bis2c plants

algae

early-diverging aquatic plant lineages.
low diversity

glaucophytes

freshwater, unicellular algae that retain a layer of peptidoglycan in the chloroplast
they use the same photosynthetic pigments as cyanobacteria (chlorophyll a)

red algae

are diverse, mostly marine, multicellular, variety of industrial uses: sushi nori
bacteria are good at digesting this. Humans cannot digest this. However, the Japanese population has had LGT in their microbiome that allows them to digest this.

green plants

multiple lineages of "green algae" and Land plants. They use chlorophyll b and store energy as starch inside their chloroplast.

streptophytes

share a unique form of cell division and retention of the egg on the parent plant
twisted flagellar bases
plasmidesmata

diplontic life cycle

have a multicellular diploid adult state (animals)

haplontic life cycle

lack a multicellular diploid (2n) stage. (algae)

embryophytes (land plants)

both a multicellular haploid and a multicellular diploid stage
synapomorphies are directly tired to the transition from water to land

alternation of generations

Byrophytes

non-vascular plants
lack vasculature, so they use rhizoids and distribute water through diffusion
live mostly in cool most habitats.
smaller than your thumb
includes: liverworts, mosses, hornworts
paraphyletic group
specialized structures: sporangia, gametangia
swimming sperm, only reproduce when conditions are wet

vascular plants

include: lycophytes, monilophytes, and seed plants

stoneworts (Chara)

are freshwater algae and often living at the edges of land and water
specialized reproductive cells and grow in branched filaments
fish tank plant

Modifications for land

protected embryo,
cuticle,
multicellular sporophyte,
gametangia,
thick-walled spores,
alternation of generations

lycophytes

superficially resemble some ferns, but lack sori and have strobili (cones)
are vascular plants that have true roots, are sporophyte dominant, and have microphylls. They do NOT produce seeds
have an extensive fossil record and formed large forested that were metamorphosed into coal deposits
1st evolution of heterospory in land plants

monilophytes

ferns + relatives

gymnosperms

cycads, Ginkgo, Gnetophytes, and Conifers
make seeds, have strobili, and do not make flowers

angiosperms

flowering plants
90% of plant diversity
characterized by flowers, double fertilization, and vessel elements
most lineages arose rapidly. earliest groups were small, inconspicuous, and uncommon in the fossil record
correlated to the diversity of insect groups

which feature below distinguishes diplontic life cycle from the haplontic life cycle?

multicellular, diplonic adult stage

how early plants lived?

alternation of generations, air dispersed spores, antheridia and archegonia, sporangia

T/F spores are distinguished from gametes by their ploidy

False

spores

are haploid cells (n) that grow into gametophytes (n) via mitosis

sporangia

specialized structures in bryophytes used for spore dispersal

archeongia

houses the egg in bryophytes

anteridia

houses the sperm in bryophytes

why are bryophytes restricted in size?

the lack lignin and an efficient vascular system

liverworts

characterize by having flat, 2-D growth called thallus. two body types: thallose & leafy

liverwort life cycle

a short, stalked gametophyte with small sporophyte.

mycorrhizae

are fungi that associate with the roots of land plants.
they are also present on the rhizoids of bryophytes
they increase the surface area and allow for greater water absorption

mosses

have taller, 3D growth with a sporophyte on a elongate stalked structure
teeth like structures
two unicellular haploid structures fro reproduction in alternation of generations

hornworts

persistently green sporophyte with indeterminate growth

why is the evolution of a persistently green sporophyte important?

continuous photosynthesis

what is required for a transition from a moss to a large, vascular plant like a tree?

lignified tracheids
branched roots
controlled stomata
loss of swimming sperm

what are synapomorphies of vascular plants?

lignified vessels, true roots, and independent sporophyte

what was the fundamental change in the sporophyte in the transition from non-vascular plants to vascular plants?

the separation of the sporophyte and the plant, lead to a larger sporophyte which has more spores leading to more plants and more dispersal.

the REDUCTION of the gametophyte is important evolutionary trend

rhyniophytes

are an extinct lineage of early vascular plants with dichotomously branched sporophyte and simple sporangia. the lack true roots and leaves, but have vasculature

xylem

conducts water
elongate and connected by pits
dead at maturity
secondary xylem is wood
produced by the bifacial vascular cambium

phloem

conducts photosynthate
it is alive at maturity and composed of two parts
1. sieve tube elements
2. companion cells
have no organelles hence the companion cells that regulate function

tracheids

first type of xylem tissue to evolve, they transport water.

more xylem--\>

more woody

vessel elements

evolved later, are larger and more efficient, but only occur in seed plants

strobilus

clusters of sporangia (cones)

megaphylls

larger than microphylls and have complex vasculature

euphyllophytes

all share a unique invasion of their chloroplast DNA

microphylls

are small leaf-like structures that have a single vein of vascular tissue.
evolved from sterilzed sporangia

heterospory

is a modification of the plant life cycle where there are two sizes of spores. each size of spore develops into a different gametophyte
evolved twice
all seed plants use this life cycle

heterospory advantage

plants develop specialized gametophytes.

seedless vascular plants are

paraphyletic

most monilophytes

are homosporous, with a free-living, nutritionally independent gametophyte

sorus

cluster of sporangia. curled around a single spore as the humidity changes spores are flung out for dispersal ability

rhizomes

modified subterranean stem from which roots grow.
true roots + extensions
plants work hard to protect stems since they have meristem tissue to grow new plant parts

fiddleheads

use in art and some species are consumed as food.
very toxic--\>liver damage

equisetum (horsetails)

characterized by having a hollow stem with a whorl of reduced leaves
considered living fossils
only one genus remains from a lineage that was a dominant part of forests over 150 million years ago

whisk ferns (psilotum)

a group of monilophytes with several unusual features
reduced roots
dichotomous branching
simple sporangia at nodes

megagametophytes

found in seed plants
greatly reduced

primary growth

increases height via apical meristems

secondary growth

increases width

microgametophytes

in seed plants are mobile (pollen)

in seed plants the gametophyte

is retained on and nourished by the sporophyte

seed

contains embryos which germinate under favorable conditions
it contains an embryo and nutritive tissue, protected by a seed coat
longevity
dispersed by water, wind, and animals
evolved only ONCE

progymnosperms

secondary growth, no seeds

In seed plants, the microgametophytes are no longer tied to

water

Gymnosperms: megasporangia

woody cones
female

Gymnosperms: microsporangia

leafy cones
male

cycads

characterized by having large, compound leaves and separate male and female plants
swimming sperm
pollinated by insects
Jurassic dinosaur plants

dioecious

separate male and female plants
the plant is only one sex

compound leaves

divided into multiple leaflets

Ginkgo biloba

last surviving member
leaves are separated into two lobes, bifurcate
swimming sperm
separate male and female parts
produce seeds with a fleshing covering (not ovary tissue, so not a seed)
uses in Asian medicine
monotypic

gnetophytes

small group that includes only three genera
paired opposite leaves,
independently evolved xylem tissue
although 2 sperm are delivered, no endosperm is formed. 2 embryos are fertilized but only one survives.

'double fertilization' in gnetophytes

not homologous (aka not a synapomorphy/monophyletic) to angiosperm because gnetophytes do not produce endosperm

welwitchia

occur in fog deserts of Namibia and Angola, using the moisture from the fog to keep them alive in the extremely arid environment
their leaves continually grow during their lifetime

ephedra

widespread, prefer sandy soils in arid environments and are used as stimulants by many cultures

gnetum

occur in tropical areas in south America and asia. their seeds are resilient are dispersed via water

conifers

most diverse gymnosperm lineage and are strong the dominant plants in the Northern Hemisphere
great ecological and economic importance
all species form trees and have adaptations for cold climates including modified leaves with resin ducts
the shape of pine needles keeps them from freezing

resin ducts

hold sap which is a deterrent to predation

serotiny

an adaptation in plants where seeds are only released when there is an environmental trigger

relictual lineages

lineages that occur nowhere else in the world
ex: sequiadendron, metasequoia, pinus longaeva

flowers

aka strobulis
combination of reproductive and non-reproductive whorls.

carpels

all the female parts of a flower

the carpel and the stamen are both derived from

modified, folded leaves that protect the sporangia

imperfect flower

one sex of flower

perfect flower

both sexes on flower

monoecious

one plant has both sexes

inflorescence

multiple flowers on a single stem

angiosperm life cycle

fruit

a means of seed dispersal and is derived from a mature, ripened ovary.
contains seeds

simple fruit

fruit that develops from a single carpel
it may have multiple seeds
includes kiwi, apple

a reduced gametophyte has

NO antheridia but HAS pollen
NO archegonia but HAS egg

aggregate fruits

result from several carpels on a single flower
includes blackberries

multiple fruits

result of the fusion of multiple flowers (carpels)
includes pineapples

accessory fruits

fruit is formed from non-ovary tissues
strawberries
durian fruit

caryopsis

a special kind of fruit in which the ovary wall is fused with the seed coat.
common in cereal grains (monocots)

synapomorphies of all plants

chloroplast through primary endosymbiosis

synapomorphies of green plants

chlorophyll b, starch storage in the chloroplast

synapomorphies of streptophytes

retention of the egg, but the zygote is kicked out after fertilization
plasmodesmata

synapomorphies of Embryophytes (land plants)

cuticle, multicellular sporophyte, zygote retained after fertilization, gametangia, alternation of generations

synapomorphies of tracheophytes (vascular plants)

tracheids, rooting structures, branching independent sporophyte

synapomorphies of euphyllophytes (true leaved plants)

megaphylls, overtopping growth form, chloroplast DNA inversion

synapomorphies of seed plants

seeds
seed coat
heterospory

synapomorphies of angiosperms

carpels
flowers
phloem + companion cells
fruit
reduced gametophyte to 7 cells and 8 nuclei

homoplasies

vessel elements--angiosperm + gnetophytes
double fertilization--angiosperm + gnetophytes
heterospory--selaginella and seed plants
absence of flagellated sperm--gnetophytes + conifers + angiosperms