chapter 21 Invertebrates Flashcards
1
Q
How many known animals species are there?
A
1.3 million
2
Q
What specific set of features do all animals have in common?
A
They have eukaryotic cells that lack cell walls
Their cells produce an extracellular matrix
They have multicellular bodies
They go through a blastula stage of development
They are heterotrophic
3
Q
What is a blatula?
A
a sphere of cells surrounding a fluid-filled cavity
4
Q
How many animal phyla are there?
A
nine
5
Q
Name all the animal phyla
A
Porifera, Cnidaria, Platyhelminthes, Mollusca, Annelida, Nematoda, Arthropoda, Echinodermata, Chorodata
6
Q
Are most animals vertebrates or invertebrates?
A
Invertebrates
7
Q
What are invertebrates?
A
animals that lack backbones
8
Q
What are vertebrates?
A
animals that have backbones
9
Q
Which phylum have vertebrates?
A
Chordata
10
Q
Where did life begin?
A
in water
11
Q
How many million years ago did the first animals arise?
A
570 million years ago
12
Q
Ancient animals probably resembled what aquatic protist?
A
choanoflagellates
13
Q
do animal features reflect shared ancestry?
A
yes
14
Q
How are animals grouped?
A
by shared features of body form, developmental characteristics, and DNA
15
Q
The first branching point in animal taxonomy distinguishes…?
A
animals having tissues or not
16
Q
what are eumetozoans?
A
animals with true body tissues
17
Q
What are parzoans?
A
animals with no true body tissues
18
Q
What does the second branching point distinguish?
A
symmetry and embryonic germ layers (2 vs 3)
19
Q
a body form in which multiple similar parts are arranged around a central axis
A
radial symmetry
20
Q
Do most eumetazoan phyla have radial symmetry or bilateral symmetry?
A
bilateral
21
Q
What do bilaterally symmetric animals have that others don’t?
A
a head and a tail
22
Q
define cephalization
A
the tendency to concentrate sensory cell and a brain at the animal’s head. Typically this is accompanied by greater sensory complexity
23
Q
do most eumetazoam phyla have 2 germ layers or 3?
A
3
24
Q
How is the gastrula formed
A
by the blastula folding on into itself
25
What is a blastula?
an embryonic ball of cells
26
What is a cup-shaped structure composed of two or three layers of tissue
gastrula
27
Name the 3 germ layers developed by the gastrula
Endoderm, ectoderm, and mesoderm
28
What does the ectoderm develop?
the skin and nervous system
29
What does the endoderm develop?
the digestive tract
30
What does the mesoderm develop?
the muscles and circulatory system
31
The third branching point distinguishes animals by...?
how their gastrula develops
32
what is a protostome
"mouth first"
If the first indention of the gastrula develops into the mouth
The anus will develop from the second opening
33
What is a deuterostome?
"anus first"
If the first indention of the gastrula develops into the anus
the mouth will develop from the second opening
34
What is a coelom?
a body cavity surrounded on all sides by mesoderm
35
Where do internal organs grow?
in the coelom
36
What is a pseudocoelom
a cavity that is lined partly with mesoderm and partly with endoderm
37
What does it mean when an animal doesn't have a coelom?
they lack a body cavity
38
Animals that have a mouth that both takes in food and ejects wastes have...?
an incomplete digestive tract
39
Animals have a {blank} if food passes in one direction from mouth to anus
complete digestive tract
40
The division of an animal body into repeated parts is...?
segmentation
41
What advantage to segmented bodies have over unsegmented bodies?
segmented bodies are more flexible and have more potential for developing specialized body parts than unsegmented bodies
42
what is direct development?
animals that resemble adults in their juvenile stage
43
What is indirect development?
Animals that have a larval stage that does not resemble the adult form
44
What does an animal with indirect development do as it matures into an adult
the larva undergoes metamorphosis
45
Porifera
```
Sponges
aquatic and sessile
no true tissues
hollow bodies
asymmetric or radially symmetric
```
46
sessile
anchored to a surface
47
how to sponges eat
filter feeder
water moves into a sponge's body through pores in its sides, then out through a hole at the top. This allows the sponge to trap food and eliminate waste
48
What are collar cells
cells that sponges have to trap food and start to digest it
49
what are amoebocytes?
cells that sponges have to digest food and distribute it to other parts of the body
50
True or false
| sponges are hermaphrodites
true
51
Do sponges reproduce sexually or asexually?
both
52
How do sponges reproduce asexually?
by budding
53
how do sponges reproduce sexually
sperm is released into the water and fertilize eggs retained in the body of the sponge
54
Cnidarians
Symmetry?
Germ layer amount?
simple eumetazoans
| aquatic, radially symmetric, 2 germ layers
55
Name the 4 groups of cnidarians
Jellyfish, hydra, coral, and sea anemones
56
what is the unique feature found in cnidarians'?
mesoglea: a jellylike, noncellular substance found between the 2 cell layers that make up a cnidarian's body
57
What are cnidocytes?
cells resembling tiny sharp harpoons used to sting predeators or prey
found in cnidarians
The sting can irritate, paralyze, or kill other animals
58
Can cnidarians reproduce sexually or asexually?
both
59
How do cnidarians reproduce?
Adults release sperm or eggs into the water. When they meet up fertilization occurs to form a zygote. The zygote develops into a larva and then a polyp, which can form a colony and release new medusae
60
What is a polyp?
a sessile cnidarian
61
Are flatworm protostomes?
yes
62
Platyhelmithes
Symmetry?
Germ layers?
flatworms
bilaterally symmetric
3 germ layers
63
3 groups of flatworms
Planarians, flukes, and tapeworms
64
do flatworms have a coelom?
no
65
what are the advantages of not having a coelom?
the flat body shape increases surface area and allows for effiecient gas exchange
66
do flatworms have a specialized respiratory and circulatory system?
no
67
What do planarians use to eat?
Pharynx: a feeding structure that brings food into the body and excretes undigested food
68
the nervous system of planarians
a brain and nerve cords
| It can sense touch, chemicals, and light
69
Are flukes and tapeworms parasitic?
yes
70
mollusks
soft unsegemented protosomes
large diverse phylum
a true coelom
71
features of a mollusk
a mantle, muscular foot, visceral mass, radula
72
Mantle
a fold of tissue that secretes a calcium carbonate shell in mollusks
73
what is a muscular foot used for?
locomotion
74
what is a visceral mass
a region of a mollusk's body where organs are found
75
what is a radula
a tougue-like strap with teeth made of chitin
| Used for feeding
76
the 4 groups of mollusks
Chitons, bivalves, gastropods, cephalopods
77
mollusk group that have eight overlapping shells
chitons
78
mollusk group with hinged shells
bivalves
79
mollusk group with spiral shells
gastropods
80
mollusk group with internal or absent shells
cephalopods
81
Do all mollusks have an open cirulatory system and reproduce sexually?
yes
82
Which of the mollusk groups have a well-developed nervous system
cephalopods
| large brain, eyes, excellent sense of touch, and impressive problem-solving abilities
83
Do mollusks have a complete digestive tract or an incomplete digestive tract?
complete
84
Annelids
segmented worms
| Each body segment functions the same as the others
85
Do annelids live in different environments?
yes
86
Earthworms
annelid that lives in soil and are crucial for keeping it aerated
87
Leeches
annelids that live in freshwater. They drink blood and eat small animals
88
Polychaetes
annelids
| marine worms
89
the 3 groups of annelids
earthworms, leeches, and polychaetes
90
annelid organ systems
complete digestive system, closed circulatory system with aortic arches, and a nervous system that includes a brain and ventral nerve cord
each body segment contains excretory organs
91
what is the saddle-like thickening area on earthworms for?
to hold eggs in a specialized cocoon
92
Nematoda
unsegmented worms
| roundworms
93
closest evolutionary relatives of roundworms are...?
arthropods
94
do roundworms cause disease?
some
parasitic roundworms such as pinworms, heartworms, and hookworms infect the intestines, muscles, blood, and lungs of humans and other animals
95
nematodes organ systems
few organ systems
| includes a brain and nerve cords.
96
Do roundworms have specialized circulatory and respiratory organs
no
| a fluid in the pseudocoelom distributes nutrients, oxygen, and carbon dioxide
97
do nematodes have a coelom, pseudocoelom, or no coelom?
pseudocoelom
98
Arthropods
largest most diverse phylum of animals. Their legs, antennae, mouthparts, and other organs are joined
99
name the 5 arthropod groups
Trilobites, chelicerates, myriapods, crustaceans, insects
100
do all arthropods have an exoskeleton?
yes
made of chitin
supports and protects the body
101
what happens as an arthropod's body grows
they molt and grow a new exoskeleton
102
specialized body segments in arthropods
head, thorax, and abdomen. Segments in each region develop specialized functions
103
organ systems of arthropods
a respiratory system made up of holes called spiracles for letting in air, and tubes called tracheae and book lungs for gas exchange
well developed nervous system, open circulatory system, and complete digestive system
104
Trilobites
extinct marine phylum of arthropods
105
chelicerates
subphyla of arthropods
grasping clawlike mouthparts
(spiders)
106
how are arthropods grouped?
by their mouthparts
107
mandibulates
subphyla of arthropods
chewing, jawlike mouthparts
(ant mandibles)
108
horseshoe crabs, mites, ticks, spiders, and scorpions are...?
chelicerates
109
Myriapods make up one group of ...
mandibulates
| The heads have jaws and antennae; the rest of the body has pairs of legs
110
Crustaceans make up another group of...
mandibulates
111
crabs, shrimp, and lobsters are...
crustaceans
| all have two pair of antennae
112
Insects are another group of ...
mandibulates
113
There are million of [blank] species. They each have one pair of antennae, six legs, and (usually) two pairs of wings
insects
114
Echinoderms
marine deuterostomes
| closely related to chordates
115
sea urchins, sea stars, and sea cucumbers are ...
echinoderms
116
do echinoderms have radial or bilateral symmetry?
radial as adults
| as larve, they are bilateral
117
pentamerism
5-part radial symmetry
118
special features of echinoderms
regeneration and tissues that switch between soft and hard
water vascular system
tube feet
119
water vascular system
a series of enclosed, water-filled canals that end in hollow tube feet
versatile, fulfilling the functions of a complex circulatory, respiratory, and excretory system
120
what do echinoderm tube feed do?
pump out water and act as locomotion and sensory systems
