All Free Biology MCQs with Answers

• A. Thrombocytes
• B. Tendon
• C. Hyaline cartilage
• D. Ciliated epithelium

Explanation: From the given four options, cell junctions come across most frequently in the preparation of ciliated epithelium.

• A. Connective tissue
• B. Epithelial tissue
• C. Neural tissue
• D. Muscular tissue

Explanation: Epithelial tissues consist of variously shaped cells closely arranged in one or more layers.

• A. Glandular
• B. Ciliated
• C. Squamous
• D. Cuboidal

Explanation: The ciliated columnar epithelial cells in humans are present in the nasal passages, oviducts (Fallopian tubes), terminal bronchioles…

• A. Biceps of the upper arm - Smooth muscle fibres
• B. Abdominal wall - Skeletal muscle
• C. Iris - Involuntary smooth muscle
• D. Heart wall - Involuntary unstriated muscle

Explanation: Smooth muscles are called involuntary muscles because the action of these muscles is controlled by the autonomic nervous system i.e.

• A. Tibia and fibula - Both form parts of the knee joint
• B. Cartilage and cornea - No blood supply but require oxygen for respiratory needs
• C. Shoulder joint and elbow joint - Ball and socket joints
• D. Premolars and molars - 20 in all and 3 rooted

Explanation: Cartilage is avascular, as the blood vessels innervate the perichondrium allowing nutrition to diffuse into cartilage cells.

• A. Ligaments
• B. Areolar tissue
• C. Bone
• D. Cartilage

Explanation: Cartilage is a semirigid supportive or skeletal connective tissue in which the matrix is solid and made of mucoprotein or proteoglycan…

• A. Smooth muscles, show branching, found in the wall of the heart
• B. Cardiac muscles, unbranched muscles, found in the walls of the heart
• C. Unstriated muscles, tapering at both ends, attached with the bones of the ribs
• D. Skeletal muscles show striations and are closely attached with the bones of the limbs

Explanation: Locomotion (performed by limbs) in humans depends on the movements of muscle fibres.

• A. Are surrounded by pericycle but no endodermis
• B. Are capable of producing secondary xylem and phloem
• C. Possess conjunctive tissue between xylem and phloem
• D. Are not surrounded by pericycle.

Explanation: (b) : In dicot stem, cambium is present between xylem and phloem, such vascular bundles are called open.

• A. All tissues external to endodermis
• B. All tissues except epidermis and vascular bundles
• C. Epidermis and cortex
• D. All tissues internal to endodermis.

Explanation: (b) : Ground tissue can be defined as all the tissues except epidermis and vascular bundles.

• A. Phelloderm
• B. Phellogen
• C. Periderm
• D. Phellem

Explanation: (c) : In hypodermis or outer cortical cells, a layer becomes meristematic which is known as cork cambium or phellogen.

• A. Endodermis
• B. Pericycle
• C. Medullary rays
• D. Xylem parenchyma

Explanation: (c): In dicot stems, the cells of cambium present between the primary xylem and primary phloem is the interfascicular cambium.

• A. Number of annual rings
• B. Diameter of its heartwood
• C. Its height and girth
• D. Biomass

Explanation: (a): Two bands of secondary xylem i.e., autumn wood and spring wood are produced in one year. These two bands make an annual ring.

• A. (iv), (i), (iii), (ii)
• B. (iv), (iii), (i), (ii)
• C. (iii), (iv), (ii), (i)
• D. (i), (ii), (iv), (iii)

Explanation: (a): In a woody dicot stem, phellem (cork) forms the outermost layer followed by phellogen and then secondary cortex (phelloderm).

• A. Bulliform cells
• B. Lenticels
• C. Complementary cells
• D. Subsidiary cells

Explanation: (d) : The leaf and stem epidermis of plant is covered with pores called stomata.

• A. Originate in the lumen of vessels
• B. Characterise the sapwood
• C. Are extensions of xylem parenchyma cells into vessels
• D. Are linked to the ascent of sap through xylem vessels

Explanation: (c): Tyloses are balloon­like extensions of parenchyma cells that protrude into the lumen of a neighboring xylem vessel or tracheid…

• A. It is highly durable
• B. It conducts water and minerals efficiently
• C. It comprises dead elements with highly lignified walls
• D. Organic compounds are deposited in it

Explanation: (b): Heartwood is the non­functional part of secondary xylem, hence, it does not conduct water and minerals.

• A. Primary phloem
• B. Secondary xylem
• C. Periderm
• D. phelloderm

Explanation: (b): Cells of vascular cambium divide periclinally both on the outer and inner sides to form secondary permanent tissues, i.e., secondary…

• A. Epidermis
• B. Parenchyma
• C. Meristem
• D. Sclerenchyma

Explanation: Sclerenchyma is a plant tissue that consists of dead cells at maturity.

• A. Areolar tissue
• B. Bony matter
• C. Hyaline cartilage
• D. White fibrous cartilage

Explanation: Costal cartilages are hyaline cartilage, providing flexibility during breathing.

• A. Fibrous joint
• B. Cartilaginous joint
• C. Synovial joint
• D. Hinge joint

Explanation: Ribs connect to sternum via hyaline cartilage, forming cartilaginous joints.