8.3 Transport in plants - Pressure Flow Hypothesis

Structure of phloem consists all below, except?

• Sieve tube

• Tracheids

• Companion cell

• Sieve plate

What is the most abudant solute in phloem sap?

• starch

• glucose

• sucrose

• water

Process in which organic substances are moved to the rest of plant by phloem is known as

• transpiration

• cellular respiration

• photosynthesis

• translocation

What happens FIRST during translocation in the phloem?

• water enters the sieve tubes from xylem vessel by osmosis

• sucrose enters the sieve tubes from source cell by active transport

• water leaves the sieve tubes to xylem vessel by osmosis

• sucrose leaves the sieve tubes to sink cell

Which of the following allows transport of sucrose from a sieve tube to a companion cell?

• sieve plate

• plasmodesmata

• cell wall

• pits

Translocation may occur as describe in Pressure Flow hypothesis. The pressure involved in this hypothesis originates from

• The root pressure

• Transpirational pull in the leaves

• Accumulation of sucrose in sieve tube

• The intake of water by sieve tube from xylem vessel by osmosis

The Pressure Flow hypothesis for phloem translocation states..

• that sink strength drives transport in the pholem

• that transport in companion cell is pressure dependent

• the water potential gradient in the sieve tube drives phloem transport

• the pressure gradient between the sieve tube at the source and the sink drives phloem transport

What molecule is the phloem responsible for transporting?

• Glucose

• Fructose

• Sucrose

• Starch

What is the best words to describe source and sink cell?

• Both are plants organ and act as storage

• Sink cell can be either fruit or leaves and source cell is root

• Source cell act as site for sugar production and sink cell will store sugar

• Companion cell carry sucrose from a source cell to a sink cell

In a tree during normal condition, it is expected that the sugars produced by the tree would flow from (i)____________ to (ii)__________________.

Choose the option that would correctly fill in the terms in the sentence above.

• (i) a leaf (ii) a growing fruit

• (i) the root (ii) a leaf

• (i) the root (ii) a growing fruit

• (i) a growing fruit (ii) a leaf