Consider statements about cell biology: 1. Prokaryotic cells lack a true nucleus. 2. Eukaryotic cells have membrane-bound organelles. 3. Plant cells lack a cell wall. Which are correct? MCQ with Answer and Explanation

Explanation:
Deforestation, the large-scale removal of trees and vegetation, exposes the topsoil to wind and water, leading to severe soil erosion and loss of fertility. Afforestation, the planting of trees in barren areas, increases biomass and helps mitigate global warming by sequestering atmospheric carbon dioxide through photosynthesis. Most plastics are synthetic polymers that are non-biodegradable, meaning they cannot be broken down by natural biological processes and persist in the environment for centuries, causing pollution. All statements are correct.

Explanation:
Bacterial infections (like tuberculosis, pneumonia) are effectively treated with antibiotics, which target specific bacterial structures or metabolic pathways. Many viral diseases (like polio, measles, influenza) can be prevented through vaccination, which stimulates the immune system to develop memory against the virus. Fungal diseases (like ringworm, candidiasis) are caused by fungi, not protozoa; protozoa cause diseases like malaria and amoebiasis. Thus, statements 1 and 2 are correct.

Explanation:
Glycogen is a highly branched polysaccharide of glucose, the storage form in animals, found mainly in the liver and skeletal muscles. Starch is the plant equivalent. Cellulose is structural in plants, sucrose is a disaccharide. Glycogen can be rapidly mobilized to maintain blood glucose.