Plants I Flashcards
another name for land plants
embryophytes
Groups within Plantae
- Glaucophytes
- red algae
- green plants
- streptophytes
- embryophytes
- vascular plants
- seed plants
- flowering plants
glaucophytes
- just chl a
- chloroplast with peptidoglycan
- some with no cell wall
- some with cellulose
red algae
- chl a
- phycobilins
- complex life cycle
- no flagellated cells
- cellulose cell wall
green plants
- chl a and b
- starch
- includes all green algae and land plants
- cellulose cell walls
streptophytes
plasmodesmata
- apical growth
- phragmoplast
- sporopollenin
- charophytes and land plants
embryophytes
oogamous
- sporic meiosis
- land plants
vascular plants
vascular tissue
seed plants
seeds and pollen grains
flowering plants
fowers and double fertiliztion to make endospores
Green algae
- which chlorophylls?
- which groups are part of it?
- degree of diversity
- what kind of reproduction?
- what type of gametes?
-most aquatic protists with chl a and b
-chlorophytes = not related to land plants (most green algae)
-charophytes = closely related to land plants
VERY diverse
- gametic, sporic, and zygotic meiosis
-oogamous, isogamous, and anisogamous
Chlorophytes
- core group has species that form a phycoplast during cell division
- system of microtubules parallel to plane of division
- nuclear envelope persists
- spindles disappear
Charophytes
-advances groups form a phragmoplast during cell division
-a system of microtubules outside the spindle and parallel to plane of division
-nuclear envelope breaks down
-spindles persist
-cell plate is formed
(chara, spirogyra, coleochacte) (land plants have it too)
Chlamydomonas
- chlorophyte
- haplontic
- zygotic meiosis
- isogomy
- flagellated zoospores can function as asexual propagules or gametes
Volvox
- chlorophyte
- colonial
- connected haploid flagellated vegetative cells
- asexual daughter colonies form from specialized gonidia –> eventually move inside parent colony
- sexual reproduction occurs when gonidia turn into egg- and sperm-producing structures = zygotic meiosis
ulva
- chlorophyte
- marine parenchymatous green algae
- sporic meiosis
- isogamous
- alteration of generations
-sporangia in sporophyte produces + OR - spores which grow into + OR - gametophytes
Coleochaete
- Charophyte
- parenchymatous
- retained egg and zygote which undergoes immediate meiosis after release (zygomatic meiosis)
- specialized multicellular structures for holding gametes (gametangia)
- sporopollenin in zygote covering
Chara
-charophyte parenchymatous -zygotic meiosis -branching apical growth -nodes and internodes -plasmodesmata -entire covering of egg
spyrogyra
- charophyte
- spiral shaped chloroplast
- “sexually” reproduces thru conjugation
- contents of 1 filament goes into the other
- filaments are haploid
What were the earliest plants to diverge from charophytes?
How do we know?
- They were similar to nonvascular plants –> liverworts
- we know bc of DNA sequencing
What is the sister to all land plants?
liverworts
Earliest plants? Earliest vascular plants?
- 470 mya (nonvascular)
- 425 mya
Traits of early land plants
- alteration of generation
- oogamous
- apical growth
- motile sperm (carry over from aquatic life cycle)
- internal conductive tissue (hydroids/leptoids or X/P)
Adaptations to terrestrial habitats
- MULTICELLULAR jacket of cells surrounding gametangia and sporangia for protection
- zygote and embryonic sporophyte protected in maternal tissue
- spores contain sporopollenin
- internal vascular system
Nonvascular plants
- are they monophyletic?
- what are the phyla?
- What’s their tissue like? any conductive structures
- Which is the dominant stage?
- any other traits?
- not monophyletic
- hepatophyla = liverworts = most basal
anthocerophyta = hornwort
bryophyla = mosses - all parenchymous. Mosses have hydroids and leptoids
- Gametophyte is dominant and sporophyte is dependant
- some have cuticles or stomates (land plants)
Liverworts
- why are they called that?
- what are the 2 “types”?
- Describe the thallus
- what do gemma cups do?
- any other traits?
- they look like liver tissue
- leafy and thallose
- dorsiventrally flattened = dorsal side w/ pores and ventral side w/ rhizoids and scales
- asexual reproduction
- no cuticle/stomata
Marchantia polymorpha
- describe its anatomy
- describe its distribution
- describe its reproductive organs/methods
- what’s the placenta?
- what are elators?
- thallose tissue with gemma cups
- worldwide
- female gametophytes make archegonia on under-surface of archegonial heads on archegoniophores
——males do the same with antheridia
motile sperm fertilizes egg and growing sporophyte grows out of the gametophyte - connection point bt gametophyte and sporophyte where sporophyte gets food
- green/blue strands in the sporophyte that absorbs water
Moss vasculature
- hydroids and leptoids in both gametophyte and sporophyte
- hydroids and leptoids function the same as x and p
- similar genes control vascular dvlpmnt in mosses and vascular plants
- lignified vscular tissue derived from nonlignified ancestral tissue
Moss reproduction
- dominant life stage
- male and female reproductive structures
- asexual reproduction
- spores
1-dominant gametophyte; sporophyte = non green and short lived
2-male gametophytes make antheridia at apices (motile sperm)
-female gametophytes make archegonia at apices (fertilization takes place at base of archegonia)
3-asexual reproduction by fragmentation (but some have gemmae)
- spores germinate to make short-lived protonema that eventually produce buds to form an upright, leafy gametophyte
Recent discovery in moss
peptidoglycan in chloroplasts of model moss, physcomitrella
Polytrichum commune
-“hairy cap moss”
moss other structures
stomata and cuticles only on sporophytes
Hornworts
- gametophytes
- sporophytes
- vascular structures
- cell structure
- example organism
- looks like thallose liverwort
- photosynthetic, but still dependent of gametophyte for water and minerals –> exhibits intermediate growth and can become independent
- hint of hydroids/leptoids and stomates/cuticles on sporophytes
- big central chloroplasts with pyrenoids (very algal)
- anthoceros
