Ch 27 & 33 & 28 exam 3 Flashcards
What is the closest living relative of animals?
Choanoflagellates
What is the first branch off animals
sponges
most animals have:
differentiated cells, tissues, organs, organ systems
what two germ layers form first and which forms later?
endoderm and ectoderm form first
mesoderm forms later
Hox genes function:
determine body plan, segmentation, number placement of appendages ect. (develop during embroynic devleopment
Radial symmetry
body parts around central axis
usually sessile or planktonic
Bilateral symmetry
two axes of orientation: front to back and top to bottom
usual w head
cephalization
concentration of sense organs usually at anterior end of body (for bilateral symm)
Diploblastic
TWO germ layers
ectoderm
two germ layers: gives rise to outer covering and nerves
endoderm
2 germ layers: digestive tract; internal organs, lungs
triploblastic
3 germ layers
mesoderm
3 germ layer: muscle bone, blood, develops between ectoderm and endoderm
Coelom
body cavity: fluid-filled space between body wall and gut (digestive tract)
-formed from tissue from mesoderm
Two development patterns:
protostomes and deuterostomes
Protostomes development:
-coelom forms from splits int he mesoderm, the MOUTH forms from the blastopore
-spiral and DETERMINANT
Deuterostome development:
-coelom forms from mesodermal outpocketings of the archenteron, the mouth forms from a secondary opening, the ANUS develops at the sit of blastopore
-radial and INDETERMINATE
Three major clades in order from top to bottom
Deuterostomia
Lophotrochozoa
Ecdysozoa
4 Distinct periods of animal evolution
-neoproterozoic era
-palezoic era
-mesozoic era
-cenozoic era
Endothermic
animals generate heat by metabolism
-birds and mammals
Ectothermic
animals gain heat from external sources
-invertebrates, fish, amphibians
basal metabolic rate
average amount of energy used by an organism in a nonactive state
smaller animals take more energy
Torpor
physiological state in which activity is low and metabolism decreases
Hibernations
long term torpor that is an adaptation to winter and food scarcity
“Summer torpor”
estivation: enables survival of high temps and scarce water
acclimatization
homeostasis adjusting to changes in external environment
Thermoregulatory controled by
hypothalamus
Heat exchange by :
radiation
convection
conduction
evaporation
Heat regulation in animals uses what system?
integumentary system (sweat glands)
Five adaptations to help animals thermoregulate:
insulation
circulatory adaptations
cooling by evaporative heat loss
behavioral responses
adjusting metabolic heat production
4 types of tissues:
epithelial
connective
muscle
nervous
single epithelial tissue layer
simple
multiple epithelial tissue layers
stratified
connective tissues are made of ____ cells
fibroblasts
loose/areolar connective tissue: cells, fibers, location
fibroblasts, macrophages, lymphocytes, neutrophils
collagen, elastic, reticular
around blood vessels, anchors epithelia
dense, fibrous connective tissue: cells, fibers, location
fibroblasts, macrophages
mostly collagen
irregular: skin; regular: tendons, ligaments
cartilage: cells, fibers, location
chondrocytes, chondroblasts
hyaline: few: collagen fibrocartilage: large amount of collagen
bone: cells, fibers, location
osteoblasts, osteocytes, osteroclasts
some: collagen, elastic
vertebrate skeletons
adipose: cells, fibers, location
adipocytes
few
adipose (flat)
blood: cells, fibers, location
red blood cells, white blood cells
none
blood
3 types of muscle tissue
skeletal
smooth
cardiac
skeletal: control, striations, location
yes
yes
skeletal muscles
smooth: control, striations, location
no
no
visceral organs
cardiac: control, striations, location
no
yes
heart
main cell of nervous system
nerons
Dendrite in Neuron
projections from the cell body; receive input
astrocyte in neuron
regulate the chemical environment
oligodendrocyte in neuron
insulate the axon so the electrical nerve impulse is transferred more efficiently
axon terminals in neuron
ending of axons through which axons make synaptic contacts with other nerve cells
Porifera characteristics
sponges
aquatic
sessile
no tissues or cephalization
pinacocyte:
sponge cell: forms the outer covering of the sponge: phagocytize large food
oocyte
egg cell: sponge
choanocyte:
sponge; generates water current and filters food particles from water
sclerocyte:
sponge; secretes silica spicules
amoebocyte
sponge: delivers nutrients to cells, and differentiates into other cell types
porocyte:
sponge; control water through ostia
lophocyte or collenocyte
secretes collagen
Four types under amoebocyte
Spongocyte
Lophocyte
Collenoctye
Sclerocyte
Osculum
opening at tope of sponge
Ostia
separation/gap between cell parts
Mesohyl
cell part (cell that forms cell) gaps between are ostia
Spongocoel
the inside of cell body
Sponge body supported by
hard spicules and protein fibers (spongin)
Sponge repro asexually
fragmentation or budding
Sponge repro sexually
hermaphroditic (M/F at different times)
no gonads
flagellated larvae
Gametes form in ______ of sponge
mesohyl
