Chapter 10: Invertebrates As Special Animals: "Have You No Spine?"

Question 1

Most invertebrates contain true body ______ which are collections of similar cells that are specialized to perform only certain body functions.

Answer 1

Tissues

Question 2

The main group of animals that are invertebrates that contain true tissues that are formed after repeated cell division in the embryo are called ______.

Answer 2

Eumetazoans

Question 3

What are some eumetazoans?

Answer 3

Starfish

Lobster

Question 4

______ are a small group of invertebrates that lack true tissues.

Answer 4

Parazoans

Question 5

Give an example of a parazoan.

Answer 5

Sponge

Question 6

What phylum do sponges belong to and why?

Answer 6

Porifera

Because their bodies are full of pores.

Question 7

The ______ ______ are the flagellated cells that sweep large amounts of water in the pores of sponges.

Answer 7

Collar cells

Question 8

What do invertebrates lack most of all?

Answer 8

A spine of backbone.

Question 9

______ is one of the characteristics of invertebrates when there is a rough balance or equality of shape and size on either side of a dividing line.

Answer 9

Symmetry

Question 10

______ or ______-______ symmetry is where an imagery line subdivides the body into two equal halves and therefore the other half of the body is considered the mirror image.

Answer 10

Bilateral

Mirror image

Question 11

When there is a rough balance of various parts or “rays” (radi) that come out from the center or axis is called ______ symmetry.

Answer 11

Radial

Question 12

______ are animals with bilateral symmetry and translates to “two-sided” animals.

Answer 12

Bilateria

Question 13

When an animal carries the characteristics of an anterior end and a posterior one it is said to have ______ where it has a definite head end and a collection of sensory organs.

Answer 13

Cephalization

Question 14

______ are a group of invertebrates that have “little rays” or spines projecting outward from their bodies.

Answer 14

Radiolarians

Question 15

Radiolarians carry no ______ where there are definite start and end parts.

Answer 15

Cephalization

Question 16

______ ______ are rings of cells in parazoans within the embryo from which specialized tissues and organs are produced.

Answer 16

Germ layers

Question 17

In mitosis, there are successive cell divisions called ______.

Answer 17

Cleavages

Question 18

A ______ is a hollow “little bladder”-like ball of cells which is what comes after several cleavages.

Answer 18

Blastula

Question 19

The ______ is what follows the blastula and is a little stomach or hollow ball of several layers of germ cells (or germ layers) where these cells eventually give rise to the specialized tissues in the later embryo and finally the adult stages of life.

Answer 19

Gastrula

Question 20

The ______ is created by an infolding of a layer of surface cells around the blastula. This infolding creates another cavity, called the archenteron or the beginning for of the intestine. The archenteron is connected to the surface by an opening.

Answer 20

Gastrula

Question 21

The ______ is the inner skin of germ cells from which the lining of the intestine and interior of other major body cavities eventually develop and covers the archenteron.

Answer 21

Endoderm

Question 22

What is the outer skin that covers the embryo?

Answer 22

Ectoderm

Question 23

In most types of animals, the ectoderm gives rise to the ______ ______ ______.

Answer 23

Central nervous system.

Question 24

Sandwiched between the endoderm and ectoderm is the ______ which is the middle the forms the muscle and most other organs.

Answer 24

Mesoderm

Question 25

The ______ is where the food is excreted as feces.

Answer 25

Anus