Most Important Biology Mcqs 21- Which microorganism causes tuberculosis ? A. StreptococcusB. Escherichia coliC. Staphylococcus aureusD. Mycobacterium tuberculosis View Answer Answer : D. Mycobacterium tuberculosis Description 22- Which part of the immune system produces antibodies ? A. Red blood cellsB. PlateletsC. B-lymphocytesD. T-lymphocytes View Answer Answer : D. B-lymphocytes Description 23- Which virus causes AIDS ? A. Hepatitis BB. InfluenzaC. HIVD. Polio View Answer Answer : C. HIV Description 24- Penicillin was discovered by: A. Alexander FlemingB. Louis PasteurC. Robert KochD. Edward Jenner View Answer Answer : A. Alexander Fleming Description 25- The vaccine for smallpox was developed by: A. Robert KochB. Edward JennerC. Louis PasteurD. Jonas Salk View Answer Answer : B. Edward Jenner Description 26- Which pigment is responsible for photosynthesis ? A. HemoglobinB. CaroteneC. XanthophyllD. Chlorophyll View Answer Answer : D. Chlorophyll Description 27- The process of water loss from plants is called ? A. TranspirationB. RespirationC. PhotosynthesisD. Condensation View Answer Answer : A. Transpiration Description 28- The movement of water in plants occurs through ? A. PhloemB. XylemC. CortexD. Epidermis View Answer Answer : B. Xylem Description 29- Which gas is released during photosynthesis ? A. NitrogenB. HydrogenC. OxygenD. Carbon dioxide View Answer Answer : C. Oxygen Description 30- Which type of plant grows in saline water? A. HalophytesB. XerophytesC. MesophytesD. Hydrophytes View Answer Answer : A. Halophytes Description 31- The human brain is part of which system ? A. Nervous systemB. Circulatory systemC. Digestive systemD. Endocrine system View Answer Answer : A. Nervous system Description 32- The smallest bone in the human body is: A. StapesB. FemurC. TibiaD. Humerus View Answer Answer : A. Stapes Description 33- Which organ filters blood in the human body? A. LiverB. HeartC. KidneysD. Lungs View Answer Answer : C. Kidneys Description 34- Which part of the human brain controls balance and coordination ? A. CerebrumB. Medulla oblongataC. CerebellumD. Hypothalamus View Answer Answer : C. Cerebellum Description 35- The human heart has how many chambers ? A. 3B. 4C. 5D. 6 View Answer Answer : B. 4 Description 36- The law of independent assortment was proposed by: A. Gregor MendelB. Charles DarwinC. Jean-Baptiste LamarckD. Alfred Wallace View Answer Answer : A. Gregor Mendel Description 37- Which type of RNA carries genetic information from DNA to ribosomes ? A. tRNAB. rRNAC. siRNAD. mRNA View Answer Answer : D. mRNA Description 38- Down syndrome is caused by ? A. Mutation in chromosome 5B. Trisomy of chromosome 21C. A bacterial infectionD. A viral infection View Answer Answer : B. Trisomy of chromosome 21 Description 39- The theory of natural selection was proposed by ? A. Gregor MendelB. Alfred WallaceC. Charles DarwinD. Louis Pasteur View Answer Answer : C. Charles Darwin Description 40- A sudden change in genetic material is called ? A. ReplicationB. TranslationC. TranscriptionD. Mutation View Answer Answer : Description 1 2 3 4 5
