Seedless vascular plants

Question 1

What is a stele?

Answer 1

central part of stems and roots containing vasculature

Question 2

What are the different arrangements of stele?

Answer 2

protostele = solid vasculature, no pith or leaf gaps

siphonophore = hollowed vasculature with central pith, sometimes leaf gaps

eustele = bundled vasculature surrounded by pith with no leaf gaps

Question 3

What are the different types of leaves?

Answer 3

not true leaves = no vasculature (ex. prophylls, leaf scales)

microphyll = single vascular strand

megaphyll = network of vascular strands

sporophyll = reproductive leaf containing sporangia

Question 4

What is the pericycle?

Answer 4

meristematic tissue in roots that grows lateral roots

Question 5

Where is the casparian strip located and what does it do?

Answer 5

• found in the endodermis (between cortex and pericycle)
• contains suberin
• regulates water entry

Question 6

What is the dominant life stage of vascular plants?

Answer 6

sporophyte

Question 7

What spore types are the following groups of seedless vascular plants?

a) club mosses/lycophytes
b) horsetails
c) true ferns
d) whisk ferns
e) spike moss (Selaginella)

Answer 7

a) homosporous
b) homosporous
c) homosporous
d) homosporous
e) heterosporous

Question 8

What is the difference between homosporous and heterosporous?

Answer 8

homosporous =
- all spores are identical in size
- produced by a single type of sporangia
- produces gametophytes with both antheridia and archegonia

heterosporous =
- has microspores (male, small) and megaspores (female, large)
- produced by microsporangia (male) and megasporangia (female)
- produces gametophytes with either antheridia or archegonia

Question 9

What part of the roots are included in steles?

Answer 9

• xylem
• pericycle
• phloem
• pith

Question 10

What three groups of plants are categorized under lycophytes?

Answer 10

• club mosses
• spike mosses
• quillworts

Question 11

What are rhizomes?

Answer 11

• branches of stem
• found in club moss and whisk ferns

Question 12

How are club moss sporangia arranged?

Answer 12

• above sporophyll (reproductive leaves)
• clustered in strobili (cones)
• spores formed via meiosis of sporocytes
• homosporous (identical spores)

Question 13

What type of stele do club mosses have?

Answer 13

protostele

Question 14

What gametophyte sexuality do club mosses produce?

Answer 14

bisexual

Question 15

What type of spores do spike moss (Selaginella) and quillworts (Isoetes) have?

Answer 15

heterosporous (distinct sporangia and differently sized spores)
–> microsporangia = microspores, megasporangia = megaspores

Question 16

Fill in the blank: all heterosporous plants must be ___

Answer 16

unisexual

Question 17

True or false: megaspores on spike mosses and quillworts disperse

Answer 17

false: too large to disperse, so female gametophytes stay in the megasporangium

Question 18

What plant groups are included in the pteridophytes?

Answer 18

• whisk ferns
• horsetails
• true ferns

Question 19

What features are on whisk ferns’ root-like system?

Answer 19

• rhizoids (anchoring)
• enations/prophylls

Question 20

What type of stele do whisk ferns have?

Answer 20

• protostele
• central stele surrounded by cortex (endodermis, ground tissue, epidermis)

Question 21

What type of spores do whisk ferns produce?

Answer 21

homospores (equal size)

Question 22

What gametophyte sexuality do whisk ferns produce?

Answer 22

bisexual (both antheridia and archegonia)

Question 23

Can whisk ferns reproduce without water?

Answer 23

no: requires water to allow sperm to swim from antheridia to archegonia

Question 24

What innovative trait do horsetails have over whisk ferns?

Answer 24

true root system (not just rhizoids)

Question 25

What are the parts of a horsetail's stem?

Answer 25

- internode - node - leaf/leaf sheath - branches (whorl)

Question 26

What type of stele do horsetails have?

Answer 26

eustele (eustele-like b/c of independent evolution)

Question 27

What are the names of the canals found in horsetails?

Answer 27

bigger canals = vallecular smaller canals = carinal

Question 28

What spore type and gametangia sexuality do horsetails have?

Answer 28

homosporous + bisexual

Question 29

Where are the sporangia found on horsetails?

Answer 29

on sporangiophores clustered into strobili structures

Question 30

How are horsetail spores dispersed?

Answer 30

using coiled elaters

Question 31

What are some differences between Lycopodium (club moss) and Selaginella (spike moss)?

Answer 31

club moss = homosporous and bisexual (makes both egg and sperm) spike moss = heterosporous and unisexual (one indiv. only makes one gamete)

Question 32

What type of leaves do the following plants have? a) true ferns b) whisk ferns c) club moss d) horsetails

Answer 32

a) megaphylls b) prophylls c) microphylls d) microphylls

Question 33

Where do true roots grow from in true ferns?

Answer 33

pericycle

Question 34

What are the different parts of a fern leaves?

Answer 34

pinnule = frond pinnae = smaller branches off pinnule rachis = midrib stipe = petiole (joins to stalk)

Question 35

What type of stele do ferns have?

Answer 35

siphonostele (with central pith), has leaf gaps

Question 36

Where are the sporangia found on ferns?

Answer 36

sporophylls (reproductive leaves)

Question 37

Define sori and indusium

Answer 37

sori = grouping of sporangia indusium = protective layer (extension of epidermis) over the sori

Question 38

What is the difference between true indusia, false indusia and no indusia?

Answer 38

true = forms in the middle of the leaf false = forms by leaves curling at the tips none = no covering at all

Question 39

What are the parts of a fern sporangia?

Answer 39

- annulus (thick outer wall) - stomium (openings of lip cells) - lip cells (thinner celled walls)

Question 40

How are fern spores dispersed?

Answer 40

- lip cells break down to form stomium openings - annulus contracts and flings spores out

Question 41

What gametangia sexuality are true ferns?

Answer 41

can be either unisexual or bisexual

Question 42

In what structures do the archegonia and antheridia form on fern gametophytes?

Answer 42

archegonia = from the central notch on the prothallus antheridia = close to the rhizoids on the prothallus

Question 43

Why are club moss spores so flammable?

Answer 43

very hydrophobic and have a high fat content