Module 1 Overview (Biodiversity) Flashcards
How old is Earth?
4.6 billion years old
ORDER the EONS that describe the HISTORY OF EARTH from OLDEST to MOST RECENT
Hadean (4.6 - 4.0 BYA) - BEFORE LIFE
Archaean (4.0 - 2.5 BYA) - EARLY LIFE
Proterozoic (2.5 - 542 MYA) - OXYGEN ACCUMULATION & FLOURISHING OF EARLY LIFE
Phanerozoic (542 MYA - present!) PROLIFERATION OF PLANT AND ANIMAL LIFE
How is the HISTORY OF EARTH arranged in terms of GREATEST TIME SCALE to SMALLEST SCALE
Eons, Eras, Period, MYA
What the THREE PRIMARY DOMAINS OF LIFE?
Eukarya, Bacteria, Archaea
How do EUKARYA differ from both BACTERIA AND ARCHAEA in a PHYSICAL SENSE?
BACTERIA AND ARCHAEA are SINGLE CELLED MICROORGANISMS WITH NO NUCLEI (PROKARYOTES) and ALL HAVE CELL WALLS
EUKARYA are different in that they have NUCLEI THAT ARE MEMBRANE BOUND FROM THE REST OF THE CELL (EUKARYOTES) and NOT ALL HAVE CELL WALLS
How do ARCHAEA AND BACTERIA REPRODUCE? EUKARYA?
Generally through BINARY FISSION (creates EXACT REPLICAS of the PARENT GENERATION UNLESS MUTATIONS***)
EUKARYA reproduce and differentiate through MITOSIS AND MEIOSIS (results in a mix of GENETIC MATERIAL - GAMETES HAPLOID)
T/F: ARCHAEA are MORE CLOSELY RELATED to BACTERIA than EUKARYA
FALSE!
ARCHAEA are more CLOSELY RELATED to EUKARYA when considering the PHYLOGENETIC TREE despite how similar they seem to BACTERIA.
WHY can PROKARYOTES occupy a BROAD SET OF ENVIRONMENTS?
Primary reason? Their DIVERSE METABOLIC CAPACITY AND PROCESSES!
PHOTOTROPHS - OBTAIN ENERGY FROM SUNLIGHT
CHEMOTROPHS - OBTAIN ENERGY FROM CHEMICAL COMPOUNDS
ALSO, they have DIFFERENT SOURCES OF CARBON
AUTOTROPHS - CAN FIX THEIR OWN CARBON
HETERTROPHS - CANNOT FIX THEIR OWN CARBON
these diversifications lead to a host of important differences that allow for PROKARYOTES to live in such a BROAD RANGE OF ENVIRONMENTS!
(https://bpb-us-w2.wpmucdn.com/sites.gatech.edu/dist/6/1810/files/2018/12/metabolic-classification-of-organisms.png)
T/F: BACTERIAL PLASMIDS have no INTRONS
TRUE!
The GENETIC SEQUENCES in EUKARYOTES carry INTRONS!
What is the BACTERIAL CELL WALL made from?
PEPTIDOGLYCAN (a STRONG POLYSACCHARIDE that can form MANY LINKAGES to STRENGTHEN ITSELF)
T/F: BACTERIA have ONE MORPHOLOGICAL STATE
FALSE!
Bacteria have DIFFERENT MORPHOLOGIES, including a COCCUS, BACILLUS, TETRAD, etc!
How do we CLASSIFY BACTERIA?
MORPHOLOGY and GRAM STAIN (GRAM NEGATIVE OR GRAM POSITIVE)
DESCRIBE the DIFFERENCE between GRAM POSITIVE and GRAM NEGATIVE
GRAM NEGATIVE stain LESS BRIGHTLY since they have a OUTER MEMBRANE COVERING CELL WALL (harder to pierce the PEPTIDOGLYCAN)
GRAM POSITIVE stain MORE BRIGHTLY - have NO MEMBRANE covering the CELL WALL
(easier to reach PEPTIDOGLYCAN)
What are THREE DIFFERENT WAYS by which BACTERIA can share GENETIC INFORMATION?
TRANSFORMATION —-> picking up something loose from the enviornment
TRANSDUCTION —–> virus infects one and the other CONJUGATION —–> pilus attatch and share information
What is QUORUM SENSING?
HOW BACTERIA COMMUNICATE WITH ONE ANOTHER!
This is HOW IT WORKS:
Bacteria RELEASE GENE REGULATORS known as AUTOINDUCERS, and they are RESPONDERS to fluctuations in CELL-POPULATION DENSITY
What FEATURES make ARCHAEA UNIQUE from the OTHER TWO DOMAINS OF LIFE?
CELL WALL DOES NOT CONTAIN PETIDOGLYCAN!
MEMBRANES ARE:
ETHER-LINKED INSTEAD OF ESTER-LINKED
BRANCHED HYDROCARBONS/ISOPRENOID CHAINS INSTEAD OF FATTY ACID CHAINS
MONOLAYERS AT TIMES INSTEAD OF BILAYERS
T/F OXYGEN ACCUMULATED QUICKLY DURING THE OXYGEN REVOLUTION
FALSE!
Evidence shows that the OCEANS weren’t fully OXYGENATED until 850 MYA and the SLOW ACCUMULATION OF OXYGEN can also be seen through the BANDED IRON FORMATIONS IN SEDIMENTARY ROCKS when free oxygen reacted with iron to form IRON OXIDE
During what EON did THE OXYGEN REVOLUTION/CATASTROPHE OCCUR?
Proterozoic
During what EON did THE CAMBRIAN EXPLOSION OCCUR?
Phanerozoic
What are TWO EXTREMELY IMPORTANT WAYS that PROKARYOTES impact HUMAN HEALTH?
Biological nitrogen fixation (BNF) and bioremediation
DESCRIBE the nature of the ENDOSYMBIOSIS THEORY
The ENDOSYMBIOSIS THEORY says that EUKARYOTES AROSE from an ARCHAEA ENGLUFING AN ANCIENT BACTERIAL CELL —> MUTUALISTIC RELATIONSHIP —> can tell that this occured because of the PRESENCE OF MITOCHONDRIA AND CHLOROPLASTS (in plant cells) and CELLS CAN’T REFORM THESE (come from REPRODUCTION) and they ALSO HAVE THEIR OWN DNA!
T/F The ENGULFMENT of a CYANOBACTERIA-LIKE ORGANISM has occured TWICE in the HISTORY OF PROKARYOTES
TRUE!
1) Englufment of cyanobacteria by Archaeplastida (MOST EVIDENT IN SPECIES)
2) Engulfment of cyanobacteria by Paulinella
What are some FORMS OF EVIDENCE for the ENDOSYMBIOSIS THEORY?
1) MITOCHONDRIA AND CHLOROPLASTS are CLOSE in SIZE to NORMAL PROKARYOTES
2) They have their OWN DNA (CIRCULAR CHROMOSOME that LACKS HISTONES)
3) Reproduce by BINARY FISSION, CELL CANNOT REPRODUCE ON THEIR OWN THROUGH OTHER MEANS (need TEMPLATE)
4) MEMBRANE COMPOSITION IS LIKE THAT OF PROKARYOTES
WHICH of the TWO (MITOCHONDRIA ENDOSYMBIOSIS and CHLOROPLASTS ENDOSYMBIOSIS) occured FIRST?
MITOCHONDRIAL ENDOSYMBIOSIS OCCURED FIRST because of the PRINCIPLE OF PARSIMONY (CHLOROPLASTS are not shared by all eukaryotes, only PHOTOSYNTHETIC ALGAE AND PLANTS)
WHAT are some FEATURES UNIQUE TO EUKARYOTES?
1) Cells with NUCLEI surrounded by a NUCLEAR ENVELOPE with NUCLEAR PORES
2) Presence of MITOCHONDRIA & CYTOSKELETON
3) LINEAR CHROMOSOMES (not CIRCULAR!)
4) MITOSIS AND MEIOSIS (some exceptions that don’t perform MEIOSIS)
T/F FOR EUKARYOTES, A SEXUAL LIFE CYCLE ALWAYS includes TWO CHANGES IN PLOIDY
TRUE!
MEIOSIS —> 2n to 1n
FERTILIZATION —-> 1n to 2n
WHAT are the THREE SEXUAL LIFE CYCLES UNDERPINNED by CHANGES IN PLOIDY
HAPLONTIC, DIPLONTIC, & HAPLODIPLONTIC (ALTERNATION OF GENERATIONS)
Describe the HAPLONTIC LIFE CYCLE
The HAPLOID STAGE is MULTICELLULAR and the DIPLOID STAGE is a SINGLE cell (FERTILIZED EGG) —> MEIOSIS occurs in the EGG immediately after FERTILIZATION —-> HAPLOID SPORES FORM —-> SPORES BECOME HAPLOID MULTICELLULAR ORGANISMS BY MITOSIS
Describe the DIPLONTIC LIFE CYCLE
The DIPLOID STAGE is MULTICELLULAR AND PRODUCES HAPLOID GAMETES —-> HAPLOID GAMETES produced by MEIOSIS over MITOSIS —> SPORES are NOT PRODUCED
Describe the ALTERNATION OF GENERATIONS
have BOTH a MULTICELLULAR DIPLOID AND HAPLOID STAGE —> DIPLOID MULTICELLULAR ORGANISMS CALLED “SPORAPHYTES” AND HAPLOID GAMETOPHYTES PRODUCE HAPLOID GAMETES BY MITOSIS CALLED “GAMETOPHYTES
What are some ROLES protists play?
Decomposers, human pathogens/parasites, photosynthesis, plant pathogens/parasites
WHERE on a PHYLOGENETIC TREE would you find LAND PLANTS?
You would most probably find them lumped together with other EUKARYOTES, but on its own clade seperate from ANIMALS and FUNGI
–> WHY? The PRESENCE OF CHLOROPLASTS IS SPECIAL TO THESE EUKARYOTIC CELLS!
WHAT is the SUPPOSED ANCESTOR of LAND PLANTS?
An AQUATIC, green, ALGAE-LIKE species
WHAT are some ADVANTAGES to living on WATER over LAND for PLANT SPECIES?
1) Plants can ABSORB WATER without the use of a SPECIALIZED TISSUE/ORGAN SYSTEM and without the worry of DESSICATION
2) WATER provides a special type of BUOYANCY, provides STRUCTURAL SUPPORT not found on land
3) SPERM AND EGG can find each other EASILY IN WATER and don’t need PROTECTION FROM DESSICATION (unlike on land)
4) WATER filters out a good bit of UV LIGHT (DESTRUCTIVE TO DNA)
WHAT are some REASONS that LAND PLANTS EVOLVED TO LIVE ON LAND?
-Presence of SUNLIGHT - much better in the open rather than in the water, vital for GROWTH
-carbon dioxide more READILY AVAILABLE in AIR OVER WATER (diffuses FASTER in AIR)
-TECHNICALLY, land plants evolved BEFORE land animals (lack of predation beforehand), afterwards, selective pressures promoted TOXINS, ADAPTATIONS, ETC.
WHY are EUKARYA and ARCHAEA considered more CLOSE that to BACTERIA?
Presence of HISTONES!
What ADAPTATIONS or CHARACTERISTICS are present in nearly ALL LAND PLANTS?
A waxy cuticle, stomata, roots, mutualistc realtionship with mycorrhizal fungi, and alternation of generations
Describe the PURPOSE of a WAXY CUTICLE
COVERS the OUTSIDE SURFACE of a plant and PREVENTS DEHYDRATION and RADIATION DAMAGE
Describe the STRUCTURE and PUROSE of STOMATA
PORES or HOLES that allow for the EXCHANGE OF GASES, NECESSARY in LAND PLANTS because the CUTICLE BLOCKS free exchange of gases
Describe the PURPOSE of ROOTS or ROOT-LIKE STRUCTURES
ANCHOR PLANTS TO SOIL and act a CONDUIT FOR WATER ABSORPTION
NOTE: BYROPHYTES DO NOT HAVE TRUE ROOTS, HAVE STRUCTURES CALLED RHIZOIDS THAT ANCHOR TO SUBSTRATE BUT DO NOT FACILITATE WATER ABSORPTION —-> they can only survive in extremely moist environments tho so it don’t rly matter for them anyways
Describe the ORDERING of EVOLUTION of LAND PLANTS
Bryophytes (non-vascular plants) < Seedless Vascular (Lycophytes, ferms and horsetails) < Gymnosperms (Seeded, non-flowering plants) < Angiosperms (Flowers, fruits, etc)
Describe the PRIMARY FEATURES (PROS AND CONS) of BRYOPHYTES
WAXY CUTICLE and ROOT-LIKE STRUCTURES (RHIZOIDS) are MAJOR ADAPTATIONS needed for LIFE ON LAND
STILL HEAVILY WATER DEPENDENT***
LIVE in MOIST environments near WATER, V SHORT (no mechanisms for moving water against gravity), SPERM AND EGG TRAVEL IN WATER, GAMETES NOT PROTECTED, etc.
Describe the PRIMARY FEATURES OF NON-SEEDED VASCULAR PLANTS and ADVANTAGES OVER BRYOPHYTES
VASCULAR TISSUE (XYLEM –> WATER AND PHLOEM —> SUGARS) —> could be TALLER than BRYOPHYTES
LIGNIN EVOLVED IN THIS GROUP (GREATER STRUCTURAL SUPPORT AND BETTER FIGHT AGAINST GRAVITY)
TRUE ROOTS (deeper than RHIZOIDS, better for extracting WATER AND NUTRIENTS)
still dependent on WATER (sperm and egg situation, gametes not protected, same bs)
DESCRIBE the PRIMARY FEATURES of SEEDED VASCULAR PLANTS and ADVANTAGE OVER NONSEEDED
TWO NEW FEATURES ALLOWED THEM TO COLONIZE DRIER HABITATS
-POLLEN (mechanism for delivering sperm to egg in the absence of water, protects sperm from desiccation)
-SEEDS (protects the FERTILIZED EGG FROM DESSICATION, halts development until FAVORABLE CONDITIONS FOR GERMINATION)
DESCRIBE the PRIMARY FEATURES of ANGIOSPERMS
Flowers - rely on POLLINATORS to move POLLEN (SPERM), less RANDOM than by WIND
-Double Fertilization and Endosperm - one sperm fertilizes the EGG to create AN EMBRYO and a second sperm fertilizes another structure NEXT TO THE EGG o create an ENDOSPERM (provides nutrients to EMBRYO AS IT GROWS)
-Fruits - any structure that aid in seed dispersal
WHICH PLANTS ARE SPOROPHYTE-DOMINATED LIFE CYCLES and which are GAMETOPHYTE-DOMINATED?
Gametophyte bigger in SEEDLESS NON-VASCULAR (BRYOPHYTES), SEEDLESS VASCULAR (has independent, free-living gametophyte),
ANGIO AND GYMNO HAVE bigger SPOROPHYTE
What PERIOD did LAND PLANTS first ARRIVE
ORDOVICIAN (paleozoic, phanerozoic)
What PERIOD did VASCULAR SEEDLESS PLANTS first ARRIVE
CARBONIFEROUS (paleozoic, phanerozoic)
What PERIOD did GYMNOSPERMS (VASCULAR, SEEDED PLANTS) first ARRIVE
JURASSIC (mesozoic, phanerozoic)
What PERIOD did ANGIOSPERMS first ARRIVE
CRETACEOUS (mesozoic, phanerozoic)
What CHARACTERISTICS do ALL FUNGI SHARE?
- chitin (tough polysacc) cell wall
- external digestion of food
Describe the TYPICAL FUNGAL CELL and its COMPONENTS
EUKARYOTIC IN NATURE
- TRUE NUCLEUS, MITCHONDRIA, INTERNAL MEMBRANE SYSTEM (ER & GOLGI)
-do NOT HAVE CHLOROPHYLL AND CHLOROPLASTS LIKE PLANT CELLS
-have a CELL WALL (CHITIN-BASED)
T/F FUNGI are typically MULTICELLULAR
TRUE!
-note: DIMOROPHIC FUNGI can CHANGE from MULTI TO UNICELLULAR based on ENVIRONMENTAL CONDITIONS
What are the TWO MORPHOLOGICAL STAGES of FUNGI?
VEGETATIVE (consists of slender HYPHAE) and REPRODUCTIVE (much more evident and NOTICABLE)
HOW are the TERMS HYPHAE and MYCELLIUM INTERTWINED?
HYPHAE are TINY THREAD-LIKE STRUCTURES that allow for the rapid movement of NUTRIENTS and SMALL MOLECULES across the fungal body
HYPHAE can form NETWORKS called MYCELLIUM that allow for the MOVEMENT
Describe the DIFFERENCE between PERFECT and IMPERFECT FUNGI
PERFECT FUNGI reproduce SEXUALLY and ASEXUALLY
IMPERFECT (or DEUTEROMYCETES) only reproduce ASEXUALLY (through MITOSIS)
Describe ASEXUAL FUNGAL REPRODUCTION
Most common is through the formation of ASEXUAL SPORES PRODUCED THROUGH MITOSIS OF ONE PARENT (GENETICALLY IDENTICAL)
-MUST be release OUTSIDE THE BODY or inside a special sac known as a SPORANGIUM
Describe SEXUAL FUNGAL REPRODUCTION
1) PLASMOGAMY - TWO HAPLOID CELLS FUSE –> DIKARYOTIC STAGE WHERE BOTH HAPLOID CELLS COEXIST (NOT TRUE DIPLOID TISSUE, n + n, not 2n!)
2) KARYOGAMY - HAPLOID NUCLEI fuse to form a DIPLOID ZYGOTE NUCLEUS
3) MEIOSIS - happens in GAMETANGIA ORGANS - gametes of different “mating types” (sort of like gender, but not) are created —> SPORES DISSEMINATED —> PROCESS STARTS ONCE MORE
WHAT are RHIZOIDS?
MODIFIED HYPHAE that attatch MYCELLIUM TO SUSBTRATE (RLY IMPORTANT TO BRYOPHYTES - NOT TRUE ROOTS!)
T/F NUCLEI of HYPHAE ARE SEPERATED
FALSE!
HYPHAE ARE NOT SEPERATED, THUS THESE CELLS ARE MULTINUCELATE AND NUCLEI ARE HAPLOID!
WHAT is the PURPOSE of MYCORRHIZHAL RELATIONSHIPS for FUNGI and PLANTS?
These associations allow for FASTER PLANT GROWTH
- PLANTS receive MINERALS FROM SOIL much more EFFICIENTLY
- FUNGUS receives ORGANIC MATERIALS AND CARBOHYDRATES LIKE SUGARS FROM PLANTS (PRODUCTS OF PHOTOSYNTHESIS!)
nearly 90% OF ALL PLANTS HAVE THESE ASSOCIATIONS (EXTREMELY BENEFICIAL)
Determine the DIFFERENCE between ARBUSCULAR MYCORRHIZA and ECTOMYCORRHIZA
ECTO - grow OVER THE TOP AND ALONG SURFACE
ARBUSCULAR - grow THROUGH CELL WALLS
WHAT TRAITS do all ANIMALS SHARE? (w/ MINOR EXCEPTIONS)
1) MULTICELLULAR BODY PLANS w/ CELLS THAT LACK CELL WALLS!
2) HETEROTROPHIC
3) MOVEMENT at SOME POINT IN LIFE CYCLE
4) NEURONS AND MUSCLE CELLS that can transmit SIGNALS AND CHANGE BODY SHAPE (EXCLUDING SPONGES***)
DEFINE an INVERTEBRATE ANIMAL
An INVERTEBRATE is an animal WITHOUT A CRANIUM and DEFINED VERTEBRAL COLUMN OR SPINE
- most also LACK AN ENDOSKELETON
WHAT is the SIMPLEST INVERTEBRATE?
PHYLUM PORIFERA! (SPONGES!)
WHY is WATER so IMPORTANT TO SPONGES?
NEEDED FOR EXCRETION, FEEDING, AND GAS EXCHANGE —> SPONGE’S BODY MOVES WATER THROUGHOUT FOR PRECISELY THIS REASON!
WHAT are the FOUR CLASSES of CNIDERIA?
HYDROZOA, ANTHOZOA, SCYPHOZOA, CUBOZOA
DETERMINE WHICH of these FOUR CLASSES are SESSILE, SWIMMING/MOTILE, OR BOTH
SESSILE: ANTHOZOA (sea anemones, corals)
MOTILE: CUBOZOA (box jellies), SCYPHOZOA (jellyfish)
BOTH: HYDROZOA
T/F CNIDERIA do not exhibit BILATERAL SYMMETRY
FALSE!
SOME CNIDERIANS ARE BILATERAL while other exhibit RADIAL SYMMETRY
DESCRIBE the TWO MORPHOLOGICAL STAGES of CNIDERIANS
POLYP AND MEDUSA
-POLYP forms are SESSILE as ADULTS with SINGLE OPENING to DIGESTIVE SYSTEM (MOUTH) facing UP with TENTACLES AROUND
-MEDUSA forms are MOTILE - mouth and tentacles HANG DOWN IN A BELL-SHAPE
-SOME CNIDERIANS ARE POLYMORPHIC AND CAN DISPLAY BOTH FORMS AT CERTAIN POINTS IN LIFE (EX. obelia)
https://bpb-us-w2.wpmucdn.com/sites.gatech.edu/dist/6/1810/files/2019/01/polypmedusa-1.jpg
WHAT are CNIDOCYTES and NEMATOCYSTS? WHAT is their PURPOSE?
Cnidocytes are specialized “stinging” cells that carry organelles known as nematocysts, or “stingers.”
Present around mouth and tentacles to immobilize prey with toxins
T/F CNIDERIANS have THREE MEMBRANE LAYERS
FALSE!
CNIDERIANS only have TWO, come from ectoderm and endoderm of embryo! (NO MESODERM!)
T/F CNIDERIANS have THREE MEMBRANE LAYERS
FALSE!
CNIDERIANS only have TWO, come from ectoderm and endoderm of embryo! (NO MESODERM!)
WHAT are PROTOSTOMES?
DESCRIBES ANIMALS WHERE THE BLASTOPORE becomes the MOUTH OPENING FOR THE FUTURE GUT (MOUTH DEVELOPS BEFORE ANUS, BOTTOM OPENING)
WHAT CLADES fall under PROTOSTOMES? WHAT PHYLUMS are within each of these CLASSIFICATIONS?
LOPHOTROCHOZOA - Flatworms, Rotifers, Worms, and Molluscs
ECDYSOZOA - Nematode Worms and Arthropods
DESCRIBE the common traits of the LOPHOTROCHOZOAN PHYLAS
-THREE LAYERS (INCLUDES MESODERM)
-ORIGINS OF CEPHALIZATION AS A RESULT OF SYMMETRY (NERVOUS TISSUES AND SENSORY ORGANS CENTERED IN AN ORGANISM’S HEAD)
-BILATERAL SYMMETRY
DESCRIBE the common traits of ECDYSOZOAN PHYLAS
-ECDYSIS - shedding or molting of the EXOSKELETON - HARD CUTICLE NEEDS TO SHED PERIODICALLY TO ADJUST FOR THEIR GROWN
DESCRIBE the KEY FEATURES of PHYLUM NAMATODA
-TRILOBLASTIC
-PSEUDOCOELEM
-BILATERAL
-MUSCLE DIFFERS FROM OTHER ANIMALS IN THAT IT IS A SINGLE LAYER —-> ALLOWS FOR WHIP-LIKE MOVEMENT
DESCRIBE the KEY FEATURES of PHYLUM ANTHROPODA
-LARGEST PHYLUM OF ANIMALIA
-terrestrial, aquatic, and aerial habitats
-FURTHER BROKEN DOWN INTO 5 SUBPHYLAS: Trilobitomorpha, Hexapoda, Myriapoda, Crustaceans, and Chelicerata
-functional SEGMENTATION of the body and presence of JOINTED APPENDAGES
-exoskeletons made primarily form CHITIN
T/F ALL CHORDATES are VERTABRATES
FALSE!
THIS PHYLUM HAS BOTH INVERTEBRATES AND VERTEBRATES!
WHAT are the key features of all CHORDATA
- a notochord,
- a dorsal hollow nerve cord
- pharyngeal slits
- a post-anal tail
What is the NOTOCHORD?
A ROD-LIKE, FLEXIBLE STRUCTURE that provides SUPPORT throughout the budy (found in ALL EMBRYONIC STAGES and some ADULT CHORDATES)
What is the DORSAL HOLLOW NERVE CORD?
Comes from ECTODERMAL TISSUE rolled into hollow tube (dorsal to notochord, hence the name) —-> develops later into brain and spinal cord (CNS)
other species have SOLID TUBES
What are PHARANGEAL SLITS?
OPENING IN PHARYNX (THROAT AREA) that EXTEND TO OUTSIDE ENVIRONMENT
-IN AQUATIC ENVIORNMENTS, allows for the EXIT OF WATER
-IN VERTEBRATE FISHES, modifies into GILL AND JAW SUPPORT FOR JAWED FISHES
-IN TETRAPODS, modified into ear and tonsil components
What is the POST-ANAL TAIL?
posterior elongation of the body, PROVIDES SOURCE OF MOVEMENT/LOCOMOTION (in humans, ITS VESTIGIAL)
