Exam 3

Question 1

Metazoa

Answer 1

animals that undergo development from an embryo stage with two or three tissue
layers. All multicellular animals except sponges.

Question 2

Eumetazoa:

Answer 2

animals with true tissues. Most animals except sponges.

Question 3

Bilateria

Answer 3

: a clade of animals with bilateral symmetry and three tissue layers.

Question 4

Body plan:

Answer 4

set of morphological features (symmetry, tissue organization, body cavity) common
to many members of a phylum of animals.

Question 5

Draw the main stages of early embryonic development in animals:

Question 6

label: Ectoderm, Endoderm, Blastopore, Archenteron. Also, indicate the
difference between protostome and deuterostome.

Question 7

Describe the three types of body symmetry in animals and provide an example of a group of
animal for each type of body symmetry.

Answer 7

-Radial symmetry: body plan in which the organism can be divided into similar halves by passing
a plane at any angle along a central axis.
Examples: cnidarians, echinoderms

-Bilateral symmetry: a body plan in which left and right sides of the organism can be divided
into approximate mirror images of each other along the midline. Two similar halves.
Examples: chordata, platyhelminthes

-Asymmetry: lack of symmetry
Exmple: porifera

Question 8

Which phylum is characterized by animals that have a segmented body:

Answer 8

anthropoda

Question 9

6. Choanoflagellates are very similar in morphology to which sponge cell type?

Answer 9

choaocyte

Question 10

An example of a diploblast would be a(n)

Answer 10

jellyfish

Question 11

The most diverse group of animals on Earth is what?

Answer 11

inscets

Question 12

Which is true about multicellularity?

Answer 12

it has evolved many times

Question 13

Based on the figure below, identify the type of body cavity:

Question 14

15. Which of the following environmental changes is thought to have contributed to the
    Cambrian explosion

Answer 14

an increase in oxygen levels in the atmosphere

Question 15

What are the two invertebrate phyla that are part of Chordates? Why are they classified within
chordates?

Answer 15

The two invertebrate phyla are urochordates and cephalochordates. They are part of Chordata because
they have the four synapomorphies characteristic of chordates at some point in their life stage. The
synapomorphies are:
1. Presence of notochord
2. Presence of dorsal hollow nerve cord
3. With pharyngeal slits
4. With post-anal tail

Question 16

How is the amniotic egg similar in regard to plant seeds.

Answer 16

Seeds and eggs contain developing embryos. Both contain food supplies for the developing embryo.
Both contain protective coverings which prevent drying.

Question 17

What is the relevance of the Cambrian period?

Answer 17

he Cambrian Period marks an important point in the history of life on Earth; it is the time when many
kinds of invertebrates and the first vertebrates—fishes—appeared in the fossil record. In other words,
most of the animal phyla that are extant as of today originated during the Cambrian period

Question 18

All animals are heterotrophic

Answer 18

T

Question 19

Most animals reproduce sexually

Answer 19

F

Question 20

9. Gastrulation is a synapomorphy of Opisthokonta

Answer 20

F

Question 21

Nematodes are part of the clade Ecdysozoa, but they lost the capacity to shed
the exoskeleton

Answer 21

F

Question 22

Nematodes are part of the clade Ecdysozoa, but they lost the capacity to shed
the exoskeleton

Answer 22

F

Question 23

Crustaceans are the most diverse group of animals in marine environments

Answer 23

T

Question 24

Leeches are part of the phylum Annelida which refers to segmented worms

Answer 24

T

Question 25

One distinction about sponges and other animals is that sponges are said to lack
true tissues

Answer 25

T

Question 26

Recent phylogenies placed birds within reptiles

Answer 26

T

Question 27

Chondrichthyes lack swim bladder

Answer 27

T

Question 28

Which of following reproductive strategies in mammals involves the mother laying eggs that hatch
outside of her body?

Answer 28

oviparous reproduction

Question 29

In a typical ray-finned fish, the swim bladder allows individuals to perform which of the following
processes?

Answer 29

reain bouyant

Question 30

Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals
and birds best explains this habit?

Answer 30

endothermy

Question 31

Which clade includes humans?

Answer 31

synapsids

Question 32

Which would be the most feasible method of figuring out to which other hominin species H. floresiensis
was most closely related?

Answer 32

Compare the skeletal morphology of H. floresiensis to that of each of the other hominin species.