What is the name of the process by which cells in the epidermis are replaced by new cells from the stratum basale? How does this process help protect the body from infection and dehydration? - The process is called keratinization. It helps protect the body by forming a tough, waterproof layer of dead cells on the surface of the skin, which prevents the entry of pathogens and reduces water loss. - Rationale: This question tests the students' knowledge of the structure and function of the skin, which is an important organ system for maintaining homeostasis. What are the three types of muscle tissue in the human body? What are their main characteristics and functions? - The three types of muscle tissue are skeletal, cardiac, and smooth. Skeletal muscle is attached to bones and enables voluntary movement. It is striated, multinucleated, and contracts rapidly and forcefully. Cardiac muscle is found in the heart and pumps blood throughout the body. It is also striated, but has a single nucleus per cell and intercalated discs that allow electrical impulses to spread quickly. Smooth muscle is found in the walls of hollow organs and vessels and controls involuntary functions such as digestion, blood pressure, and pupil dilation. It is not striated, has a single nucleus per cell, and contracts slowly and rhythmically. - Rationale: This question tests the students' knowledge of the different types of muscle tissue, which are responsible for various types of movement and force generation in the body. What are the two main divisions of the nervous system? What are their components and functions? - The two main divisions of the nervous system are the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord, which process sensory information and coordinate motor responses. The PNS consists of all the nerves that connect the CNS to the rest of the body, which carry sensory signals to the CNS and motor signals from the CNS. The PNS can be further divided into the somatic nervous system, which controls voluntary actions, and the autonomic nervous system, which controls involuntary functions such as heart rate, breathing, and digestion. - Rationale: This question tests the students' knowledge of the organization and function of the nervous system, which is essential for communication and control in the body. What are the four main types of bones in the human skeleton? Give an example of each type and explain how their shape relates to their function. - The four main types of bones are long bones, short bones, flat bones, and irregular bones. Long bones are longer than they are wide and have a shaft and two ends. They provide leverage and support for movement. An example is the femur. Short bones are roughly cube-shaped and have a thin layer of compact bone surrounding a core of spongy bone. They provide stability and shock absorption. An example is the carpal bones. Flat bones are thin and curved and have two layers of compact bone with spongy bone in between. They provide protection for vital organs and attachment sites for muscles. An example is the sternum. Irregular bones have complex shapes that do not fit into any other category. They have various functions depending on their location. An example is the vertebrae