The type of epithelial tissue that lines the urinary bladder and allows stretching is: MCQ with Answer and Explanation

Explanation:
During intense exercise, when oxygen supply is insufficient, muscle cells switch to anaerobic glycolysis, producing ATP and lactic acid from glucose. Lactic acid accumulation lowers pH, causing muscle fatigue, soreness, and cramps. It is later converted back to glucose in the liver (Cori cycle). Ethanol is produced by yeast fermentation.

Explanation:
Cyclic adenosine monophosphate (cAMP) is a common intracellular second messenger produced by adenylyl cyclase upon hormone receptor activation (e.g., glucagon, adrenaline). It activates protein kinase A, triggering a cascade of cellular responses. Other second messengers include IP₃, DAG, Ca²⁺.

Explanation:
Archaeopteryx lithographica, a Jurassic fossil, exhibits features of both reptiles (teeth, bony tail, claws) and birds (feathers, wings), supporting the theory that birds evolved from theropod dinosaurs. It is a classic transitional fossil. Tiktaalik links fish and amphibians, cynodonts link reptiles and mammals.