Exam 1 Flashcards
before 1960s, all life was in one of two kingdoms
plants and animals
field of view
-amount of slide visible at one time decreases as magnification increases
depth of field
-thickness of slide in focus at one time decreases as magnification increases
light intensity
-amount of light passing through to your eye
-decreases as magnification increases
-controlled by :
-rheostat (adjusts intensity)
-iris diaphragm (adjusts contrast)
drawing for biology
-art and science coexist
-much of science began with artists observing natural organisms and phenomenon
-careful observation is a fundamental skill as a biologist
-scientific drawings help to keep a record of oberservatins of your specimens
Blind contour drawing
an exercise where you draw the outline of a subject without looking at the paper
contour drawing
-about depiciting the object only with lines, and not shading
-a contour refers to the outside line of a form. it establishes the layout, size, and emphasis
scientific drawings
-must be in pencil
-draw more than one cell for tissues
-dont use shading
-labels to right when few
-draw only what is actually visable
-include detailed figure caption
taxonomy
-based on evolutinoary relationships
-three parts
1: classification
2: nomenclature
3: identification
-three domain system
-archaea, bacteria, eukarya
classification: hierarchy
Domain = eukarya
kingdom = animalia
phylum =chordata
class = mammalia
order = primates
family= hominidae
genus = homo
species = sapiens
domain is most inclusive, species is least inclusive
nomenclature
-names of taxa at various levels of hierachy come from latin and greek roots
-binomial names
-exclusive 2-part name for each organism
-genus + specific epithet = species
-often descriptive for certain traits of the organism
example: canis familiaris
canis from latin for dog, familiaris from latin for family
phylogeny
-evolutionary history of group of related organisms
-represented as “tree”
-branching reflects evolutionary relationships (lineages)
node
-point of change of a trait from one state to another (derived)
-defines a lineage
-represent the common ancestor of lineages after branch point
-taxa that are more related share a more recent common ancestor
identification: Dichotomous keys
-used to identify unknown specimens
-provide a series of couplets that lead to an identification (1a, 1b)
-each part of a couplet is mutually exclusive of the other
-focus on characters unique to given group of organisms
-good keys will use 2-3 characters at each step
there are three broad groups that organisms fall
Domain Bacteria, Domain Archaea, and Domain Eukarya (Eukaryotes)
organisms previously classed as kingdom monera (prokaryotes) are now
split into 2 domains- bacteria and archaea
Domain Eukarya organisms are further classified into informally groups called-
supergroups
phylogeny definition
history of evolution of a species or group, especially in reference to lines of decent and relationships among broad groups of organisms
taxonomy definition
a system of classification
taxonomy is the-
branch of biology that deals with all aspects of classifying the diverse forms of life
what are the three facets to taxonomy:
1: arrangement of organisms into groups based on shared similar characters (classification)
2) assignment of names to taxa or groups (nonmenclature)
3) arrangement of the classification into a form that can be used to identify specimens, such as a dichotomous key ( identification)
1) classification
descriptions based on quantitative or qualitative traits
based on obersevations of traits and the development of detailed descriptions to differentiate a group of species from all other species
once it is described it is grouped with others like it and ranked in a hierarchical manner called classification
qualitative
why, how, what behind behaviours
quantitative
how many or measurable data
2) Nomenclature
Whats in the name?
a system for scientific naming of organisms within an internationally accepted set of rules
once species have been determined to be a novel and the relationship to other related species determined, the taxonomist can choose a name
new name can relate to some characteristic of the new organism such as shape, colour, size, geographic location, or may be named in honour of somone
genus is always-
capitalized while the specific epithet remians in lower case
always italic or underlined
Helianthus annuus
when refereing to more than one genus, it is written as Helianthus spp.
if the species name in unknown you can use Helianthus sp. (sp is regular font)
binomial
a two-part latin name
always written out in full the first time, then the genus can be abbreviated
H. annuus
Hierarchy
a wolf is first recognized as Eukarya (Domain), then as an animal (Kingdom), then Chordata (Phylum), mammmalia (class), Carnivora (order), canidae (family)
what is the entire hierarchy from most to least inclusive?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, species
(DOGS KICK PEOPLE CUZ OLDER FEMALES GOT SPICEY)
how do trees work
-the names along the top of the figure are the taxa (taxon)
-the line connecting each taxon is a branch and the point where two or more branches connect is called the node
-the node represents the common ancestor of the taxa at the end of the connecting branches.
we can trace related taxa back to a common ancestor from which the inherited specific traits
identification
dichotomous keys are useful and are the fastest and most reliable method
keys are contructed in a series of paired, mutually exclusive statements (couplets) that divide a set of objects into smaller groups in a series of steps
at each step you will choose between two statements, then either determine or move to another couplet
another word for dichtomous key
taxonomic
rules to dichotomous keys
-each step requires a couplet with mutually exclusive characteristics
-couplets are designated by numbers and statements within the couplet by lower case letters 1a and 1b
-each step in a group distinguishes the organisms into two smaller units where each unit either identifies and names an object or gives directions as to where to go next in the key
-the beginning couplets tend to focus on more general characteristics while later couplets refer to increasingly specific traits
-couplets should not be based on statements of relative size, subtle differences in colour, general shape, etc. as these characteristics can be ambiguous, can change in preserved specimens, and often are only distinguishable if all aspects can be compared in the specimens
-each couplet should contain more than one characteristic in case some features are not distungishable on the specimen. it is not good form to use the statement “not above characters”
2 scales of evolution
microevoluton
macroevolution
evolution occurs through
natural selection
gene flow
genetic drift
mutations and adaptations
-random changes in DNA
-Favourbale changes are preserved
allele
an alternative version of a specific gene
genotype
genetic composion of an organism
phenotype
expression of measurable triats based on genotype
population
a group of individuals sharing the same space and time
gene pool
the total number and kind of alleles in genes of interest in a population
natural selection
-observations
-variation among individual inherited traits
-not all offsrping survive to reproduce due to competition for limited resources
-inferences
-best adapted individuals leave more offspring
-most favorable traits passed on
evolution via natural selection
-heritability
-veriabliity
-reproductive advantage
evidence for adaptive evolution sea urchin
-they belong to phylum echinodermata
-dwell on ocean floor and tidal zones
-bilateral larvae
-secondary radial symmetry as adults
-spiny calcareous endoskeleton
-well developed body cavity
-unique locomotion, feeding and gas exchange (water vascular system)
-complete digestive tract