Ans: Support: The ability of an organism to stand erect is called support. Movement: The response shown by living to stimulus is called movement. Stimulus: Any change in the internal or external environment of an organism is called a stimulus. Locomotion: The free movement of organisms from one place to another place is called locomotion.
Q 2: Explain the human skeleton in detail? Ans. Skeleton: The framework of hard structures provides physical support and protection for the bodies of animals. OR The framework around which the body of an organism is built is called the skeleton. The shape of an organism depends upon the skeleton. At the time of birth, each child has 350 bones but when the child grows, some of these bones fused together, and only 206 bones remain in the adult stage. Skeleton provides support to the body.
Parts of human Skeleton: The human skeleton is divided into two parts. I. Axial skeleton II. Appendicular skeleton
I. Axial skeleton: The skeleton that forms the main axis of the body is called Axial skeleton. It consists of 80 bones of the skull, neck, vertebral column, and chest. i. Skull: Skull is divided into two parts.
A. Cranium: The cranium consists of 8 bones. Out of the 4 bones namely frontal, occipital, sphenoid, and ethmoid are unpaired bones where 2 bones are paired namely parietal and temporal. The cranium protects the brain.
B. Facial bone: Facial bones consist of 14 bones that make our face. Out of these 14 bones, 2 bones are unpaired and 6 bones are paired. The unpaired bones are mandible and vomer. The paired are maxilla, zygomatic, nasal, lacrimal, palatine, and inferior concha. ii) Vertebral column: The vertebral column extends from the skull to the pelvis. It consists of 33 vertebrae. These vertebras are named according to their location in the body. These are
Cervical vertebra. 7 bones
Thoracic vertebra 12 bones
lumber–vertebra. 5 bones
Sacrum vertebra. 5 bones
Coccyx vertebra. 4 bones
iii. Ribs cage and sternum: Ribs cage is composed of twelve pairs of ribs. These ribs are attached to the dorsal side with the thoracic vertebra. Out of 12 pairs of ribs, the upper 10 paired are connecting with the chest bone (sternum), and the lower two pairs of ribs are not attached to the sternum called floating ribs. Ribs provide support to the thoracic cavity in which vital organs like the heart, lungs are present.