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 913 of 993
- A. Granules
- B. Cysts
- C. Spores
- D. Plasmids
Explanation: Spores are thick, dormant, and tough structures produced by some bacteria that provide resistance or protection against harsh or adverse…
Correct answer: Spores- A. Mycoplasma
- B. Streplococcus
- C. Escherichia
- D. Bacillus
Explanation: These bacteria lack a cell wall and are among the tiniest free-living organisms.
Correct answer: Mycoplasma- A. Spirochete
- B. Ecoli
- C. Pseudomonas
- D. Campylobacter
Explanation: Option A: Spirochetes are a diverse group of bacteria that exhibit a helical or spiral shape.
Correct answer: Campylobacter- A. Antonie Van Leeuwenhoek
- B. Robert Koch
- C. Louis Pasteur
- D. Twort
Explanation: Option A is the right answer. Leeuwenhoek first discovered microbes and called them animalcules.
Correct answer: Antonie Van Leeuwenhoek- A. Louis Pasteur
- B. Robert Koch
- C. Christain Gram
- D. None of above
Explanation: Germ Theory states that microorganisms known as pathogens or "germs" can lead to disease.
Correct answer: Robert Koch- A. Diplococcus
- B. Peritrichous
- C. Monotrichous
- D. A tetrad
Explanation: Bacteria can be classified according to the number of flagella on their cell wall, and peritrichous is a type will many flagella all over…
Correct answer: Peritrichous- A. Gram-negative bacteria are more likely to cause systemic effects because they lack an outer membrane which means they can infect host cells more quickly.
- B. Gram-negative bacteria are more likely to cause systemic effects because they have an outer membrane which is supposed to protect them from antibiotics
- C. Both Options A and B are correct
- D. None of these options is correct
Explanation: d) None of these options is correct.This option is the most accurate. Both Option A and Option B have inaccuracies in their statements.
Correct answer: None of these options is correct- A. Cube of eight cocci
- B. Square of four cocci
- C. Irregular structure
- D. Triangular 6 cocci
Explanation: Option A is correct since Sarcina is a cube of 8 cocci.
Correct answer: Cube of eight cocci- A. Gram-positive
- B. Gram-negative
- C. Both A and B
- D. None of these
Explanation: Correct option: A (fact) (Gram positive bacteria retain bluish purple dye when being tested).
Correct answer: Gram-positive- A. Tuberculosis and thyphoid
- B. Tuberculosis and measles
- C. Tuberculosis and cholera
- D. All of the above
Explanation: German physician Robert Koch was one of the founders of bacteriology. He discovered the anthrax disease cycle (1876) and the bacteria…
Correct answer: Tuberculosis and cholera- A. Robert Koch
- B. Louis Pasteur
- C. Alexander Fleming
- D. Leeuwenhoek
Explanation: Robert Koch was a German scientist who discovered the causative agents for deadly diseases like tuberculosis, cholera, and anthrax.
Correct answer: Robert Koch- A. Oral groove
- B. Contractive vacuole
- C. Vesicle
- D. Vacuole
Explanation: Freshwater protozoans or Protoctista pump excess water out of their body with the help of contractile vacuole because they do not have an…
Correct answer: Contractive vacuole- A. Vinegar
- B. Saliva
- C. Rainwater
- D. All of these options are correct
Explanation: Small creatures were first seen by Antony Leeuwenhoek, he called these creatures animalcules.
Correct answer: Rainwater- A. i only
- B. i, ii & iii
- C. i & iv
- D. ii, iii & v
- E. i, ii, iii & v
Explanation: Explanation for this question will be added soon.
Correct answer: ii, iii & v- A. Lamarck
- B. Darwin
- C. Weismann
- D. De Vries
Explanation: Lamarckism is a theory of evolution based on the principle that physical changes in organisms during their lifetime.
Correct answer: Lamarck- A. Skin
- B. Liver
- C. Large intestine
- D. Both A and B
Explanation: Skin covers our entire body hence has the largest surface area out of all the organs.
Correct answer: Skin- A. 1, 2 and 3
- B. 2, 1 and 4
- C. 1 and 4 only
- D. 2 and 3 only
Explanation: Triglycerides are formed by linking fatty acids with an ester linkage to three alcohol groups in glycerol.
Correct answer: 2 and 3 only- A. Vitamin A
- B. Vitamin B
- C. Vitamin C
- D. Vitamin D
Explanation: d) Vitamin D:Ergocalciferol is the name of Vitamin D2. It is a type of vitamin D that is synthesized in plants and is also known as…
Correct answer: Vitamin D- A. Replacement of a corner fatty acid in acyl glycerol by phosphate group
- B. Their place of occurrence
- C. Phospholipid is a lipid and acyl glycerol is not
- D. Difference in number of C in fatty acid chains
- E. They are the same
Explanation: Explanation for this question will be added soon.
Correct answer: Replacement of a corner fatty acid in acyl glycerol by phosphate group- A. Terpenes
- B. Terpenoids
- C. Waxes
- D. Carotenoids
- E. Unsaturated acyl glycerol
Explanation: Explanation for this question will be added soon.
Correct answer: Waxes