Chapter Five: Roots

Question 1

underground part of a plant

Answer 1

roots

Question 2

3 major functions of roots

Answer 2

1. anchor plant to substrate
2. absorb, transport, and store water and minerals
3. absorb oxygen

Question 3

two main types of roots

Answer 3

1. taproots
2. fibrous roots

Question 4

taproots are primarily found in ___

Answer 4

monocots

Question 5

in taproots, the radical becomes the ___

Answer 5

mature root system

Question 6

fibrous roots are primarily found in ___

Answer 6

dicots

Question 7

in fibrous roots, the radical ___ a few days after sprouting

Answer 7

dies

Question 8

in fibrous roots, the mature root system develops from ____

Answer 8

adventitious roots from the meristem

Question 9

four areas of the root tip

Answer 9

1. root cap
2. zone of cell division
3. zone of elongation
4. zone of maturation

Question 10

the root cap is a cluster of ____ that function to ___

Answer 10

parenchymal cells
protect the growing tip of the root

Question 11

a root will continue to grow until ____

Answer 11

its root cap is worn off

Question 12

the root cap also secretes a ____ that functions to ___

Answer 12

slimy substance
lubricate the root’s passage through the soil

Question 13

the zone of cell division consists of the ____; it is where most ____ takes place

Answer 13

apical meristem
cell division

Question 14

the ___ merges with the apical meristem

Answer 14

zone of elongation

Question 15

what do cells do in the zone of elongation

Answer 15

grow several times their original length and somewhat wider

Question 16

which structure inside the cells forms in the zone of elongation

Answer 16

tiny vacuoles merge and grow together into one or two large vacuoles

Question 17

cells in the zone of maturation ____ and ____ also form here

Answer 17

differentiate into cell types
root hairs

Question 18

root hairs are extensions of the ____

Answer 18

epidermis

Question 19

3 functions of root hairs

Answer 19

1. absorb water and minerals
2. adhere to the soil
3. increase total absorptive surface for the root

Question 20

refines and regulates water’s passage into and out of the vascular stele

Answer 20

endodermis

Question 21

the endodermis is ___ thick

Answer 21

one cell layer

Question 22

bands that surround endodermal cells that only allow water to pass through the face and rear

Answer 22

Casparian strips

Question 23

wax that is in casparian strips

Answer 23

suberin

Question 24

meristematic tissue in roots

Answer 24

pericycle

Question 25

the pericycle surrounds ___ and sits just inside the ___

Answer 25

vascular tissue endodermis

Question 26

the pericycle is ___ thick

Answer 26

one cell layer

Question 27

the pericycle gives rise to ___

Answer 27

lateral roots

Question 28

lateral roots grow when ___ or ___

Answer 28

root cap wears off and root stops growing or in the zone of maturation while apical growth is still occurring

Question 29

which tissues do lateral roots have to grow through

Answer 29

endodermis, cortex, and epidermis

Question 30

roots that are modified to enlarge and store large quantities of starch and other carbs

Answer 30

storage roots

Question 31

the starch and carbs help in storage roots can later be used for ___

Answer 31

extensive growth

Question 32

some plants have ____, especially plants in arid environments or plants that live where precipitation is rare

Answer 32

water storage roots

Question 33

spongy roots located on plants that live in water that extend above the water to enhance gas exchange

Answer 33

pneumatophores

Question 34

why are pneumatophores necessary

Answer 34

plants that live in the water might not get enough gas exchange in their roots because oxygen concentration of water is low

Question 35

roots that function to prevent loss of moisture

Answer 35

aerial roots

Question 36

roots that function to pull the plant deeper into the soil

Answer 36

contractile root

Question 37

huge roots toward the base of a tree trunk that give the tree great stability

Answer 37

buttress roots

Question 38

when are parasitic roots beneficial

Answer 38

some plants do not produce chlorophyll, so they have to rely on chlorophyll producing plants for their nutrition; these roots can parasitize the chlorophyll producing plant to gain access to this

Question 39

as association that most plants have with fungi

Answer 39

mycorrhizae

Question 40

mycorrhizae greatly enhances the plants ability to ___, ___ and ___

Answer 40

eat, drink, and breathe from the soil

Question 41

mycorrhizae can help get rid of ___ for the plant

Answer 41

nematodes or other harmful things

Question 42

mycorrhizae can sometimes connect ____

Answer 42

all the plants in a community

Question 43

why is it so difficult for a grassland to grow back after being tilled

Answer 43

the mycorrhizal connections are cut, which take thousands of years to form; therefore, the land will probably just grow back as a forest

Question 44

nitrogen fixing bacteria

Answer 44

rhizobium

Question 45

plants cannot convert nitrogen gas to ____

Answer 45

usable forms

Question 46

rhizobium produce the ___ necessary to convert nitrogen gas into something that plants can use

Answer 46

enzymes

Question 47

contain large amounts of rhizobium on a plant

Answer 47

root nodules