LAB 2

Question 1

What does ‘caudal’ refer to in anatomy?

Answer 1

The tail region of an animal

Question 2

What is the definition of ‘posterior’?

Answer 2

The tail or hind end of an animal

Question 3

Define ‘anterior’.

Answer 3

The front or head end of an animal

Question 4

What does ‘cephalic’ mean?

Answer 4

The head region, specifically

Question 5

What is meant by ‘ventral’?

Answer 5

The underside of an animal

Question 6

What does ‘dorsal’ refer to?

Answer 6

The back or uppermost of an animal

Question 7

What does ‘distal’ mean in anatomical terms?

Answer 7

Structure farthest away from a point of reference

Question 8

Define ‘proximal’.

Answer 8

Structure nearest to a point of reference

Question 9

What does ‘oral’ refer to?

Answer 9

Mouth region

Question 10

What is the current understanding of animal classification?

Answer 10

Animals are monophyletic and belong to a single clade, the Metazoa

Question 11

What does the phylum ‘Porifera’ consist of?

Answer 11

Sponges

Question 12

What organisms are included in the phylum ‘Cnidaria’?

Answer 12

Corals, anemones, jellies

Question 13

Name the organisms classified under the phylum ‘Echinodermata’.

Answer 13

Sea stars, sea cucumbers, sea urchins

Question 14

What is included in the phylum ‘Chordata’?

Answer 14

Fish, amphibians, reptiles (including birds), mammals

Question 15

What type of organisms are found in the phylum ‘Platyhelminthes’?

Answer 15

Flat worms

Question 16

What are examples of organisms in the phylum ‘Annelida’?

Answer 16

Segmented worms

Question 17

What does the phylum ‘Mollusca’ include?

Answer 17

Chitons, slugs, snails, clams, squid, octopi

Question 18

What does the phylum ‘Brachiopoda’ consist of?

Answer 18

Lampshells

Question 19

What are organisms in the phylum ‘Nematoda’ commonly known as?

Answer 19

Round worms

Question 20

What does the phylum ‘Arthropoda’ include?

Answer 20

Spiders, centipedes, crustaceans, insects

Question 21

What is the first stage of animal development after fertilization?

Answer 21

Cleavage

Question 22

What occurs during the cleavage stage?

Answer 22

A series of rapid cell cycles with short to no G1 or G2 phases

Question 23

What is the result of cleavage?

Answer 23

A solid ball of cells known as the morula, which hollows out to become a blastula

Question 24

What is the blastula?

Answer 24

A hollow ball that is typically one cell layer thick

Question 25

Define 'gastrulation'.

Answer 25

The process where the one-layered embryo folds in to produce a multiple layered embryo—the gastrula

Question 26

What is the archenteron?

Answer 26

The beginnings of the digestive tract in the gastrula

Question 27

What is the significance of the blastopore?

Answer 27

It is the first opening that develops into the digestive tract

Question 28

True or False: Sponges have a protein layer that isolates their cells.

Answer 28

False

Question 29

What is the evolutionary significance of radial symmetry?

Answer 29

There are numerous ways to cut them in half

Question 30

What characterizes bilateral symmetry?

Answer 30

There is only a single plane of symmetry

Question 31

What is 'cephalization'?

Answer 31

The evolution of the head

Question 32

What group do cnidarians belong to?

Answer 32

The Radiata

Question 33

True or False: The Radiata is a monophyletic group.

Answer 33

False

Question 34

In what forms can Obelia be found?

Answer 34

In polyp form (hydroid stage) and as adult free-swimming medusa

Question 35

What surrounds the mouth in the hydroid stage of Obelia?

Answer 35

Tentacles

Question 36

In the medusa stage of Obelia, where does the mouth extend from?

Answer 36

Centrally located stomach

Question 37

What is the body form of Hydra?

Answer 37

Polyp body form

Question 38

What type of symmetry do radially symmetrical cnidarians exhibit?

Answer 38

Multiple planes of symmetry

Question 39

What is the single body axis of radially symmetrical organisms called?

Answer 39

Oral-aboral axis

Question 40

In animals with bilateral symmetry, what separates their right and left halves?

Answer 40

Cutting these animals in half

Question 41

What are the dorsal and ventral sides of an animal with bilateral symmetry?

Answer 41

Dorsal: back, Ventral: belly

Question 42

What are the two major tissue layers found in Eumetazoan embryos?

Answer 42

Ectoderm and endoderm

Question 43

What term describes animals with only two tissue layers?

Answer 43

Diploblastic

Question 44

What term describes animals with three tissue layers?

Answer 44

Triploblastic

Question 45

What is the process called that leads to the development of distinct tissue layers in embryos?

Answer 45

Gastrulation

Question 46

What is formed during gastrulation that becomes the opening to the digestive tract?

Answer 46

Blastopore

Question 47

What are animals whose blastopore becomes the mouth called?

Answer 47

Protostomes

Question 48

What are animals whose blastopore becomes the anus called?

Answer 48

Deuterostomes

Question 49

What does the term 'deuterostome' literally translate to?

Answer 49

Second mouth

Question 50

Which two phyla are included in the clade Deuterostomia?

Answer 50

* Echinodermata * Chordata

Question 51

What is the basal taxon of chordates?

Answer 51

Cephalochordata

Question 52

What is a notable feature of the amphioxus?

Answer 52

Large notochord

Question 53

What is located dorsal to the notochord in amphioxus?

Answer 53

Dorsal hollow nerve cord

Question 54

What type of gut does amphioxus have?

Answer 54

Simple gut from mouth to anus

Question 55

Fill in the blank: The two types of animals with true tissues are _______ and _______.

Answer 55

Diploblastic, Triploblastic

Question 56

True or False: All diploblastic animals have two openings to their digestive tract.

Answer 56

False

Question 57

What are the three clades into which chordate representatives are divided?

Answer 57

* Cephalochordata * Urochordata * Vertebrata

Question 58

How do amphioxus primarily perform gas exchange?

Answer 58

Through thin skin and pharyngeal gill slits ## Footnote Pharyngeal gill slits assist in creating a water current for suspension feeding.

Question 59

Which group of organisms is more closely related to vertebrates than cephalochordates?

Answer 59

Urochordates ## Footnote This relationship is based on molecular evidence.

Question 60

What are tunicates commonly known as?

Answer 60

Sea squirts ## Footnote They are named for the thin covering (tunic) over their body.

Question 61

What key chordate features are present in the larval stages of urochordates?

Answer 61

Gill slits, post anal tail, notochord, dorsal hollow nerve cord ## Footnote The rudimentary brain and sensory organs are also located in the head.

Question 62

What happens to the notochord and dorsal hollow nerve cord in adult urochordates?

Answer 62

They are absent; only a simple nerve ganglion is present.

Question 63

What are the three major clades within Bilateria?

Answer 63

Deuterostomia, Lophotrochozoa, Ecdysozoa ## Footnote These clades are established based primarily on molecular homologies.

Question 64

How do members of the Lophotrochozoa grow?

Answer 64

Continuously ## Footnote This contrasts with the Ecdysozoa, which grow by spurts.

Question 65

List some phyla included in the Lophotrochozoa clade.

Answer 65

* Platyhelminthes * Brachiopoda * Annelida * Mollusca * 14 other phyla ## Footnote It is a vast and diverse group of animals.

Question 66

What ciliated feeding structure do some Lophotrochozoa, like brachiopods, possess?

Answer 66

Lophophore

Question 67

What is the ciliated larval stage called that annelids and molluscs go through?

Answer 67

Trochophore

Question 68

What common feature do all members of the Lophotrochozoa exhibit?

Answer 68

Continuous growth ## Footnote Juveniles gradually get larger until reaching adult size.

Question 69

How do Ecdysozoans grow?

Answer 69

By shedding a hardened covering or cuticle (moult) and growing rapidly before creating a new one.

Question 70

True or False: All deuterostomes grow continuously.

Answer 70

True

Question 71

What distinguishes growth patterns between the two protostome clades?

Answer 71

Continuous growth in Lophotrochozoa vs. spurts in Ecdysozoa.