Which scientist is credited with disproving the theory of spontaneous generation? MCQ with Answer and Explanation

Explanation:
The ozone layer, a region of high ozone concentration, is located in the stratosphere, approximately 15 to 35 kilometers above Earth's surface, where it absorbs harmful UV radiation. Chlorofluorocarbons (CFCs), once widely used in refrigerants and aerosols, release chlorine atoms in the stratosphere that catalytically destroy ozone molecules, leading to ozone depletion. Global warming is primarily caused by an increase, not a decrease, in atmospheric greenhouse gases like carbon dioxide (CO2), which trap more heat. Thus, statements 1 and 2 are correct.

Explanation:
The Casparian strip is a waterproof band of suberin and lignin found in the radial and transverse cell walls of the endodermis (the innermost layer of the cortex) in plant roots. It acts as a barrier to the passive flow of water and dissolved minerals through the cell walls (the apoplastic pathway). This forces water and solutes to cross the selectively permeable plasma membrane and enter the symplastic pathway, allowing the plant to control and filter what enters the vascular cylinder (stele).

Explanation:
Charles Darwin, in 'On the Origin of Species' (1859), proposed natural selection as the mechanism for evolution, based on variation, inheritance, and differential survival. Mendel discovered genetics, Pasteur disproved spontaneous generation, Lamarck proposed inheritance of acquired characters. Wallace independently arrived at natural selection.