Exam 4 Flashcards
Innovations from phragmoplasts
plasmodesmata, intercellular communication, multicellularity From streptophytes
Rosette proteins
used to build cellulose wall build from inside, strands separate instead of stretch as cell grows changing orientation of microtubules to weave instead of parallel can change shape of cell: established controlled directionality of cell growth, determines plant form
Tissue differentiation
results from phragmoplasts and rosette proteins working together
apical meristem
streptophyte synapomorphy region of extreme growth/mitosis
lateral branches
streptophyte synapomorphy greater exposure for photosynthesis
gametangia
from streptophytes multicellular sex organs with protective jacket layers
gametophyte
gamete-producing plants, use mitosis, haploid
archegonia
gametophyte that develops egg
antheridium
gametophyte that develops sperm
oogamy
differentiation between gametes, egg and sperm, gives eggs more food and investment and makes sperm smaller expensive, lower in number, one motile and one sessile, more resources to egg
isogamy
equivalent gametes, cheap, high in number, both motile, any two gametes, less resources for offspring
parental investment
putting more energy into offspring to increase their chances of survival
2 changes from oogamy
egg retention post fertilization enlargement of zygote
gametophytic iteroparity
only gametes are used up, rest of plant is capable of continued growth only possible because of phragmoplasts, rosette proteins, tissue differentiation, parental investment
zygospores
new individuals produced by meiosis
First degree synapomorphies for embryophyta
cuticle, delayed meiosis, stoma
Streptophyte first degree synapomorphies
phragmoplast, rosette protein, tissue differentiation, parental investment, gametophytic iteroparity
cuticle
layer of waxes and cutin over a discoid shape (good for PS) that protects plant from UVB radiation (mutations, heat) and prevents water loss
delayed meiosis
diploid zygote conducts mitosis rather than meiosis while in archegonium, producing multicellular diploid (embryo) Huge increase in fitness
embryo
mass of diploid cells in archegonium
sporophyte
multicellular diploid that undergoes meiosis to produce spores
placental transfer tissue
connection between gametophyte and sporophyte that enhances nutrient transfer thru increased SA
sporangium
multicellular diploid structure, covered by layer of cells, undergoes meiosis to produce spores
embryophyte problems
increased energy costs, must feed sporophyte dispersion of propagules feeding the developing sporophyte (placental transfer tissue)
stem
increases dispersal of spores through wind caused by lifting of sporangium by elongated placental transfer cells clear color, no PS, parasitic on host plant embryophytes
Pros and cons of embryophyte adaptations
Pros: upright sporophyte allows for better dispersal, 2n reduced mutations, shape allows for less heat absorption Cons: limited growth potential, semelparous sporophyte, parasitic sporophyte, cuticle covered sporophyte can’t get oxygen
stomatal complexes
allows for opening in cuticle, can be opened/closed for water and gas exchange, lets heat escape thru water embryophytes
Tracheophyte synapomorphies
branching, vascular tissue, diploid dominance
branching
doubles fitness potential by doubling spore output per sporophyte still semelparous, can be made iteroparous by making more stems without sporangia size limited by water transfer to top cells (sun dries them out) after sporophyte is established, gametophyte undergoes senescence back to gametophytic semelparity sporophytes are now PS tracheophyta
vascular tissue
xylem, tracheids, phloem very expensive to make, no PS cells that support and transfer materials thru plant, let them grow bigger tracheophyta
xylem
wood, water conducting cells, faster transfer, structural support part of vascular tissue tracheophyta
phloem
food transfer cells vascular tissue from tracheophyta
diploid dominance
allows for less impact from UVB induced mutations allows for functionality in a wider environmental gradient 2n is more expensive to replicate more genetic load tracheophyta
euphyllophyta synapomorphies
“true leaf” megaphyll
webbing
connects stems and increases PS area
leaf
complex set of branches
What enabled leaves?
Planation of branches, then webbing connected them
sympodium
overtopping of branches, led to planation to increase PS area
sequence that produced leaves
branching, overtopping, planation, webbing
homospory
single spore establishes bisexual gametophyte all spores are identical sexual expression occurs when egg/sperm are produced pros: relatively cheap and small, colonization potential cons: heterozygosity issues, low initial offspring fitness
When is sexual expression in heterospory?
When spores are being produced
Microspores
produce male gametes that only make sperm
megaspores
produce female gametes that only make eggs
Heterospory
Two kind of sporangium make two kinds of spores Earlier gender expression Free-sporing in ferns and lycopods can’t diffuse using wind since spores are too small
free-sporing
heterosporous ferns and lycopods spores released into environment where they develop gametophytes
Ovules
spermatophytes
integumented sporangia megasporangia surrounded by parental cup-shaped tissue (integuments) Opening at top allows microspores in to form embryo ovule becomes seed after fertilization
Pollen
male gamete in the wind
How do ovules catch microgametes?
Release water at the tip of ovule, catch gamete, gamete releases hormone causing ovule to bring it back in
Anthophyta synapomorphies
flower, carpel, pollen tube, fruit
flower
short stem with highly modified leaves
carpel
modified leaf, protects ovules, evolutionary structural unit of pistil
Fruit
nothing more than a modified leaf
Steps of embryonic development
zygote > 8-cell stage > blastula > gastrula
gastrulation
blastula to gastrula, blastula invaginates and creates a hole
blastocoel
hollow hole in middle of blastula
Hox genes
regulate development of body form, part placement highly conserved, only in animals
Fossil formation
permineralization - minerals replace organic tissue molds, cast, impressions - can leave behind evidence of activity whole organism preservation
Neoproterozoic era
first generally accepted animal fossils Ediacaran fauna
Paleozoic era
Cambrian explosion first appearance of many major groups of living animals
Causes of increased body part diversity
Hox genes for developmental flexibility rise in atmospheric O2, allows metabolisms and more energy predator-prey relationships, arms race
Mesozoic Era
age of the dinosaurs as dominant terrestrial animals coral reefs emerged ended with comet impact, left niches for small animals
Cenozoic Era
began with mass extinction of terrestrial and marine animals modern mammals and insects diversified during this time
What are body plans traditionally based on?
Presence or abscence of different tissue types Type of body symmetry Presence or absence of true body cavity (coelom) Embryonic development patterns
common ancestor of modern animals
ancestral colonial choanoflagellate
Tissue
cells of specialized function together sharing a basement membrane
organ
multiple tissue types working together
organ system
combination of organs
organism
series of organ systems
cephalization
development of a head, sensory organs to front caused by predator-prey relationships and bilateral symmetry allows for brain and more complex nervous systems
Types of gut
Gastrovascular: sac-like gut that fills with water, same mouth/anus, jellyfish Incomplete: mid-body mouth, same mouth/anus, planaria Complete: separate mouth/anus, food goes one way
schizocoelus
solid masses of mesoderm split and form coelom
enterocoelus
folds of archenteron form coelom
coelom
true body cavity, derived from mesoderm
coelomate
true coelom surrounded by tissue from mesoderm cavity derived from mesoderm
pseudocoelomate
body cavity only partially lined by tissue from mesoderm cavity derived from blastocoel
acoelomate
lack body cavity between digestive tract and outer body wall
hydrostatic skeleton
use water pressure to provide rigidity in body turgid column of water within body space
exoskeleton
shell outside of a snail, involves molting/ecdysis
endoskeleton
bones inside body (humans)
strobilation
segment divided by another process, used for reproduction
protostome
cleavage is spiral and determinate, schizocoelus, blastopore becomes mouth, anus secondarily developed
deuterostome
cleavage is radial and indeterminate, enterocoelus, blastopore becomes anus, mouth secondarily developed
determinate vs. indeterminate
determinate: each cell already has a determined function at the 8-cell stage indeterminate: each cell could grow a whole new organism if removed at 8-cell stage
lophophore
lophotrochozoans horseshoe shaped crown of cilia waved in water to catch food
porifera
parazoans, no true tissues sponges closest lineage to colonial choanoflagellates sessile, relatively unspecialized cells suspension feeders, flagellated choanocytes line spongocoel and use flagella to create flow of water, catch food in collars no basement membrane
Cnidarians
eumetazoa, radiata jellyfish, anemones include polyp (sessile) and medusa (floating) forms have basement membrane carnivores, use tentacles/cnidocytes to catch prey
ctenaphores
eumetazoa, radiata, triploblastic comb jellies 8 rows of comblike plates composed of fused cilia long pair of retractable tentacles
platyhelminthes
flukes, tapeworms, planaria flattened dorsoventrally, have gastrovascular cavity
mollusca
snails, slugs, oysters, clams, octopi, squids soft bodied, muscular foot, visceral mass, mantle trochophore larval stage
annelids
segmented worms, series of fused rings marine and terrestrial worms, leeches leeches = hirudinea, secrete hirudin as anticoagulant
ecdysozoa
nematoda some of the most widespread animals
arthropods
segmented coelomates, exoskeleton, jointed appendages became more specialized thru evolution body covered by cuticle grew because of angiosperms (flowers)
echinodermata
modified radial symmetry, five parts simple nervous system, no head or brain starfish, sea urchins, sea dollars, sea cucumbers
chordata
notochord - single flexible rod dorsal, hollow nerve cord pharyngeal slits (gills) postanal tail
craniates
have cranium - protective bony or cartilaginous opening neural crest - embryonic cells that disperse thru embryo and lead to development of skeleton hagfish, include vertebrates
vertebrates
craniates with a backbone vertebral column - notochord replaced by interlocking vertebrae endoskeleton of cartilage or bone, two pairs of appendages internal organs - liver, kidneys, heart with at least two chambers
Where did jaws first develop?
fish
chondricthyes
sharks and rays skeleton made of flexible cartilage among first to develop teeth lateral line for pressure wave detection
oviparous, ovoviparous, viviparous
oviparous lay eggs ovoviparous have egg retained in female, no placenta viviparous have eggs develop in uterus and placenta to nourish young
