

Sphincter muscle in urinary system present near the junction of:

NUMS 2019 Reconduct
Biology
Homeostasis
Elimination Tool:

A) Pelvis and ureter

B) Ureter and urinary bladder

C) Urinary bladder and urethra

D) Urethra and bladder

47 / 65

When a frog is kept in water for some time it sheds a thin covering of skin called ____

NUMS 2014
Biology
Homeostasis
Elimination Tool:

A) Cuboidal epithelium

B) Squamous epithelium

C) Columnar epithelium

D) Ciliated epithelium

48 / 65

Purine and pyrimidine catabolism results in production of

Creatinine

Trimethyamine oxide

Xanthine

None of these

49 / 65

Right kidney is slightly lower than left kidney due to:

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Heart

B) Liver

D) Lungs

C) Pancreas

50 / 65

In a marine environment, the ion secreted by the kidney is:

NUMS 2020
Biology
Homeostasis
Elimination Tool:

A) Na+

B) K+

C) Mg2+

D) Cl-

51 / 65

The disease in which patients passed urine that rapidly turned black on exposure to air is called:

NTS 2011
Biology
Homeostasis
Elimination Tool:

A) Phenylketonuria

B) Alkaptonuria

C) Sickle cell anemia

D) Hemophilia

52 / 65

The active uptake of sodium in the ascending limb or thick loop of Henle is promoted by the action of:

PMC 2020
Biology
Homeostasis
Elimination Tool:

A) Aldosterone

B) Thyroxine

C) ADH

D) Cortisone

53 / 65

Which of the following marine fishes are considered direct descendents of fresh water ancestors?

Hagfish

Jelly Fish

Star Fish

Bony fishes

54 / 65

Which of the following structure in plant’s body is called excretophores?

Stem

Leaves

Flowers

Roots

55 / 65

When the temperature of the surrounding environment rises, body responds by:

PMC 2020
Biology
Homeostasis
Elimination Tool:

A) Vasoconstriction

B) Vasodilation

C) Shivering

D) Raising body hairs

56 / 65

Capillaries present around the loop of Henle:

NUMS 2018
Biology
Homeostasis
Elimination Tool:

A) Vasa recta

B) Peritubular

C) Lacteals

D) Glomerulus

57 / 65

Terrestrial animals like kangaroo rat survive even without drinking water since

They don't require water for their metabolic process

They can retain excessive water in their body during raining season.

They feed on carbohydrate rich seeds which can provide them with metabolic water

They are anhydrobiotic organisms

58 / 65

Thick, waxy & leathery cuticle around leaves is present in

Hydrophytes

Mesophytes

Xerophytes

Halophytes

59 / 65

Which of the following types of transpiration account for 5 – 7 % of total transpiration that take place in plants?

NUMS 2019 Cancelled
Biology
Homeostasis
Elimination Tool:

A) Cuticular

B) Lenticular

C) Stomatal

D) Leaves

60 / 65

Which of the following reduces the rate of transpiration by adaptations in xerophytes?

NUMS 2019 Cancelled
Biology
Homeostasis
Elimination Tool:

A) Large surface area of leaves

B) Increase number of stomata

C) Thick waxy cuticle

D) Excessive loss of water

61 / 65

Marine fish can keep their internal environment hypertonic with respect to the surrounding salty water by retaining.

Excessive urea which will increase their internal solute concentration and prevent body shrinkage in hypertonic environment

Trimethyl alanine

Ammonia

Trimethylamine oxide

62 / 65

In plants which of the following is a waste product produced both during photosynthesis and respiration

CO2

H2O

Both A and B

63 / 65

The site and principal mechanism for the passage of glucose into the bloodstream in the human kidney is the:

NTS 2014
Biology
Homeostasis
Elimination Tool:

A) collecting duct …. by active secretion

C) glomerulus …. by selective reabsorption

D) glomerulus …. by ultrafiltration

E) Proximal convoluted tubule …. By active reabsorption

64 / 65

The condition of a stable internal environment in an organism is:

NTS 2015 SMBBMC
Biology
Homeostasis
Elimination Tool:

A) Coordination

B) Organisation

C) Homeostasis

D) Integration

65 / 65

The technique used for the non-surgical removal of kidney stones is called:

NUMS 2016
Biology
Homeostasis
Elimination Tool:

A) Ultrasound

B) Lithotripsy

C) Dialysis

D) X-rays

Your score is

The average score is 59%

Importance of Homeostasis in Second Year Competitive Biology

A strong grasp of Homeostasis helps students understand complex physiological processes such as the role of kidneys, liver, pancreas, endocrine glands, and nervous system in maintaining internal balance. Topics like negative and positive feedback loops, diabetes, dehydration, and electrolyte balance are commonly asked in entry tests. Practicing chapter-wise MCQs, diagrams, and topic-wise exercises improves accuracy, problem-solving speed, and exam performance.

Effective Preparation and Practice Resources for Second Year Students

Effective preparation for Homeostasis includes regular revision, MCQ practice, and mock tests. Solving past papers and exam-oriented questions helps students identify important areas and commonly repeated concepts. PLS Academy provides structured learning resources that help students systematically master Homeostasis and perform confidently in medical entry tests and FSC Second Year board examinations.

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