All Free Biology MCQs with Answers

2041. Bony callus formation completes in___________?

• A. 2-3 weeks
• B. 3-4 weeks.
• C. 2-3 months.
• D. 3-4 months.

Explanation: A bony callus develops after the soft callus and usually becomes established over about 2 to 3 months as new bone bridges the fracture. The likely mistake is choosing 3 to 4 weeks, which is closer to the early soft-callus stage rather than completion of bony callus formation.

2042. Which of the following cells are involved in soft callus formation?

• A. Fibroblast and osteoblast.
• B. Osteoblast and osteoclast.
• C. Osteoclast and osteocyte
• D. Onteocyte and osteoblast

Explanation: Soft callus formation involves fibroblasts producing connective tissue and osteoblasts beginning new bone formation around the fracture. Osteoclasts mainly resorb old bone, so students may incorrectly choose option b because they confuse bone-remodelling cells with the cells that produce the initial repair tissue.

2043. A fracture hematoma has____________?

• A. Healing properties.
• B. Destructive properties.
• C. Neutralizing properties.
• D. Dead cells

Explanation: A fracture hematoma contains pooled blood, damaged tissue and dead cells produced when blood vessels and bone are torn. Students may choose option a because the hematoma occurs during healing, but the hematoma itself does not have healing properties and is mainly the initial injury response.

2044. Which of the following statements about fractures in old age is incorrect?

• A. They are more common than in adult age.
• B. Occur as a result of bone being thin and weak.
• C. Due to good blood supply it results in quick healing.
• D. It involves osteoblasts and osteocytes.

Explanation: Fractures heal more slowly in old age because bone is weaker and repair activity and blood supply are generally reduced, not improved. Therefore, option c is incorrect; option a may attract students who overlook that osteoporosis makes fractures more common in older people.

2045. Which of the following statement about osteoporosis is incorrect.

• A. It results from estrogen deficiency.
• B. Bone eating process takes over bone formation process.
• C. There is reduction of bone mass and change in chemical composition of the matrix
• D. It is common in old age.

Explanation: Osteoporosis reduces bone mass, but the remaining bone matrix generally has normal chemical composition; its amount and microscopic structure are reduced. Thus option c is incorrect, while option a is correct because reduced oestrogen after menopause increases bone resorption.

2046. Which of the follwing is a childhood disease resulting from nutritive Ca2+ deficiency?

• A. Hypocalcaemia Tatanic spasms.
• B. Osteomalacis.
• C. Rickets.
• D. Tetany

Explanation: Calcium deficiency during childhood weakens the developing bones and causes rickets, often with bowed legs and poor mineralisation. Osteomalacia is the corresponding defective mineralisation disorder mainly described in adults, so option b is the likely confusion.

2047. Number of cervical vertebrae is_____________?

• A. 5
• B. 7
• C. 9
• D. 12

Explanation: The cervical region of the human vertebral column contains seven vertebrae, labelled C1 to C7. Students may choose five by confusing cervical vertebrae with the five lumbar vertebrae, which are located in the lower back.

2048. Hyaline cartilage does not posses?

• A. Fibers
• B. Cells
• C. Laucane
• D. Blood capillaries

Explanation: Hyaline cartilage contains chondrocytes in lacunae and has fine collagen fibres embedded in a smooth matrix, but it is avascular and therefore has no blood capillaries. Nutrients reach its cells by diffusion through the matrix. Students may choose fibres because they are difficult to see in hyaline cartilage, but fine fibres are present even though capillaries are absent.

2049. What are our nose and ears made of___________?

• A. Cartilage
• B. Charades
• C. Charcoal
• D. Chitin

Explanation: The external framework of the nose and the outer parts of the ears are supported mainly by cartilage, a flexible connective tissue that is stronger than soft tissue but more flexible than bone. Chitin is found in arthropod exoskeletons, while charcoal is a carbon-rich material and charades is unrelated. Students may choose chitin because its name sounds similar to cartilage, but the two materials occur in different biological structures.

2050. Joints between flat bones of skull are termed as ____________ ?

• A. Suture
• B. Sutural joints
• C. Syndesmosis
• D. Both A and B

Explanation: A suture, also called a sutural joint, is an immovable fibrous joint between the flat bones of the skull. Students may choose only suture or sutural joints, but options A and B describe the same type of joint, so both A and B is correct.