8.4 Transport in plants: Phloem DB024

Structure of phloem consists all below, except?

• Sieve tube element

• Tracheids

• Companion cell

• Sieve plate

What is the most abudant solute in phloem sap?

• amino acids

• hormones

• sugar

• minerals

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

• transpiration

• respiration

• photosynthesis

• translocation

What happens first during translocation in the phloem?

• water enters the sieve tubes by osmosis

• sucrose enters the sieve tubes by active transport

• water leaves the sieve tubes by osmosis

• sucrose leaves the sieve tubes by active transport

Which of the following allows transport of substances from a sieve element cell to a companion cell?

• sieve plate

• plasmodesmata

• cell wall

• pits

Translocation may occur as the mass flow hypothesis. The pressure involved in this hypothesis originates from

• The root pressure

• Transpiration in the leaves

• Accumulation of minerals and water in leaves

• The intake of water by sieve tubes in the leaves

The pressure flow model for phloem translocation states..

• that sink strength drives transport in the pholem

• that transport in treachery elements is pressure dependent

• the water potential gradient in the sieve elements drives transport

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

What molecule is the phloem responsible for transporting?

• Glucose
• Water
• Sucrose
• Glycogen

What is the best words to describe sugar source and sugar sink

• Both are plants organ and act as storage

• Sugar sink can be either roots, fruit or mature leaves and sugar source is shoots

• Sugar source act as site for sugar production and sugar sink will store sugar

• Companion tube carry food from a sugar source to a sugar sink

Tags

NGSS.MS-LS1-6

In an apple tree, 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 apple

• (i) the trunk (ii) a leaf

• (i) the roots (ii) a growing shoot

• (i) a growing shoot (ii) a leaf

Tags

NGSS.MS-LS1-6

NGSS.MS-LS1-7