6. Chapter 35.1: Roots, Stems and Leaves

Question 1

What type of root system does monocots have? What about eudicots?

Answer 1

1. Fibrous root systems: consist of a mat of thin roots

2. Taproots, one large vertical taproot produces many small lateral roots; often store food.

Question 2

Describe five characteristics of monocots.

Answer 2

1. one cotyledon (can’t rip apart; think corn)
2. veins usually parallel
3. vascular bundle (primary tissue) usually complexly arranged
4. fibrous root system
5. floral parts usually in multiples of three

Question 3

Describe five characteristics of eudicots.

Answer 3

1. two cotlyledons (think peanuts and beans)
2. veins usually netlike (network)
3. vascular bundle (primary tissue) arranged in ring
4. taproot usually present
5. floral parts usually in multiples of 4 or 5

Question 4

List two examples of modified roots and their adaptation.

Answer 4

1. aerial roots: help to support, attach to other structures

2. prop roots: help supports tall stems

Question 5

What are the function of tiny root hairs?

Answer 5

increase the surface area enormously for nutrient and water absorption

Question 6

What do shoots consist of?

Answer 6

Stems and leaves

Question 7

What is stem a system of?

Answer 7

Nodes and internodes

Question 8

Where is the growth of a young shoot usually concentrated at?

Answer 8

Terminal bud

Question 9

What can modified stems be mistaken for? List three examples of modified stems and their adaptation.

Answer 9

Mistaken for roots.

1. Stolons: “runners” of strawberry; on surface; enable asexual colonization
2. Tubers: potatoes; swollen rhizomes; food storage
3. Bulbs: gladiola corn, underground shoots; store food

Question 10

What are the main photosynthetic organs?

Answer 10

Leaves and green stems

Question 11

What do plant taxonomies use to categorize?

Answer 11

leaf shape, spatial arrangement of leaves and patterns

Question 12

Give some examples of leaves that have adapted for other functions.

Answer 12

1. tendrils
2. spines of cacti
3. water storage modification
4. brightly coloured leaves

Question 13

What are the three tissue systems that plants have?

Answer 13

1. the epidermal
2. vascular
3. ground (cortex and pith)

Question 14

Define epidermis. What does it secrete?

Answer 14

a single layer of tightly packed cells that covers and protects the plant. (Secretes waxy coating, the cuticle)

Question 15

What is the function of the vascular tissue? What is it composed of?

Answer 15

1. is involved transport
2. composed of xylem, conveys water and dissolved minerals and phloem, transport food made in mature leave to non-photosynthetic parts.

Question 16

In eudicot stems, what is the ground tissue divided into? What is the function of the ground tissue?

Answer 16

1. pith and cortex

2. photosynthesis (i.e. buttercup), storage, and support

Question 17

How does plant growth and animal growth differ?

Answer 17

Plants demonstrate indeterminate growth (grow as long as they live), animals cease to grow after they reach a certain size.

Question 18

How long is the life cycle of annual plants? Examples?

Answer 18

complete in a single year or less (from germination to seed production to death; cereals, legumes and grains)

Question 19

What is the life span of biennial plants?

Answer 19

Two years: Growth season and flowering season.

Question 20

What are plants that live many years called? (i.e. trees)

Answer 20

Perennials

Question 21

Where are apical meristems located? What is its function?

Answer 21

located at the tips of roots and shoots, supply cells for plant to grow in length. This elongation, primary growth, enables roots and shoots to extend their exposure.

Question 22

What is secondary growth?

Answer 22

Progressive thickening of roots and shoots (thicken and strengthen older plant each season: i.e. Woody plants)

Question 23

Describe stomata

Answer 23

tiny pores flanked by guard cells that interrupt the epidermal barrier

Question 24

What are the cells in the ground tissue of the leaf equipped with?

Answer 24

1. Chloroplasts for photosynthesis.
2. In many dicots, columnar palisade parenchyma cells life over spongy parenchyma (Sponginess allows CO2 and O2 to circulate)

Question 25

What does the vascular cambium produce?

Answer 25

1. Secondary xylem and secondary phloem.
2. Secondary xylem accumulate to produce wood.
   (In temperate regions, perennial plants ceases during winter producing annual growth rings)

Question 26

List the cross-section of a tree from the centre outwards.

Answer 26

Pith -> primary xylem -> secondary xylem -> vascular cambium -> secondary phloem -> primary phloem -> cortex -> epidermal layer -> bark

Question 27

What are the functions of guard cells?

Answer 27

1. control size of stomata

2. help balance plant’s need to conserve H2O with its requirements for photosynthesis

Question 28

What climates have xerophytes adapted to? How?

Answer 28

arid climates

• small thick leaves reduce surface are relative to volume
• spines or scales for protection
• stomata concentrated in depressions that shelter pores from dry winds
• “hairs” break up flow of air
  (i. e. oleander)

Question 29

What adaptations has the water lily adapted to?

Answer 29

1. Big air pockets (buoyancy)

2. Openings were at the top

Question 30

The is the Greek meaning for the word ‘hormone’? What do hormones do?

Answer 30

“to excite”- chemical signals that trigger responses in target cells and tissues. (Minute quantities induce substantial change)

Question 31

What is tropism? What are the two types? Example?

Answer 31

• Any growth response that results in growth toward or away from stimuli.
• Positive phototropism, gravitropism
• grass seedling curves toward light (cells on darker side elongate faster than brighter side)

Question 32

What is the hypothesis of auxin?

Answer 32

an symmetrical distribution of auxin moving down from tip causes cells on darker side to elongate (tip senses, below tip grows)

Question 33

List some other major classes of plant hormones.

Answer 33

gibberellins (stem elongation), juglone (inhibit fungal spores from germinating)