exam 3 Flashcards
are angiosperms hetero or homosporous
heterosporous
what does the microsporangia produce
microspores (pollen) develops into male gametophyte
what does the megasporangia produce and what is it found inside of
megaspores, inside ovules develop into female gametophyte
major stages of the angiosperm life cycle
gametophyte development, pollination, double fertilization, seed development
male flower reproductive structure and what does it contain
stamen: contains anther where microsporangia develop
female flower reproductive structure and what does it contain
carpel: contains ovary and ovules where megasporangia develop
double fertilization
1st sperm fuses with egg to form zygote, second fuses with 2 polar nuclei to form a triploid endosperm
pollination process
pollen is transferred to the stigma, produces a pollen tube that grows down the style into the ovary and discharges two sperm cells into the embryo sac
how did early pollination work
it was undirected and wind driven
what kind of symbiotic relationship is pollination
mutualism, plants reproduce in exchange for food
Coevolution
2 species involve interdependently
what do wind pollinated plants look like
small inconspicuous flowers, typically green or feathery
what is a seed made of
embryo, food supply, protective covering
are bees the only pollinator, what are some other ones
no. hummingbirds, butterflies, moths, flies, wasps, beetles
what breaks seed dormancy
environmental cues such as heavy rainfall
types of seed dispersal
gravity, animal digestion, animal attachment, water, wind, exploding, cultivation
An important innovation for efficient seed dispersal
Tissues derived from the ovary are often nutritious and brightly colored to attract animal seed-dispersers
what did flowers make more efficient
pollination
what did fruit make more efficient
seed dispersal
evidence that fungi are most closely related to animals
- DNA sequence data
- Both animals and fungi make chitin
- Animals and chytrids (basal fungi) have similar flagella
- Both fungi & animals use glycogen to store energy (plants use starch)
two major fungi growth forms
yeasts: unicellular
mycelia: multicellular mycelium filaments
What makes fungi such good symbiotic partners to plants?
Chitin allows fungi cell walls to stay strong mycelia adapted for absorption
Mycorrhizae
plant-fungal symbiosis in which fungal hyphae transfer nutrients to the plant partner
may have helped plants without roots colonize land
Ectomycorrhizal Fungi (EMF)
- Go in between root cells, but do NOT
actually enter them - in temperate and boreal forests
- fruiting body
Arbuscular Mycorrhizal Fungi (AMF)
- Grow into the cells of plant’s root tissue and directly contact the plasma membrane of the plant cell
- most ancient and found nearly everywhere
- microscopic
chytrids
basal fungi, found in wet habitats Have flagellated spores. motile
zygomycetes
include decomposers, parasites, and
commensal symbionts
glomeromycetes
Form arbuscular mycorrhizae with plant roots.
ascomycetes
Live in marine, freshwater, and terrestrial habitats. Fruiting bodies are called ascocarps
basidiomycetes
Important decomposers and ectomycorrhizal fungi. Fruiting bodies are called mushrooms
Mushrooms
fungal fruiting bodies (reproductive organs) of densely-packed hyphae.
what do fungi have instead of sexes
tens of thousands of mating types
plasmogamy
occurs when the cytoplasms of two haploid hyphae from different mating types fuse
Karyogamy
occurs when the two different nuclei fuse to form a diploid zygote
fungi ecological importance
plant and animal diseases, most important decomposers (digest lignin), symbiotic relationships such as mycorrhizae, antibiotics, food (bread and alc)
Lichen
symbiotic relationship between a fungus and algae, algae provides nutrients to fungus, some also have yeast
Sponges (Phylum Porifera)
lack tissue, Choanocytes ingest food, Amoebocytes digest food and distribute nutrients, metazoans
Cnidaria
eumetazoans, diploblasts, no systems, cnidocytes, nerve net
what did the cambrian explosion give rise to
bilateral animals, hard bodied organisms, predators, prey
Ectoderm
gave rise to the skin and nervous system
mesoderm
gave rise to circulatory system, muscle, and organs
Endoderm
lines digestive tract
Acoelomates
no body cavity
Pseudocoelomates
Body cavity between mesoderm and
endoderm
Coelomates
Body cavity entirely within the mesoderm
what does a body cavity do
acts as a hydrostatic skeleton which allows movement without limbs
what do all animals past porifera and cnidaria have
central nervous system
protostome
mouth before anus, blocks of solid mesoderm split into coelom
deuterostome
anus before mouth, mesoderm pockets pinch off gut to form coelom
clade lophotrochozoa
wormlike, Name comes from a feeding structure called lophophore and larva called a trochophore
Ectoprocta/bryozoans
sessile colonies, suspension feeders
Platyhelminthes
flatworms, acoelomate, move by cilia on underside or undulated swimming
Annelida
segmented worms like earthworms
Mollusca
body has 3 main parts:
1. foot for movement
2. visceral mass contains organs
3. mantle secretes shell
clade ecdysozoa
nematodes and arthropods, cuticle made of chitin, undergo ecdysis (shedding)
nematoda
parasitic roundworms with a cuticle
arthropoda
segmented exoskeleton, jointed limbs
Hox genes
influence segmentation and organization of body parts
mutations in hox genes drastically change body plan
arthropoda: myriopoda
centipedes: carnivorous, venemous, one pair of legs per segment
millipedes: herbivores, two pairs of legs per segment
arthropoda: chelicerata
spiders, ticks, mites, scorpions,
horseshoe crabs
Characterized by chelicerae: pair of appendages near the mouth
arthropoda: crustacea
Crabs, shrimps, lobsters,
barnacles
cephalothorax and abdomen, two pairs of antennae
arthropoda: hexopoda
most abundant animal group, six legs
Echinodermata
starfish
bilateral larva, radial symmetry as adults
feed using tube feet
how do Invertebrate chordates support the dorsal nerve chord
lancelets and tunicates
support dorsal nerve chord with notochord
how do Vertebrate chordates support the dorsal nerve chord
vertebral column (spine) supports dorsal nerve chord
four synapomorphies of chordates
- hollow, dorsal nerve chord
- notochord
- muscular post anal tail
- Pharyngeal slits/ gill slits
chordata: vertebrata
Synapomorphies: vertebral column, cranium, internal organs, endoskeleton
jawless vertebrates/cyclostomes
lamprey and hagfish
Chondrichthyes
sharks, rays, chimaeras
cartilaginous skeletons
bony fish
internal skeleton, swim bladder, gill covers
ray finned fish and lobe finned fish
bony fish: ray finned fish
almost all fish alive today, bony rods in fins
lobe finned fish
Coelacanths and lungfish
fins are fleshy lobes
evolved into amphibians
what changes were required for animals to come to land
lungs, legs, redesigned heart, prevent egg drying, prevent body desiccation
amphibians
Anura – frogs & toads
Caudata – salamanders
Apoda - caecilians
lay jelly coated eggs in water
what two clades are amniotes
reptiles and mammals
anmniote traits
amniotic egg, ribcage, don’t breathe through skin
amniotic egg
4 membranes, amnion, chorion
reptile derived characteristics
scales with keratin, shelled eggs, internal fertilization, ectothermic (except birds)
turtles
turtles and tortises
box like shell fused to skeleton
squametes
snakes and lizards
Snakes are carnivorous and have adaptations for predation such as sensory receptors
Crocodilians
alligators and crocodiles
breathe through upturned nostrils, build nests and care for their young, four chambered heart, most closely related to birds
birds
most diverse vertebrates, amniotic egg, endothermal, scales on legs, hollow bones
mammal traits
hair, kidneys, metabolism, specialized teeth, mammary glands
Mammalia: Prototheria
Monotremes, most primitive, lay eggs, cloaca
Mammalia: Marsupials
anmniotic egg with no shell
after birth, crawls into marsupial pouch
Placenta
organ grown during pregnacy, provides O2 & nutrients
viviparous
give live birth
primate traits
opposable thumbs, long slender limbs that move freely at hip and shoulder, short jaws, flexible hands, social organization
Hominoids
humans and apes that arose from old world monkeys (gibbons, Orangutans, gorillas, chimps)
Hominin
Consists of humans and the extinct species more closely related to them than chimpanzees
hominin evolutions to bipedalism
straight spine, wide pelvis, arched feet, no opposable big toe
Homo neanderthalensis
lived on cold climates
cared for the aged and the sick: indication of advanced social cooperation,
liked art and religion, outcompeted by humans
Homo sapiens
humans
Ecology
how organisms interact with the abiotic and biotic environment
Organismal ecology
how individual organisms interact with the environment
Population ecology
Considers factors affecting population size over time, one species
Community ecology
how interactions between species affect community structure
Ecosystem ecology
Emphasizes energy flow and chemical cycling between organisms and the environment
Landscape ecology
focuses on the factors controlling energy, material, organism exchange over multiple ecosystems
Global ecology
focuses on biosphere, or global ecosystem, which is the sum of all the planet’s ecosystems and landscapes
Climate
long term weather patterns
weather
short term conditions
4 abiotic factors affecting climate
- temperature
- precipitation
- sunlight
- wind
Major Drivers of Earth’s climate system
- Uneven heating of the Earth
- Earth’s movements in space (Milankovitch Cycles)
- Global Air Circulation
- bodies of water
- mountains
Latitudinal Variation in Sunlight
Higher latitudes: angled, less sunlight
Midlatitudes: direct sunlight, warmer
More sun =
more heat and light per unit of surface area
what causes seasons
earth’s tilt
Wind pattern change=
altered ocean current patterns
Milankovitch Cycles
Periodic changes in Earth’s orbit that affect climate
tilt, wobble, orbit
take thousands of years
what latitude are deserts found at
30 degrees
what latitude are rainforests found at
0 degrees
global air circulation
moist air rises, cools, and releases moisture as rain
circulates every 30 degrees
60% of heat transfer
bodies of water
prevailing winds blow over the ocean and produce ocean currents
40% of heat transfer
rain shadows
cool air goes up windward side of mountain, rains, dry leeward side of mountain
how do we study past climates
historical records, tree ring data, corals, sediments, ice
how do we study the current climate
satellites
measurements of: CO2 & Methane, Precipitation, Cloud coverage, Ocean changes
climograph
plots the annual mean temperature and precipitation in a region
ecotone
area of intergradation between 2 biomes
what biome is lichen most common in
tundra
how are aquatic biomes divided
into vertical and horizontal zones
thermocline
narrow layer of abrupt temp change in water
