Chapter 33: Introduction to Invertebrates Flashcards
1
Q
Important characteristics of sponges?
A
- Filter feeders: filter out food particles suspended in surrounding water as they draw it through their body
- Water drawn through pores into central cavity (spongocoel) and flow out of opening (osculum)
- Said to be basal animals and lack true tissues
- Lining of sponges includes choanocytes
- Mostly hermaphrodites
- Phylum porifera
2
Q
Suspension feeding
A
- Feeds by removing suspended food particles from surrounding medium by a capture, trapping, or filtration mechanism
3
Q
Dominant types of cells in sponges
A
- Epidermis: Outer layer consists of tightly packed cells
- Meshyl: Separates the two layers of cells (gelatinous)
- Amoebocytes: Move through mesohyl and have many functions; transport nutrients, produce materials, become any type of sponge cell needed
- Spongocoel is on inside (cavity); lined with choanocytes
4
Q
Function of each type of cell in the sponges
A
- Amoebocytes: Eat shit, build shit
- Spongocoel: Linvd with choanocytes that beat flagella
5
Q
Invertebrate
A
- An animal lacking a backbone
- Account for 95% of known animal species
6
Q
Two variations of Cnidarian body plan?
A
- Basic: Membranous sac with central digestive compounds
- Polyp (Sessile): Anchored to floor, up to cavity, mouth/anus and extending tentacles
- Medusa (Free Floating): Free floating, anus/mouth faces downward, tentacles extend downward
7
Q
How do Cnidarians capture their prey?
A
- Use tentacles arranged in ring around mouth to capture prey and push food into gastrovascular cavity
- Tentacles armed with cnidocytes: cells unique to cnidarians that function in defense and prey capture
8
Q
Four major groups of organisms in Lophotrochozoa
A
- Clade identified with molecular data
- Flatworms
- Rotifers
- Molluscs
- Annelids
9
Q
Parthenogenic
A
- Form of asexual reproduction in which females produce offspring from unfertilized eggs
10
Q
Three components of mollusk body plan?
A
- Muscular foot for movement
- Visceral mass containing most of internal organs
- Mantle: Fold of tissue that drapes over visceral mass and secretes a shell
11
Q
Major groups of mollusks
A
- Chitons, gastropods, and cephalopods
12
Q
Ecdysis?
A
- Molting
13
Q
Invertebrate
A
- An animal lacking a backbone
- Account for 95% of known animal species
14
Q
Nematocyst
A
- Specialized cnidae have these; contain stinging thread that can penetrate the body wall of the cnidarian’s prey
15
Q
Anthozoans
A
Corals and anemones
16
Q
Flatworms
A
- Live in marine, freshwater, and damp terrestrial habitats
- Thin bodies that are flattened dorsoventrally
- Simple excretory apparatus functions maintaining osmotic balance (pronoephridia: network of tubules with ciliated structures that pull fluid through branched ducts)
17
Q
Rotifers
A
- Tiny animals that inhabit freshwater, marin, and damp soil habitats
- Range from 50 micrometers to 2 millimeters
- Have alimentary canal (digestive tube with two openings)
- Cilia draws forex of water into mouth
- Many parthenogenic
18
Q
Molluscs
A
- Second most diverse phylum
- Have muscular foot (movement), visceral mass (contains most of internal organs), mantle (fold of tissue that drapes over visceral mass + secretes shell)
- Include chitons, gastropods, bivalves, cephalopods
19
Q
Chiton
A
- Oval shaped body and shell composed of 8 dorsal plates
- Unsegmented boy
- Use radula to scrape off algae
20
Q
Gastropods
A
- 3/4 of living species of mollusks
- Most are marine, some freshwater
- Use radula to graze on algae
- Several are predators
21
Q
Bivalves
A
- All aquatic and include clams, oysters, mussels, scallops
22
Q
Cephalopods
A
- Active marine predators
- Use tentacles to grab prey
- Include squids, octopi,
- Have closed circulatory system (blood remains separate from fluid in body cavity)
23
Q
Ammonites
A
Shelled cephalopods
24
Q
Annelid
A
- Refers to resemblance to series of fused rings
- Segmented worms that live in sea, freshwater habitats,and damp soil
- Coelomates
- Errantians, sedentarians (leeches, earthworms)
25
Ecdysozoans
- Most species-rich animal group
| - Comprised of nematodes and arthropods
26
Nematodes
- Most ubiquitous of animals
- Found in most aquatic habitats, soil, moist tissues of plants, body fluids, tissues of animals
- 1mm - 1m long
- Have alimentary canal, lack circulatory system
- Important role in nutrient cycling and decomposition
- Can be beneficial or harmful
27
Arthropods
- Segmented body
- Hard exoskeleton
- Jointed appendages
- Open circulatory system (fluid propelled through heart and into spaces)
- 4 majors: Chelicerates, myriapods, hexapods, and crustaceans
28
Exoskeleton
- Layers of chitin
- Protection and support
- Points of attachment for muscles
- Prevents desiccation
- Must be shed to grow
29
Chelicerates
- Arthropods
- Claylike feeding appendages called chelicerae
- Lack antennae
- Bulk is comprised of arachnids, ticks, and mites
30
Book Lungs
- Feature present in arachnids; stacked platelike structures contained in an internal chamber
31
Crustaceans
- Crabs, lobsters, shrimps, barnacles, others
- Marine, freshwater, terrestrial
- Specialized appendages
- Exchange gases across thin areas of cuticle or have gills
32
Insects
- Hexapods
- Have several complex organ systems
- Radiated in response to new plant species
- Many have one or two pairs of wings
- Some undergo metamorphosis
33
Myriapods
- Centipedes, millipedes
| - Carnivores or scavengers
34
Tardigrada
- survive just about anything
35
Incomplete metamorphosis
- young resemble adults but are not sexually mature
36
Complete metamorphosis
Have larval sages specialized for eating and growing (known as caterpillar, maggot, grub)
37
Echinoderm
- Sea stars, slow-moving or sessile marine animals
- Thin epidermis covers endoskeleton of hard calcareous plates
- Water vascular system
- Bilaterally symmetrical ancestors
- Tube feet
38
Water vascular system
Present in echinoderms; network of hydraulic canals branching into extensions called tube feet that function in locomotion and feeding
39
Chordates
- Two basal groups of invertebrates (lancelets and tunicates)
- Bilaterally symmetrical coelomates with segmented bodies
