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The existence of an object, non-superimposable on its mirror image, constitutes the phenomenon of chirality. This phenomenon is often treated as a curiosity without broader practical consequences. This paper aims to show the significant implications of chirality for chemistry and biology. Chirality is inherent to all living organisms and is essential for their function. For instance, biomolecules are composed of chiral building blocks (amino acids, monosaccharides), which are chiral and occur predominantly with one sense of handedness (homochirality of life). The explanation of the evolution of the homochirality of life therefore helps answer one of the important questions connected with the origin of life.. The paper concludes with a section devoted to current Czech stereochemical terminology. An experimental procedure describing the isolation of carvone enantiomers from natural sources is also included. [ABSTRACT FROM AUTHOR]

Most woody plants belonging to the order Pinales have needles. Their anatomy has adapted to external conditions – mainly the deficit of water during winter. In cross section, the needles are different in shape, but the leaf anatomy of coniferous species is quite similar. However, there are inter-species differences in arrangement of hypodermis, in the type of mesophyll, in the number and arrangement of resin ducts, and in the number of vascular bundles. Needles are a suitable material for Biology lectures. Their advantage is their availability every season of the year. This paper offers some options for the observation of needle anatomy, recognition of species differences, and the use of an anatomical identification key. [ABSTRACT FROM AUTHOR]