Phloem and Bark

Question 1

What is phloem

Answer 1

living tissue that transports the organic compounds from photosynthesis

Question 2

Where does phloem originate

Answer 2

vascular cambium

Question 3

Sugars move in the phloem from

Answer 3

sources to sinks

Question 4

Source

Answer 4

UP. Location where it is produced or stored

Question 5

Sink

Answer 5

DOWN. Location where it is used

Question 6

Connections between cells allow

Answer 6

sap to flow

Question 7

Sieve tubes (angiosperms)

Answer 7

closely associated with one or more companion cells. no nucleus so it needs them

Question 8

Sieve cells (gymnosperms)

Answer 8

cells overlap. phloem moves from cell to cell through pits. angiosperms have them too

Question 9

Why is phloem thin

Answer 9

not much is made in the cambium. phloem is only active for one year

Question 10

What is bark

Answer 10

the outermost layers of a woody stem

Question 11

Purpose of bark

Answer 11

1. protection from bacteria/fungi/insects/animals
2. protection from attack with cinnamon, tennis, juglone
3. protection from fire

Question 12

Outer bark

Answer 12

composed of old inner bark (phloem) and cork is added to waterproof

Question 13

Outer bark development

Answer 13

1. epidermis
2. periderm
3. cork cambium
4. dead phloem cells get pushed to outer bark

Question 14

How does bark cope with tree expansion

Answer 14

phloem grows before the xylem. phloem dies and gets suberized by cork cambium and then becomes innermost layer of dead portion of bark. outermost layers split or shed

Question 15

How do some trees get cambium cells oxygen

Answer 15

lenticels

Question 16

Thorns

Answer 16

modified branches w/ vascular tissue

Question 17

Spines

Answer 17

modified stipules or leaf veins w/ vascular tissue

Question 18

Prickles

Answer 18

extension of epidermis w/ NO vascular tissue