The direction of phloem transport is:
Unidirectional, always upwards
Unidirectional, always downwards
Source to sink
Sink to source
Related Questions
I. Made up of sclerenchymatous cellsII. Generally absent in primary phloemIII. Much elongated and pointedGiven above characters belongs to which of the following?
Phloem fibre
Xylem fibre
Companion cells
Sieve cells
Which of the following is not a part of epidermal tissue system?
Companion cells
Trichomes
Root hairs
Guard cells
The sieve plates in phloem are involved in:
Preventing backflow of phloem sap
Storing food materials
Maintaining continuous flow of phloem sap
Absorbing water from xylem
The specific arrangement of sieve elements and companion cells in phloem tissue, where a single companion cell is associated with multiple sieve elements, is MOST characteristic of which plant group?
Angiosperms
Gymnosperms
Bryophytes
Pteridophytes
The primary driving force for the movement of substances in the phloem is:
Transpiration pull
Capillary action
Root pressure
A pressure gradient created by active loading and unloading of sugars
The seed coats of legumes are hard due to?
Meristem
Fibers
Collenchyma
Sclereids
Which substance is NOT transported by the phloem?
Sucrose
Amino acids
Hormones
Water and minerals
Which cell type, responsible for assisting in the conduction of nutrients in angiosperm phloem, is absent in gymnosperms?
Sieve cells
Companion cells
Albuminous cells
Phloem fibers
The 'polymer trapping' model explains phloem loading by suggesting that sucrose is converted into larger molecules in which specific cell type?
Sieve elements
Companion cells
Phloem parenchyma cells
Bundle sheath cells
Simple sieve plate with single perforation is present in
Cucurbita
Prunus
Pyrus
Vitis
