Lecture 3

Question 1

what were some characteristics of early land plants

Answer 1

• remaining close to the substratum
• crowding of semi-aquatic habitats
• soil formation

Question 2

what did the early land plants need to have (evolve) protection from

Answer 2

• airy (dry) conditions

- UV radiation (photo-bleaching of pigments)

Question 3

how did early land plants change to evolve to conditions

Answer 3

• need for water (reproductive strategy changes)
• need for dormancy (propagules)
• protected cells (embryo-bytes)
• lignified walls for strength so they could grow upright

Question 4

what evolved as a result of plants coming out of water and onto land

Answer 4

lignified walls, roots, vasculature, stems/branching, leaves, flowers, fruits, seeds

Question 5

what did the rhyniophytes branch off to give rise to

Answer 5

lycophytes

Question 6

what are rhyniophytes

Answer 6

early vascular plants (ex. cooksonia caledonica)

Question 7

what type of branching did the rhyniophytes (early vascular plants) have

Answer 7

dichotomous branching

Question 8

what are the three types of branching

Answer 8

dichotomous, pseudomonopodial, monopodial

Question 9

what is protostele vs siphonostele

Answer 9

protostele has no pith and siphonostele has pith in the centre

Question 10

what is sporogenous tissue

Answer 10

spore generating tissue

Question 11

what is homosporous tissue

Answer 11

when the tissue gives rise to spores that all look and behave the same

Question 12

what is heterosporous tissue

Answer 12

when meiosis results in spores of two sizes and sexes

Question 13

what are the distinguishing features of lycophytes

Answer 13

• lateral sporangia
• exarch protostele
• microphylls
• heterosporous
• presented by only 5 genera

Question 14

what are microphylls

Answer 14

like leaves, flaps of photosynthetic tissue with only one vein
- thin vasculature

Question 15

what are megaphylls

Answer 15

flaps of photosynthetic tissue with branching veins

- increasingly vascularized

Question 16

what is lateral sporangia

Answer 16

when the sporangia or spore producing structures are located on the sides of a stem

Question 17

what to micro and megaspores lead to

Answer 17

micro and megagametophytes

Question 18

what is an exarch protostele

Answer 18

metaxylem on the outside and protaoxylem on the inside layers

Question 19

what are lycopodium

Answer 19

genera of lycophytes

• genus of clubmosses
• isosporus
• spores clustered into club shaped strobili
• gametophytes are subterranean and associate with mycorrhizae

Question 20

what are microsporophylls vs megasporophylls

Answer 20

microsporophylls are male and megasporophylls are female sporangia

Question 21

what are equisetum

Answer 21

• horsetails

Question 22

what do ferns have

Answer 22

• rhizomes
• green fronds
• spores clustered in sori
• prothalli as gametophyte
• asexual reproduction

Question 23

what is a prothallus and how is it made

Answer 23

the gametophyte, created from spores that fall onto the ground

Question 24

what is the indusium

Answer 24

umbrella like covering over the sorus

Question 25

what are sori

Answer 25

clusters of spores, position and location of sori is used to distinguish between ferns

Question 26

what is the megasporangium of the ovule

Answer 26

2n, gives rise to and contains the egg

Question 27

what is the functional megaspore of the ovule

Answer 27

haploid n, the egg

Question 28

what is the integument ovule

Answer 28

the covering over the ovule, hard covering

Question 29

what is a seed

Answer 29

unit of perennation and dispersal in spermatophytes formed by ovule maturation after fertilization

Question 30

what is a spermatophyte

Answer 30

a seed producing plant

Question 31

are spermatophytes homosporous or heterosporous

Answer 31

heterosporous

Question 32

what is pollen

Answer 32

microspore containing a microgametophyte (male) that is transferred passively to the megagametophyte via pollination

Question 33

what is the ovule

Answer 33

structure that combines integuments, megagametophyte and nucellus

Question 34

what is the carpel

Answer 34

consists of the stigma, style, ovary - develops into ovules which develop into seeds after fertilization - the rest of the carpel develops into a fruit

Question 35

describe the gymnosperms

Answer 35

vascular land plants with naked (gymnosperms) seeds, use special reproductive structures called cones, pine leaves

Question 36

what is a cone

Answer 36

modified branch with woody, scale like leaves (sporophylls)

Question 37

what are sporophylls

Answer 37

woody scale like leaves on male pinecones

Question 38

what are ovuliferous scales

Answer 38

on female pinecones

Question 39

describe ovuliferous scales

Answer 39

have two exposed/naked ovules on the upper surface and a subtending sterile bract

Question 40

describe the inside of the male cone

Answer 40

microangiospores have microspore mother cells that produce 4 haploid spores after meiosis

Question 41

how do microspores develop in male cones

Answer 41

the develop into a winged pollen grain which contains two prothallial cells, a generative cell and a tube cell

Question 42

when does pollen shedding of gymnosperms occur

Answer 42

in spring (sulphur showers)

Question 43

what is a spermatogenous cell

Answer 43

a sperm body cell

Question 44

are gymnosperms gametophyte or sporophyte dominant

Answer 44

sporophyte

Question 45

how are the ovules placed in gymnosperms

Answer 45

- they are exposed and the pollen grains reach the egg passively - embryo develops relatively sheltered but is easily dislodged by animals

Question 46

are angiosperms sporophyte or gametophyte dominant

Answer 46

sporophyte

Question 47

do flowers have sterile or fertile components or both

Answer 47

both

Question 48

how is the sperm cell delivered to the egg cell

Answer 48

via pollen tube formation

Question 49

what do carpels contain and what do they do

Answer 49

stigma, style and ovule - stigma and style develop into the fruit - ovule develops into seeds

Question 50

what is the name for "closed flowers" (ones that are self pollinating

Answer 50

cleistogamous

Question 51

what is the name for cross pollinating plants

Answer 51

chasmogamous

Question 52

what does anemophilous describe

Answer 52

cross pollination by wind

Question 53

what does entomophilous describe

Answer 53

cross pollination by insects (ex bees)

Question 54

what does zoophilious describe

Answer 54

cross pollination by vertebrates (ex birds)

Question 55

what is the visual difference between cleistogamous and chasmogamous flowers

Answer 55

cleistogamous flowers do not involve pollinating agents or have nectar and elaborate showy petals

Question 56

what are phyllomes

Answer 56

vegetative leaves

Question 57

what does it mean that a structure is a determinate structure

Answer 57

it is a final structure

Question 58

what is unique about nymphaea (water lily)

Answer 58

there is a gradual transformation of petals to stamens, and filaments of outer stamens actually appear petalloid

Question 59

distinguish between gynoecium and androecium

Answer 59

gynoecium is the female reproductive parts of flowers, androecium is the male parts

Question 60

what is corolla plural for

Answer 60

petals of a flower

Question 61

what is the calyx

Answer 61

plural for the sepals of a flower

Question 62

what is a perianth

Answer 62

the corolla (petals) and calyx (sepals) collectively

Question 63

what is a tepal

Answer 63

when perianth (corolla/petals and calyx/sepals are not distinguishable

Question 64

what is the difference between actinomorphic and zygomorphic flower symmetry

Answer 64

actinomorphic means it exhibits radial symmetry and zygomorphic means it exhibits bilateral symmetry (only divides equally into one plane)

Question 65

what is special about scaevola taccada

Answer 65

the flowers look like only half a flower (like half the petals are picked off) which means it exhibits unique symmetry