2.6a the need for transport in plants

Question 1

What do plants need transport systems for?

Answer 1

To move substances such as water from one place to another

Question 2

Why do plants need water?

Answer 2

To transport materials and carry out photosynthesis

Question 3

How is water and minerals transported through in plants?

Answer 3

in xylem vessels

Question 4

What are xylem vessels strengthened by?

Answer 4

lignin rings and spirals

Question 5

Where is the upper epidermis found and what is its function?

Answer 5

• at the very top of the leaf, above the palisade mesophyll cells
• skin-like tissue forming the upper covering of leaves

Question 6

Where are palisade mesophyll cells found and what are their function?

Answer 6

• below the upper epidermis and above spongey mesophyll cells
• main photosynthetic tissue in the left containing many chloroplasts

Question 7

Where are spongey mesophyll cells found and what are their function?

Answer 7

• bellow the palisade mesophyll cells and above the lower epidermis
• plant leaf tissue with loosely packed cells and air spaces between them to allow gas exchange

Question 8

Where is the lower epidermis found and what is its function?

Answer 8

• at the very bottom of the leaf, bellow the spongey mesophyll cells
• skin-like tissue forming the lower covering of leaves

Question 9

What are stomata?

Answer 9

tiny pores in the leaf epidermis that allow gas exchange. They also allow water to leave the cell by evaporation and carbon dioxide and oxygen to enter/ leave the cell.

Question 10

What are guard cells and what is their function?

Answer 10

• Cells that are found on either side of the stomata

- they control gas exchange in leaves by controlling the opening and closing of the stomata.

Question 11

What is transpiration?

Answer 11

water loss through the leaves of a plant by evaporation through the stomata.

Question 12

Describe the flow of water through the plant

Answer 12

• water passes into the root hair cells by osmosis
• water passes up the stem through the xylem
• water lost through the stomata (evaporation) by transpiration

Question 13

State the factors that can increase the rate of transpiration

Answer 13

• higher temperature

- higher windspeed

Question 14

State the factor that can reduce the rate of transpiration

Answer 14

-increased humidity

Question 15

How is sugar transported up and down the plant?

Answer 15

living phloem cells

Question 16

Why do plants need water?

Answer 16

• photosynthesis-hydrogen from water combines with carbon dioxide to produce water
• transport-minerals are transported dissolved in water
• support-water sweets vacuoles making cells turgid
• cooling-evaportion of water from leaves has a cooling effect

Question 17

What apparatus can be used to measure transpiration rate?

Answer 17

potometer

Question 18

Describe the structure of xylem vessels

Answer 18

made up of dead tube-shaped cells with no cell contents but with lignin rings and spirals to give support.

Question 19

Describe the structure of phloem cells

Answer 19

living phloem tissue made up of sieve tube cells connected by sieve plates with no nucleus. They have companion cells.

Question 20

What is the function of a leaf vein?

Answer 20

tissue consisting of xylem vessels and phloem tubes running through a leaf.

Question 21

What is the roles of xylem vessels?

Answer 21

• transport water from the roots to all other areas of the plant
• transport of minerals which are dissolved in the water
• helps strengthen the stem of the plant

Question 22

What do the guard cells do to the stomata if there is little water supple?

Answer 22

they close the stomata

Question 23

What do the guard cells do the the stomata if there is a good water supply?

Answer 23

they open the stomata