Biology MDCAT MCQs

Cell biology, genetics & physiology MCQs

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Showing 305 MCQs in Biology
Biology
A. Charles Darwin
B. Gregor Mendel
C. Louis Pasteur
D. Robert Koch
Answer: Gregor Mendel established the fundamental laws of inheritance through his work with pea plants.
Biology
A. Mitochondria
B. Ribosome
C. Chloroplast
D. Vacuole
Answer: Chloroplasts are called the kitchen of the cell because they synthesize food through photosynthesis.
Biology
A. Deoxyribonucleic acid
B. Dinitrogen acid
C. Deoxynitrate acid
D. Dioxyribonucleic acid
Answer: DNA (Deoxyribonucleic acid) is the molecule that carries genetic information in all living organisms.
Biology
A. HBB gene
B. CFTR gene
C. BRCA1 gene
D. TP53 gene
Answer: The CFTR gene codes for a chloride channel protein; its mutation causes thick mucus buildup.
Biology
A. Carries genetic code from DNA
B. Translates mRNA to protein
C. Transfers amino acids to ribosomes
D. Stores genetic information
Answer: tRNA (transfer RNA) carries specific amino acids to the ribosome during translation.
Biology
A. Skin color
B. Height
C. Roan coat color in cattle
D. Tongue rolling
Answer: In roan cattle, both red and white hairs are expressed equally, showing co-dominance.
Biology
A. Soil
B. Water
C. Sunlight
D. Bacteria
Answer: Bacteria are living organisms and thus biotic components of an ecosystem.
Biology
A. Replication
B. Transcription
C. Translation
D. Transformation
Answer: Translation occurs at ribosomes where mRNA is decoded to build a polypeptide chain.
Biology
A. Coal
B. Petroleum
C. Solar energy
D. Natural gas
Answer: Solar energy is continuously replenished and classified as a renewable resource.
Biology
A. Bile production
B. Detoxification
C. Insulin production
D. Glycogen storage
Answer: Insulin is produced by the beta cells of the pancreas, not the liver.
Biology
A. Helicase
B. Primase
C. Ligase
D. Polymerase
Answer: DNA ligase seals the gaps between Okazaki fragments on the lagging strand during replication.
Biology
A. Transcription
B. Translation
C. Replication
D. Transformation
Answer: DNA replication produces an identical copy of DNA before cell division.
Biology
A. Alanine
B. Glycine
C. Leucine
D. Serine
Answer: Leucine is one of the nine essential amino acids that cannot be synthesized by the human body.
Biology
A. Tuberculosis
B. Malaria
C. Cholera
D. Hepatitis B
Answer: Malaria is transmitted by female Anopheles mosquitoes carrying the Plasmodium parasite.
Biology
A. A group of the same species
B. Living organisms and their physical environment
C. A community of plants only
D. All organisms on Earth
Answer: An ecosystem includes all living (biotic) and non-living (abiotic) components in an area.
Biology
A. Neutrophil
B. Eosinophil
C. B-lymphocyte
D. Monocyte
Answer: B-lymphocytes differentiate into plasma cells that produce antibodies.
Biology
A. Chromosomal mutation
B. Point mutation
C. Deletion
D. Insertion
Answer: A point mutation involves a change in a single nucleotide base pair in the DNA sequence.
Biology
A. Epidermis
B. Mesophyll
C. Vascular bundle
D. Cuticle
Answer: Mesophyll cells contain chloroplasts and are the primary site of photosynthesis.
Biology
A. Sexual reproduction
B. Asexual reproduction
C. Cross-fertilization
D. Pollination
Answer: Asexual reproduction involves a single parent and produces clones without genetic variation.
Biology
A. Carbon cycle
B. Nitrogen cycle
C. Water cycle
D. Phosphorus cycle
Answer: The phosphorus cycle occurs mainly through rock, soil, and water without a significant atmospheric phase.
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