The formation of erythrocytes in foetus takes place in

Correct Answer: C

Rationale: In a fetus, erythropoiesis (erythrocyte formation) primarily occurs in the liver and spleen during early development, before red bone marrow takes over after birth. Sarcoplasm is muscle cell cytoplasm, and blood is where erythrocytes reside, not where they form, making the liver and spleen the correct fetal sites.

Correct Answer: A

Rationale: The appendicular skeleton includes the pectoral girdles (4 bones), upper limbs (60 bones), pelvic girdle (2 bones), and lower limbs (60 bones), totaling 126 bones. The axial skeleton has 80 bones, making 100 and 110 incorrect estimates.

Correct Answer: A

Rationale: Most cranial bones (e.g., frontal, parietal, occipital) are flat, providing a broad, protective shield for the brain. Irregular bones (e.g., sphenoid, ethmoid) exist in the skull, but flat bones predominate in the cranium.

Correct Answer: A

Rationale: The mandible (lower jaw) is the only movable bone of the skull, articulating at the temporomandibular joint for actions like chewing. The hyoid, while in the neck, is not part of the skull and doesn’t move in the same context.

Correct Answer: B

Rationale: The vertebral arch, posterior to the body, consists of two pedicles (attaching to the body) and two laminae (flat plates forming the arch’s roof). Processes (e.g., spinous, transverse) project from the arch but are not its core components.