29 Plant Diversity: How Plants Colonised Land Flashcards Preview

5 Evolutionary History of Biological Diversity > 29 Plant Diversity: How Plants Colonised Land > Flashcards

Flashcards in 29 Plant Diversity: How Plants Colonised Land Deck (151):
1

What organism have cell walls made of cellulose?

Green algae, dinoflagellates, brown algae and plants

2

Do algae have cell walls made of cellulose?

Yep

3

In what organisms are chloroplasts with chlorophyll a and b seems?

Green algae, euglenids, plants and a few dinoflagellates

4

What did land plants evolve from?

Charophyte algae.

5

What suggests that land plants evolved form charophyte algae?

They share 4 basic characteristics: rings of cellulose-synthesising proteins, peroxisome enzymes, similarly structured flagellated sperm and the formation of a phragmoplast.

6

How are charophyte algae similar to land plants in terms of rings of cellulose-synthesising proteins?

The cells of both land plants and charophytes have distinctive circular rings of proteins in the plasma membrane. These protein rings synthesize the cellulose microfibrils of the cell wall.

Noncharophyte algae have linear sets of proteins that synthesize cellulose.

7

How are charophyte algae similar to land plants in terms of peroxisome enzymes?

The peroxisomes of both land plants and charophytes contain enzymes that help minimize the loss of organic products resulting from photorespiration.

8

How are charophyte algae similar to land plants in terms of the formation of a phragmoplast?

In land plants and certain charophytes, a group of microtubules called the phragmoplast forms between the daughter nuclei of a dividing cell.

A cell plate then develops in the middle of the phragmoplast, across the midline of the dividing cell. The cell plate, in turn, gives rise to a new cross wall that separates the daughter cells.

9

What is a phragmoplast?

A group of microtubules that forms between the daughter nuclei of a dividing cell in plants and charophyte algae.

A cell plate develops in the middle of the phragmoplast and eventually becomes a cell wall.

10

How are the zygotes of charophytes protected form desiccation?

They are surrounded by a layer of a durable polymer called sporopollenin that prevents the exposed zygotes from drying out.

11

What is sporopllenin?

A durable polymer that surrounds the zygotes of charophytes to prevent them from desiccation.

12

What are the main challenges of life on earth?

-Need more structural support - note how jellyfish flops when out of water
-Desiccation
-Distribution of gametes.

13

What are land plants most closely related to?

Charophytes

14

What does ’viridiplantae’ refer to?

A proposed kingdom that would include chlorophytes, charophytes and embryophytes (land plants) but not red algae

15

What does ’streptophylta’ refer to?

A proposed kingdom that would include charophytes and embryophytes (land plants) but not red algae or chlorophytes

16

What are land plants also known as?

Embryophytes

17

What are embryophytes?

Land plants

18

What are the derived characteristics of land plants?

Alternation of generations & Multicellular, dependant embryos,

Walled spores produced by Sporangia

Multicellular gametangia

Apical meristems

19

Do algae have apical meristems?

No, this is a derived trait of land plants

20

In what organisms does alternation of generations occur?

In some algae but not charophytes (analogy)

Obviously in land plants etc.

21

What is the basic idea of alternation of generations in plants?

The multicellular haploid gametophyte produce haploid gametes (eggs and sperm) by MITOSIS that fuse during fertilisation, forming diploid zygotes.

To zygote undergoes mitosis to multicellular diploid sporophyte. Meiosis in a mature sporophyte produces haploid spores, eproductive cells that can develop into a new haploid organism without fusing with another cell.

Mitotic division of the spore cell produces a new multicellular gametophyte, and the cycle repeats

22

How do plant embryos differ from algae?

Multicellular plant embryos develop from zygotes that are retained within the tissues of the female parent (a gametophyte).

The parental tissues provide the developing embryo with nutrients, such as sugars and amino acids.

23

How does the plant embryo receive nutrients from the parent?

It has specialised ‘placental transfer cells’ to transfer sugars etc.

24

What are placental transfer cells?

Specialised cells found in the plant embryo to help it acquire nutrients from the parent

25

Why are plants called embryophytes?

They have multicellular embryos that are dependant on the parent.

26

What is unique about land plant spores?

They are walled and produced by sporangia

27

Where are land plant spores produced?

In multicellular organs called sporangia

28

What do sporangia produce?

Land plant spores

29

How are land plant spores produced?

Within a sporangium, diploid cells called sporocytes ('spore mother cells'), undergo meiosis and generate the haploid spores.

The outer tissues of the sporangium protect the developing spores until they are released

30

What structure within the sporangia forms the spores?

Sporocytes

31

What are sporocytes also know as?

'Spore mother cells'

32

What are spore mother cells?

Sporocytes

33

Where are gametes produced in land plants?

Gametangia

34

What are gametangia?

The multicellular organs in land plants that form gametes

35

What are the types of gametangia?

Archegonia and antheridia

36

What is archegonia?

The type of gametangia that produces female gametes (eggs)

37

What is antheridia?

The type of gametangia that produces male gametes (sperm)

38

What is the form of gametangia that produces male gametes?

Antheridia produces sperm

39

What is the form of gametangia that produces female gametes?

Archegonia produces eggs

40

What is a key adaptation of land plants to prevent desiccation?

A waxy cuticle

41

What were the roots of early land plants like?

Short and not well developed

42

How did early land plants survive with primitive roots?

They formed symbiotic relationships with mycorrhizae

43

What are ’secondary compounds’?

Products that are produced by plants from secondary metabolic pathways. These include alkaloids, terpenes, tannins and flavonoids which serve many purposes such as discouraging herbivores.

Note that secondary metabolic pathways are side branches of the primary metabolic pathways that produce lipids, carbohydrates and amino acids etc.

44

What are the products of ancillary metabolic pathways in plants called?

'Secondary compounds’

(note that ancillary metabolic pathways is not a technical term)

45

What are ’secondary metabolic pathways’?

Those that branch off from the primary metabolic pathways such as those that produce carbohydrates and amino acids.

46

What are ‘primary metabolic pathways’?

The basic ones that are fundamentally important for plant life. They include the synthesis of lipids, amino acids and carbohydrates.

47

Why are secondary compounds important to the plant?

Various alkaloids, terpenes, and tannins have a bitter taste, strong odor, or toxic effect that helps defend a plant against herbivores and parasites.

Flavonoids absorb harmful UV radiation, and some related compounds deter attack by pathogens.

48

What is is the most basal group of land plants?

Bryophytes

49

What are bryophytes?

Non-vascular plants

50

What are nonvascular plants called?

Bryophytes

51

What groups of organisms does bryophyte include?

Moss, liverworts and hornworts

52

What is a ‘grade'?

A group of biological organisms that share a key trait

53

What is a group of biological organisms that share a key trait called?

A 'grade'

54

What are vascular plants divided into?

'Seedless vascular plants' and 'seed plants'

55

What groups of plants are seedless vascular plants?

Lycophytes and Pterophytes

56

What group are lycophytes in?

Seedless vascular plants.

57

What organisms are lycophytes?

Club mosses, spike mosses and quilworts (not normal mosses)

58

What group are club mosses in?

Lycophytes and thus seedless vascular plants (not bryophytes)

59

What group are spike mosses in?

Lycophytes and thus seedless vascular plants (not bryophytes)

60

What groups of organisms are pterophytes?

Ferns, horsetails and whisk ferns

61

What groups of organisms are ferns?

Pterophytes and thus seedless vascular plants.

62

What groups of organism are seed plants?

Gymnosperms and angiosperms

63

What type of organism are gymnosperms?

Seed plants

64

What is the fundamental trait of gymnosperms?

They do not have enclosed chambers in which seeds mature

65

What is the fundamental difference between angiosperms and gymnosperms?

Angiosperms have enclosed chambers in which seeds mature, gymnosperms do not.

66

What are the steps in the reproductive lifecycle of a moss?

Spores develop into small threadlike haploid ‘protonemata’

The protonemata produce ”buds” that divide by mitosis and grow into gametophores.

The gametaphores of males produce sperm that travel in a film of moisture to reach the female egg, which remains in the archegonia of the female gametophore.

Fertilisation takes place in the archegonium of the female to produce a diploid zygote.

The zygote develops into the sporophyte embryo.

The sporophyte grows a long stalk (seta) that emerges from the archegonium.

Attached by its foot, the sporophyte remains nutritionally dependant on the gametophyte.

Meiosis occurs and haploid spores develop in the capsule. When the capsule is mature, its lid pops off, and the spores are released.

67

What is the capsule?

The organ at the end of the seta which consists of sporangium that produces spores.

68

What is the structure of a moss?

It has a root called a rhizoid, a “stalk” called the ’seta’ which terminates in the capsule

69

What is the seta of a moss?

Its “stalk"

70

What is at the end of a moss’s seta?

Its capsule

71

What is the “stalk” of a moss called?

Its seta

72

What are the “roots” of mosses called?

Rhizoids

73

How do mosses gain the water needed for life processes?

Not through their rhizoids

74

What is the role of rhizoids?

Anchoring

They lack specialised water conducting cells and thus do no play a primary role in water and mineral absorption

75

Why are rhizoids not heavily involved in mineral and water absorption?

They lack specialised water conducting cells

76

What is the structure of rhizoids?

Long, tubular single cells (in liverworts and hornworts) or filaments of cells (in mosses).

Unlike roots, which are found in vascular plant sporophytes, rhizoids are not composed of tissues.

77

What are the groups of bryophytes (common names)?

Liverworts, hornworts and mosses

Technical name:

78

What are the groups of bryophytes (scientific names)?

Hepatophyta, anthocerophyta and bryophyta

79

What are liverworts technically called?

Hepatophyta

80

What are hornworts technically called?

Anthocerophyta

81

What are mosses technically called?

Bryophyta

82

What does ’hepatophyta’ refer to?

The bryophyte phylum that consists of liverworts.

83

What does ’anthocerophyta’ refer to?

The bryophyte phylum that consists of hornworts.

84

What does ’bryophyta’ refer to?

The bryophyte phylum that consists of mosses.

85

What does ’thalloid’ refer to?

When describing plants it means that they do not have a distinct stem and leaves.

86

What is the structure of liverworts?

Many have liver shaped leaves (technically thalluses) that are the gametophytes.

In some the gametophore emerges and branches out like a little plan tree. Sporophytes dangle form this structure.

87

What is the structure of hornworts?

They are basically just tall tubes.

This sporophyte can grow up to 5 cm tall and consists entirely are sporangium, with no seta produced.

88

What structures make up the sporophyte of a moss?

The capsule and seta.

89

What does ’brood bodies’ refer to?

Some mosses reproduce asexually by forming brood bodies, small plantlets that detach from the parent plant and grow into new, genetically identical copies of their parent.

90

How are spores released from the capsule?

In most mosses, the seta becomes elongates to elevate the capsule. Typically, the upper part of the capsule features a ring of interlocking, tooth-like structures known as the peristome.

These “teeth” open under dry conditions and close again when it is moist. This allows spores to be discharged gradually, via periodic gusts of wind that can carry them long distances.

91

What are ‘peristomes’?

Teeth-like structures around the capsule that can be opened and closed to allow the controlled release of spores

92

What structure in the capsule allows spore release to be regulates?

The ‘periostomes'

93

Why are peristomes important?

They allow the spores to be slowly released.

They also allow the plant to control when they are released such. For example it is advantageous to release them during dry days with high winds.

94

In what organisms are stomata found?

Plants but also mosses and hornworts

95

Do mosses have stomata?

Yes

96

Do liverworts have stomata?

No

97

Do hornworts have stomata?

Yes

98

Why are stomata important for mosses and hornworts?

They support photosynthesis by allowing the exchange of CO2 and O2 between the outside air and the sporophyte interior

They also provide evaporative cooling

99

What is peat?

A large deposit of partially decayed organic material such as dead moss

100

What were the first tall plants?

Ferns and other seedless vascular plants.

101

What are the stages in the reproductive cycle of ferns?

Sporangia release spores. Most fern species produce a single type of spore that develops into a bisexual photosynthetic gametophyte.

Each gametophyte develops spermproducing organs called antheridia and egg-producing organs called archegonia.

Sperm use flagella to swim to eggs in the archegonia of a different gametophyte. An attractant secreted by archegonia helps direct the sperm.

Fertilisation occurs to produce a zygote that develops into a new sporophyte. The young plant grows out from an archegonium of its parent, the gametophyte.

On the underside of the sporophyte‘s reproductive leaves are spots called sori. Each sorus is a cluster of sporangia that produces spores through meiosis

102

What is the sporangium of ferns found?

In dots on the underside of the leaves called ’sori’ (singular: sorus)

103

What does ’sorus’ refer to?

The dots on the underside of a fern leaf that contain the sporangium (plural: sori)

104

What does ’sori’ refer to?

The dots on the underside of a fern leaf that contain the sporangium (singular: sorus)

105

What are the structures that produce spores in ferns called?

Sori (sing.: sorus)

106

What are the dots on the underside of ferns?

Sori (produce spores)

107

In ferns is the sporophyte or gametophyte dominant

Sporophyte

108

Are the large fern leaves sporophytes or gametophytes?

Sporophytes

109

What are the leaves of lycophytes called?

Microphylls

110

What are microphylls?

The small, usually spine-shaped leaves supported by a single strand of vascular tissue that are found only in lycophytes

111

What are most plant leaves?

Megaphylls (not microphyls)

112

What plants have megaphylls?

All plants except bryophytes

113

What are megaphylls?

Leaves with highly branched vascular systems.

114

What are leaves with highly branched vascular systems called?

Megaphylls

115

What are sporophylls?

Modified leaves that have sporangia

116

What are modified leaves with sporangia called?

Sporophylls

117

What are cones technically called?

Strobili

118

What are strobili?

Groups of sporophylls (leaves with sporangia) formed into cone-like structures.

119

What are sporophylls arranged into cone-like structures called?

Stroboli

120

How can seedless vascular plants be divided into based on the spores they produce?

Heterosporous or homosporuos.

121

What are homosporus plants?

Those that have one type of sporangium that produces one type of spore, which typically develops into a bisexual gametophyte,

122

What are heterosporous plants?

Those that have two types of sporangia and produces two kinds of spores.

Megasporangia on megasporophylls produce megaspores, which develop into female gametophytes

Microsporangia on microsporophylls produce the smaller microspores, which develop into male gametophytes.

123

What are the basic stages of homosporous spore production?

Sporangium on the sporophyll produces a single type of spore.

This spore develops into a bisexual gametophyte that produces eggs and sperm

124

What are the basic stages of heterosporous spore production?

Megasporangium on the megasporophyll produces megaspores that develop into female gametophytes that produce eggs.

Microsporangium on the microsporophyll produces microspores that develop into male gametophytes that produce sperm

125

What is megasporangium?

The tissue in heterosporous plants which produces megaspores

126

What is microsporangium

The tissue in heterosporous plants which produces microspores

127

What are microspores?

The spores produced by the microsporangium that develop into sperm-producing male gametophytes

128

What are sporophyls?

Leaves which contain spore-producing sporangium

129

What is a megasporophyll?

A leaf that contains megasporangium which produces megaspores

130

What is a microsporophyll?

A leaf that contains microsporangium which produces microspores

131

What are megaspores?

The spores produced by the megasporangium that develop into egg-producing female gametophytes.

132

What nutritional role do many lycophytes play?

Many are epiphytes

133

What do the lycophytes include?

Club mosses, spike mosses and quilworts

134

In what phylum are ferns?

Pterophyta

135

In what phylum are horsetails?

Pterophyta

136

In what phylum are whisk ferns?

Pterophyta

137

In what phylum are club mosses?

Lycophyta

138

In what phylum are spike mosses?

Lycophyta

139

In what phylum are quillworts?

Lycophyta

140

What is a protonema?

The thin filaments formed as mosses first emerge from spores.

141

What is the foot of a moss?

The part that connects it to the gametophyte (not to be confused with the rhizoid roots)

142

What is the part that joins the moss gametophyte and sporophyte?

The foot

143

What is the gametophyte form of a moss?

The tall green bits at the bottom

144

What is the sporophyte form of a moss?

The brown bits at the top that terminate in the capsule

145

Is the green bit of a moss the gametophyte or sporophyte?

Gametophyte

146

What is the ploidy of moss gametophytes?

Haploid

147

Are the brown bits at the top of the mosses gametophytes or sporophytes?

Sporophytes

148

What is the gametophyte form of a fern?

The small little disks that have rhizoids

149

Are the small disks the gametophyte or sporophyte form of ferns?

Gametophyte

150

What is the sporophyte form of ferns?

The large green leaves we are familiar with

151

Are the large green leaves of a fern the gametophyte or the sporophyte?

Sporophyte