The term for the death of brain tissue due to lack of blood flow is: MCQ with Answer and Explanation

Explanation:
Imbibition is a physical process where solid, hydrophilic (water-loving) colloidal materials (like cellulose, pectin, proteins, and starch) adsorb water, causing a tremendous increase in their volume and generating significant imbibitional pressure. This process is the very first step in seed germination. When a dry seed is exposed to water, its cell walls and storage materials imbibe water, causing the seed to swell, rupturing the seed coat, and initiating the metabolic activities required for the seedling to grow. It is also responsible for the splitting of rocks by plant roots.

Explanation:
Phenylketonuria (PKU) is an autosomal recessive disorder due to deficiency of phenylalanine hydroxylase, leading to accumulation of phenylalanine, causing mental retardation if untreated. Albinism is tyrosinase deficiency, sickle cell HbS mutation, cystic fibrosis CFTR defect.

Explanation:
The 'ozone hole' is a severe, seasonal thinning of the stratospheric ozone layer that occurs most prominently over the Antarctic region during the Southern Hemisphere's spring (September to November). This is due to the unique meteorological conditions in the Antarctic stratosphere, including the formation of Polar Stratospheric Clouds (PSCs) during the dark, cold winter, which provide surfaces for chemical reactions that release active chlorine from CFCs, rapidly destroying ozone when sunlight returns.