(1) Life & Architecture / Development Flashcards
Protoplasmic Grade
Unicellular organism, differentiated into organelles capable of performing specialised functions
Example;
(Archae)bacteria/(Eu)bacteria
Most Protista
Cellular/Cell Aggregate Grade
Aggregation of cells that are functionally differentiated
-No tissue
Example:
Multicellular Protista
Phylum Porifera (sponge)
Cell-Tissue Grade
a group of cells united to perform a clear function together
-no organs
Example:
Phylum Cnidaria (jellyfish, sea anemone)
Organ-Tissue Grade
More specialised, múltiple tissues
- no organ systems
Example:
Phylum Platyhelminthes (flatworms)
Organ System
Everything else
Example:
Phylum Nematoda (roundworms), Mollusca, Annelida (earthworms), Arthropoda, Chordata (vertebrates)
*organisms are classified according to their highest level of organisation
Body Fluids- Intracellular
Cytoplasm
- 36% human body weight
Body Fluids- Extracellular
a). Blood plasma
- within blood vessels/heart
- 4%
b). Interstitial fluid
- surrounding cells
- 20%
Body Plans
- Unicellular vs Multicellular
- Cell aggregate vs tissue
- Radical va bilateral symmetry
Acoelomate
-no body cavity vs tube-within-tube design (does have a cavity)
Example:
Phylum Platyhelminthes (tapeworms)
Coelom
Body cavity
Pseudo
False
Pseudocoelomate
Body cavity not entirely lined with mesoderm
Example:
Phylum Nematoda or roundworms
Eucoelomate
Entire body cavity lined with mesoderm
Example:
Phylum Annelida (earthworms), Mollusca, Arthropoda, Chordata (vertebrates)
Deuterostomes vs Protostomes
Deuterostomes: anus forms first
Protostomes: mouth forms first
Metemerism
Having a body segmentation
Example:
Annelida (earthworms), Arthropoda, Chordata (fish)
Cephalization
Having a head
Example:
Annelida (earthworms), Arthropoda, Chordata (fish)
*earthworms don’t really have a head
Gamete Formation
Spermatogenesis/oogenesis
Preformation
Miniature embryo in gambete(s) “unfolds”
NO
Epigenesis
Fertilised egg contains raw materials only, that assemble
YES
Purposes of Fertilization
- Provide for genetic diversity
- Restore diploidy (full # of chromosomes)
- Activate egg - revises active metabolisms
Events of Development
- Jelly Layer
- Fusion
- Fertilisation cone
- Polyspermy prevention
- Male and female pronuclei
- Removal of inhibitors
- Egg cytoplasm
- Jelly Layer
Penetrated by sperm
- Fusion with vitelline envelope
If egg recognition and sperm receptor proteins match
- Fertilised cone
Draws sperm head in
- Polyspermy prevention
No mote than one
a. Electrical potential change to vitelline membrane
- blocks other sperms fusion=“fast block”
b. Cortical reaction: lifts vitelline envelope away
c. Envelope hardens = fertilisation membrane = “slows block”
- Male and Female
Pronuclei (1N+1N)
- Removal of inhibitors
To egg metabolism
- Egg cytoplasm
Spatially reorganises
Egg cleaves
Blastomeres
(It divides to create embryo)
Isolecithal (yolk amount and distribution)
Sparse, evenly distributed yolk
Example:
Mammals, starfish, insects
Iso= same
Mesolecithal (yolk amount and distribution)
Moderate amount of yolk at one end
Example:
Amphibians
Meso= middle
Telolecithal (yolk amount and distribution)
Mostly dense yolk; only a dice of cytoplasm on surface divides
Example: birds, reptiles, egg-laying mammals, fish
Telo= ends
Holoblastic
While egg cleaved
(yolk slows but does not prevent it)
Example:
Isolecithal and mesolecithal
Meroblastic
Only cytoplasm cleaved
(yolk too dense to cleave)
Example:
Telolecithial
What is life?
DNA
Cellular
Complex
Grow and develop
Metabolism
Reproduce
Respond to stimuli
Homeostasis
What is an animal?
Multicellular heterotroph
Is motile during some point of its life
Entomology
Study of bugs
Icthyology
Study of fish
Herpetology
Study of reptiles and amphibians
Ornithology
Study of birds
Mammalogy
Study of mammals
Microbiology
Study of Protozoa, virus, etc
Histology
Study of tissues
Ecology
Study of interactions
Telolecithal (significance of yolk amount)
Embryo development slow/more complete relying on extensive yolk
Example:
egg laying vertebrates (birds, reptiles, egg mammals, fish)
Isolecithal & Mesolecithal (significance of yolk amount)
placenta nourishes embryo, or egg develops quickly into self-feeding larva
Example:
mammals, amphibians, insects
Indirect Development
egg-larva-pupa-adult
Metamorphosis
*most iso and meso eggs
Direct Development
egg-embryo-adult
*placental mammals and telo eggs
Blastula
hollow balls of cells
Blastocoel
blastula’s cavity
Gastrulation
make the stomach
Invagination (Gastrulation)
blastula intended -> gastrula
Archenteron (Gastrulation)
Primitive gut
Blastopore (Gastrulation)
gut’s opening
Protostome (Blastopore)
blastopore forms mouth first
Example:
arthropoda, molluscs, worms, etc
Deuterostomes (Blastopore)
Blastopore forms anus first
Example: chordates, echinodermata
End result - three germ layers (Gastrulation)
- Ectoderm
- Mesoderm
- Endoderm
Ectoderm (three germ layers)
forms external epithelium, nervous system
Mesoderm (three germ layers)
forms muscle tissue, bone, cartilage, repro system, circulatory system, body cavity lining (peritoneum)
Endoderm (three germ layers)
forms lining of digestive system
Induction (embryonic)
cells in particular regions of developing embryo determine the developmental response of neighboring cells
Primary organizer (embryonic)
region of dorsal lip of gastrula’s blastopore responsible for PRIMARY INDUCTION event leading to complete embryo
Secondary Induction (embryonic)
one tissue induced to differentiate induces another tissue, and so on
Homeotic Genes (gene expression)
specify the identity of specific body segments
Example: thorax with legs
Homeotic Mutation (gene expression)
cause development of wrong structures in a given region
Amniotes
grouping of reptiles, birds, and mammals (terrestial)
Amnion (Extraembryonc membranes)
fluid filled; prevents dying, a shock absorber
Yok Sac (Extraembryonc membranes)
provides nourishment
Allantois (Extraembryonc membranes)
stores wastes, with chorion exchanges gases
Chorion (Extraembryonc membranes)
with allantois exchanges gases
