All Free Biology MCQs with Answers

• A. Smooth muscle cells
• B. Cardiac muscle cells
• C. Skeletal muscle cells
• D. Fibroelastic cartilage cells

Explanation: Skeletal muscle cells have regular striation, while smooth muscle cells do not have striation.

• A. Cardiac
• B. Skeletal
• C. Smooth
• D. Striated

Explanation: Smooth muscles are found both in invertebrates and vertebrates while caradic and skeletal muscles are found only in vertebrates and are…

• A. Tendon
• B. Ligament
• C. Skeletal muscle
• D. Nerves

Explanation: The main functional partner of bones is skeletal muscles. Both these can work together to bring about movement in the body.

• A. Smooth muscles
• B. Skeletal muscles
• C. Caradic muscles
• D. Involuntary muscle

Explanation: Cardiac and smooth muscles have irregular striations and no striations respectively.

• A. Smooth muscles
• B. Skeletal muscles
• C. Cardiac muscles
• D. Glandular muscles

Explanation: Cardiac and smooth muscles are involuntary in action, while skeletal muscles are voluntary in their functions.

• A. Golgi bodies
• B. Smooth endoplasmic reticulum
• C. Cytoskeletal fibers
• D. Ribosomes

Explanation: Sarcoplasmic retreulum is the modified form of smooth endoplasmic reticulum as they devoid of ribosomes are found in muscles.

• A. Lipoprotein
• B. Glycolipids
• C. Glycoprotein
• D. Nucleoproteins

Explanation: Since sarcolemma is the membrane of muscle cells, so its chemical compostion is lipoproteins.

• A. H-zone
• B. Z-band
• C. M-line
• D. A-band

Explanation: A sarcomere is bound by two Z-lines and its center is bisected by dark line called M-line.

• A. It is non-polarizing
• B. It contains only actin
• C. It is isotropic
• D. Myosin acts as a polarizer of light

Explanation: Each dark band in the skeletal muscles is called A-band because it is anisotropic i.e it can polarize visible light.

• A. Z-line
• B. M-line
• C. A-I junction
• D. H-zone

Explanation: T-tubule is found at A-I junction in skeletal muscle while at Z-line in cardiac muscle.

• A. Muscle cell has many muscle fibers
• B. Muscle fiber has many muscle cells
• C. Muscle cell has many myofibrils
• D. Sarcomere has bundles of muscle fiber

Explanation: Muscle cell has many myofibrils: This statement is true. Within a muscle cell, there are numerous myofibrils.

• A. A-band
• B. Muscle bundle
• C. I-band
• D. Muscle fiber

Explanation: The I-band allows most of the light to pass through it compared to the other options.

• A. Actin
• B. Troponin
• C. Myosin
• D. Fibrous proteins

Explanation: The chief component of thin filaments in muscle fibers is actin. Actin molecules polymerize to form the twisted structure of thin…

• A. Tubulin
• B. Myoglobin
• C. Myosin
• D. Actin

Explanation: Myosin is the sliding protein of muscle and is primarily responsible for generating force and producing muscle contractions.

• A. Neuro-muscular
• B. Mechanical
• C. Chemical
• D. Synaptic

Explanation: The correct option is a) Neuro-muscular junction.Let's explain each option individually:The neuro-muscular junction is the point of…

• A. M-lines
• B. I-bands
• C. Z-lines
• D. T-tubules

Explanation: Z-lines, also called Z-discs, are protein structures that act as anchoring points for the thin filaments within the sarcomere.

• A. Myofilaments
• B. Z-lines
• C. Sarcoplasmic reticulum
• D. Transverse tubules

Explanation: Transverse tubules, also known as T-tubules, are invaginations of the sarcolemma that penetrate deep into the sarcoplasm of muscle fibers.

• A. A-Band
• B. M-line
• C. I-band
• D. Z-line

Explanation: The A-band is a region within a sarcomere, which is the basic functional unit of a muscle fiber.

• A. Myosin
• B. Microtubules
• C. Microfilaments
• D. Myofibrils

Explanation: Myofibrils are the long threads or cylindrical structures found within muscle fibers.

• A. Tropomyosin
• B. Myosin
• C. Tubulin
• D. Actin

Explanation: Tubulin is the protein that makes up microtubules, which are hollow tubular structures in the cytoskeleton of cells.