Consider statements about evolution: 1. Mutations provide raw material for evolution. 2. Genetic drift occurs in large populations. 3. Speciation can result from geographic isolation. Which are correct? MCQ with Answer and Explanation

Explanation:
The Philadelphia chromosome is a specific genetic abnormality found in the bone marrow cells of most patients with Chronic Myelogenous Leukemia (CML). It is formed by a reciprocal translocation between the long arms of chromosome 9 and chromosome 22, denoted as t(9;22). This translocation fuses the BCR gene on chromosome 22 with the ABL1 gene on chromosome 9, creating a mutant BCR-ABL1 fusion protein with constitutive tyrosine kinase activity, driving uncontrolled cell division.

Explanation:
Typhoid fever is a systemic bacterial infection caused by Salmonella enterica serotype Typhi, transmitted through contaminated food and water. Malaria is a life-threatening disease caused by protozoan parasites of the genus Plasmodium (like P. falciparum), transmitted by Anopheles mosquitoes. Dengue fever is a viral infection caused by the Dengue virus (a flavivirus), transmitted by Aedes mosquitoes. All three statements correctly identify the causative agents of these major diseases.

Explanation:
The stomach's gastric glands secrete hydrochloric acid (HCl), which creates an acidic environment necessary for the activation of pepsin and the initial digestion of proteins. The small intestine, with its vast surface area provided by villi and microvilli, is the primary site for the final digestion and absorption of most nutrients into the bloodstream. The liver is a large, multifunctional organ that continuously produces bile, which is stored in the gall bladder and released into the small intestine to emulsify fats. All statements are correct.