Robert Koch is famous for establishing 'Koch's postulates', which are a set of criteria used to: MCQ with Answer and Explanation

Explanation:
DNA is typically a double-stranded helical molecule carrying genetic information. Genes are specific sequences of DNA located linearly on chromosomes. RNA is generally single-stranded and contains the nitrogenous base uracil instead of thymine, which is found in DNA. Therefore, statements 1 and 3 are correct, while statement 2 is incorrect.

Explanation:
Ovulation is the process where a mature ovum (secondary oocyte) is released from the Graafian follicle of the ovary, typically around day 14 of the menstrual cycle, triggered by the LH surge. The ovum is captured by the fimbriae of the fallopian tube. Fertilization is fusion with sperm, menstruation is shedding of the uterine lining, implantation is embedding of the blastocyst.

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).