Consider the following statements about the pancreas: 1. It has both endocrine and exocrine functions. 2. Alpha cells secrete insulin. 3. Beta cells secrete glucagon. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
A food chain is a linear sequence illustrating the transfer of energy and matter from one organism to another through consumption. A food web is a complex, interconnected network of multiple food chains, representing the realistic, multiple feeding relationships in an ecosystem. The pyramid of energy, which shows the amount of energy available at each trophic level, is always upright, never inverted, because energy is lost as heat at each transfer according to the 10% law. Thus, statements 1 and 2 are correct.

Explanation:
Bacteria are prokaryotes that primarily reproduce asexually through binary fission, where a single cell divides into two identical daughter cells. Fungi are eukaryotes characterized by having cell walls primarily composed of chitin, a tough polysaccharide. Viruses lack cellular structure and metabolic machinery; they are obligate parasites that rely entirely on the host cell's machinery for replication. Thus, statements 1 and 3 are correct.

Explanation:
Ribosomes are dense, spherical, non-membranous structures composed of RNA and proteins. They are the cellular factories for protein synthesis. Prokaryotic ribosomes are 70S (50S + 30S subunits), while eukaryotic cytoplasmic ribosomes are 80S (60S + 40S subunits). Therefore, statements 1 and 3 are correct, but statement 2 is false.