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ch 27 Flashcards

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1
Q

A series of key evolutionary adaptations led to

A

the major animal phyla.

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2
Q

Sponges are the simplest kind of animals. They lack

A

tissues and body symmetry and live attached to the sea floor, where they filter food particles from the water.

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3
Q

Cnidarians have

A

tissues, tentacles, and radial symmetry. They digest their food extracellularly, in a digestive cavity.

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4
Q

Flatworms lack

A

a body cavity and have bilateral symmetry, simple organs, and a digestive tract with a single opening.

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5
Q

Roundworms have

A

a body cavity (pseudocoelom), muscle tissue, and a gut that is open at two ends.

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6
Q

Mollusks, and all animal phyla that evolved after this group, have

A

a coelom, which enabled the formation of advanced body systems.

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7
Q

Segmented worms have evolved

A

complex body systems, including a nervous system and a circulatory system.

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8
Q

Arthropods, such as spiders, scorpions, crabs, and lobsters, are characterized by

A

jointed appendages and an exoskeleton.

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9
Q

Echinoderms and chordates have similar

A

patterns of development and very likely share a common ancestor

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10
Q

Echinoderms have

A

an endoskeleton, radial symmetry, a simple nervous system, and a water vascular system.

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11
Q

All chordates develop a

A

hollow dorsal nerve cord, notochord, and pharyngeal slits sometime during their lifetime. Vertebrates are chordates that have a cartilaginous or bony endoskeleton that includes a vertebral column.

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12
Q

Animal evolutionary stages:

A

multicellularity,
tissues,
bilateral symmetry (body parts growing around central point or axis),
body cavity/pseudocoelum(fluid filled cavity BETWEEN mesoderm and endoderm) and one way/two opening gut,
coelom (fluid filled cavity ENTIRELY within mesoderm),
segmentation,
jointed appendages and exoskeleton or endoskeleton,
deuterostomic development,
notochord.

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13
Q

Animals evolved from

A

a heterotrophic protist

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14
Q

Most animals live where

A

in water.

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15
Q

Animals are

A

heterotrophs – most ingest food b4 digesting.

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16
Q

99% of animals are

A

invertebrates (sans backbone)

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17
Q

35 phyla in

A

the animal kingdom, most in sea less in fresh water and much less on land.

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18
Q

3 phyla dominate land life:

A

Arthropoda (spiders, insects & crustaceans), Mollusca (snails) and Chordata (most backboned).

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19
Q

Animals cells lack

A

cell wall – flexible

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20
Q

Cells of animals (except sponges) organized into

A

structural & functional units called tissues.

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21
Q

Ability to move by contraction of muscle cells is

A

outstanding characteristic of animals (except sponges).

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22
Q

Most animals reproduce how

A

sexually with motile sperm and non-motile egg (both are the only haploid cells).

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23
Q

Sponges

A

simplest animals, no symmetry, most live in salt water, no tissues or organs, digest food by endocytosis, multicellular, do have key property of animal cells – able to recognize other body cells.

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24
Q

Internal cavity of sponges lined with

A

choanocytes (AKA collar cells) that have flagella that beat and draw water through sponge pores which filter for food.

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25
All other animals have tissues and symmetry and
are eumetazoans “true animals”.
26
3 tissues of eumetazoans:
Ectoderm Mesoderm Endoderm
27
Ectoderm
outer layer develops epidermis (skin) and nervous system
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Mesoderm
middle layer develops skeleton and muscles
29
Endoderm
inner layer develops digestive system and digestive organs
30
Cnidaria and Ctenophora
two primitive eumetazoan phyla
31
Cnidaria and Ctenophora exhibit
radial symmetry, specialized tissue, extracelluar digestion of food in a digestion cavity
32
Cnidaria include
jellyfish, anemone, hydra and coral – all carnivores.
33
Stinging cells called cnidocytes have
small barbed harpoons called nematocysts which spears prey. Two forms: free floating medusae and attached polyps. Some life cycles go through both phases.
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cnidocytes
Stinging cells
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nematocysts
small barbed harpoons which spears prey
36
All eumetazoans except Cnidaria and Ctenophora exhibit
bilateral symmetry.
37
Dorsal =, Ventral =
= top, = bottom
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Anterior =, Posterior=
= head,= tail
39
Simplest bilateral organisms are
solid worms.
40
Phylum Platyhelminthes
solid body flatworms.
41
Worms are the simplest animals with
organs (collect of tissue working together to perform certain function). Some free living but many parasites.
42
Pseudocoelum and Coelum
fluid filled body cavity.
43
Acoelomate –
no body cavity. Nutrients and waste move to and from digestive cavity by diffusion.
44
All bilaterally symmetrical organism except flat worms have
body cavity. Some are pseudocoelomates. Some are Coelomates
45
Coelomates
body cavity entirely within mesoderm.
46
pseudocoelomates
body cavity between endoderm (digestive cavity) and mesoderm.
47
Body cavity provides:
- Circulation of nutrients from digestive cavity to body parts. - Makes for rigid (fluid) body which aids in movement. - Organs in body cavity can function without interference from surrounding tissues. - Place for organs to develop
48
Pseudocoelomates have
one way gut that offers assembly line specialization capability and multitasking. (doesn’t have to wait to expel waste before taking in food and no dillution=more diffusion. 2 phyla of pseudocoelomates. Only 1 is large – Nematoda (round worms).
49
Coelomates
body cavity entirely within mesoderm allows contact between mesoderm and endoderm – essential for primary induction process during embryonic development to allow development (and evolution) of more specialized tissues organs. Body cavity within mesoderm might limit circulation – circulation system fix problem (network of vessels that carries fluids to all parts of body).
50
Simplest Coelomates are
mollusks, the only coelomate phylum without segmented bodies.
51
Second is numbers next to
arthropoda (insects).
52
3 part bodies of mollusca:
- Visceral mass contains body organs, - mantle – heavy fold surrounding visceral mass (protection), - foot –muscle region.
53
3 types of mollusks:
Gastropods Bivalves Cephalopods
54
Gastropods
snails and slugs use muscular foot to move.
55
Bivalves
Clams, oysters, scallops secrete hinged two part shell. Draw in water and filter food.
56
Cephalopods
Octopuses and squid with jet propulsion mechanism under mantle.
57
Radula
rasping tongue-like organ used mostly in feeding (scraping algae, weapon)
58
Evolutionary advancements in coelomates:
Segmentation, jointed appendages with exo and endo skeletons, deuterostomic development (post embryo cell specialization), notochords.
59
Segmentation
allows for evolutionary and developmental flexibility – specialization of segments.
60
Annelids (worms)
first segmented animals.
61
Annelids share 3 characteristics:
Repeated segments divided internally, muscle in each segment can function independently of other segments. Specialized segments – containing special organs. Cerebral ganglion in anterior segment.
62
Connections between segments
circulatory and nerve chord connect segments.
63
All advanced coelomates exhibit
segmentation at one time in development.
64
Arthropods
first animals with jointed appendages, which allow more movement flexibility. Evolved form Annelids.
65
Individual segments exist only in
larval stage (immature organism). Segments fused later into functional units.
66
Insects have three units:
Head, thorax (middle) & abdomen (posterior).
67
More than half of named species are
arthropods.
68
Arthropods have
rigid hard exoskeleton made of chitin. Muscles attached to exoskeleton. Protects and conserves water. Can’t support great weight so limits size. Exoskeloten can’t grow so arthropods must shed periodically (molting).
69
2 Embryonic patterns of development for coelomates:
Protosomes – cells form spirally, cell specialization determined only in embryo stage, mouth forms first from Blastopore (initial indentation in embryo. Deuterostomes – cells form radically, specialization continues after embryo stage because controlled by chromosomes (offers greater developmental flexibility & diversity)
70
Echinoderms
first Deuterostomes. Form hard an first with endoskeletonossicles. Bilaterally symmetrical at larva stage, develop into radial symmetrical as adults. Radial symmetry seems to preclude brain development. under ectoderm – made of calcium rich plate
71
Echinoderms also evolved
hydraulic system for movement called water vascular system.
72
Second major group of Deuterostomes are
chordates – animals with completely internal endoskeleton – strong, allows greater size and flexibility.
73
3 characteristics of chordates:
Nerve chord –single, hollow, dorsal. Notochord- rod forms beneath nerve chord. Becomes vertebral column in vertebrates. Pharyngeal slits – connects mouth to digestive tract and windpipe.
74
Feature: Cell recognition Benefit Organism in which first evolved
Better coordination among different cell types Sponges
75
Feature: Tissues (similar cells performing similar coordinated function) Benefit Organism in which first evolved
more efficient Cnidarians & Ctenophores
76
Feature: Symmetry (radial) Benefit Organism in which first evolved
More coordinated movement Cnidarians & Ctenophores
77
Feature: Extracellular digestion IN a digestive cavity Benefit Organism in which first evolved
Multi-tasking – can ingest and then digest while doing other things Cnidarians & Ctenophores
78
Feature: Bilateral Symmetry Benefit Organism in which first evolved
- Cephalization (head making) with more developed complex nervous system. - More specialized areas - specialized functions - more efficient Flatworms (Platyhelminthes)
79
Feature: Organs Benefit Organism in which first evolved
Different tissue work together to perform special functions - more efficient Flatworms (Platyhelminthes)
80
Feature: Pseudocoelom (body cavity) Benefit Organism in which first evolved
- Simple circulatory system. - Provided rigidity against which muscles can pull - better movement. - Space for organs to develop - Space for organ to function without impingement from surrounding muscles Roundworms (Nematoda-largest phylum)
81
Feature: One way/two opening digestive tract Benefit Organism in which first evolved
- Multi-tasking - More efficient movement of food and wastes. Don’t have to excrete before taking in more food. - More efficient assembly-line processing of food moving in one way- specialization along the assembly line - more efficient food processing - Eliminates dilution of food with waste. No dillution=more diffusion. Roundworms (Nematoda-largest phylum)
82
Feature: Coelom enclosed entirely within mesoderm tissue Benefit Organism in which first evolved
Specialization - When mesoderm can come in contact with endoderm during embryonic primary induction allows more specialized tissue/organs can develop - specialized functions - more efficient Mollusks
83
Feature: Segmentation Benefit Organism in which first evolved
Specialization - When cells in segments are relatively isolated from cells in other segments, during embryonic development, different genes can be turned on or off in the different segments to create different tissues and organs Anelids
84
Feature: Jointed appendages Benefit Organism in which first evolved
More complex movement Arthropods
85
Feature: Exoskelton Benefit Organism in which first evolved
Functions to support body and provide rigidly for muscle to pull against AND provide protection from enemies and prevent water loss. Limitations: -Joints not as flexible -Chitin is brittle and has poor strength to weight ration so that arthropods cannot get to big. Arthropods
86
Feature: Endoskeleton Benefit Organism in which first evolved
- Functions to support body and provide rigidly for muscle to pull against. - Bone has better strength to weight ratio than chitin - can support more weight - larger bodies. - Endoskeleton has several different types of joints - better more complex movement Echinoderms
87
Feature: Deuterostomic developement Benefit Organism in which first evolved
Specialization - Embryonic primary tissue cells in deuterostomes have much more developmental flexibility than protostomes – they have potential to become more different types of cells - more specialized tissue/organs can develop - specialized functions - more efficient Echinoderms

Biology (16 decks)

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