Animal Diversity

Question 1

What is the process wherein the single cell repeatedly divides?

Answer 1

Cleavage

Question 2

What are blastomeres?

Answer 2

Smaller cells produced by cell division (cleavage)

Question 3

What are cnidarian polyps with no medusa stage? They are also called “flower animals”

Answer 3

Anthozoa

Question 4

Describe the septa of tube anemones.

Answer 4

completely unpaired

Question 5

Give at least three characteristics of an animal.

Answer 5

1. eukaryotic
2. heterotrophic
3. capable of aerobic respiration
4. reproduces sexually
5. motile at some point
6. grows from a blastula

Question 6

What is a zygote?

Answer 6

The union of male and female gametes

Question 7

What is the epidermis?

Answer 7

outer layer of body wall

Question 8

What do you call the lining of the gut cavity?

Answer 8

gastrodermis

Question 9

What is a triploblast organism?

Answer 9

It has three embryological layers

Question 10

What is an acoelomate?

Answer 10

It is an animal that has no internal, fluid-filled body cavity separating its body wall from its digestive tract.

Question 11

What is a pseudocoelomate?

Answer 11

It is an organism that has false body cavities. It has a fluid-filled body cavity separating the gut of the organism from the body wall but it is not lined by mesoderm.

Question 12

What is a coelomate?

Answer 12

It is an organism that has coelom or body cavity surrounded by mesoderm

Question 13

What is protoplasmic organization?

Answer 13

Layer of organization exhibited by all unicellular organisms such as paramecium; all life functions confined within one cell

Question 14

What is cellular organization?

Answer 14

It refers to an aggregation of differentiated cells working together

Question 15

What is cell-tissue organization?

Answer 15

It refers to an organization of cells to form tissues (e.g. hydra have tissues but no organs)

Question 16

What is tissue-organ organization?

Answer 16

It refers to tissues that aggregate to form organs (planarians have organs but no organ systems)

Question 17

What is organ-system organization?

Answer 17

It refers to organisms with organs that work together to perform functions and become organ systems

Question 18

Define spherical symmetry.

Answer 18

Any plane through the center divides the organism into mirrored halves; no animals possess this

Question 19

Define radial symmetry.

Answer 19

It is the symmetry around a central axis (more than two planes produce mirrored halves); examples are cnidarians, echinoderms, sponges

Question 20

Define biradial symmetry.

Answer 20

Only two planes produce mirrored halves; example is comb jellies

Question 21

Define bilateral symmetry.

Answer 21

The sagittal plane divides into mirrored halves; most of such animals also show anterior cephalization

Question 22

It separates posterior (back) and anterior (front) planes

Answer 22

Transverse plane

Question 23

It separates the dorsal (top) and ventral (bottom) planes

Answer 23

Frontal plane

Question 24

It separates the left and right halves (mirror images)

Answer 24

Sagittal plane

Question 25

Define porifera.

Answer 25

- have specialized cells and chambers - supported by a skeleton of spongin protein composed of calcium carbonate or silica

Question 26

Define cnidaria.

Answer 26

- have specialized stinging cells called cnidocytes (which contain stinging structures called nematocysts) - have unique stages (polyp and medusa stage)

Question 27

Define platyhelminthes.

Answer 27

- flatworms - have the most primitive "brain" - nervous system organized into a pair of lateral nerve cords and anterior enlargement (cerebral ganglion) - have a special excretory organ called nephridia or flame cells

Question 28

Define nematoda.

Answer 28

- roundworms - have a pseudocoelom (a cavity between mesoderm and ectoderms) - can be both free-living and parasitic

Question 29

Define mollusca.

Answer 29

- have a hard external shell - have thin structure called the mantle, which secretes the shell - have a visceral mass where organs - have a muscular foot for locomotion - have a feeding organ composed of chitinous teeth called radula

Question 30

Define annelida.

Answer 30

- segmented worms - inhabit marine, terrestrial and freshwater habitats - exhibit metamerism or true segmentation - hermaphrodites

Question 31

Define arthropoda.

Answer 31

- have very thick exoskeleton made up of chitin - can be identified by the number of pairs of appendages and number of segments in their body (cephalization)

Question 32

Define echinodermata.

Answer 32

- only found in marine habitats - have a water-vascular system that serves their circulatory system - have endoskeleton composed of ossicles made up of calcium carbonate

Question 33

Define chordata

Answer 33

- has notochord, a slender rod lying between the dorsal nerve cord and gut that provides flexible structure - have pharyngeal slits at one point in their lives/development - have dorsal tubular nerve cord - has post-anal tail