Chapter 4: Transport in plants

Question 1

What are the two main types of vascular tissues?

Answer 1

• xylem

- phloem

Question 2

What is the necessity of transport in plants?

Answer 2

• needs a transport system to transport water and mineral salts

Question 3

Plants that have a transport system are known as ______ _______. ___-______ _____ like alga and moss do not have any transport system.

Answer 3

• vascular plants

- non-vascular plants

Question 4

The xylem tissue consists of ____ _____ and ______.

Answer 4

• xylem vessels

- tracheids

Question 5

What does the xylem vessel consist of?

Answer 5

• dead cells at maturity which do not have cytoplasm

Question 6

What is the structure of the xylem vessel?

Answer 6

• arranged longitudinally from end to end to form a continuous tube

Question 7

Why does the xylem vessel have lignin thickening?

Answer 7

• give strength to prevent them from collapsing due to the tension force
• prevent it from being bent

Question 8

Explain tracheids.

Answer 8

• consists of dead cells
• a long, narrow, and hollow tube with a tapered end
• has small openings called pits to allow water movement to adjacent cells

Question 9

What does phloem tissue consist of?

Answer 9

• sieve tube

- companion cells

Question 10

Explain the sieve tube.

Answer 10

• made up of living cells with no nucleus

Question 11

On both ends of the sieve tube, there is a _____ _____ that has pores through which organic substances can flow from one sieve-tube to the other.

Answer 11

• sieve plate

Question 12

Explain companion cells.

Answer 12

• located beside a sieve tube
• consists of a nucleus, cytoplasm, and many mitochondria
• the mitochondria provide energy to sieve tubes to transport organic substances through active transport

Question 13

Explain transpirational pull.

Answer 13

• produced when water that is evaporated from the stoma, pulls water from the leaves

Question 14

Explain capillary action.

Answer 14

• produced from adhesive force and cohesive force of water molecules which moves water upwards in the stem against gravity

Question 15

What is root pressure?

Answer 15

• moves water from the soil into the xylem vessels of the root via osmosis

Question 16

What are the three things that help water and mineral slats movement from the soil to the leaves?

Answer 16

• transpirational pull
• capillary action
• root pressure

Question 17

How does water move from the soil into the xylem vessel?

Answer 17

• water potential in the root hair cells is lower because the mineral ions are actively pumped into the vacuole
• diffuses into root hair cells and epidermal cells via osmosis
• high water potential in the root hair cells causes the water to diffuse into cortex cells
• causes osmosis to continuously occur throughout the cortex, endodermis, and pericycle

Question 18

How does water move in the xylem vessels?

Answer 18

• is helped by capillary action and transpirational pull
• capillary action causes water to move water upward in the xylem vessel
• during transpiration, water vapour diffuses out from the air spaces through the stoma
• spongy mesophyll cells lose water and have low water potential
• water diffuses in from the adjacent cells
• this produces a transpirational pull

Question 19

What is guttation?

Answer 19

• a secretion of water droplets at the end of leaf veins without involving the stomata caused by a high root pressure

Question 20

When does guttation occur?

Answer 20

• when the air humidity is high and the surrounding temperature is low

Question 21

What are the similarities between transpiration and guttation?

Answer 21

• occur through leaf

- cause water loss from plant

Question 22

What are the differences between transpiration and guttation?

Answer 22

Transpiration
- happens on hot a day
- in all plants
- released as water vapor
- released through the stoma
- controlled by stomatal opening and closing
Guttation
- night and early morning
- only in herbaceous plants
- released as water droplets
- released through the end of leaf veins
- when root pressure is high

Question 23

What occurs if plants do not undergo guttation?

Answer 23

• root pressure cannot be maintained which abrupts water absorption
• waste substances cannot be released
• causes leaf veins to burst and exposing them to pathogens

Question 24

What occurs if plants do not undergo transpiration?

Answer 24

• optimum temperature cannot be maintained and can denature cells
• mineral ions cannot be transported
• die in the long run

Question 25

What is translocation?

Answer 25

• transporting organic substances such as sucrose and amino acids in the phloem from the leaves to other parts of the plant

Question 26

Explain the necessity of translocation in plants.

Answer 26

• helps in transporting photosynthetic products

- transports excess photosynthetic products to other parts of plants such as rhizomes or tubers

Question 27

What are the pathways of translocation in plants?

Answer 27

• sucrose is actively transported into the sieve tube
• reduces water potential in the sieve tube that causes water to diffuse from the xylem into the sieve tube via osmosis
• diffusion increases hydrostatic pressure
• this causes the phloem sap to be pushed along the sieve tube to the other organs
• phloem sap ( sucrose ) is transported to parts such as stems, roots, and fruits
• high water potential in phloem causes water to diffuse into the xylem

Question 28

What is phytoremediation?

Answer 28

• one of the treatment methods which uses plants for the purpose of degradation or elimination of pollute substances from soil and water

Question 29

_____ _____ removes diesel pollutants in synthetic waste.

Answer 29

• floating fern ( Salvinia molesta )

Question 30

____ ______ has long roots and accumulates heavy ____ such as copper and lead in water.

Answer 30

• water hyacinth

- metals

Question 31

Sunflower acts as a __________ which can eliminate heavy metals such as ____, chromium, and lead.

Answer 31

• hyperaccumulator

- zinc

Question 32

_____ lettuce _____ which has a fast growth rate, can accumulate heavy metals and absorb nutrients in the waste plant.

Answer 32

• water

- plant

Question 33

What are the uses of phytoremediation?

Answer 33

• remove contaminants and treat polluted water