All Free Biology MCQs with Answers

• A. Leaf veins
• B. Cristae
• C. Capillaries
• D. Brush border

Explanation: Microvilli are small, finger-like projections on the surface of epithelial cells, especially in the small intestine, where they are known…

• A. Paramylum
• B. Amyloplasts
• C. Leucoplasts
• D. Glycoplasts

Explanation: The correct answer is Amyloplasts. These are specialized plastids within plant cells that synthesize and store starch granules.

• A. 1-2 µm
• B. 2-4 µm
• C. 4-6 µm
• D. 6-8 µm

Explanation: Chloroplasts are a type of plastid. They are chlorophyll-containing organelles within the cells of plants and green algae that are the…

• A. Higher plant cells
• B. Lower plant cells
• C. Animals cells
• D. Both (B) &(C)

Explanation: Only lower plant cells and animal cells have centrioles at right angle to each other so correct option is D

• A. Microfilament and inter mediate filaments
• B. Microfilaments and microtubules
• C. Inter mediate filaments and micro tubules
• D. Only microfilaments

Explanation: The functional roles for microfilaments involve cell membrane motility, endo- and exocytosis, secretion and vesicle transfer so option…

• A. Thylakoids are assembled into stacks
• B. Thylakoids exist as a maze of folded membranes.
• C. The space surrounding thylakoids is called stroma.
• D. Thylakoids contain chlorophyll.

Explanation: Thylakoids are stacks of granum, they are surrounded by stroma that is the colorless fluid surrounding the grana within the chloroplast.

• A. Nucleus
• B. Ribosomes
• C. Lysosome
• D. Plastids

Explanation: The Golgi apparatus, also known as Golgi bodies, plays a crucial role in modifying, sorting, and packaging proteins and lipids for…

• A. 70S unit
• B. 80S unit
• C. 90S unit
• D. 100S unit

Explanation: The correct answer is the 80S unit, which is formed by the assembly of the 40S and 60S ribosomal subunits in eukaryotic cells.

• A. Endoplasmic reticulum
• B. Golgi bodies
• C. Mitochondria
• D. Vacoule

Explanation: Option C is correct.Mitochondria are regarded as self-replicating organelles.

• A. Ribosomes
• B. Golgi bodies
• C. Mitochondria
• D. Endoplasmic reticulum

Explanation: Option D is correct.Lipid synthesis occurs in the endoplasmic reticulum (ER) of the cell.

• A. Cell organelle only
• B. Insoluble waste only
• C. Storage products only
• D. Cell organelle, insoluble waste and storage products

Explanation: The cytoplasm contains cell organelles, insoluble waste, and storage products.

• A. Cell membrane
• B. Nucleus
• C. Lysosomes
• D. Vacuole

Explanation: Option C is correct.Tay-Sach's disease particularly results from the malfunctioning of lysosomes.

• A. Muscle cells
• B. Cardiac cells
• C. Mature RBC's
• D. WBC's

Explanation: Option C is correct.Mitochondria are usually absent in mature RBC's. Mature RBC's, or erythrocytes, are the most abundant type of blood…

• A. Amylase
• B. Lysosomal
• C. Lyase
• D. Lipase

Explanation: Storage diseases, also known as lysosomal storage diseases, are a group of genetic disorders caused by defects (mutations) in lysosomal…

• A. Paleontology
• B. Genetics
• C. Biochemistry
• D. Physiology

Explanation: Neo-Darwinism, also known as the modern synthesis, emphasizes the role of genetics in explaining how evolution works.

• A. 2317 Kcal
• B. 232 kcal
• C. 1564 kcal
• D. None of above.

Explanation: The correct answer is 'None of above.' This is because as organisms move up trophic levels, there is a significant loss of energy, with…

• A. Night
• B. Day
• C. Twilight
• D. Spring

Explanation: Crepuscular animals are active during the twilight period, which is the time between day and night.

• A. Habitat
• B. Biome
• C. Community
• D. Population

Explanation: A community is a group or association of populations of two or more different species occupying the same geographical area at the same time.

• A. Symbiosis
• B. Parasitism
• C. Predation
• D. Mutualism

Explanation: A parasitic relationship is one in which one organism, the parasite, lives off of another organism, the host, harming it and possibly…

• A. Community
• B. Niche
• C. Habitat
• D. Species

Explanation: In ecology, a niche refers to the specific role or position that an organism occupies within an ecosystem.