Exam 1 Flashcards
Inductive Reasoning
a type of logical thinking that involves forming a generalized explanation or conclusion based on a set of observations or known facts – “bottom-up logic”
Deductive Reasoning
a type of logical thinking that forms a prediction or conclusion based on accepted premises – “topdown logic”
Hypothesis
a candidate mechanism or explanation that
accounts for a set of observations or phenomena
Theory
a scientifically accepted general principle offered to
explain many predictable observations or phenomena
Predictions
Expectation from experiment or more detailed observations
Falsifiable
Experimental results can disprove it
Hierarchical levels in biology
The expanse of the living world can be “reduced” in a
hierarchical way from the biosphere to individual atoms. Organelles, cells, tissues, organs and organ systems, organisms, populations and communities, ecosystems, biosphere
Holism
Emergent properties and behaviors that cannot be fully understood from studying the lower level parts
Reductionism
A problem/ question at one level of organization is addressed by picking apart features at a lower level of organization
Emergent properties
With rising levels of biological organization, new properties and patterns will emerge
Properties possessed at one level are not apparent in members of the lower level, they emerge at the new higher level of organization
Biological organization is described as hierarchical in terms of
genetics, physical structures or phenotypes, behavioral interactions
Physical model
can see and touch, shows how parts relate to each other. ex. model of a cell
Conceptual model
ex. phylogenetic tree
Mathematical or computer model
equations and data
binomial species name
Genus species, italicized
systematics
Science involved with the determination of evolutionary relationships among organisms which establishes the foundation for modern natural classification
taxonomy
Science of classifying and naming organisms
nomenclature
the devising or choosing of names for things, especially in a science or other discipline.
phylogenetics
study of evolutionary relationships
cladistics
method of determining evolutionary relationships
clade
all of the descendants of a common ancestor
cladogram
branching diagrams
monophyletic group
ancestor and all of its descendants
polyphyletic group
two convergent descendants but not their common ancestor. A and C, but not B.
paraphyletic group
includes ancestor and some of its descendants. B and C, but not A.
synapomorphies
(homologous structures) structures are similar because they were inherited from common ancestor
homoplasies
(analogous features) structures that are similar between unrelated organisms
Natural Classification
based on natural evolutionary relationships. grouping organisms based on similarities first then identifying shared characteristics
Artificial Classification
Common for plants and fungi- field guides- color, shape, size, etc
Fossil Classification
Form genera- similar appearing fossils are organized together
Prokaryote
No true nucleus or membrane-bound organelles, 1 billion years before eukaryotes
Eukaryote
true nuclei and membrane-bound organelles
stromatolite
3.7 billion year old prokaryotes, lime secreting cyanobacteria
endosymbiosis
one cell engulfing another such that the engulfed cell survives and both cells benefit
plastid
specialize in photosynthesis and food storage, photosynthetic chloroplasts, primary endosymbiosis
chloroplast
photosynthetic plastids
heterokont
endosymbiosis of red algae, secondary endosymbosis ER of heterokont that engulfed the red algae
Lignophytes
Woody plants, monophyletic group
Megasporophyll
contain megagametophytes are arranged in upright cone-like structures
Microsporophyll
spores that grow into male gametophyte.
Seed
a fertilized ovule with a dormant embryonic sporophyte retained within and protected and nourished by parent sporophyte tissue
Integument
protective tissue of the sporophyte
fertilization of seed plants
- megasporangium releases spores, land in moist location and germinate.
- Develop into a free living gametophyte.
- After fertilization of egg, an embryonic sporophyte develops.
- To develop ovule, sporangium makes single large megaspore, embryo is retained in megagametophyte (seed)
Pollen tube
a tubular structure produced by the male gametophyte of seed plants when it germinates. it arrives at ovary and is attracted to ovule that contains egg cell.
Integument
protective sterile tissue of the sporophyte
Vascular cambium
zone of regenerating cells that divide to produce secondary xylem and phloem
Megastrobilus
cone bearing megasporophylls (leaves with megasporangia)
Progymnosperms
extinct group of woody plants, unlimited potential for growth of wood with new type of vascular cambium, no seeds, spores
Spermatophytes
seed plants
Gymnosperms
naked ovules, not enclosed in carpal
Division Coniferophyta
woody trees or large shrubs, needle or scale-like simple leaves, male and female sporangia are born on separate pollen bearing and seed-bearing cones. pines, junipers, spruce, cedars
Division Cycadophyta
resemble ferns or palms, tropical areas, form separate male and female plants bearing pollen and seeds on dense cones, sperm cells still have flagella
Division Ginkgophyta
single species, dichotomously veined leaves, look like flowering plants, but are more closely related to cycads, Ginkgo biloba
Division Gnetophyta
3 groups: gnetum, ephedra, and welwitschia. leaves reduced to small dry scales, stems are photosynthetic, tube grows from egg to meet with pollen tubes for fertilization
Microstrobilus
male cone contains leaves called microsporophylls
angiosperm
flowering plants, a seed plant with ovules and seeds enclosed in a carpel
flower
a determinate compressed shoot with fertile spore-bearing leaves (and often sterile leaves) in the angiosperms
fruit
a mature (with fertilized ovules) ovary or ovaries of one or more flowers.
carpel
Structure surrounding angiosperm ovules, often considered to represent a folded megasporophyll
sepal
outer protective structure of immature flower while flower is still in bud
petal
leaf-like colorful part
stamen
microsporophylls or fertile leaf-like structures that develop microsporangia
anther
release microspores called pollen grains
pistil
formed by single or group of fused carpels, leaf-like structures folded around ovules
filament
supports anther, where pollen is developed
style
long extension through which the pollen tubes must grow to get to ovules
ovary (flowering plant)
ovules contained in ovary, bottom sole and part of pistil
pericarp
part of a fruit formed from the wall of the ripened ovary
polar nuclei
located in central cell in megagametophyte development
double fertilization
growth of pollen tube one sperm fuses with and fertilizes the egg, forming diploid zygote. other sperm fuses with the two polar nuclei, forming triploid cell
endosperm
nutritive triploid tissue, primary food source for germinating seed
basal angiosperms
are the flowering plants which diverged from the lineage leading to most flowering plants. most primitive angiosperms
cotyledons
leaf-like structure in embryo in seed plants
parallel venation
all the veins of a leaf are parallel to each other. (monocots)
reticulated venation
When veins (or the nerves) shows network or web-like arrangement all over the leaf blade or lamina (eudicots)
basal angiosperms
the flowering plants which diverged from the lineage leading to most flowering plants
eudicots
flowering plants mainly characterized by having two seed leaves upon germination. Reticulated venation in leaves, Flower parts often in groups of 4 or 5, Two cotyledons on seed embryo
monocots
grass and grass-like flowering plants, the seeds of which typically contain only one embryonic leaf, or cotyledon. Parallel veined leaves, Flower parts generally in groups of 3, Single large cotyledon on seed embryo, Most species are herbs
photosynthetic autotrophs
make food using the energy in sunlight, include (a) plants, (b) algae, and (c) certain bacteria
heterotrophs
obtain energy and nutrients by feeding on living prey or by decomposing dead organic matter
saprotrophs
decomposed dead organic material as an energy and nutrient source
mixotrophs
organism that can use a mix of different sources of energy and carbon, instead of having a single trophic mode on the continuum from complete autotrophy at one end to heterotrophy at the other
phylogenomics
analysis that involves genome data and evolutionary reconstructions
cilia
small projections around the organism, paramecium
pseudopod
arm-like projection, amoeba
flagellum
slender threadlike structure, euglena
eukaryotic supergroups (6)
6 eukaryotic supergroups: archaeplastida, amoebozoa, opisthokonta, rhizaria, chromalveolata, excavata
archaeplastida
share a common origin with an ancestor that obtained chloroplasts through primary endosymbiosis of a cyanobacterium. ex red algae, chlorophytes (green algae), charophytes (green algae), land plants
lack flagella
amoebozoa
pseudopodia type of motility most are unicellular but some form large single cells with many nuclei or aggregate together during some parts of the life cycle into multicellular forms. ex. slime molds, gymnamoebas, entamoebas
has pseudopodia, no shell of fixed body
opisthokonta
single posterior flagellum. ex. animals, fungi, choanoflagellates, nucleariids
rhizaria
includes amoeboid type organisms with long needle-like pseudopodium, many make elaborate tests or hard outer bodies from precipitated salts such as calcium carbonate. ex. cercozoans, forams, radiolarians
chromalveolata
taxa with chloroplast derived from secondary endosymbiosis of single-celled red algae the stramino piles or heteroconstants. ex. dinoflagellates, apicomplexans, ciliates, diatoms, golden algae, brown algae, oomycetes, “hairy” flagellum
excavata
excavated feeding trough on the side of their single-celled bodies. ex. diplomonads, parabasalids, euglenozoans
syngamy
the fusion of two cells
diploid
containing two complete sets of chromosomes, one from each parent
haploid
having a single set of unpaired chromosomes
monobiontic life cycle
(multicellular diploid stage) 1. meiosis 2. haploid gametes 3. syngamy 4. zygote 5. mitosis 6. each cell is diploid
dibiontic life cycle
alternation of generations. 2 living and persistent phases of life - sporophyte and gametophyte
isomorphic generations and heteromorphic generations life cycle
(dibiontic) 1. meiosis 2. spores, not gametes 3. haploid generation 4. mitosis 5. gametes 6. syngamy 7. zygote 8. mitosis 9. diploid generation
isomorphic vs heteromorphic generations
isomorphic: the sporophyte and gametophyte generations look the same. heteromorphic: the sporophyte and gametophyte generations look different (true plants)
spores
a haploid reproductive cell which gives rise to a gametophyte
gametes
haploid reproductive cells in sexually reproducing organisms that fuse with one another during fertilization
sporophyte
spore-bearing generation
- 2n plant produces spores by meiosis
gametophyte
gamete-bearing generation
- 1n plant produces gametes by mitosis
sporangia
the structure producing spores
gametangia
the structure producing gametes
cuticle
on the outside of the plant body that will be necessary for life on land to reduce water loss to dry air
parenchyma
opportunities for evolution of tissue specialization, transport water
embryophytes
true plants, develop drought resistant spores, large compact multicellular bodies of parenchyma, develop waxy cuticle, develop multicellular jacket over reproductive structures
bryophytes, the 4 chararacteristics
- no vascular tissues 2. gametophyte is the dominant photosynthetic phase of the life cycle 3. sporophytes are never physically or functionally independent of the gametophyte 4. strictly terrestrial and have cuticle all over their bodies and in many cases stomata
division bryophyta
mosses. at the bases of the gametophytes are root-like filaments, rhizoids, which serve to anchor the plant to the ground. have structures that look like leaves, roots and stems of flowering plants
division hepatophyta
liverworts, have rhizoids, gemmae (flat) considered less
complex than mosses, have lobed, leaf-like bodies referred to as thalli, usually prostrate (lying down not upright) and smooth surface
division anthocerotophyta
hornworts (spiky))Members of this group have a thalloid gametophyte and a green, photosynthetic sporophyte, mucus-filled cavities within the thallus with cyanobacteria
stomata
pores that allow movements of gases in and out
sphagnum
peat moss used for gardening. draining bogs causes oxidation of exposed organic material, adds to CO2 emissions
tracheophyte
vascular plants
interpolation theory
- Earliest land plants had no sporophyte generation (monobiontic)
- Later, zygote after fertilization would germinate mitotically, retained on gametophyte
(dibiontic) - With continued evolution, sporophyte became more elaborate and independent and
gametophyte became simpler
transformation theory
- Earliest land plants had upright, branched and vascularized gametophytes and
sporophytes (dibiontic) - Over time, sporophytes became larger and more complex, and gametophytes became
simpler
*This theory then predicts that “bryophytes” diverged early, and afterward lost vascular
tissue and evolved dominant unbranched gametophytes and reduced, unbranched
sporophytes
xylem
water transportation
phloem
sugar transportation
epidermis
outer layer of tissue
tracheid
water-conducting cell in xylem
microphyll
small leaves, one single, unbranched leaf vein
megaphyll
large leaves, branched leaf veins
enations
small green photosynthetic flaps of tissue
planation
process of small stems evolve to grow into flat two-dimensional planes
strobili
cones
fiddlehead
curled large compound leaves that unfurl
petiole
leaf stalk
sori
clusters of sporangia, sling spores into the air
annulus
snaps forward to hurl spores into the wind
rhyniophytes
1) Naked stems, no leaves
2) Epidermis with cuticle
3) Cortex with parenchyma and vascular bundle in middle
4) Ends of branches – sporangia with several layers of sterile outer cells
lycophyta
club mosses. look like mosses, have prostrate stems and true roots. Sporangia of lycopods are associated with specialized microphylls called sporophylls, and are either single or multiple, forming a cone-like structure called a strobilius.
arthrophyta/ sphenophyta
horsetails. prominent ribs with whorls of needle-like leaves. Horsetails also have underground rhizomes with advantageous roots. Horsetails bear cones (strobili) at the tips of some stems which contain sporangiophores with sporangia at their edges.
pteridophyta
ferns. the stems and roots are simple with the stems composed mostly of rhizomes. The fronds (leaves) produce clusters of mature sporangia (called sori) that contain single-cell spores.
