Topic 3.1.3 Transport in Plants

Question 1

What are some examples of chemicals that plants use?

Answer 1

• carbon dioxide
• oxygen
• organic nutrients
• mineral ions and water
• hormones

Question 2

How does a plant use carbon dioxide?

Answer 2

photosynthetic plant cells require CO2 during daylight

Question 3

How does a plant use oxygen?

Answer 3

• all plants require oxygen for respiration
• actively photosynthesising cells produce enough oxygen for their own needs
• cells which aren’t photosynthesising take in oxygen from their environment

Question 4

How does a plant use organic nutrients?

Answer 4

• e.g. glucose
• made by some plant cells by photosynthesis
• plant cells which don’t photosynthesise are supplied with organic nutrients from photosynthesising cells

Question 5

How does a plant use mineral ions and water?

Answer 5

• taken up from the soil through the roots

- transported to all regions of the plant

Question 6

How does a plant use hormones?

Answer 6

• made in one part of the plant

- transported to other areas for growth

Question 7

Why do plants need transport systems?

Answer 7

• metabolic demands
• size
• surface area : volume

Question 8

How does a plant’s metabolic demands impact on its need for a transport system?

Answer 8

• cells in the plant require energy to perform reactions and functions but not all cells can photosynthesise
• mineral ions, hormones, oxygen and glucose need to be transported around the plant to areas that require them to function

Question 9

How does a plant’s size impact on its need for a transport system?

Answer 9

• large plants and trees can grow very tall

- need to move large distances from roots to the top of the plant

Question 10

How does a plant’s surface area : volume impact on its need for a transport system?

Answer 10

• simple diffusion in large plants and trees will not provide the areas furthest from the roots and leaves with the substances they require
• to ensure they obtain these substances they use a transport system

Question 11

What does xylem tissue transport in plants?

Answer 11

water and dissolved mineral salts

Question 12

What does phloem tissue transport in plants?

Answer 12

sucrose and amino acids

Question 13

What is vascular tissue?

Answer 13

• it is distributed throughout the plant
• the xylem and phloem are found together in vascular bundles
• vascular bundles often contain other types of tissue to give the bundle some strength and to support the plant
• the xylem and phloem are close together

Question 14

What type of cells are found between the xylem and phloem?

Answer 14

cambium cells

Question 15

What is the position of the vascular bundles in the leaves of plants?

Answer 15

forms main veins and side veins

Question 16

what is the position of xylem and phloem in the vascular bundle of the leaf?

Answer 16

xylem is on top of phloem

Question 17

What is the position of the vascular bundles in stem of plants?

Answer 17

found near the outer edge of the stem

Question 18

What is the position of the xylem and phloem in the vascular bundle in the stem?

Answer 18

• phloem points outwards

- xylem points inwards

Question 19

What is the position of the vascular bundles in the root?

Answer 19

one central vascular bundle called the stele

Question 20

What is the position of the xylem and the phloem in the vascular bundle in the root?

Answer 20

• central star shaped xylem

- phloem found in between the ‘arms’ of the star

Question 21

What is the xylem in plants?

Answer 21

• the vascular tissue in plants that conducts water and dissolved nutrients upwards from the root
• helps to form the woody element in the stem

Question 22

What is the phloem in plants?

Answer 22

• the vascular tissue in plants which conducts sugars and other metabolic products downwards from the leaves

Question 23

What is the vascular bundle in plants?

Answer 23

• a strand of primary tissues found within the stem of a plant
• consisting of xylem and phloem, along with cambium

Question 24

What are the cambium cells in plants?

Answer 24

• layer of actively dividing cells between xylem and phloem tissues
• responsible for secondary growth of stems and roots

Question 25

What is the meristem in plants?

Answer 25

• regions of unspecialised cells in plants that are capable of cell division
• found in the tip of roots and shoots and in between the xylem and phloem

Question 26

What is the stele in plants?

Answer 26

• the central part of the root or stem

- contains the tissues derived from the procambium (the primary meristem where vascular tissues develop from)

Question 27

What are the palisade mesophyll cells in plants?

Answer 27

• cells that contain most of the chloroplasts in plant leaves
• located under the upper epidermis so they are well positioned to absorb light for photosynthesis

Question 28

What are the spongy mesophyll cells?

Answer 28

• covered by a thin layer of water in which gasses dissolve as they move into and out of cells
• key during photosynthesis

Question 29

What are the stomata?

Answer 29

• tiny holes found in the underside of leaves that control water loss and gas exchange by opening and closing

Question 30

What are the two main functions of xylem tissue?

Answer 30

• support

- transport (water and solutes from the roots to the leaves)