Deck 36: Roots and Mineral Nutrition

Question 1

Minerals move into endodermal cells via:

A) osmosis.
B) simple diffusion.
C) facilitated diffusion.
D) aquaporins.
E) active transport.

Answer 1

E

Question 2

The symplast:

A) greatly increases the surface area of the root.
B) is a waterproof band surrounding the endodermis.
C) is a continuum of living cytoplasm.
D) secretes suberin, which waterproofs the cells.
E) allows nutrient minerals to move against their concentration gradient.

Answer 2

C

Question 3

The difference between taproot and fibrous root systems is that a taproot system:

A) consists of many roots of the same size, while a fibrous root system has one main root with lateral roots.
B) consists of one main root with lateral roots, while a fibrous root system has many roots of the same size.
C) is characteristic of most monocots, while a fibrous root system is usually found in eudicots.
D) can be modified for storage, while a fibrous root system cannot.
E) is considered adventitious, while a fibrous root system is not.

Answer 3

B

Question 4

Which statement concerning the root epidermis is true?

A) It does not secrete a waxy cuticle over the root hairs.
B) It consists of protective tissue several layers thick.
C) It contains large intercellular spaces among the cells.
D) It comprises the bulk of the eudicot root.
E) It is the site of storage of surplus sugars produced in the leaves.

Question 5

The thick layers of cells covering and protecting the delicate apical meristem is called the:

A) root cap.
B) root hairs.
C) pericycle.
D) adventitious root.
E) radicle.

Question 6

The large intercellular spaces, common features of the root cortex, provide:

A) a pathway for water uptake.
B) aeration of the root.
C) structural support.
D) protection.
E) aeration and a pathway for water uptake

Question 7

Root hairs are:

A) flattened extensions of epidermal cells.
B) formed once in the area of cell maturation.
C) small in number.
D) located in front of the root tip.
E) short-lived.

Question 8

The center of a primary eudicot root is known as the:

A) phloem.
B) symplast.
C) cortex.
D) pericycle.
E) stele.

Question 9

Which of the following statements about the pericycle is false ?

A) It gives rise to branch roots.
B) It is a single layer of cells inside the endodermis.
C) It is composed of parenchyma cells.
D) Its cells lose their ability to divide upon maturation.
E) It is involved in the formation of lateral meristems.

Question 10

The ground tissue lacking in the primary eudicot root is:

A) pith
B) periderm
C) cortex
D) vascular cambium
E) pericycle

Question 11

A taproot system originates from an enlarging:

A) adventitious root.
B) lateral root.
C) root cap.
D) root hair.
E) radicle.

Question 12

Which layer of cells controls the movement of nutrient minerals entering the xylem in the root's interior?

A) endodermis
B) Casparian strip
C) epidermis
D) cortex
E) periderm

Question 13

Unlike eudicot roots, the center of most monocot roots is occupied by the:

A) cortex.
B) pith.
C) phloem.
D) vascular cambium.
E) xylem.

Question 14

One function of roots is:

A) the absorption of dissolved sugars for use by the plant.
B) photosynthesis.
C) the storage of food reserves.
D) sexual reproduction.
E) the production of micronutrients.

Question 15

Root hairs:

A) protect the delicate cells of the apical meristem.
B) help orient the root so it will grow downward.
C) increase the capacity of roots to absorb water.
D) are sparse and extremely long.
E) are located at each node on the root.

Question 16

The bulk of an herbaceous eudicot root consists of loosely arranged parenchyma cells in the:

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

Question 17

Which is the correct horizontal pathway of water from the soil to the center of the root?

A) epidermis → root hair → cortex → pericycle → endodermis → xylem
B) epidermis → cortex → pericycle → endodermis → phloem → xylem
C) root hair → epidermis → cortex → endodermis → pericycle → xylem
D) root hair → cortex → endodermis → pericycle → epidermis → xylem
E) root hair → epidermis → endodermis → cortex → xylem → phloem

Question 18

Which of the following statements about a root cap is false ?

A) It protects the delicate root apical meristem
B) It secretes lubricating polysaccharides
C) It orients the root that it grows downward
D) It loses cells during root growth.
E) It absorbs nutrients.

Question 19

The ____ is involved in forming the lateral meristems that produce secondary growth in woody roots.

A) endodermis
B) periderm
C) cortex
D) vascular cambium
E) pericycle

Question 20

The ____ is a single layer of parenchyma cells that give rise to muticellular lateral roots.

A) endodermis
B) periderm
C) cortex
D) vascular cambium
E) pericycle

Question 21

In the establishment of rhizobia in a legume, infection threads are found in the:

A) stele.
B) cortex.
C) root hairs.
D) xylem.
E) phloem.

Question 22

Which statement with regard to pore spaces is false ?

A) Minerals are removed from soil via leaching.
B) Water is held in the smaller pores, and air is found in the larger pores.
C) They occupy approximately 50% of a soil's volume.
D) They typically contain more carbon dioxide than found in the atmosphere.
E) Immediately after a heavy rain, most pore spaces remain filled with air.

Question 23

The tropical rainforest trees form shallow roots concentrated near the surface in a mat few centimeters thick. These swollen bases or braces are called:

A) prop roots.
B) pneumatophores.
C) aerial roots.
D) buttress roots.
E) velamen roots.

Question 24

Which of the following about soil with low pH is false ?

A) Aluminum is more soluble.
B) Calcium phosphate becomes less soluble.
C) Acidic soil can be found in Pygmy forest in California.
D) Potassium is leached more readily from the soil.
E) Manganese may be available in toxic concentrations.

Question 25

The partly decayed organic portion of soil is called:

A) silt.
B) clay.
C) sand.
D) humus.
E) castings.

Question 26

Prop roots are more common in:

A) annuals.
B) eudicots.
C) monocots.
D) epiphytes.
E) parasitic plants.

Question 27

Epiphytes have ____ that anchor the plants to the surface on which they grow.

A) pneumatophores
B) buttress roots
C) prop roots
D) aerial roots
E) root hairs

Question 28

Rhizobia help plants meet their ____ requirements by producing ____.

A) nitrogen; NH₃
B) phosphorus; PO₄
C) potassium; K₂O
D) nitrogen; NO₃
E) phosphorus; ATP

Question 29

The most abundant organisms in soil are:

A) earthworms.
B) fungi.
C) algae.
D) protozoa.
E) bacteria.

Question 30

Which list correctly orders soil particles in increasing diameter?

A) clay, sand, silt
B) clay, silt, sand
C) silt, sand, clay
D) silt, clay, sand
E) sand, silt, clay

Question 31

Legumes secrete ____ to attract rhizobial bacteria in low nitrogen soils.

A) cytokin
B) flavonoids
C) nod factors
D) calcium
E) water

Question 32

Plants connected by mycorrhizal fungi:

A) must be of the same species.
B) can only exchange carbon dioxide in one direction.
C) are an excellent example of a parasitic relationship.
D) compete for light.
E) exchange organic materials in both directions.

Question 33

Plants that are adapted to growing in flooded soils that are depleted of oxygen have:

A) aerial roots.
B) contractile roots.
C) pneumatophores.
D) prop roots.
E) buttress roots.

Question 34

Roots that arise from branches or vertical stems, and that are used to support a plant in an upright position, are referred to as:

A) prop roots.
B) contractile roots.
C) pneumatophores.
D) lateral roots.
E) tap roots.

Question 35

Which pair demonstrates a mutualistic relationship?

A) orchid and its host
B) rhizobia and strawberry plants
C) soil fungus and soil bacteria
D) mistletoe and its host
E) mychorrhizae and roots

Question 36

Figure 36-1 Use the figure to answer the corresponding question(s). Refer to the accompanying figure. During the development of secondary vascular tissues, which of the following structures is replaced by periderm?

A) 1
B) 3
C) 5
D) 6
E) 7

Question 37

What group of organisms fixes nitrogen?

A) bacteria
B) earthworms
C) fungi
D) protozoa
E) algae

Question 38

Figure 36-1 Use the figure to answer the corresponding question(s). Refer to the accompanying figure. The endodermis is the structure labeled as:

A) 3
B) 4
C) 5
D) 6
E) 7

Question 39

The ideal agricultural soil is:

A) loam.
B) silt.
C) sand.
D) clay.
E) dry.

Question 40

____ contain a waterproof fatty material called suberin.

A) Aquaporins
B) Casparian strips
C) Vascular cylinders
D) Vessel elements
E) Plasmodesmata

Question 41

The water balance problem of plants living in salty soil is the result of:

A) water moving out of plant roots by osmosis.
B) extensive leaching.
C) a low soil pH.
D) low concentrations of micronutrients.
E) excessive run off.

Question 42

Figure 36-2 Refer to the accompanying figure. Absorption of positively charged mineral ions by the root is facilitated by the movement of:

A) clay particles into the root hair.
B) water into the root hair.
C) protons into the root hair.
D) protons out of the root hair.
E) Mg⁺ out of the root hair.

Question 43

The formation of soil by gradually breaking rock into smaller particles by biological, chemical, and physical processes is known as:

A) erosion.
B) inorganic synthesis.
C) cation exchange.
D) salinization.
E) weathering.

Question 44

Diagram and label a cross section of a primary eudicot root. Identify the function of three of the labeled tissues.

Question 45

Explain how you would distinguish a monocot from a eudicot by looking at the anatomy of their roots.

Question 46

Which of the following statements about acid precipitation is false ?

A) It can decrease soil pH.
B) It is implicated in forest decline.
C) It drops sulfuric and nitric acids on the Earth.
D) It is caused by human activities.
E) It prevents the leaching of essential cations.

Question 47

Irrigation can cause salt to accumulate in the soil, a process known as:

A) erosion.
B) decomposition.
C) mineralization.
D) salinization.
E) weathering.

Question 48

Which element is correctly matched with its major function in plants?

A) phosphorus − alters membrane permeability
B) sulfur − essential part of chlorophyll
C) potassium − opens and closes stomata
D) carbon − maintains turgidity of cells
E) calcium − involved in nitrogen-fixation

Question 49

Sufficient ____ reduces soil erosion.

A) irrigation
B) soil fertilization
C) plant cover
D) weathering
E) limiting resources

Question 50

Figure 36-2 The process illustrated in the accompanying figure is known as:

A) humus formation.
B) weathering.
C) cation exchange.
D) soil erosion.
E) salinization.

Question 51

The two major factors that contribute to the weathering of rock are climate and:

A) inorganic minerals.
B) atmospheric carbon dioxide.
C) organisms.
D) aeration.
E) atmospheric oxygen..

Question 52

Cation exchange between soil particles and root hairs is the process in which:

A) protons are exchanged for positively charged mineral ions.
B) electrons are exchanged for positively charged mineral ions.
C) protons are exchanged for negatively charged mineral ions.
D) electrons are exchanged for negatively charged mineral ions.
E) water is exchanged for positively charged mineral ions.

Question 53

What three elements are most often limiting factors for plant growth?

A) carbon, potassium, and magnesium
B) carbon, oxygen, and nitrogen
C) hydrogen, magnesium, and oxygen
D) sulfur, calcium, and nitrogen
E) nitrogen, phosphorus, and potassium

Question 54

While working in a soil-testing laboratory, you are given a sample of a "typical" soil to analyze. Which of the following do you correctly conclude is present in the largest amount?

A) water
B) inorganic mineral particles
C) rocks
D) air
E) organic material

Question 55

What would be the consequence for the plant if it lacked Casparian strips?

Question 56

Which element is a macronutrient in plants?

A) sodium
B) calcium
C) manganese
D) zinc
E) copper

Question 57

Which element is a micronutrient in plants?

A) chlorine
B) hydrogen
C) potassium
D) calcium
E) magnesium

Question 58

Suppose a plant were grown in a nutrient solution containing all known essential elements except for a particular one in question. This would be an application of:

A) agriculture.
B) mutualism.
C) weathering.
D) hydroponics.
E) salinization.

Question 59

Water, wind, and ice are agents of:

A) erosion.
B) decomposition.
C) mineralization.
D) salinization.
E) soil pH.

Question 60

Which list of elements below is present in all biomolecules in plants?

A) sulfur, silicon, and calcium
B) oxygen, hydrogen, and carbon
C) chlorine, iron, and zinc
D) phosphorus, nitrogen, and carbon
E) potassium, oxygen, and magnesium

Question 61

The symplast is the continuum of living cytoplasm .

Question 62

Buttress roots help trees obtain oxygen from flooded soil.

Question 63

An example of a(n) micronutrient is phosphorus.

Question 64

The removal of dissolved materials from soil by percolating water is called illuviation .

Question 65

A root hair is an extension of a(n) endodermal cell.

Question 66

A typical soil is composed mostly of humus .

Question 67

A(n) adventitious root is one that occurs in an unusual location.

Question 68

Identify two plant macronutrients and two micronutrients and provide a physiological role for each.

Question 69

Hydroponics refers to the growing of plants in aerated water rather than soil.

Question 70

In woody plants, the root epidermis is replaced by periderm .

Question 71

The roots of certain epiphytes are photosynthetic.

Question 72

Differentiate between the following specialized roots.
A. prop root
B. buttress root
C. pneumatophore
D. storage root
E. photosynthetic root

Question 73

The outermost layer of the stele is the pericycle .

Question 74

Lateral roots arise from cells of the cortex .

Question 75

The portion of a mycorrhizal fungus that penetrates the cell walls of the root cortex is called a(n) arbuscule .

Question 76

Root hair development is under the control of two genes that code for transcription factors .

Question 77

Explain the process of soil formation by weathering.

Question 78

The nodules found in the roots of legumes characteristically contain mycorrhizae .

Question 79

The root cortex is composed mostly of collenchyma cells.

Question 80

Water flowing inward through the endodermis moves next into the pericycle .