Animal Classifications

Question 1

What are the general characteristics of animals?

Answer 1

• Multicellular with specialized cells that form tissues and organs.
• Possesses nervous and muscular tissues that allow for mobility (locomotion).
• Have a life cycle in which the adult is typically diploid.
• Usually undergo sexual reproduction and produce an embryo that goes through developmental stages.
• Heterotrophs that acquire food by ingestion, followed by digestion.

Question 2

The animal kingdom is currently divided into ___ groups or phyla.

Answer 2

30

Question 3

The animal kingdom is currently divided into 30 groups or phyla where the majority of these animals are ___.

Answer 3

invertebrates

Question 4

___ lack an internal skeleton, or endoskeleton, of bone or cartilage. They evolved first, and they far outnumber the vertebrates (animals with an endoskeleton).

Answer 4

Invertebrates

Question 5

This tree represents the relationships among different animal groups or phyla. It shows different species that evolved from a common ancestors over time. Provides insight to the diversity of life

Answer 5

Evolutionary tree

Question 6

___ have played a major role in establishing evolutionary relationships, because the more closely related two organisms are, the more their DNA sequences will have in common

Answer 6

Molecular comparisons

Question 7

It is characterized based on body structures or morphology.

Answer 7

Phylum/Phyla

Question 8

In eumetazoans, multicellularity led to the formation of ___ (ectoderm, mesoderm, endoderm).

Answer 8

germ layers

Question 9

___ preceded bilateral symmetry.

Answer 9

Radial symmetry

Question 10

Bilateral symmetry led to __, or the formation of a head containing a brain and sensory receptors.

Answer 10

cephalization

Question 11

Bilaterally symmetrical animals undergo either ___ development or ___ development.

Answer 11

protostome, deuterostome

Question 12

In protostomes, the __ embryonic opening becomes the mouth. They are also characterized by spiral cell division.

Answer 12

first

Question 13

In deuterostomes, the __ embryonic opening becomes the mouth while the first opening is the ___. They are also characterized by radial cell division.

Answer 13

second, anus

Question 14

Animals may be further identified as ___, ___, or ___, depending on the structure of their body cavity.

Answer 14

coelomates, pseudocoelomates, acoelomates

Question 15

Some ___ animals exhibit segmentation or repetition of parts of the body.

Answer 15

coelomate

Question 16

What are the evolutionary trends?

Answer 16

1. Germ layers
2. Animal symmetry
3. Animal development
4. Animal body cavities
5. Animal segmentation

Question 17

How many germs layers does a diploblast have?

Answer 17

2

Question 18

How many germs layers does a triploblast have?

Answer 18

3

Question 19

What are the three germ layers?

Answer 19

1. Ectoderm
2. Mesoderm
3. Endoderm

Question 20

This germ layer forms many external and neural structures including the epidermis (skin), hair, nails, formation of exoskeleton (not all animals have exoskeletons), etc. Serves as outer covering

Answer 20

Ectoderm

Question 21

This germ layer develops into organs.

Answer 21

Mesoderm

Question 22

This germ layer forms the inner lining of organs in digestion and respiration systems.

Answer 22

Endoderm

Question 23

What germ layer does a diploblast don’t contain?

Answer 23

Mesoderm

Question 24

With __, two mirror images are obtained no matter how the animal is sliced longitudinally. This is common in animals that live underwater or those who are sessile (animals that don’t move that much). Top - oral side (mouth is located), aboral - opposite of the oral side.

Answer 24

radial symmetry

Question 25

With __, mirror images are obtained only if the animal is sliced down the *middle.* This is common in animals who are *locomotive.*

Answer 25

bilateral symmetry

Question 26

This kind of animals has *no body cavity.* Their body are filled with *mesenchyme*, a *solid tissue* where the organs are embedded; *Flatworms*

Answer 26

Acoelomate

Question 27

This kind of animals *has body cavity.*; Dirtworms

Answer 27

Coelomate

Question 28

This kind of animals's body cavity is *incompletely lined by mesoderm.* ;Nematodes, roundworms

Answer 28

Pseudocoelomate

Question 29

This is the *repetition* of the body units along the length of the body of animals.

Answer 29

Segmentation

Question 30

What are *the early animals?*

Answer 30

Sponges (porifera) and cnidarians

Question 31

__ have saclike bodies perforated by many *pores* called *ostia*. They are multicellular (lack tissues) and some have various symmetries or no symmetries at all.

Answer 31

Sponges (porifera)

Question 32

__ have two tissue layers, are *radially symmetrical*, *have a saclike digestive cavity* (with only one opening), and possess *nematocytes* are specialized cells that *contain nematocysts*, which are the organelles that deliver a sting.

Answer 32

Cnidarians

Question 33

___ are characterized by *feeding structure and larval development.* They *increase their body mass gradually without molting.*

Answer 33

Lophotrochozoans

Question 34

What are the *lophotrochozoans?*

Answer 34

Flatworms, Mollusks, and Annelids

Question 35

___ have three germ layers but *no coelom.* They are bilaterally symmetrical and have a saclike digestive cavity. Many are hermaphrodites. Ex. planarians, tapeworms

Answer 35

Flatworms

Question 36

The body of a mollusc or __ typically contains a *visceral mass, a mantle* (may secret a shell), and *a foot.*

Answer 36

mollusks

Question 37

What are the three main types of *mollusks?*

Answer 37

1. Gastropods 2. Cephalopods 3. Bivalves

Question 38

*Snails*, representatives of this group. * flat foot * one-part shell * mantle cavity (that carries on gas exchange.)

Answer 38

Gastropods

Question 39

___ such as *clams* * muscular foot * two-part shell * filter feeder

Answer 39

Bivalves

Question 40

*Octopuses and squids* * marked cephalization, * move rapidly by jet propulsion, * closed circulatory system

Answer 40

Cephalopods

Question 41

___ are *segmented worms;* segmentation is seen both externally and internally.

Answer 41

Annelids

Question 42

What are the three major classes of *annelids?*

Answer 42

1. Polychaetes 2. Oligochaetes 3. Leeches

Question 43

__ are worms that have many setae. A clam worm is a predatory marine worm with a *well-defined head region.*

Answer 43

Polychaetes

Question 44

These are annelids that *do not have a well-defined head region.* An example of these are *earthworms* that scavenge for food in the soil.

Answer 44

oligochaetes

Question 45

___ are annelids that feed by sucking blood.

Answer 45

Leeches

Question 46

___ have a pseudocoelom and a complete digestive tract.

Answer 46

Roundworms

Question 47

They have *jointed appendages.* They are the *most varied and numerous of animals.* Their success is largely attributable to a flexible exoskeleton (composed mostly of chitin) and specialized body regions.

Answer 47

Arthropods

Question 48

The ___ are invertebrate protostomes that *increase their body mass by molting their exoskeleton, or cuticle.*

Answer 48

ecdysozoans

Question 49

What are the three major groups of *arthropods?*

Answer 49

1. Crustaceans 2. Arachnids 3. Insects

Question 50

___ have a head that bears compound eyes, antennae, and mouthparts. *Five pairs* of walking legs are present.

Answer 50

Crustaceans

Question 51

___ include spiders, scorpions, ticks, mites, harvestmen, and horseshoe crabs. Spiders live on land and spin silk, which they use to capture prey as well as for other purposes.

Answer 51

Arachnids

Question 52

___ have *three pairs of legs attached to the thorax.* They have adaptations to a terrestrial life.

Answer 52

Insects

Question 53

What are the ecdysozoans?

Answer 53

Roundworms and Arthropods

Question 54

They have a *pseudocoelom and a complete digestive tract.*

Answer 54

Roundworms

Question 55

Characterized by *jointed appendages.* They are also the *most varied and numerous of animals.* Their success is largely attributable to a flexible exoskeleton (composed mostly of chitin) and specialized body regions.

Answer 55

Arthropods

Question 56

They have a head that bears compound eyes, *antennae,* and mouthparts. *Five pairs of walking legs* are present.

Answer 56

Crustaceans

Question 57

They include spiders, scorpions, ticks, mites, harvestmen, and horseshoe crabs. Spiders live on land and spin silk, which they use to capture prey as well as for other purposes.

Answer 57

Arachnids

Question 58

They have *three pairs of legs* attached to the thorax. They have adaptations to a terrestrial life.

Answer 58

Insects

Question 59

What are the deuterostomes?

Answer 59

Echinoderms and Chordates

Question 60

They have *radial symmetry as adults* (not as larvae) and endoskeletal spines. Typically, they have tiny skin gills, a central nerve ring with branches, and a water vascular system for locomotion, as exemplified by the *sea star.*

Answer 60

Echinoderms

Question 61

An example of them are *adult tunicates* which *lack chordate characteristics except gill slits*, but *adult lancelets have the four chordate characteristics* and show obvious segmentation.

Answer 61

Invertebrate chordates

Question 62

They have a *notochord*, a *dorsal tubular nerve cord*,*pharyngeal pouches, and a postanal tail* at some time in their life history.

Answer 62

Chordates

Question 63

What are the *vertebrate chordates?*

Answer 63

1. Fish 2. Amphibians 3. Reptiles 4. Birds 5. Mammals

Question 64

What are the three types of *fishes?*

Answer 64

1. Jawless fishes 2. Cartilaginous fishes 3. Bony fishes

Question 65

The first vertebrates, the ___ (represented by *hagfishes and lampreys*), lacked jaws and fins.

Answer 65

jawless fishes

Question 66

___ have jaws and fins supported by bony spikes; these fishes include the *ray-finned fishes* and *lobe-finned fishes.* Some of the lobe-finned fishes have lungs.

Answer 66

Bony fishes

Question 67

___, represented by *sharks and rays*, have jaws and a skeleton made of cartilage.

Answer 67

Cartilaginous fishes

Question 68

They *evolved from ancient lobe-finned fishes* and have two pairs of jointed vertebrate limbs. Examples of them are frogs, toads, newts, and salamanders,

Answer 68

Amphibians

Question 69

___, such as snakes, lizards, turtles, crocodiles, and birds, *lay a shelled egg,* which contains extraembryonic membranes, including an amnion that allows them to reproduce on land.

Answer 69

Reptiles

Question 70

These are *feathered reptiles,* which helps them maintain a constant body temperature. They are adapted for flight; their bones are hollow, with air cavities; lungs form air sacs that allow one-way ventilation; and they have well-developed sense organs.

Answer 70

Birds

Question 71

All reptiles, except birds, are ___. Birds are ___

Answer 71

ectothermic, endothermic.

Question 72

___ are amniotes that have *hair and mammary glands.* The former helps them maintain a constant body temperature, and the latter allow them to nurse their young.

Answer 72

Mammals

Question 73

What are the three kinds of *mammals?*

Answer 73

1. Monotremes 2. Marsupials 3. Placental mammals

Question 74

This kind of mammals lay eggs.

Answer 74

Monotremes

Question 75

This kind of mammal have a *pouch* in which the newborn matures.

Answer 75

Marsupials

Question 76

This kind of mammal are far more varied and numerous, retain offspring inside the uterus until birth.

Answer 76

Placental mammals

Question 77

__ is *created by development*, it has different characteristics that allow different species to adapt and survive in diverse environments.

Answer 77

Animal Evolution

Question 78

___ are extremely diverse, they share some important differences from other multicellular eukaryotes, plants, and fungi.

Answer 78

Animals

Question 79

Unlike plants, which make their food through photosynthesis, animals are ___ and must acquire nutrients from an external source

Answer 79

heterotrophs

Question 80

Unlike __ which *digest* their food *externally* and *absorb the breakdown products*, __ *ingest* (eat) whole food and *digest it internally.*

Answer 80

fungi, animals

Question 81

___ are animals with ‘true tissue’

Answer 81

Eumetazoa

Question 82

Radial symmetry comes first before bilateral symmetry. True or false?

Answer 82

True

Question 83

Allows us to categorize animals based on how their bodies can be *divided into parts*

Answer 83

Animal symmetry

Question 84

This is the *first opening* developed in animals and which characterized animals into two groups.

Answer 84

Blastophore

Question 85

Usually, animals undergo sexual reproduction and form the embryo, the embryo is composed of___ that interact with each other from __ to contribute to the formation of tissue and organs.

Answer 85

germ cells, germ layers

Question 86

Transitioning from *unicellular to a multicellular* organism

Answer 86

Metazoans