All Free Biology MCQs with Answers

Every Biology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

19,844 questions · page 932 of 993

  • A. Lymphocytes
  • B. Monocyte
  • C. Eosinophils
  • D. Basophils

Explanation: Option [A] Lymphocytes are the agranulocytes .They create antibodies to fight against bacteria, viruses, and other potentially harmful…

Correct answer: Monocyte
  • A. External pressure applied becomes greater than the systolic pressure
  • B. External pressure applied is equal to systolic pressure
  • C. External pressure applied is less than the systolic pressure
  • D. External pressure applied is zero

Explanation: The correct answer is A. External pressure applied becomes greater than the systolic pressure.

Correct answer: External pressure applied becomes greater than the systolic pressure
  • A. Prothrombin
  • B. Fibrinogen
  • C. Immunoglobulin
  • D. Globulin
  • E. Both A and B

Explanation: Prothrombin is a protein made by the liver. Prothrombin helps blood to clot.

Correct answer: Both A and B
  • A. Aorta
  • B. Arteries
  • C. Veins
  • D. Both options A and B

Explanation: The elastic fibres are essential in the recoil and the stretch of the blood vessel in order to survive high blood pressure.

Correct answer: Veins
  • A. Arteries
  • B. Capillaries
  • C. Veins
  • D. Arterioles

Explanation: Valves in veins are one-way(semi lunar) flaps that help prevent blood from flowing backward in the circulatory system.

Correct answer: Veins
  • A. Heart directly
  • B. Pre-capillary sphincters
  • C. Meta-arterioles
  • D. Valves

Explanation: The flow of blood in the capillaries is primarily adjusted by pre-capillary sphincters, which regulate the entry of blood into the…

Correct answer: Pre-capillary sphincters
  • A. iliac vein
  • B. iliac artery
  • C. temporal artery
  • D. Sciatic artery

Explanation: The descending aorta is bifurcated into two vessels called the common iliac arteries (Option B).

Correct answer: iliac artery
  • A. Midbrain.
  • B. Medulla.
  • C. Pons.
  • D. Cerebellum.

Explanation: Medulla controls several automatic functions, such as breathing, heart rate, blood pressure and swallowing.

Correct answer: Medulla.
  • A. Alzheimer's disease.
  • B. Epilepsy.
  • C. Parkinson's disease.
  • D. None of these.

Explanation: Alzheimer's disease is a brain disorder that slowly destroys memory and thinking skills and eventually the ability to carry out the…

Correct answer: Alzheimer's disease.
  • A. Bulimia nervosa.
  • B. Anorexia nervosa.
  • C. Dyspepsia.
  • D. Salmonella.

Explanation: Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging; and excessive…

Correct answer: Bulimia nervosa.
  • A. Biological rhythms, territorial, courtship and development
  • B. The responses that do produce same result in different conditions
  • C. Aggression, mating and altruism
  • D. The responses that are predetermined like differentiation

Explanation: A is incorrect because development is not a type of reflexes and instincts.B is incorrect because reflexes and instincts are extremely…

Correct answer: Aggression, mating and altruism
  • A. Cerebrum
  • B. Cerebellum
  • C. Medulla
  • D. Hypothalamus

Explanation: The medulla is responsible for, among other things, the controlling of involuntary activities, such as heartbeat, respiration, etc.

Correct answer: Medulla
  • A. Epilepsy
  • B. Parkinson's Disease
  • C. Alzheimer's Disease
  • D. Huntington's Disease

Explanation: Epilepsy is a neurological disorder characterized by unpredictable and recurrent seizures.

Correct answer: Epilepsy
  • A. Medulla
  • B. Cerebellum
  • C. Pons
  • D. Thalamus

Explanation: The cerebellum is important in maintaining body position, and balance and coordinating movements of the body.

Correct answer: Cerebellum
  • A. Lumbar vertebrae
  • B. Coccyx
  • C. Vertebral column
  • D. Cranium

Explanation: Cranium, which is a part of the skull is made up of 8 bones to form a brain box to protect the brain.

Correct answer: Cranium
  • A. Fever
  • B. Alzheimer's Disease
  • C. Epilepsy
  • D. Parkinson's Disease

Explanation: Parkinson's disease is caused by the loss of brain cells; these cells are associated with the release of dopamine.

Correct answer: Parkinson's Disease
  • A. Parkinson's Disease
  • B. Epilepsy
  • C. Alzheimer's Disease
  • D. Diabetes

Explanation: Alzheimer's disease is a neurological disorder characterized by a progressive decline in cognitive function, memory loss, and difficulty…

Correct answer: Alzheimer's Disease
  • A. Meningitis
  • B. Alzheimer's Disease
  • C. Epilepsy
  • D. Parkinson's sensory

Explanation: A key point in this MCQ is chaotic activity in the motor AND SENSORY areas, which gives a meaning to seizures.

Correct answer: Epilepsy
  • A. Three layers of meninges
  • B. One layer of moninx
  • C. 4 layers of meninges
  • D. 2 layers of meninges

Explanation: The CNS is covered with three layers of protective coverings called meninges.

Correct answer: Three layers of meninges
  • A. Parkinson's disease
  • B. Alzheimer's disease
  • C. Lesch-Nyhan syndrome
  • D. Fragile X-syndrome

Explanation: There is evidence that high levels of aluminium may contribute to the onset of Alzheimer's disease.

Correct answer: Alzheimer's disease