Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO203 > Secondary growth and water relations of the cell > Flashcards

Secondary growth and water relations of the cell Flashcards

1
Q

Why don’t plants fall over as they increase in height?

A

Compensate for increased height by adding bulk and strength to their stems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is lateral/secondary growth concerned with?

A

Increasing plant girth and strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the purpose of primary growth?

A

Establishing the architecture of the plant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

where is primary growth from?

A

Root apex and shoot apex,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which meristems are associated with primary growth?

A

SAM and RAM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What meristem is associated with secondary growth?

A

The cambium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the pattern of tissue as you move further down from the SAM?

A

Tissue gets older as you move further down from the SAM.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When does metaxylem form?

A

After the tissue/organ it is associated with has completed growth/elongation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does water move in and out of the metaxylem.

A

The metaxylem has perforations that allow for water movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of tissue is wood?

A

Secondary xylem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain why wood is so light even though it is so strong.

A

Wood is mostly air. Tough tubes with mainly air inside.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the main difference between the xylem of gymnosperms and the xylem of angiosperms?

A

Xylem of gymnosperms only has tracheids. The xylem of angiosperms contains both tracheids and vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does secondary growth occur?

A

By the addition of new xylem and phloem to the primary stem to make a secondarily-thickened stem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Provide examples of plants that undergo secondary growth.

A

Trees, shrubs (woody dicots)
conifers (gymnosperms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do meristems add to girth?

A

mainly lateral divisions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Is this picture an image of primary or secondary growth? Identify the names of the labels.

A

Primary growth
A = phloem
B = (pro)cambium
C = xylem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where does primary growth occur?

A

In the vascular bundles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does secondary growth start?

A

A new meristem is introduced between the vascular bundles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is interfascicular cambium?

A

Meristem that arises between vascular bundles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is fascicular cambium?

A

The meristem inside the vascular bundles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the cambial ring?

A

Eventually the cambial cells unite to form a ring of meristematic tissue within the stem. These cells eventually differentiate to form rings of secondary xylem and phloem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are initials?

A

Meristematic cells that can give rise to other cell types.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does the addition of new cells do to the meristem?

A

Addition of new cells pushes the circumference of the meristem out.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Give a general of radial growth in the meristem.

A

Cell of vascular cambium divides -> one cell differentiates into xylem, one stay meristematic -> division -> one cell differentiates into phloem, the other remains meristematic -> divisions and differentiation continue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How do cambial cells add xylem or phloem?

A

Cambial cells divide in longitudinal periclinal fashion. Gives rise to either 1 phloem cell + 1 initial or 1 xylem cell + 1 initial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How do initials add to the vascular cambium? Why do they do this?

A

To add to vascular cambium, initials divide anticlinally. They do this to compensate for increasing girth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where is the cambium located?

A

Between xylem and phloem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Is this an image of an angiosperm or gymnosperm? How can you tell?

A

Angiosperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Locate the cambium, xylem and phloem in this image.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How old is this tree? How do you know?

A

3 because there are three rings of xylem present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Does this wood belong to an angiosperm or a gymnosperm? How do you know?

A

Gymnosperm because there are no vessels present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the red arrows pointing to? What do these things do?

A

Resin ducts/canals are toxic and help protect against microbial growth and predators. They can also turn into amber.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Outline the general transition from primary to secondary growth.

A
  1. Isolated procambial strands begin to differentiate.
  2. Primary xylem and phloem form
  3. Cambial ring forms, secondary growth commences
  4. Cork cambium and periderm develop
34
Q

How does secondary growth change based on the season?

A

Slower growth in autumn and winter than in spring and summer.

35
Q

What kind of information do annual rings provide us with?

A

Rate of growth, amount of lignification

36
Q

What are possible explanations for figured wood?

A

Mutations; bacteria that invade plant genome (plant cells grow like crazy, producing substances only bacteria can consume)

37
Q

What is the function of vascular rays?

A

Transport substances in and out of xylem rings; storage to support cambial growth after winter.

38
Q

How is the xylem of heartwood characterized?

A

Xylem is no longer functional

39
Q

How is the xylem of sapwood characterized?

A

Most likely still functional (more likely the closer you get to cambium); unlignified.

40
Q

What do fusiform cells produce?

A

Elements of secondary xylem and phloem

41
Q

What do ray initials give rise to?

A

Rays

42
Q

What are the two cell types in the vascular cambium?

A

Fusiform initials and ray initials

43
Q

What type of cells are ray cells?

A

Living parenchyma

44
Q

WHich is more abundant, secondary xylem or secondary phloem?

A

Secondary phloem.

45
Q

What is the function of lenticels?

A

Allow entrance of oxygen to outer cells inside the bark.

46
Q

Where do lenticels generally arise?

A

Where stomata were present on the primary stem.

47
Q

Do monocots have secondary growth?

A

No, only eudicots.

48
Q

How is the woody characteristic achieved in monocots?

A

Extensive primary thickening, especially in leaf bases; phloem remains active for longer periods of time

49
Q

Which cells are active in secondary phloem?

A

Only the youngest. The rest are crushed.

50
Q

Where does the cork cambium arise?

A

Below epidermis.

51
Q

WHat does the cork cambium give rise to?

A

Outer bark

52
Q

List some reasons why water is important to plants.

A
  • Hydrates cell contents, acts as a solvent
  • Participates in biochem reactions
  • Medium for transport of solutes
  • Maintains shape
  • Needed for cell expansion and growth
  • Cooling
53
Q

How much of the water that enters through the roots is transpired?

A

> 99%

54
Q

What causes wilting?

A

Leaf having less than the full amount of water they can have

55
Q

Why might some leaves wilt and others not in a plant?

A

a) Doesn’t have enough water and is allocating water to areas where growth is most important
b) Has enough water but some factor (such as infection) is preventing movement of water to certain areas.
c) Too much water in soil (kills/reduces function of root system)

56
Q

How can plants regulate temperature?

A

Evaporative transpiration used for cooling (like sweating)

57
Q

How do cells elongate?

A

Water entering cell and then into vacuole, weakening cell wall, expanding cell wall.

58
Q

Why can plant cells grow so quickly?

A

Elongation essentially just happens due to water. Don’t require as much new cytoplasm to be produced, thus requiring less energy.

59
Q

What regulates the loosening of the cell wall, etc. during elongation?

A

Cytoskeleton, specifically microtubules and actin. Direct enzymes used.

60
Q

How do you calculate the water content of a tissue/organ/plant?

A

Fresh weight - dry weight
= (water + cell wall weight + cell content weight) - (cell wall weight + cell contents)

61
Q

What is osmosis?

A

Movement of water across cell membrane according to relative concentrations of dissolved substances inside and outside cell.

62
Q

How do cells enable osmosis?

A

Selective membrane permeability

63
Q

WHy is the cell wall necessary in plants in relation to water?

A

Able to resist pressure, prevents cell from bursting.

64
Q

What are the two selectively permeable membranes located in plant cells?

A

Plasma membrane and tonoplast

65
Q

What do aquaporins do?

A

Aid in faster movement of water across membranes

66
Q

What is water potential? What is the variable used to denote it?

A

The chemical potential of water, referred to as psi.

67
Q

What is the psi of distilled water in an open glass container at sea level?

A

0

68
Q

In which direction does water move?

A

From high water potential to low water potential

69
Q

What happens to psi when solutes are added to water?

A

It is lowered because energy is used to dissolve said solutes

70
Q

What is the osmotic potential of water? What represents it?

A

Difference between potential of pure water and water plus solute. Represented by psi pi.

71
Q

How does increasing pressure affect psi?

A

Increases because energy is gained with added pressure.

72
Q

What is the pressure potential? What is it denoted by?

A

Difference between potential of pure water and water under pressure. Represented by psi p.

73
Q

Is positive or negative pressure used during transpiration?

A

Negative; water being ‘sucked up’

74
Q

What is the water potential equation?

A

osmotic potential + pressure potential (+ possibly psi m)

75
Q

When is dynamic equilibrium reached in the cell?

A

when psi pi = psi p, water potential of cell = 0. Occurs in fully hydrated cell

76
Q

What is the wilting point?

A

When water potential is equal to osmotic potential, pressure potential = 0

77
Q

What unit is psi expressed in?

A

MPa

78
Q

What is the matrix potential?

A

Potential to absorb water, psi m

79
Q

Is the matrix potential positive or negative? Why?

A

Negative, water loses energy when absorbed.

80
Q

When is matrix potential significant?

A

In dry plants/parts and drought situations

BIO203 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions