Translocation

Question 1

WHat is translocation?

Answer 1

the transport of organic compounds in the phloem from sources to sinks

in many plants translocation is an active process tha trequres energy and substances to be transported

the products of photosynthesis that are transported are known as assimilates

main assimilate is sucrose

Question 2

What are the main sources of assimilates in plants?

Answer 2

green leaves/stems

storage organs such as tubers and tap roots that are unloading their stores at the beginning of a growth period

food stores in seeds when they germinate

Question 3

What are the main sinks?

Answer 3

roots that are growing and/or actively absorbing mineral ions

meristems that are actively dividing

any parts of the plant that are laying down food stores such as developing seeds, fruits or storage organs

Question 4

Why is sucrose used?

Answer 4

soluble but metabolically inactive

not used during transport

Question 5

How is transport in phloem similar to transport in xylem

Answer 5

both use mass flow

both transport mineral salts

solutes carried in soln

Question 6

How is transport in phloem different to transport in xylem?

Answer 6

phloem does not use capillary action, adhesion. cohesion

phloem uses live cells, xylem doesnt

Question 7

HHow can some parts of a plant act as both a source and sink

Answer 7

store and release carbs when needed e.g. root or leaves

different times of year