Erythroblastosis fetalis is a severe condition caused by the incompatibility of blood groups between the mother and fetus, specifically involving the: MCQ with Answer and Explanation

Explanation:
The Casparian strip is a band of cell wall material that runs radially and transversely through the cell walls of the endodermal cells in plant roots, but is absent from the tangential walls. It is primarily composed of suberin (a waxy, waterproof substance) and lignin (a complex polymer). This strip acts as a physical and chemical barrier, blocking the passive, apoplastic flow of water and dissolved minerals between the cells. It forces these substances to cross the selectively permeable plasma membrane and enter the symplastic pathway, allowing the plant to control what enters the vascular cylinder.

Explanation:
Chlorophyll a is the primary photosynthetic pigment, essential for converting light energy into chemical energy. It directly participates in the light reactions. Chlorophyll b, carotenes, and xanthophylls are accessory pigments that capture additional wavelengths and transfer energy to chlorophyll a. These accessory pigments also protect chlorophyll from photo-oxidation.

Explanation:
Aspergillus niger is a fungus widely used for the industrial production of citric acid (a common food additive) through fermentation. Penicillium chrysogenum produces penicillin, Saccharomyces cerevisiae is used in baking and brewing, Rhizobium is a nitrogen-fixing bacterium. Citric acid is used as a preservative and flavor enhancer.