phloem

Question 1

what are some structural adaptations of the phloem?

Answer 1

1. sieve tube has only a thin layer of cytoplasm without any organelles
2. sieve tube has a perforated sieve plate
3. companion cell has numerous mitochondria to release ATP for loading of surcrose

Question 2

what are the functions of these adaptations?

Answer 2

1. transports sucrose and amino acids between parts of plant (source to sink)
2. reduces resistance