Lecture exam #2 part 2 Flashcards
the evolutionary history of species or group of related species
phylogeny
the discipline that classifies organisms and determines their evolutionary relationships
systematics
what do systematics use fossil, molecular and morphological data for?
to infer evolutionary relationships
the ordered division and naming of organism
taxonomy
what did Carolus Linneaus publish?
a system of taxonomy based on resembelences
two key features of Carolus Linnaeus’ system that remain useful today
1) two-part name for species
2) hierachial classification
the two-part scientific name of species
binomial
first part of a name
genus
the second part of a name
specific epithet
what is the specific epithet (the 2nd part of a name) unique for?
each species within the genus
how is the binomial name written?
the first letter is capitalized, and the entire species is italicized
what makes up the binomial name?
both part together (not the specific epithet alone) (homosapien)
what did Linnaeus introduce a system for?
grouping species in increasingly broad categories
taxonomic groups from broad to narrow (8) (DKPCOFGS)
1) domain
2) kingdom
3) phylum
4) class
5) order
6) family
7) genus
8) species
the way systemtatists depict evolutionary relationships
branching phylogenetic trees
what does Linnean classification differ from?
phylogeny
proposed by systamists, which recognizes only groups that include a common ancestor and all its descendents
phyloCode
how does a phylogenetic tree represent a hypothesis about evolutionary relationships (4) (ESRP)
1) each branch point represents divergence in 2 species
2) sister taxa are groups that share an immediate
common ancestor
3) a rooted tree includes a branch to represent the last common ancestor of all taxa in the tree
4) a polytomy is a branch from which more than two groups emerge
what do phylogenetic trees show patterns of?
descent
what do phylogenetic tree not indicated?
when species evolved or how much genetic change occurred in lineage
what shouldn’t be assumed about a taxon?
that is evolved from the taxon next to it
what does phylogeny provide important information about?
similar characteristics in closely related species
what was a phylogeny used to identify the species of?
whale from which “whale meat” originated
what are organisms with similar morphologies or DNA sequences more likely to be?
closely related than organisms with different structures or sequences
what do systemastists need to distinguish when constructing a phylogeny?
whether the similarity is the result of homology or analogy
similarity due to shared ancestry
homology
similarity due to convergent evolution
analogy
occurs when similar environmental pressures and natural selection produce similar (analogous) adaptions in organisms from different evolutionary lineages
convergent evolution
types of clades
1) monophyeticing
2) paraphyletic
3) polyphyletic
a valid clade that is signifying that it consists of the ancestor species and all its descendents
monophyletic
grouping consists of an ancestrial species and some, but not all, of the descendents
paraphyletic
grouping consists of various species that lack a common ancestor
polyphyletic
in comparison with its ancestor what does an organism have?
both shared and different characteristics
a character that originated in an ancestor of the taxon
shared ancesteral character
an evolutionary novelty unique to a particular clade
shared derived character
what can a character be and what does it depend on?
both ancesteral and derived depending on its context
when inferring evolutionary relationships what is it useful to know?
in which clade a shared derived character first appeared
what are the homologies shared by the outgroup and ingroup?
ancestral characters
what do ancestral character predate?
the divergence of both groups from a common ancestor
what does the tree of life suggest about eukaryotes and archaea?
that they are more closely related to each other than bacteria
what is the tree of life based largely on?
rRNA genes as these have evolved slowly
what was the terrestrial surface for much of Earth’s history
lifeless
what likely existed on land 1.2 billion years ago?
cyanoacteria and protists
what emerged on land around 500 million years ago?
small plants, fungi and animals
what did the 290,000 living species diversify from since colonizing land ?
plants
having terrestrial ancestors, even though some are now aquatic
land plants
what do land plants NOT include?
photosynthetic protists (algae)
what do plants supply and what are they the ultimate source of?
oxygen and they are the ultimate source of most foot eaten by land animals
green algae that are the closes relatives of land plants
charophytes
what do many charactertistics of land plants also appear in?
algae
characteristics that land plants share ONLY with charophytes
1) rings of cellulose-synthesizing proteins
2) structure of flagellated sperm
3) formation of phragmoplast
in charophpytes, a layer of durable polymer that prevents exposed zygotes from drying out
sporopollenin
where is sporopollenin also found in?
plant spore walls
what does the movement onto land by charophyte ancestors proved? (3) UMN
1) unflitered sun
2) more plentiful CO2
3) nutrient-rich soil
what did land present challenged for charophytes? (2) (SL)
1) scarcity of water
2) lack of nutrient-rich soil
why did land plants diversify as adaptions evolved?
to enable them to thrive despite challenges
what is the subject of an ongoing debate about plants and algae?
the placement of boundary dividing them
5 key traits that appear in nearly all land plants but are ABSENT in the charophytes (5) (AMWMA)
1) alternation of generations
2) multicellular, dependent embryos
3) walled spores produced in sporangia
4) multicellular gametangia
5) apical meristems
when plants alternate between two multicellular stages, a reproductive cycle
alternation of generations
part of alternation of generations, a haploid and produced haploid gametes by mitosis
gametophyte
in alternation of genrations, what fusion of the gametes gives rise to.
sporophyte
what does sporophytes produce?
haploid spores by meiosis
in multicellular, dependent embryos what is the diploid embryo retained within?
the tissue of the female gametophyte
in multicellular, dependent embryos what are nutrients transferred from and to and through what?
from parent to embryo through placental transfer cells
in multicellular, dependent embryos what lands plants are called because of the dependency of the embryo on the parent
embryophyte
the organ that sporophyte produces spores in
sporangia
in walled spores produced in sporangia, it’s what diploid cells are called that undergo meiosis to generate haploid spores
sporocytes
what do spore walls contain?
sporopollenin
what does sporopollenin make spore walls?
resistant to harsh environments
the organs that gametes are produced within
ganetangia
female gamentangia, produces eggs and are the site of fertilization
aarchegonia
male ganetangia, produce and release sperm
antheridia
where do plants sustain their continual growth in?
their apical meristems
what do cells from the apical meristems differentiate into?
various tissues
a waxy covering of the epidermis
cuticle
specialized cells that allow for gas exchange between the outside air and the plant
stomata
symbiotic associations between fungi and land plants that may have helped plants without true roots to obtain nutrients
mycorrhizae
what did fossil evidence indicate was on land at least 470 million years ago?
plants
what has been extracted from 450-million-year old rocks?
fossilized spores and tissues
example of plants being on land 425 million years ago?
sporangia
what gave rise to modern plants?
ancestral species
clades of non vascular plants (bryophytes) (3) (PPP)
1) phylum hepatophyta (liveworts)
2) phylum brophyta (mosses)
3) phylum anthocerophyta (hornworts)
clades of vascular seedless plants (2) (PP)
1) phylum lycophyta (lycophytes)
2) phylum monilophyta (monilophytes)
clades of vascular seed plants (gymnosperms) (4) (PPPP)
1) phylum ginkophyta (Ginko)
2) phylum cyadophyta (cyads)
3) phylum gnetophyta (gnetophytes)
4) phylum coniferophyta (conifers)
seed vascular plants (angiosperms)
phylum anthophyla (flowering plants)
what are land plants informally based on the presence or absence of?
vascular tissue
what do most plants have and what does it constitute them as?
vascular tissue, vascular plants
what are nonvascular plants commonly called?
bryophytes
what are bryophytes NOT?
a monophyletic group
what can seedless vascular plants be divided into?
clades
what do seeldess vascular plants not form?
a clade
organisms that are groups based on shared key biological features, rather than shared ancestry
grade
an embryo and nutrients surrounded by a protective coat
seed
what do seed plants form and can be divided into?
clades and can be divided into further clades
the “naked seed” plants including confiers
gymnosperms
the flowering plants
angiosperms
3 phyla of bryophytes (LMH)
1) liveworts (hepatophyta)
2) mosses (bryophyta)
3) hornworts (anthocerpophyta)
in all three bryophyte phyla what are gametophytes?
larger and longer-living than sporophytes
when are sporophytes typically present?
only part of the time
what is a spore that germinates into a gametophyte composed of? (2) (PG)
1) a protonema
2) gamete-producing gametophore
what are the height of gametophytes constrained by?
the lack of vascular tissues
what anchors gametophytes to substrate?
rhizoids
what do mature gametophytes produced flagellated sperm in?
antheridia and an egg in each archengonium
what do sperm swim through?
a film of water to reach and fertilize the egg
what do bryophytes grow out of?
archegonia
what type of plants are bryophytes?
the smallest and simplest sporophytes of all extant plant groups
parts of a sporophyte
1) foot
2) seta (stalk)
3) a sporangium (a capsule)
what does the capsule of a sporophyte discharge through its pores?
a peristome
what do hornwart and moss sporophytes have that liveworts does not?
stomata
what are mosses capable of inhabiting?
diverse and sometimes extreme environments
what are mosses especially common in?
moist forests and wetlands
what do some mosses help retain?
nitrogen in the soil
forms extensive deposits of partially decayed organic material
sphagnum or “peat moss”
what can peat be used as a source for?
fuel
what do low temperature, pH and oxygen level of peatlands inhibit?
decay of moss and other organisms
what is an important global reservoir of organic carbon?
sphagnum
what can overharvesting or sphaghum and/or a drop in water level in peatlands release?
stored CO2 to the atmosphere
what were prominent types of vegitation during the first 100 million years of plant evolution?
bryophytes
what allowed the earliest plants to grow tall?
vascular tissue
what did early vascular plants have?
independent, branching sporophytes
living vascular plants characertizations (3) (LVW)
1 )life cycles with dominant sporophytes
2) vascular tissue called xylem and phloem
3) well-developed roots and leaves
in contrast with bryophytes what are sporphytesl of seedless vascular plants?
the larger gerneration in familiar ferns
iny plants that grow below the soil surface
gametophytes
two types of vascular tissues
1 )xylem
2) phloem
conducts most of the water and minerals and includes tube-shaped cells called tracheids
xylem
what are water-conduccting cells strengthened by and what do they provide?
lignin and they provide structural support
has cells arranged into tubes and distribute sugars, amino acids, and other organic products
phloem
what does vascular tissue allow for and what does it provide?
increased height and it provides evolutionary advantage
organs that anchor vascular plants
roots
what do roots enable vascular plants to do?
absorb water and nutrients from soil
what may have roots evolved from?
subterranean stems
organs that increase the surface area of vascular plants, thereby capturing more solar energy that is used for photosynthesis
leaves
two types of leaves
1) microphylls
2) megaphylls
leaves with a single vein
microphylls
leaves with a highly branches vascular system
megaphylls
modified leaves with sporangia
sporophylls
clusters of sporangia on the undersides of sporophylls
sori
cone-like structures formed from groups of sporophylls
strobili
what are most seedless vascular plants?
homosporous
producuing one type of spore that develops into a bisexual gametophyte
homosporous
all seed plants and some seedless vascular seedplants
heterosporous
what do heterosporous species produce?
megaspores
gives rise to female gametophytes and microspores which give rise to male gametophytes
megapsores
2 clades of seedless vascular plants (2) (PP)
1 )phylum lycophyta (club mosses, spike mosses and quillworts)
2) phylum monilophyta (ferns, horestails and whisk ferns and their relatives)
what thrived for millions of years in moist swamps?
giant lycophyte trees
what are surviving species?
small heraceaous plants
what do club mosses and spike mosses have?
vascular tissues and are not true mosses
what are the most widespread seedless vascular plants with more than 120,000 species
ferns
where are ferns the most diverse?
in the tropics but also thrive in termperate forests
when were horsetails diverse during?
the carboniferous period
what are horesetails now restricted to?
the genus Equisetum
what do whisk ferns resemble?
ancestral vascular plants but are closely related to modern ferns
what did modern lycophytes, horestails and ferns grow to and when?
great heights during the devonian and carboniferious
what did lycophytes, horsetails and ferns form?
the first forests
what did increased growth and photosynthesis removed from the atmosphere that may have contributed to global cooling and when?
CO2 during the carboniferous period
what did the decaying plants of these carboniferous forests evenetually become?
coal
