Vocabulary Flashcards
Extant
still in existance
Chemical evolution
formation of complex organic molecules from simpler inorganic molecules through chemical reactions
Organic evolution
the process by which changes in the genetic composition of populations of organisms occur in response to environmental changes
Homology
Similarity of parts or organs of different organism caused by evolutionary derivation from the corresponding part or organ in a common ancestor.
Perpetual Change
The living world is always changing
Reproductive barriers
biological barriers that prevent interbreeding
LUCA
Last Universal Common Ancestor
Homology
Character similarity resulting from common ancestry
Reproductive barriers
biological barriers that prevent interbreeding
Allopatric speciation
ancestral population geographically divided
Vicariant speciation
- Type of Allopatric speciation
- climate/geology causes populations to fragment
Founder Effect
a small number of individuals disperse to a distant place and form new populations
Sympatric speciation
diverging lineages co-occupy a geographic area
Gradualism
small changes accumulate steadily over time
Punctuated equilibirum
long periods of stasis, punctuated by brief events of speciation
Natural selection
organisms better adapted to their environment tend to survive and produce more offsprings
Adaptation
a change or the process of change by which an organism or species becomes better suited to its environment
Exaptation
process by which features acquire functions for which they were not originally adapted or selected
Modern synthesis
microevolution + macroevolution
Microevolution
evolutionary changes in frequencies of variant forms of genes within populations
Macroevolution:
Evolution on a long timescale
Mass extinction
extinction occurring simultaneously across many lineages
Interspecific hybrid
offspring produced by mating of individuals from two different species
Species
- Individuals descend from a common ancestral population
- reproductive compatibility
- genotypic and phenotypic cohesion (similarity)
Phylogeny
origin and diversification of any taxon, or the evolutionary history of its origin and diversification
Phylogenic tree
branching diagram showing the inferred evolutionary relationships among various biological species
Homoplasy
non-homologous similarities that may be found in various organisms –> arose independently of common ancestry
Cladistics
approach for classifying organisms based on common evolutionary descent
Cladogram
diagram used in cladistics to show evolutionary relationships between organisms
Clade
unit of evolutionary common descent that includes ancestral lineage and all descendants
Character
organismal feature that varies between species
Ancestral character
character state present in the common ancestor
Derived character
all other variant forms that arose later within the group
Monophyletic clade
includes most recent common ancestor and some but not all descendants of that ancestor
Paraphyletic clade
includes most recent common ancestor and some but not all descendants of that ancestor
Polyphyletic clade
includes all of the descendants of the most recent common ancestor without including that ancestor
Sexual reproduction
fusion of two specialized cells, or gametes
Muller’s Ratchet
accumulation of deleterious mutations in asexual reproduction
Binary Fission
- Asexual
Parent divides by mitosis into two parts. each grows into an individual similar to the parent
Multiple Fission
- Asexual
nucleus divides repeatedly. cytoplasmic division then produces many daughter cells simultaneously
Schizogony
= multiple fission
Budding
- asexual
unequal division of an organism
Gemmulation
- asexual
formation of a new individual from an aggregation of cells which are surrounded by a gemmule
gemmule
resistant capsule
Fragmentation
- asexual
= binary fission for multicellular organisms
Breaks into two or more fragments that become a new individual
“twofold” cost of sex
males do not directly produce offspring
Bisexual reproduction
- sexual
- male and female gametes are produced
- 2 x n –> 2n
Hermaphroditism
- sexual
male and female organs occur in the same individual
Parthenogenesis
- both asexual and sexual reproduction
- embryo develops from an unfertilized egg. sperm activates egg but does not fuse with it.
Dioecious
Having male and female gonads in separate individuals
Monoecious
having both male and female gonads in the same organism - hermaphroditic
Oviparous
- external or internal fertilization
- eggs are released by the female –> development of offspring occurs outside maternal body
Viviparous
- internal fertilization
- eggs develop within female body –> nutritional aid
Ovoviviparous
- internal fertilization
- eggs develop within the maternal body without nutritional aid
- eggs either hatch within the parent of immediately after laying
Ontogeny
developmental history of an organism throughout its entire life
Gamete formation
sperm and eggs form, mature
fertilization
egg and sperm fuse –> zygote
Cleavage
embryo divides repeatedly without growth
Blastomeres
smaller egg cells that were once a single large egg cell
Blastula
The zygote after cleavage
blastocoel
fluid-filled cavity where egg cells are formed
Gastrulation
converts blastula into germ layers
organogenesis
organ development from specific germ layers + formation of the nervous system from the ectoderm
Egg
organic vessel where an embryo develops (ovum)
ovum
the female reproductive or germ cell
Germ cell
a haploid cell whose fertilization by one of the opposite kind produces a diploid zygote
gamete
mature haploid sex cell
Animal pole
contains most of the cytoplasm and nucleus
Vegetal pole
contains most of the yolk
Isolecithal
very little yolk, evenly distributed through egg
Mesolecithal
moderate amount of yolk concentrated at vegetal pole
Telolecithal
abundance of yolk densely concentrated at vegetal pole
centrolecithal
large centrally located mass of yolk
Direct development
embryo –> miniature adult –> full-grown adult
Indirect development
passes through larval stage –> metamorphosis
Holoblastic cleavage
complete and approximately equal division of cells
Meroblastic cleavage
restricted to small area of egg
invagination
one side of the blastula bends inwards
gut cavity
internal pouch
archenteron
= gut cavity = internal pouch
gastrocoel
= gut cavity = internal pouch
blastopore
opening of the gut cavity
ectoderm
outer layer of cells lining the blastocoel
endoderm
inner layer of cells lining gut
blind gut
when the gut opens only at the blastopore
complete gut
gut has two opening. second = the anus
mesoderm
third layer formed from the endoderm
coelom
cavity completely surrounded by mesoderm
diploblastic
two germ layers
triploblastic
three germ layers
Schizocoely
- formation of coelom
- band of mesoderm forms around gut first, then coelom is formed
Enterocoely
- formation of coelom
- sides of endoderm push outward into coelomic compartment that then pinches off.
Acoelomate
- Schizocoely
- no coelom
pseudocoelomate
- schizocoely
- fake coelom not surrounded completely by mesoderm
eucoelomate
- schizocoely, enterocoely
- true coelom
cytoplasmic determinants
organelles, mRNAs, enzymes, transcription factors…
cytoplasmic specification
unequal blastomeres that fate’s is determined by cytoplasmic determinants
mosaic development
each of the early blastomeres that are dissociated lacks the potential of developing into a complete organism, and removing a blastomere eliminates a future body part.
conditional specification
cell fate is not fixed until it receives positional information from neighbouring cells
induction
capacity of some cells to evoke a developmental response from other cells
regulative development
what a cell becomes depends upon its position in the embryo. if cells are removed from the embryo, the remaining cells can regulate and compensate for the missing part
polytomy
a node on phylogeny where more than two lineages descend from a single common ancestor`
flagella
whip-like organelle
cilia
hair-like organelle
pseudopodia
temporary cytoplasmic protrusion extended out from an ameboid cell.
Undulipodia
cilia + flagella
ectoplasm
semi-solid outer layer of cytoplasm
endoplasm
inner fluid of cytoplasm
test
shell outside amoebas
holozoic feeders
ingest visible particles of food
saprozoic feeders
ingest food in a soluble form
cytostome
cell mouth in unicellular eukaryotes
cytoproct
anus of unicellular eukaryotes
conjugation
- sexual reproduction
- temporary union of two individuals to exchange chromosomal material
apicomplexa
phylum of parasitic protists
endoparasites
live within another organisms
ectoparasite
live outside of host
Plasmodium
protozoan that causes malaria
definite host
the host where symbiont matures and reproduces
intermediate host
host where development of a symbiont may occur.
sporogony
special case of schizogony
protoplasmic
unicellular organism organismal complexity
cellular complexity
can be colonial or multicellular
chitin
- nitrogenous polysaccharide
- fungi cell wall
- exoskeleton of arthropods
extracellular digestion
release digestive enzymes into the environment and then absorb nutrient through their cell walls
asconoid
flagellated spongocoel
syconoid
flagellated canals
leuconoid
flagellated chambers
ostia
spores for incoming water
oscula
spore for water outlet
pinanocytes
epithelial cell. protective and contractile
porocytes
pore cells found only in asconoid sponges
choanocytes
flagellated collar cells
mesohyl
ECM in sponges
microvilli
absorption of food on choanocytes
archeocytes
amoeboid cells
collencytes
secrete collagen
spongin
a form of collagen. forms the skeletal network of some sponges
spicules
many different shape - skeleton of sponges
cephalization
the differentiation of a head region and the concentration of nervous tissues and sense organs in the front area
frontal plane
divides body into dorsal and ventral halves
sagittal plane
divides body to right and left
transverse plane
divides body into anterior and posterior halves
eumetazoa
multicellular animal with distinct germ layers
substratum
solid surface
mesoglea
jellylike layer between tissues of polyp and medusa that gives the form its buoyancy
intracellular digestion
phagocytosis of food particles
head-foot
well-developed head with mouth and sensory organs
radula
rasping tonguelike organ found in most molluscs
mantle
sheath of skin, extending the visceral mass
- protects and secretes the shell
mantle cavity
houses respiratory organs
participates in gas exchange
trochophore larvae
free-swimming ciliated marine larvae
veliger larva
free-swimming larva of most marine snails and bivalves
closed circulatory system
blood is contained within vessels
open circulatory system
blood is confined to vessels in only a portion of circuit through body.
hemolymph
blood mixed with fluid in the hemocoel
ocelli
simple eye
pen
internal shell in cephalopods
cuticle
external skeleton in arthropods and nematodes
ecdysis
shedding of outer cuticle
metamerism
segmentation
tagmata
compound body section of an arthropod resulting from embryonic fusion of two or more segments
appendage
external attachment
tracheae
system of air tubes for gas exchange
insight learning
when faced with a new problem, can organize memories to construct a new response
metamorphosis
sharp change in form during post-embryonic development
ametabolous
direct development - no metamorphosis
- egg, juvenile, adult
hemimetabolous
incomplete metamorphosis
- egg, nymph, adult
holometabolous
complete metamorphosis
- egg, larva, pupa, adult
cnidocytes
stinging cells
cnida
stinging organelle
nematocyst
most common type of cnida
cnidocil
modified cilium that triggers the nematocyst to fire
