Govt. Exams
Entrance Exams
The endodermis contains Casparian strips—bands of suberin and lignin that prevent lateral movement of water and minerals, forcing them through the cell.
Monocot stems have scattered vascular bundles distributed throughout the ground tissue, whereas dicot stems have bundles arranged in a ring.
Sieve tube elements are enucleate at maturity, losing their nucleus to facilitate the flow of photosynthates. Companion cells remain nucleate and control sieve tube metabolism.
Guard cells are specialized epidermal cells that change shape to open or close the stomatal pore.
Stomata are pores in the leaf epidermis that regulate gas exchange (CO2 intake, O2 release) and transpiration.
Monocot stems have scattered vascular bundles throughout the ground tissue, unlike dicots which have ring-arranged bundles.
Cork tissue (phellem) is produced outward by the cork cambium (phellogen), which is a lateral meristem.
Xylem is a vascular tissue that transports water and mineral nutrients from roots to aerial parts of the plant.
Gymnosperms are characterized by naked ovules that are not enclosed within an ovary wall. This distinguishes them from angiosperms (which have ovules in ovaries) and pteridophytes (which lack seeds). The term 'gymnosperm' literally means 'naked seed'.
Flowers attract pollinators through various mechanisms (color, scent, nectar) and provide protection to reproductive organs, making sexual reproduction more efficient compared to gymnosperms.
