Support and transport in plants

Question 1

Seed plants are divided into two main groups

Answer 1

• gymnosperms
• angiosperms

Question 2

gymnosperms

Answer 2

• Non-flowering seed plants
• e.g. pine trees, yellowwood trees and cycads

Question 3

angiosperms

Answer 3

• flowering plants
• e.g. sunflowers, corn and orange trees

Question 4

Angiosperms are divided into two main groups

Answer 4

• dicotyledons (dicots)
• monocotyledons (monocots)

Question 5

Main support tissues in plants

Answer 5

• collenchyma
• sclerenchyma
• xylem

Question 6

Main transport tissues in plants

Answer 6

• xylem
• phloem

Question 7

Xylem tissue is made up of…

Answer 7

• xylem vessels
• xylem tracheids
• xylem sclerenchyma fibres
• xylem parenchyma

Question 8

Xylem vessel features…

Answer 8

• primary cell wall made of cellulose
• dead cells, no cytoplasm
• long, cylindrical tubes
• ends of tubes (cross walls) have perforated plates
• thick secondary walls of lignin
• lignin either annular, spiral, scalariform or pitted

Question 9

Xylem tracheid features…

Answer 9

• similar to tracheids
• cell ends tapered (pointed)
• narrow diameter

Question 10

Xylem suited for support because…

Answer 10

• thick secondary walls of lignin
• round shape in cross section
• strong to resist shearing forces (forces acting at different angles to the cell)

Question 11

Xylem suited for transport because…

Answer 11

• cross walls perforated
• cells are dead and hollow
• pits and gaps in thickening allow water to move sideways between cells

Question 12

Xylem transports…

Answer 12

• water
• dissolved mineral salts

Question 13

Phloem transports…

Answer 13

• manufactured organic foods
• e.g. glucose and sucrose

Question 14

Phloem tissue is made up of…

Answer 14

• sieve tubes
• companion cells
• phloem schlerenchyma fibres
• phloem parenchyma

Question 15

Sieve tube features…

Answer 15

• Primary cell wall of cellulose
• no secondary thickening
• living cells with no nucleus or cytoplasm
• long, tube like
• sieve plates at ends with holes
• Large vacuoles (cell body) with cytoplasmic threads

Question 16

Companion cell features…

Answer 16

• Living cells
• dense cytoplasm with a nucleus
• found next to sieve tubes to manage their metabolism

Question 17

Functions of the root system in plants…

Answer 17

• anchorage
• support
• storage
• nutrient uptake
• transport
• reproduction

Question 18

First root in angiosperms?

Answer 18

• Primary embryonic root
• called the radicle

Question 19

First shoot in angiosperms?

Answer 19

• Embryonic shoot
• called the plumule

Question 20

Describe dicot roots

Answer 20

• tap root system
• radicle develops into a tap root
• lateral roots branch outwards from this

Question 21

Describe monocot roots

Answer 21

• Fibrous or adventitious
• radicle dies
• replaced with secondary roots from stem
• form a shallower fibrous root system

Question 22

Region of root where xylem and phloem are found…

Answer 22

• the stele

Question 23

Support tissues in a root…

Answer 23

• collenchyma
• schlerenchyma
• xylem

Question 24

Transport tissues in a root…

Answer 24

• Xylem
• Phloem

Question 25

Describe the outermost layer of a root…

Answer 25

• Epidermis tissue
• No cuticle to be able to absorb water
• Root hairs may be present to increase surface area

Question 26

The two main root regions of a dicot (cross section)

Answer 26

• Cortex (outer)
• Stele (inner)

Question 27

Describe the cortex in a dicot…

Answer 27

From outside inwards:

• (Epidermis)
• Exodermis
• central cortex
• endodermis (innermost layer)

Question 28

Describe the endodermis…

Answer 28

• Single layer of parenchyma cells
• Wall thickening called Casparian band (helps control water movement)

Question 29

Describe the stele…

Answer 29

• Pericycle tissue - produces secondary roots
• Conducting tissue - xylem and phloem