Roots

Question 1

What are the functions of roots?

Answer 1

1. Anchorage of the plant in a substrate
2. Absorbs water and minerals from the soil
3. Production of hormones for growth and development

Question 2

It develops from an embryonic cell known as the “radicle” and grows to be the largest root in the system

Answer 2

Tap root

Question 3

Similarly sized roots and arose because the radicle dies during or immediately after germination

Answer 3

Fibrous root

Question 4

Does not arise from pre-existing roots and increases the absorptive and transfer capacity of the root system

Answer 4

Adventitious root

Question 5

Type of adventitious root that arises from the main trunk stem

Answer 5

Brace root

Question 6

Type of adventitious root that arises from lateral branches of the main stem

Answer 6

Prop root

Question 7

The root tips are protected by ___?

Answer 7

Root caps

Question 8

Give the 3 parts of the root cap

Answer 8

1. Slime or mucigel
2. Columella and peripheral cells
3. Quiescent center

Question 9

What is the function of the slime or mucigel?

Answer 9

Lubricates the passage of the root through the soil

Question 10

What is the function of the quiescent center?

Answer 10

It is a mitotically inactive region which acts as a reserve of health cells and is resistant to toxic substance.s

Question 11

What are the parts of the internal structure of young dicot root?

Answer 11

1. Dermal region
2. Cortex
3. Stele or vascular cylinder

Question 12

Explain dermal region

Answer 12

It is simply the epidermis with root hairs

Question 13

Explain cortex

Answer 13

Outer collenchyma, middle parenchyma, inner endodermis

Question 14

Explain stele

Answer 14

Consists of pericycle, vascular cambium, primary xylem and primary phloem

Question 15

It controls the passage of minerals across the vascular tissues

Answer 15

Endodermis

Question 16

What consists the endodermis?

Answer 16

Thick-walled cells with casparian strips and thin-walled cells known as the “passage cells”

Question 17

What is casparian strip?

Answer 17

Bands of lignin and suberin across the radial walls causing the cell wall to be come waterproof

Question 18

What is the type of stele present in a dicot root?

Answer 18

Protostele

Question 19

What is the type of stele present in a monocot root?

Answer 19

Siphonostele

Question 20

Type of diffusion wherein the water and mineral diffuse only through the walls in intercellular spaces

Answer 20

Apoplastic

Question 21

Type of diffusion wherein the material has passed through a plasma membrane and enters the protoplasm

Answer 21

Symplastic

Question 22

What are the parts of the internal structure of a monocot root?

Answer 22

1. Dermal
2. Cortex
3. Stele or vascular cylinder - siphonostele

Question 23

Where does the lateral root originate?

Answer 23

Pericycle

Question 24

What are the parts of the internal structure of an OLD dicot root?

Answer 24

1. Region of secondary vascular tissues: secondary phloem, secondary xylem and vascular cambium
2. Region of periderm layers: phellem, phellogen, phelloderm

Question 25

It is the zone of cell division

Answer 25

Apical meristem

Question 26

Region where growth in length occurs

Answer 26

Root tip

Question 27

Rapidly dividing cell and is protected by a thick layer of cell

Answer 27

Zone of cell division or meristem

Question 28

What are the three primary meristem?

Answer 28

1. Protoderm - epidermis 2. Ground meristem - stores food and uptake of minerals 3. Procambium - gives rise to stele

Question 29

Region where cells expands greatly there cells can be seen. It is also where cells begin to differentiate to visible patterns

Answer 29

Zone of elongation

Question 30

True or false: There is no cell maturation in the zone of elongation

Answer 30

True

Question 31

Zone where root hairs grow, no distinct boundary exist between elongation and maturation, transfer minerals from the epidermis to the vascular bundle

Answer 31

Zone of maturation

Question 32

Structure of zone of maturation: Function only for several days, after which they die and degenerate, increases absorption of water and minerals

Answer 32

Root hairs

Question 33

Structure of zone of maturation: Outermost layer

Answer 33

Epidermis

Question 34

Structure of zone of maturation: Innermost layer of cortical cell differentiated as a cylinder and is a tangential wall

Answer 34

Endodermis

Question 35

Structure of zone of maturation: Transfer minerals from the epidermis to the vascular tissue

Answer 35

Cortex

Question 36

Structure of zone of maturation: Irregular region, between the vascular tissue and endodermis and where lateral roots arise

Answer 36

Pericycle

Question 37

Food conducting tissue

Answer 37

Phloem

Question 38

Water conducting tissue

Answer 38

Xylem