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Living Organisms 2 Flashcards

1
Q

List the kingdom systems.

A

Plantae, Animalia, fungi, Protista, eubacteria, archaea

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2
Q

When did the transition from prokaryotes to eukaryotes take place?

A

between 1.2 and 2 billion years ago.

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3
Q

Describe organisms found in Kingdom Protista

A
  • Very heterogeneous group
  • Remained at eukaryotic, unicellular level of organization
  • Evolved along numerous lines through specialization of
  • cellular organelles (many unique) and/or • theskeleton(test)
  • Simplicity and complexity reflected in number and nature of organelles and skeletons
  • Compare: multicellular animals (tissues and organs)
  • Occur wherever moisture is present (sea, freshwater, soil)
  • Most are free-living
  • Many are commensal, parasitic, or even mutualistic
  • Solitary or colonial forms
  • Microscopic to visible
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4
Q

What does protozoa mean?

A

Animal like protist

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5
Q

What are the types of animal like protist?

A

Amoeboid protozoa, Flagellated protozoa, Ciliated protozoa, Spore-forming protozoa

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6
Q

What are the different types/phylum of amoeboid like protozoa?

A
  • Phylum Rhizopoda- ‘Naked’amoebae • ‘Shelled’ amoebae
  • Phylum Granuloreticulosa - Foraminiferans a.k.a. “forams”
  • Phylum Actinopoda
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7
Q

What are the types of Rhizopoda?

A

Naked amoebae and Shelled amoebae

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8
Q

Describe the naked amoebae?

A
  • E.g. Amoeba spp. live in sea, freshwater, moist soil
  • Size range – few μm to several mm
  • Cytoplasm divided - Stiff, outer ectoplasm (contracted proteins) • Fluid, inner endoplasm (relaxed proteins)
  • Nucleus, food vacuoles, contractile vacuoles, Golgi complex, endoplasmic reticulum, etc. also present (few mitochondria)
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9
Q

What are the two types of pseudopodia in naked amoeba?

A

• Lobopodia (seen in most amoebae) - wide round / blunted tips; tubular; ecto- and endoplasm; feeding and locomotion
• Filopodia (seen in small amoebae) • pointedends;composedof
ectoplasm only
1. Axopodia - locomotion only
2. Reticulopodia – feeding and locomotion

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10
Q

Describe shelled amoeba?

A
  • Inhabit freshwater, damp soil, moss • Shell (or test) is either
  • secreted by ectoplasm (chitinoid/silaceous) e.g. Arcella sp.
  • composed of foreign materials embedded in a (secreted) cementing matrix e.g. Difflugia sp.
  • Amoeba attached to inner wall of shell
  • Pseudopodia protrude through hole in shell
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11
Q

Describe Phylum Granuloreticulosa

A
  • “Forams” exist in great numbers at sea bottom
  • Few μm – several mm in size (Numulites 50myo; 19cm!)
  • Posses shells of CaCO3 (sometimes with sand reinforcement) • Contribute to chalk formation e.g. Cliffs of Dover, UK
  • Ectoplasm extends over outside of shell (c.f. shelled amoebae) • Single chambered – unilocular
  • Multichambered – multilocular
  • Chambers added as animal grows
  • Reticulopodia (nets) assist with food capture (diatoms, bacteria, etc) • Extracorporeal digestion followed by internal digestion
  • Majority exist as fossils e.g. Elphidium crispum
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12
Q

What are the classes of Actinopoda?

A

Radiolaria (marine) and Heliozoa (freshwater)

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13
Q

Describe Phylum Actinopoda?

A

Pseudopodia - as axopodia – pseudopodia linked internally with microtubules (axoneme)
Inorganic endoskeleton - 1. radiating spicules of strontium sulphate on some species 2. spherical shell of silica which may also have radiating elements 3. Some are naked

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14
Q

Explain locomotion in amoebae?

A

• Best developed in naked amoebae
• Flowing movement allowed for by
pseudopodia (three types)
•“Front-contraction” theory - At anterior end: endoplasmic proteins undergo contraction to form ectoplasm. At posterior end: ectoplasm is liquified during change to endoplasm
• Animal is pulled forward by contraction at anterior end
• Sticky surface on base of pseudopod

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15
Q

Explain feeding and nutrition in amoeba?

A

Entirely holozoic (feeding like an animal– eating other organisms or their products)

• Phagocytosis - 1. Lobopodia extend around prey(e.g.
bacterium) in a cup-like fashion 2. Intracellular digestion follows (GERL) 3. Residual vacuole contents exocytosed

• Pinocytosis - Ingestion of dissolved nutrients
(aminoacids, monosaccharides, etc.)

• Extracorporealdigestion - 1. Involves hydrolytic enzymes followed by phagocytosis/ pinocytosis of products 2. Seen in parasitic species e.g. Entamoeba histolytica

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16
Q

how does reproduction take place in amoebae?

A
  • Mostly asexual (binary fission)
  • Sexual: hologamy – fusion followed by detachment of two amoebae (genetic exchange?)
  • Metagenesis – “Alternation of generations”
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17
Q

How does reproduction take place in shelled amoebae?

A
  • Soft shells divide into two parts

* New hard shells are secreted/deposited on bud

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18
Q

How does reproduction take place in foraminifera?

A
  • Budding

* Metagenesis

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19
Q

How does reproduction take place in actinopoda?

A
  • binary fission

* Biflagellate ‘swarmers’

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20
Q

Name the different phylum found in flagellated protozoa

A

• Phylum Metamonada • Phylum Kinetoplastida • Phylum Opalinata

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21
Q

what is the class under Granuloreticulosa

A

“foraminifera” (having chambers) aka forams

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22
Q

describe the phylum metamonada

A

• Zooflagellates with few to many flagella
• These are commensals or parasites in the guts of
animals
• Lost mitochrondria secondarily
• retain nuclear genes derived from them
• mitochondrial relics include hydrogenosomes, which produce hydrogen, and small structures called mitosomes (contain mito-proteins)

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23
Q

What are the classes of the phylum matamonada?

A

Diplomonada and Parabasalia

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24
Q

Describe the class parabasalia

A
  • An example from this class is Trichonympha sp.
  • Lives in the hindgut of termites (insect)
  • They have no mitochondria and have a symbiotic relationship with the termites as they breakdown the cellulose in the wood and plant fibres that are eaten by these termites.
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25
Q

why is multicellularity important?

A

Multicellular organisms thus have the competitive advantages of an increase in size without its limitations. They can have longer lifespans as they can continue living when individual cells die. Multicellularity also permits increasing complexity by allowing differentiation of cell types within one organism.

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26
Q

What is cellularisation theory?

A

a multinucleate protist could evolve internal membrane partitions around each of its nuclei, confining its sphere of operation to a certain region of the body, and thereby become internally compartmented

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27
Q

What is the symbiotic theory?

A

different types of protist could together symbiotically form a composite multicellular organism, similarly to the manner thought likely to be the origin of the eukaryote cell from different prokaryotes, and of lichens by algal and fungal partners

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28
Q

What is the colonial theory?

A

the asexual division products of a single individual protist could remain together after fission, and multicellularity arise via an intermediate colonial stage

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29
Q

Describe kingdom fungi

A

Eukaryotic, multicellular, heterotrophic organisms with cell walls made of chitin and that reproduce via spores.
• Body (mycelium) made up of an interwoven mass of threadlike filaments (hyphae) that are one cell thick.
• E.g. Mushrooms, rusts, smuts, puffballs, truffles, morels, molds and yeasts.

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30
Q

list characteristics of fungi

A
  1. Eukaryotic (membrane bound nuclei ……………)
  2. Body composed of thread-like hyphae (one-cell thick) which form an interwoven mass called a mycelium. Temporary reproductive structures (e.g. mushrooms) extend from the body (mycelium)
  3. Heterotrophic- release extracellular enzymes and feed by absorption (break down nutrients stored in bodies or waste of other organisms- living or dead)
  4. Almost every biological material can be broken down by at least one fungal species.
  5. One predatory feeding on tiny worms in soil.
    6.Non-photosynthetic, non-motile- filaments grow rapidly in any direction.
  6. Chitin in cell walls (n-acetyl glucosamine units)
  7. Absence of motile cells at any stage of life cycle but
    choanoflagellate ancestry similar to that of animals.
  8. Capable of sexual and asexual reproduction. Reproduce asexually under most conditions
  9. Do not form embryos – form spores small and light and numerous (giant puffball contains 5 trillion spores)
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31
Q

What features do fungi share with animals?

A

No chloroplast.
heterotrophic organisms.
Require pre-formed organic compounds as energy sources.
Produce storage compounds, including glycogen, which is also found in animals.

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32
Q

What features does fungi share with plants?

A

possess a cell wall and vacuoles.
they reproduce both sexually and asexually.
they usually have haploid nuclei.

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33
Q

Unique features of fungi

A
  • The fungal cell wall is composed of glucans and chitin; while the former compounds are also found in plants and the latter in the exoskeleton of arthropods
  • Fungi are the only organisms that combine these two structural molecules in their cell wall.
  • Unique body form-hyphae and mycelium
  • Primary decomposers
  • In contrast to plants fungal cell walls do not contain cellulose.
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34
Q

What are the importances of fungi?

A

Primary decomposers
provide antibiotics.
can be eaten by humans.
Fungi + plant root association (mycorrhizae) help make nutrients and water available to the roots.

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35
Q

what are the Lower and Higher fungi?

A

Lower Fungi:
Phylum: Chytridiomycota - Various species on spathodea seed wings
Phylum: Zygomycota - Rhizopus or Mucor
Phylum: Oomycota - Photographs of Phytophthora or Pythium showing the lemon shaped or globose sporangia, respectively

Higher Fungi:
Phylum: Ascomycota - Sordaria or slides of Erysiphe. In boht, the asci are within fruiting bodies.
Phylum: Basidiomycota - Mushrooms and/or bracket fungi

Nonsexual Fungi - Aspergillus, Penicillium, or Saccharomyces cerevisiae (baker’s yeast)

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36
Q

Describe Kingdom Animalia.

A

Multicellular, heterotrophic, motile with a blastula stage in embryonic development

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37
Q

What are the characteristics of animals?

A
  1. Animals are multicellular
  2. Animals are heterotrophs - Ingest food and digest it in a central cavity (except for sponges).
  3. Animal cells lack cell walls
  4. Animals have a period of embryonic development- Progresses from blastula – gastrula – germ layers – tissues (cells become specialized as tissues form)
  5. Animals are motile
  6. Animals have nervous and muscle tissue
  7. Animals are diploid (diplontic life cycle) - Their gametes are heterogametes (different sizes); eggs larger than sperm. Gametes are produced by meiosis
  8. Most animals are symmetrical
  9. Most Animals possess a body cavity (embryonic) - A fluid filled space (coelom)…If none (acoelus)
  10. Many animals have a mouth and intestine
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38
Q

What is Basal lamina?

A

is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. (layer of extracellular proteins) supports the cells ≡ Tissues.

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39
Q

What are the types of symmetry?

A

Radial, Bilateral, Asymmetry

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40
Q

Describe radial symmetry

A

 The body parts -arranged around a central axis
 The animal can be cut along the axis in more than one plane to produce identical halves.
 Animals tend to be sessile or sessile pelagic (e.g. jelly fishes)
 Radial symmetry allows them to reach out in all directions.

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41
Q

Describe bilateral symmetry

A

 Only one cut along the longitudinal axis will produce identical halves.
 Bilateral symmetry is best for motile animals.

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42
Q

Describe asymmetry

A

 Asymmetrical animals have no pattern of symmetry.

 The simplest animals? (sponges) are asymmetrical.

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43
Q

Which metazoan groups have certain types of symmetry?

A

Bilateral Symmetry - flatworms, round worms, protostomes, deuterosomes, mollusks, anthropoids, annelids, echinoderms, chordates,

Radial symmetry - cnidarians
asymmetry - sponges

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44
Q

What is extracellular digestion?

A

The gut - enables the animal to digest food outside of the cells

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45
Q

What is intracellular digestion?

A

In animals without a digestive tract, food items are brought into the cell for digestion

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46
Q

What are the different types of guts?

A

 A sac-like gut - one opening. Food enters and leaves through the same opening
 A complete gut - two openings, a mouth and an anus

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47
Q

What is the purpose of a gut?

A

A gut- allows for the specialization of parts along the tube E.g. food storage, secreting digestive enzymes, absorbing nutrients

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48
Q

Which metazoan groups have certain types of guts?

A

Complete gut - flatworms, round worms, protostomes, deuterosomes, mollusks, anthropoids, annelids, echinoderms, chordates,
Sac-like gut - flatworms, cnidarians

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49
Q

What are the different embryonic germ layers?

A

Ectoderm - Surface epithelia (skin) and nervous system
Mesoderm - Muscles, connective tissues (incl. blood), skeleton, kidneys, circulatory
and reproductive organs
Endoderm - Gives rise to the intestine and associated organs

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50
Q

What does diploblastic mean?

A

having two germ layers

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51
Q

What does triploblastic mean?

A

Having three germ layers

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52
Q

what is the body cavity?

A

A body cavity is any space or compartment, or potential space in the animal body. Cavities accommodate organs and other structures; cavities as potential spaces contain fluid.

53
Q

what is the function of the body cavity?

A

 Hydrostatic skeleton
 Site for temporary accumulation of excess fluids, waste (2o circulatory system)
 Site for maturation of eggs and sperm
 Site allowing enlargement of internal organs
( e.g. gonads)

54
Q

what does acoelomate mean?

A

An acoelomate is an animal that does not possess a body cavity.(solid mesoderm) e.g.- flatworms

55
Q

what is haemocoel?

A

the primary body cavity of most invertebrates, containing circulatory fluid.

56
Q

What is a pseudocoelomate?

A

A pseudocoelomate is an organism with body cavity that is not derived from the mesoderm, as in a true coelom, or body cavity. A pseudocoelomate is also known as a blastocoelomate, as the body cavity is derived from the blastocoel, or cavity within the embryo. Body cavity, fluid-filled, between the mesoderm and endoderm. e.g. nematodes (roundworms)

57
Q

what is coelomate?

A

any animal possessing a fluid-filled cavity within which the digestive system is suspended. occurs entirely in the mesoderm e.g annelids, echinoderms and chordates

58
Q

Which metazoan groups have certain types of embryonic germ layers?

A
  1. 3 layers (triploblastic) coelomate - protostomes, deuterosomes, mollusks, anthropoids, annelids, echinoderms, chordates,
  2. 3 layers (triploblastic) pseudocoelomate - roundworms
  3. triploblastic acoelomate - flatworms
  4. diploblastic (two layers) acoelomate - Cnidarians
  5. multicell no tissues - sponges
59
Q

Whats the difference in embryonic development between protostomes and deuterostomes?

A

protostomes are animals in which the first opening that appears in the embryo ( blastopore) is the mouth (1st mouth) while in deuterostome the first opening is the anus (2nd mouth)

60
Q

describe embryonic development

A

fertilised animal egg divides to produce a solid ball of cells (morula). cell migration results in a hollow ball (blastula). cells near one end of the blastula migrate inward - gastrula. opening is the blastopore. tube produced by this process will become the gut. in species that have a separate mouth and anus the tube will eventually extend through the length of the embryo and fuse with the opposite side. one opening will become the mouth the other will become the anus

61
Q

what sub-kingdom and phylum are sponges?

A

sub-kingdom - parazoa (beside animals)

phylum - Porifera

62
Q

describe the external features of Porifera (sponges)

A 
tubular, encrusting, fingerlike. 
Brightly coloured (live sponges in aquarium) 
Body covered in pores- Porifera= pore bearer
63
Q

What are the different body types of Porifera?

A

 Asconoid  Syconoid  Leuconoid

64
Q

What is Spongocoel/ atrium?

A

is the large, central cavity of sponges. Water enters the spongocoel through hundreds of tiny pores (ostia) and exits through the larger opening (osculum).

65
Q

Describe the different sponge body types

A

 Asconoid - Large reservoir of water. Small SA:V ratio. Inefficient use of
water. Restricted to smaller size classes
 Syconoid - Larger SA:V ratio. More efficient use
of water. Still relatively small size classes
 Leuconoid - Large SA:V ratio. Most efficient use
of water. Most sponges are of this type. Encrusting to large, goblet varieties

66
Q

describe porifera skeletal structure

A

Body supported by a skeleton composed of spicules (hard mineralised) and collagen/protein fibres (spongin).

67
Q

what are archaeocytes?

A
  1. Totipotent 2. Phagocytic 3. Secretory (spicules and spongin
    these are specialised cells that secrete picules (hard mineralised) and collagen/protein fibres (spongin).
68
Q

What are the different types of spicules?

A

calcareous spicules.
siliceous demosponge spicules.
siliceous hexactine spicules.

69
Q

What are the different cell types found in sponges?

A

Pinacocytes. Porocytes. Choanocytes. Archaeocytes.

70
Q

What are Choanocytes?

A

Collar cells lining the inner walls of the body- responsible for pulling water into the sponge.

71
Q

How do collar cells work?

A

beating of flagellum pulls water through the collar and away from the cell body.

72
Q

What are Porocytes?

A

tubular cells forming the intake pores

73
Q

What are pinococytes?

A

flattened cells that form the dermal layer – Pinacoderm (line the outer layer of the body)

74
Q

How do sponges feed?

A

 Bacteria and other very small particles trapped on
the collar of the choanocyte.
 Filter – collar microvilli (0.1 um apart).
 Cells engulf particles + other cells along the channels (amoebocyets)- intracellular digestion
 One small group of sponges considered carnivorous- animals pulled in via water current.

75
Q

describe sponges nervous system

A

 Sponges have no nervous system
 Local reactions
 Coordination by transmission of messenger substances (chemicals like hormones)
 Wandering ameboid cells
 Fixed cells in contact with each other- no junctions
 Defense: sponges produce biochemicals (toxic to fish, kill competitors, rash in humans- Red Caribbean fire sponge Tedania sp.)

76
Q

List animal characteristics

A
  1. multicellular
  2. heterotrophic
  3. embryonic development (blastula)
  4. no cell walls (possess skeletal structures)
  5. motile
  6. nervous and muscle tissue
  7. symmetrical
  8. body cavity present
  9. possess a gut
  10. diploid
77
Q

describe the sub-kingdom metazoa

A
  1. tissues - basal lamina
  2. grouped to form organs
  3. definite mouth and anus (digestive system)
  4. definite symmetry
  5. layer and structures of the body derived from germ layers
  6. embryonic development progresses beyond morula and blastula. gastrula- germ layers
78
Q

describe the phylum cnideria

A

multicellular, radial symmetry with tissues and organs and possessing a “gastro/vascular” cavity or gut. no other body cavity. most cnideria live in shallow water and most are marine. includes hydras, jellyfish, sea anemones and corals.

79
Q

What is the function nematocysts?

A

These are located throughout the epidermis. they are used for defence and prey capture. they can be toxic or non-toxic.

80
Q

describe support in cnideria

A

soft bodied (jellyfish etc)- mesoglea
hydrozoans often have periderm of chitin over the epidermis
corals secret calcareous material

81
Q

describe locomotion in cnideria

A

hydra sessile - can somersault or show inch worm like movement
jellyfish swim - contracting muscles of the umbrella margin and general surface.

82
Q

What is the gastrovascular cavity?

A

enzymes reduce food to a broth - mixed by beating flagella in cavity.

83
Q

What cnideria are exceptions to the carnivorous feeding?

A

aurelia - particlate feeding
cassiopeia - symbionts
corals - symbionts

84
Q

what is the gastrodermis?

A

The gastrodermis is the inner layer of cells that serves as a lining membrane of the gastrovascular cavity of Cnidarians

85
Q

what is pedal lacerations?

A

in sea anemones is a mode of fission which involves the spreading of the pedal disk and the degradation of tissue between the margin of the pedal disk and the body column. This produces crescent-shaped fragments which then regenerate into fully formed polyps.

86
Q

How does reproduction take place in cnidernia?

A

dioecious (opposite of hermaphrodites)
gonads may be epidermal or gastrodermal
free swimming planula larva is the characteristic first larval stage
asexual reproduction by budding, fission and pedal lacerations.

87
Q

what is planula?

A

is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species

88
Q

what is the life cycle of Aurelia?

A

spermatozoa released via gastrovascular cavity from gonad. pass out through mouth. fertilised - planula larva
planula settles - scyphistoma. asexual reproduction by budding. example alteration of generations

89
Q

what is scyphistoma?

A

the fixed polyp-like stage in the life cycle of a jellyfish, which reproduces asexually by budding

90
Q

describe bilateral animals

A

 Remaining phyla are essentially bilaterally symmetrical correlated with motility
 Both sides of the animal are identical – encounter new environment in same way
 Anterior portion meets new environment - bears sense organs (Cephalization- head development)
 Upper and lower surfaces differ – lower in contact with substratum (Dorsal vs. ventral epithelium)
 1st bilateral animals (flatworms, roundworms, annelid worms) – Different architecture.

91
Q

what is the Peritoneum?

A

The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom.

92
Q

what is the mesentery?

A

The mesentery is an organ which surrounds the organs of the gut, and suspends them from the abdominal wall. The mesentery is made of mesoderm cells,

93
Q

What are the characteristics of phylum Platyhelminthes (flatworms)?

A

 Bilateral
 Vermiform- “wormlike”
 Elongated, bilateral animals reduced appendages-
 Large numbers are parasitic
 Important pathogens of humans and domestic animals.
 Parasitic forms- Bodies severely modified.
 Use non-parasitic members to give general features (Phylum characteristics) Non-parasitic, free-living form: Auricles (ear lobes), Ocelli- eye spots, pharynx
 Range of sizes (2 mm or less to more than a meter long- some tapeworms are meters long)
 Flattened, leaf-like, long and ribbon-like

94
Q

what are Rhabdites in Platyhelminthes?

A

Defense/protection; disintegrate to form a slimy covering around the animal; most numerous on dorsal surface

95
Q

How does Platyhelminthes (flatworms) move?

A

 Mucous glands: located marginally; provide temporary sheet of mucous on which animal glides
 Cilia “row” on mucous
 Active swimming: From transverse waves of muscle contractions

96
Q

what are the functions of the Platyhelminthes structure?

A
  1. packing tissue support
  2. facilitates diffusion of nutrients and oxygen around body
  3. represents a source of undifferentiated cells (pluripotent) which can migrate to wounded areas to facilitate tissue regeneration.
97
Q

describe nutrition in Platyhelminthes

A

Carnivores. Digestive system: mouth, pharynx (muscular and can be protruded) and intestine.
no anus; faeces voided through mouth.
central mouth opens anywhere along the ventral midline.
intestinal structure provides basis for classification- simple or branched intestines.

98
Q

Describe circulation and respiration in platyhelminthes

A

no special respiration organs.
gaseous exchange; diffusion all over body.
no circulatory system: parenchymal system may facilitate transport of nutrients and oxygen to internal tissues.
shape and structure of body important in these respects (dorsoventral flattening and small size) this is because they absorb oxygen directly through their skin so their flat shape helps this.

99
Q

How does excretion work in Platyhelminthes?

A

excretory system composed of fine ramifying tubes.
open on surface via pores.
proto-nephridia
flame cell type flagellated cell
located in blind - ending portions of the body
probably used more for osmoregulation rather than excretion.
excretory product ammonia
diffuses through body surface + pores on the outside.

100
Q

what is protonephridia?

A

The nephridium is an invertebrate organ, found in pairs and performing a function similar to the vertebrate kidney. Nephridia remove metabolic wastes from an animal’s body. Nephridia come in two basic categories: metanephridia and protonephridia. Protonephridia are a type of nephridia that occur in invertebrates, including the phyla Platyhelminthes, Nemertea, Rotifera, and Chordata (lancelets). Metanephridia are the other type of nephridia which occur in invertebrates, including the phyla Annelida, Arthropoda, and Mollusca.

101
Q

what are flame cells?

A

A flame cell is a specialized excretory cell found in the simplest freshwater invertebrates, including flatworms, rotifers and nemerteans. Flame cells function like a kidney, removing waste materials. Bundles of flame cells are called protonephridia.

102
Q

what is negative phototactic

A

A negative phototaxis is one in which the organism moves away from the light source as demonstrated by certain insects such as cockroaches.

103
Q

what are statocyst?

A

a small organ of balance and orientation in some aquatic invertebrates,

104
Q

what are rheoreceptors?

A

a receptor in that responds to water currents

105
Q

what is an auricle?

A

a structure resembling an ear or ear lobe in plnarians.

106
Q

What kind of reproduction does flatworms have?

A

asexual that occurs by fission. if spilt in half longitudinally will have two heads.
sexual -

107
Q

what is Cuticle in phylum nematoda (roundworms)?

A

The nematode cuticle is an extremely flexible and resilient exoskeleton that permits locomotion via attachment to muscle, confers environmental protection and allows growth by molting

108
Q

describe longitudinal muscle

A

 Unique feature: Each muscle extends processes/fibers to connect to the dorsal or ventral nerve.
 Rather than the nerve extending an axon to connect with the muscle

109
Q

how does locomotion work in nematoda?

A

 Via undulating waves of muscle contractions passing along the muscle fibres of the body wall
 Antangonistic forces: Hydrostatic skeleton of pseudocoelomic fluid and the elasticity of the cuticle
 Aqueous environment required; move on side

110
Q

what is a opisthaptor?

A

the posterior and usually complex adhesive organ of a monogenetic trematode.

111
Q

what are prohaptors?

A

that is used for feeding and attachment. It is not the primary attachment organ but can anchor the body while the opisthaptor is being repositioned.

112
Q

what is a definite host vs indefinite host?

A

The definitive host refers to the organism wherein the parasite reaches its mature form. Thus, the parasite at this stage is typically capable of reproduction.

an organism that supports the immature or non-reproductive forms of a parasite.

113
Q

advantages of a coelom

A

 Hydrostatic skeleton – facilitating support & movement
(fluid has little metabolic demand)
 Site for temporary accumulation and movement of
nutrients, waste, gasses (2o circulatory system)  Space for maturation of eggs and sperm
 Space allowing enlargement of internal organs
( e.g. gonads)

114
Q

what is cephalisation?

A

Cephalization is an evolutionary trend in which, over many generations, the mouth, sense organs, and nerve ganglia become concentrated at the front end of an animal, producing a head region.

115
Q

why is cephalisation reduced in earthworms?

A

the earthworm’s nervous system is distributed throughout its segments along the central nerve cord,

116
Q

describe the different kinds of annelid movement

A
  1. Peristalsis: Alternate contraction of circular and longitudinal muscles + setae
  2. Wriggling/Parapodial stepping: Setae or parapodia providing contact with the substrate.
    • Circular muscles extend worm
    • Longitudinal muscles shorten worm.
117
Q

What are the different pigments of blood in annelids?

A
  • haemoglobin (red)
  • chlorocruorin (green)
  • haemerythrin (pink/violet)
118
Q

what is Enteronephric system?

A

of an excretory system. : discharging into the intestine (as in certain annelid worms)

119
Q

what are Typhlosole?

A

A typhlosole is an internal fold of the intestine or intestine inner wall. increases the surface area for absorption of food & re-absorption of water.

120
Q

what is Clitellum

A

The clitellum is a thick, saddle-like ring found in the epidermis (skin) of the worm, usually with a light-colored pigment. To form a cocoon for its eggs, the clitellum secretes a viscous fluid.

121
Q

What is a radula?

A

The radula (/ˈrædjʊlə/; plural radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus.

122
Q

what is a odontophore?

A

a cartilaginous projection in the mouth of a mollusc, on which the radula is supported.

123
Q

what is Crystalline style?

A

A style, sometimes referred to as a crystalline style, is a rod made of glycoprotein located in the midgut of most bivalves and some gastropods which aids in extracellular digestion

124
Q

what is Haemocyanin?

A

Haemocyanin (or hemocyanin) is a protein which transports oxygen in the bodies of some invertebrates.

125
Q

what is Myoglobin?

A

Myoglobin is an iron- and oxygen-binding protein found in the skeletal muscle tissue of vertebrates

126
Q

what is Osphradia?

A

The olfactory organ in certain molluscs, linked with the respiration organ. Its main function is to test incoming water for silt and other possible food particles.

127
Q

what is a gonoduct?

A

Either of a pair of ducts, leading from a gonad to the exterior, through which gametes pass.

128
Q

Adductor muscle function

A

The muscles are strong enough to close the valves of the shell when they contract, and they are what enable the animal to close its valves tightly when necessary, such as when the bivalve is exposed to the air by low water levels, or when it is attacked by a predator.

129
Q

what is operculum?

A

is a hard, plate-like, bony flap that covers the gills of a bony fish

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