transport in plants

Question 1

What does the xylem transport throughout a plant?

Answer 1

The xylem transports water and mineral ions

Question 2

What direction does the xylem flow?

Answer 2

Only up

Question 3

What does the phloem transport?

Answer 3

The phloem transports assimilates such as sucrose

Question 4

What direction does the phloem transport materials?

Answer 4

Both up and down

Question 5

What is the cambium?

Answer 5

It is a layer of meristem cells found in between the xylem and phloem in the stem

Question 6

Where is the xylem found in the stem?

Answer 6

The xylem is closest to the center of the stem

Question 7

What are meristem cells?

Answer 7

Meristem cells are cells that divide to produce new cells

Question 8

Where is the phloem found in the stem?

Answer 8

The phloem is farthest from the center with the cambium separating the xylem and phloem

Question 9

What is the epidermis?

Answer 9

The epidermis is the outermost layer of the plant almost like skin

Question 10

What is the xylem made of?

Answer 10

Dead cells so water and mineral ions can be transported

Question 11

What is the phloem made of?

Answer 11

Sieve tube elements and companion cells

Question 12

What is sclerenchyma?

Answer 12

It offers support and structure around cells as its thickened with lignin and cellulose

Question 13

What is collenchyma?

Answer 13

Found near epidermis.
thick cellulose walls provides flexibility and aids growth.

Question 14

What is parenchyma?

Answer 14

its a soft packing-tissue that fills spaces between other tissues.

Question 15

What can parenchyma store?

Answer 15

stores starch in roots

chloroplasts to photosynthesise

has air spaces in aquatic plants to aid with buoyancy

Question 16

What are the main functions of the xylem?

Answer 16

provide structural support. transport water and mineral ions

Question 17

What is the structure of the xylem?

Answer 17

Long hollow tubes made up of thick, lignified dead cells

Question 18

What is the role of lignin in the xylem?

Answer 18

lignin is deposited in the xylem cell walls, killing the cells, but makes it waterproof and stronger

Question 19

what are bordered pits in the xylem?

Answer 19

they are small non-lignified regions of the xylem. they allow water and mineral ions to move laterally between xylem vessels

Question 20

What does the parenchyma store?

Answer 20

The parenchyma stores food and contains Tannin

Question 21

What is Tannin?

Answer 21

A bitter-tasting chemical that protects plant tissues from attacks by chemicals and infection from bacteria and fungi

Question 22

What is transpiration?

Answer 22

The loss of water from the stomata in the leaves due to evaporation

Question 23

What are the adaptations of sieve tube elements?

Answer 23

Elongated
No nucleus
Very little cytoplasm

Question 24

Does the xylem contain dead/alive cells?

Answer 24

The xylem is made up of dead cells

Question 25

Does the Phloem contain dead/alive cells?

Answer 25

The phloem is made up of living cells

Question 26

What are the roles of water?

Answer 26

Photosynthesis Structure and support Transport Cooling

Question 27

What are the adaptations of root hair cells?

Answer 27

Microscopic size allows it to easily penetrate soil particles. Large SA:V ratio Thin surface layer so short diffusion High conc. of solutes maintain steep water potential gradient.

Question 28

What are the 3 ways water moves from the root hair to the xylem?

Answer 28

Apoplast - through intercellular space Symplast - through plasmodesmata Vacuolar - same as symplast but can pass through vacuoles as well

Question 29

What is the slowest pathway water can take to reach the xylem?

Answer 29

The vacuolar pathway is the slowest

Question 30

What is the slowest pathway water can take to reach the xylem?

Answer 30

The vacuolar pathway is the slowest

Question 31

What is the casparian strip?

Answer 31

A band of waxy material called Suberin that waterproofs the vascular bundle

Question 32

What happens at the casparian strip?

Answer 32

Water in apoplast pathway can’t continue, it it forced into the cytoplasm of the cell, joining the symplast pathway. This ensures any harmful solutes in the water are excluded as carrier protein won’t admit them into the cell.

Question 33

What is root pressure?

Answer 33

Root pressure is a tiny force that gives water a ‘push’ up the xylem. However it can’t account for water reaching the top of tall trees. Root pressure ≠ transpiration

Question 34

What is the evidence for root pressure?

Answer 34

Root pressure increases with temp suggesting it is dependent on active transport. Cyanide (affects mitochondria) reduces root pressure. Suggesting it’s an active process. Guttation If oxygen levels or respiratory substances fall, so does root pressure.