Deck 5: Roots and Soils

Question 1

Roots that develop from an organ OTHER than an existing root are called

A) root hairs
B) fibrous roots
C) radicle
D) adventitious roots
E) primary root

Answer 1

D

Question 2

Which of the following cells is relatively thin-walled?

A) stone cell
B) fiber
C) tracheid
D) vessel element
E) passage cell

Answer 2

E

Question 3

Cells of an endodermis that do not have Casparian strips are

A) sieve-tube elements.
B) tracheids.
C) fibers.
D) collenchyma.
E) passage cells.

Answer 3

E

Question 4

Cells of the apical meristem

A) have large vacuoles.
B) divide at a fairly steady rate.
C) have little to do with the root cap.
D) are generally cuboidal in shape.
E) have no nuclei.

Question 5

In traversing the root to the central xylem vessels, the last living tissue that water passes through before entering the xylem is the

A) endodermis.
B) pericycle.
C) cortex.
D) phloem.
E) epidermis.

Question 6

The perception of gravity by a root takes place in

A) root hairs.
B) the region of elongation.
C) the region of cell division (apical meristem).
D) the region of maturation.
E) the root cap.

Question 7

A root system may function in which of the following?

A) anchorage and storage
B) growth
C) absorption and conduction
D) production of new roots
E) All of the answers are correct.

Question 8

Which of the following is a part of the embryo of a seed?

A) root hairs
B) radicle
C) fibrous roots
D) taproot
E) adventitious roots

Question 9

The tissue adjacent to the endodermis toward the center of a root is the

A) cortex.
B) pith.
C) pericycle.
D) xylem.
E) phloem.

Question 10

In addition to anchoring a plant, roots usually function directly in which of the following processes?

A) photosynthesis
B) production of new leaves
C) production of bud scales
D) absorption of minerals in solution
E) All of these answers are correct.

Question 11

Rhythmic cell divisions in young roots often

A) occur about once a week.
B) reach a peak once or twice a day.
C) peak several times during a 24-hour period.
D) result in a given root growing several meters a day.
E) do not occur in monocots.

Question 12

The perception of gravity by roots is aided by

A) amyloplasts.
B) chloroplasts.
C) chromoplasts.
D) leucoplasts.
E) gravoplasts.

Question 13

________ root systems develop from the radicle.

A) Adventitious
B) Climbing
C) Stem cutting
D) Fibrous
E) Taproot

Question 14

Monocots, such as grasses, usually have ________ root systems.

A) simple, straight
B) taproot
C) fibrous
D) secondary
E) aerial

Question 15

Parts of the pericycle and parenchyma between the arms of xylem and patches of phloem in young roots of many dicots and conifers become

A) cork cambium.
B) endodermis.
C) cortex.
D) vascular cambium.
E) Casparian strips.

Question 16

Typical root systems form up to ________ of the total dry biomass of a plant.

A) one tenth
B) one fifth
C) one fourth
D) one third
E) one half

Question 17

Root hairs are prominent in the

A) root cap.
B) apical meristem.
C) region of elongation.
D) root axils.
E) region of maturation.

Question 18

When trees undergo root grafting with one another, an unfortunate result can be

A) strangling of one tree by another.
B) disease spreads to healthy trees.
C) insufficient food for all the trees.
D) fewer leaves on the trees.
E) the development of thinner bark.

Question 19

The most abundant cell type in periderm is

A) parenchyma.
B) collenchyma.
C) cork.
D) vessel elements.
E) ray initials.

Question 20

Which of the following tissues is common in roots but not in stems?

A) endodermis
B) parenchyma
C) cortex
D) epidermis
E) pith

Question 21

Root hairs are found in the region of the root called the

A) root cap.
B) apical meristem.
C) region of elongation.
D) region of maturation.
E) endodermis.

Question 22

Which of the following is NOT a specialized root?

A) branch or lateral roots
B) food storage root of sweet potato
C) prop root of corn
D) contractile roots
E) propagative roots

Question 23

The region of elongation is characterized by ________.

A) root hair production
B) development of the root cap
C) producing ground meristem
D) production of branch roots
E) increase in size of cells

Question 24

One unique function of the root cap is

A) the sensing of a gravitational force.
B) production of root hairs.
C) formation of bud scales.
D) production of an ion barrier.
E) Both the sensing of a gravitational force and production of root hairs are correct.

Question 25

Which of the following is/are absent in dicot roots?

A) xylem
B) phloem
C) epidermis
D) cortex
E) nodes

Question 26

The region of cell division in a root is also known as ________.

A) the root apical meristem
B) shoot apical meristem
C) region of root hair production
D) zone of elongation
E) endodermis

Question 27

Root hairs

A) are specialized epidermal cells.
B) are covered with a waxy cuticle.
C) increase the surface area for absorption of water.
D) live only one day.
E) Both are specialized epidermal cells and increase the surface area for absorption of water are correct.

Question 28

How does monocot root structure differ from dicot root structure?

A) Monocot endodermis cells lack a Casparian strip.
B) Dicot roots lack a central pith region.
C) Monocot roots usually form a tap root system.
D) Dicot roots do not form branch roots.
E) There is no structural difference between monocot and dicot root systems.

Question 29

This tissue (region) is present in monocot roots but absent in dicot roots.

A) phloem
B) epidermis
C) cortex
D) xylem
E) pith

Question 30

A unique feature of the pericycle is

A) its retention of meristematic potential.
B) the production of lateral roots.
C) the presence of a Casparian strip.
D) its location next to the epidermis.
E) Both its retention of meristematic potential and the production of lateral roots are correct.

Question 31

The tissue in which a cork cambium first develops in woody dicot roots is the

A) pericycle.
B) endodermis.
C) primary xylem.
D) primary phloem.
E) cortex.

Question 32

Cells of the root cap ease the growth of young roots through the soil by ________.

A) secreting slippery lipids like waxes
B) producing oils
C) producing a mucilaginous lubricant
D) forcing a passage between soil particles
E) none of the above

Question 33

Specialized roots that permit aquatic plants to facilitate gas exchange are called

A) velamen roots.
B) water-storage roots.
C) buttress roots.
D) pneumatophores.
E) prop roots.

Question 34

The rootlike projections of parasitic plants that develop along their stems and penetrate the host plants' tissues are called

A) parenchyma.
B) mycorrhizae.
C) haustoria.
D) mutualistic.
E) aerial roots.

Question 35

Which statement about mycorrhizae is INCORRECT?

A) The type of mycorrhizae in which the fungi invade the plant cells is called endotrophic.
B) Only the plants benefit from a mycorrhizae association.
C) Ectotrophic mycorrhizae do not enter the tree root cells.
D) Mycorrhizae benefit both the plants and the fungi..
E) Mycorrhizae are essential for normal growth and development of trees and many herbaceous plants.

Question 36

Buds that develop on roots are referred to as

A) axillary.
B) terminal.
C) intrusive.
D) adventitious.
E) pseudobuds.

Question 37

Which of the following spices or flavorings is obtained from roots?

A) sarsaparilla
B) angelica
C) licorice
D) sassafras
E) All of these answers are correct.

Question 38

How do lateral roots differ from root hairs?

A) Lateral roots have a root cap; root hairs do not.
B) Lateral roots are formed of many cells; root hairs are a single cell.
C) Lateral roots form from the pericycle; root hairs develop in region of maturation.
D) Lateral roots may live for many months; root hairs live for a few days.
E) All of the above are true.

Question 39

Stored food, especially starch and other carbohydrates in storage roots, can be found in this tissue of a root:

A) endodermis.
B) epidermis.
C) pericycle.
D) cortex.
E) cork.

Question 40

Mycorrhizae roots are those that

A) have a symbiotic association with fungi.
B) have a symbiotic association with nitrogen fixing bacteria.
C) contain hyphae of parasitic fungi.
D) are above ground roots that serve to support the stem.
E) are propagative roots.

Question 41

A root hair consists of a short row of cells.

Question 42

Liming is used to counteract soil acidity.

Question 43

The best soil for plant growth is

A) clay.
B) sand.
C) loam.
D) peat.
E) both clay and sand are correct.

Question 44

Good agricultural soils are granular soils with pore spaces that occupy which of the following percentages of the total volume of the soil?

A) 10% to 20%
B) 20% to 30%
C) 40% to 60%
D) 60% to 70%
E) None of these answers are correct.

Question 45

The protective suberin bands called Casparian strips are confined to the cells of the epidermis.

Question 46

The arrangement of soil particles into groups called aggregates refers to

A) soil structure.
B) soil texture.
C) parent material.
D) micelles.
E) soil nutrients.

Question 47

Soils in low wet areas tend to contain hardly any organic matter.

Question 48

Soil parent material extends down to bedrock.

Question 49

Branch roots arise from buds initiated on the outer surface of a root.

Question 50

People harvest the storage roots of biennials such as ________ for their food value.

A) carrots
B) licorice
C) reserpine
D) rotenone
E) All of these answers are correct.

Question 51

A colloid is a mixture of water and particles that are smaller than average molecules in size.

Question 52

Soil water between field capacity and the permanent wilting point is called

A) hygroscopic water.
B) gravitational water.
C) capillary water.
D) intermediate water.
E) available water.

Question 53

Clay particles have negative electric charge which tend to retard water drainage and retain positively charged ions.

Question 54

Pith tissue is absent in dicot roots.

Question 55

Water that drains out of the pores in soils after a rain is called

A) capillary water.
B) gravitational water.
C) hygroscopic water.
D) field capacity.
E) available water.

Question 56

In a soil profile, topsoil is called the

A) A horizon.
B) B horizon.
C) C horizon.
D) parent material.
E) metamorphic quotient.

Question 57

What does too much water do to the soil?

A) depletes mineral nutrients
B) slows mineralization
C) interferes with plant growth
D) accelerates the breakdown of nitrates
E) All of these answers are correct.

Question 58

When a seed germinates, the part of the embryo that develops into the first root is called a radicle.

Question 59

Soil bacteria and fungi are important components of soil because they contribute to soil porosity and release useable minerals by decomposing organic matter.

Question 60

Which soil horizon is the most important agriculturally?

A) A horizon
B) B horizon
C) C horizon
D) D horizon
E) both B horizon and C horizon are correct.

Question 61

Plant root systems can detect and respond to gravity within 30 minutes to a few hours.

Question 62

Haustoria and mycorrhizae are two examples of tap roots.

Question 63

Casparian strips are composed primarily of suberin.

Question 64

Outer cells of the root cap secrete mucilage.

Question 65

Contractile roots are common in woody plants.

Question 66

The term saprophyte is correctly applied to plants such as orchids that grow on other plants and obtain water and nutrients from the air and/or rain.

Question 67

Grasses generally produce a fibrous root system.

Question 68

The function of mycorrhizae fungi is to facilitate uptake and availability of water and minerals, especially phosphorous.

Question 69

Natural grafting between roots of different trees of the same species is well known in the tropics.

Question 70

The vascular tissue of a new lateral (branch) root connects with the vascular tissue of the older root for continuous conduction of water and minerals.

Question 71

In dicot roots the xylem is formed in discrete patches.