Transport in Plants Test - 9

Uniport is a transport mechanism that drives a single compound or ion across a membrane, not coupled with transport of any other compound or ion.

Active absorption takes place by utilizingenergy molecules ATP and opposite to the concentration gradient. So, active absorption differ from passive absorption in direction and utilization of ATP.

The accepted mechanism used for the translocation of sugars from source to sink is called the pressure flow hypothesis. . As glucose is prepared at the source (by photosynthesis) it is converted to sucrose (a dissacharide).

Phloem tissue is composed of sieve tube cells, which form long columns with holes in their end walls called sieve plates. Cytoplasmic strands pass through the holes in the sieve plates, so forming continuous filaments.

In angiosperms and gymnosperms (but not in ferns and lycopsids), Accumulation of ABA triggers closing of the stomata when soil water is insufficient to keep up with transpiration.

For preserving food stuff vinegar, salt and sugar is used. Ethanol is antiseptic in nature but not used for preserving food stuff.

Lenticels are minute pore in stems through which exchange of gases takes place between plant and atmosphere.

The cells surrounding the stomata pore is called guard cell. It is bean shaped in dicots and dumbbell shape in monocots. Cellulose microfibrils are arranged radially in guard cell.

A hydathode is a type of secretory tissue in leaves, commonly found in angiosperms, that secretes water through pores in the epidermis or leaf margin, typically at the tip of a marginal tooth or serration.

The cytoplasm of two adjacent cells are connected through a bridge plasmodesmata. Movement of substance in plants takes place through this plasmodesmata.