Animal Tissue and Anatomy

Spider monkeys are New World monkeys known for their prehensile tails that function as a 'fifth hand'. They use this highly adapted tail to grasp branches, hold food, and maintain balance while moving through trees. They do not spin webs (that's spiders) or play structured games like 'follow the leader'.

Blackbirds, including species like the common blackbird and red-winged blackbird, are known for their melodious whistling songs. They produce clear, flute-like whistles as part of their territorial and mating calls. 'Whistle' accurately describes their primary vocalization.

The skin is the largest organ in the human body by weight and surface area. It protects the body, regulates temperature, and provides sensory information. The liver is the largest internal organ.

The medulla oblongata is the lowest part of the brainstem, connecting the brain to the spinal cord. It controls vital autonomic functions like breathing, heart rate, and blood pressure.

The labyrinth is the complex bony structure of the inner ear that contains the cochlea and vestibular system. It's essential for hearing and balance.

The trachea, commonly called the windpipe, is the tube that connects the pharynx and larynx to the lungs, allowing air to pass through.

The skin is the largest organ in the human body. It covers the entire body surface with an area of approximately 20 square feet and weighs about 6 pounds in an average adult, making it larger than any internal organ.

Diphtheria is a bacterial infection that primarily affects the throat and respiratory tract. It causes a thick coating to develop in the throat, making breathing difficult. The other options (gums, ears, muscles) are not the primary sites of diphtheria infection.

Jaundice is a condition characterized by yellowing of skin and eyes due to elevated bilirubin levels. The liver is responsible for processing bilirubin, so liver dysfunction is the primary cause of jaundice, making option D correct.

Pyorrhoea (also called periodontal disease or periodontitis) is a gum infection that damages the soft tissue and bone supporting the teeth. It primarily affects the gums, making option C correct. Bones, abdomen, and liver are not the primary affected areas.

Typhoid fever is a bacterial infection caused by Salmonella Typhi. It primarily affects the intestines, causing intestinal inflammation and ulcers. The bacteria also spread through the bloodstream. The intestines (option B) are correct, not lungs or liver.

'Chest' is the odd one out. Nose, lip, and ear are all facial features located on the head. Chest is a torso/body region, not on the face. The other three are specific sensory or prominent features of the face, while chest refers to the front of the upper body.

Among these body parts, the chest is the only one that is not primarily a sense organ. The ear (hearing), lip (taste), and nose (smell) are all involved in sensory perception. The chest contains vital organs like the heart and lungs but is not classified as a sense organ.

The liver is the second-largest organ in the human body after skin (which is the largest overall). It is also the largest internal organ, performing vital metabolic functions. The heart, brain, and spleen are not the second-largest.

A synapse is the junction between two nerve cells (neurons) where electrical signals are converted to chemical signals via neurotransmitters. It is not related to the bile duct, blood vessels, or heart chambers.