Bio Ch 27 Flashcards Need to Know

Features of Animals (8)

multicellular, complex tissues, heterotrophy (gets energy through consumption), active movements, diversity (form + size), sexual reproduction (haploid gametes —> diploid zygote), offspring have developmental stages, body planes

Traits of Complex tissue (2)

• no cell wall

• gap junction (intercellular communication)

Connective Tissue

-provides support in extracellular matrix (cartilage, bones)

Epithelial Tissue

covers internal + external body surfaces

Nervous Tissue

communication via electrical signals for movement

Muscle Tissue

contraction for physical movement

Explain the process of complex tissue formation

Cleavge: miotic cell division (after 3 divisons becomes 8 cell stage)

-does not increase in size, remains in zygote size

Blastula cross section: (6-32 cell, hollow ball with one layer of cells on outside and blastocoel inside

Grastulation: cells begin to fold inward, opening —> blastopore, more folding = complex tissue forming

What does invagination in grastulation form?

Blastopore (opening) and archenteron (embroyotic gut —> digestive tract)

How are animals classified

symmetry, tissue layers, origin of mouth + anus, body plans + cavities

Endoderm

(mucosal epithelium, inner lining), inner lining of GI tract, respritory system, endocrine glands, urinary + reproductive lining

Mesoderm

muscle tissue, connective tissue

ectoderm

covers nervous system + kerantized epithelium (skin, outer layer)

Traits of coelom/body cavity

-defines triploblast

-dervied from mesoderm

-fluid filled for shock abosrbtion

-organs move within cavity

Acoelmates

lack body cavity, instead of mesoderm has tissue (ex: platyhelments (flatworms))

Pseudocoelmates

-partially lined w mesoderm

-endo + meso

-nematodes

Coelmates

-completly lined with mesoderm

-tissue holds organs in place, allowing motion

2 types of coelmates

protosomes and duetoerosomes

protosomes and duetoerosomes formation of mouth/anus

protosomes=mouth 1st anus 2nd

duetersomes= anus 1st mouth 2nd

Cleavge patterns of protosomes

-sprial cleavege pattern on embryo

Determinate Cleavege: cell already specialized

Clevage patterns of dueterosomes

-radial cleavege (in 90 degrees)

-Indeterminate Cleveage: fate of cell determiend later

Why classifying by morphological traits is misleading

-convergent evolution, characters lost

common ancestor of eumetazoa and parazoa

chanoflagulete

eumetazoa (2) clades

-radiata (cnidaria, ctempohora), bilateria (all other animals)

2 clades of bilateria

deuterosomes, protosomes

Clades of Protosomes

Lophotrohoza, Ecdysoza

Clades of Deuterosomes

Echinoderm (starfish), Chordates (vertebrae)

What characterizes lophotrochoza

lopho for feeding stage or trochoza for larvae

What characterizes Ecdysoza

exoskeleton molting

What clades are in ecdysoza

nematods (roundworms), arthropods (joints in exoskeleton)

Traits of Radiata

-no body cavity (b/c no mesoderm) but do have gastrocavity (cnidraia)

-ctenphorenes (full digestive tract)

Cambrian Explosion (7 main points)

-increased O2, reduced CO2

-planet cooled

-more complex ecology —> stable ecosystem

-high ocean Ca levels

-predator/prey relationships

-new gene innovations (ex: Hox)

-shallow seas=ecosystem variety

end of Ordovician extinction

450 MYA

end of Denovian

375 MYA

end of Permian

250 MYA

end Trissac

200 MYA

end Crutaseous

75 MYA

Which extinction is called the “Great Dying” and Why?

Permian Triassic Boundry, cause: lots of climate change + volcanic activity

effect: no more dinosaurs

Describe Hox genes

almost homoglous across all animals, determines body plans. Regulates genes via transription factors. Highly conserved

benefits of a coelom

helps with movement