Science MCQs

Practice multiple choice questions with instant feedback. Select an option to see if you're correct.

Total Questions
2100
Page 41 of 210
Question 401 Easy

What is the ability of an organism's body to defend itself against disease-causing organisms called?

A
Infection
B
Immunity
C
Antibodies
D
Pathogens
Question 402 Easy

Which of the following is a disease-causing microorganism?

A
Antibody
B
Antigen
C
Pathogen
D
Melanin
Question 403 Easy

What is the entry and growth of microorganisms into the body called?

A
Immunity
B
Infection
C
Inflammation
D
Phagocytosis
Question 404 Easy

Which of these is a physical barrier against pathogens?

A
Antibodies
B
Skin
C
Phagocytes
D
Lymphocytes
Question 405 Easy

What is the thick fluid produced by mucous membranes called?

A
Sebum
B
Mucus
C
Saliva
D
Melanin
Question 406 Easy

Which part of the body filters dust and microbes from the air?

A
Hairs in nose
B
Cilia in lungs
C
Saliva in mouth
D
Skin
Question 407 Easy

What does saliva in the mouth contain that kills microorganisms?

A
Melanin
B
Hydrochloric acid
C
Antiseptic properties
D
Sebum
Question 408 Easy

Which acid in the stomach kills pathogens present in food?

A
Citric acid
B
Hydrochloric acid
C
Lactic acid
D
Acetic acid
Question 409 Easy

What is the process of ingesting and eliminating foreign substances by cells called?

A
Inflammation
B
Phagocytosis
C
Immunity
D
Infection
Question 410 Easy

Which cells perform the function of phagocytosis?

A
Red blood cells
B
Phagocytes
C
Platelets
D
Lymphocytes
Showing 401-410 of 2100 questions

Quick Stats

Total Questions 10900
easy 5797
medium 2983
hard 2120

Practice Tips

Time Management

Practice with time limits for better preparation

Review Mistakes

Always check explanations for wrong answers

Track Progress

Monitor your improvement across subjects

Did You Know?

Practice Makes Perfect

Regular practice with MCQs can improve your test-taking speed and accuracy by up to 40%.

Active Recall

MCQs engage active recall, which is 50% more effective for long-term memory than passive reading.