Chapter 7 Invertebrates Flashcards Preview

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Flashcards in Chapter 7 Invertebrates Deck (25):
1

radial symmetry

organisms have several ways in which they can be sectioned in half, and still have two equal halves, each being a mirror image of the other.

2

Bilateral Symmetry

There is only one way in which the animal can be divided in half to make two equal halves with each half being a mirror image of the other

3

Asymmetric

In these organisms, there is no way in which it can be divided into two equal halves which are mirror images. They have an irregular shape.

4

Monecious

one individual has both male and female sex organs ("one-house")

5

Dioecious

two separate sexes. Each individual is either a male or a female ("two houses")

6

Asexual

new individuals develop without gametes; either by "budding" or by "regeneration."

7

Oral

mouth end

8

aboral

end opposite of the mouth

9

distal (terminal)

end of appendage opposite to where it is attached.

10

basal (proximal)

end of appendage to where it is attached

11

anterior

front end (i.e. the direction it moves)

12

dorsal

back

13

lateral

side

14

ventral

belly

15

posterior

rear end

16

cross section

cut upon a segmented worm vertically and it is the middle portion.

17

median longitudinal cross section

cut a worm horizontally into long sections

18

Phylum: Cnidaria (polyp - sea anemone, medusa - jellyfish, and coral).

What are the three characteristics?

-gastrovascular cavity
-tentacles
-stinging cells

19

3 Classes of sponges

1. Bath sponge: contain "spongin" which are elastic fibers.
2. Calcareous sponges: contain calcium carbonate making them hard like tiny needles.
3. Glass sponges: contain silica (glass-like) spicules.

20

Phylum: Platyhelminthes

What are the three classes?

1. Free-living (i.e. planarians)
2. Tapeworms - intestinal parasite in humans or other vertebrates.
-have segments
-each segment has both female and male sex organs
-has scolex, suckers, and spines which allows it to attach to the wall of the hosts intestines.
3. Flukes
- look similar to freeliving flat worms
-have complex life cycle

21

Phylum: Nematoda (Ascaris, Hookworm, Pinworm)

What are some characteristics?

-contain roundworms
-they have no circulatory system
-they have no hair
-have a flat, non-muscular digestive tract

22

Why do Ascaris produce so many eggs?

Because the life cycle is complex so by producing many eggs it ensures at least 1 will survive.

23

Phylum: Annelida

-bodies composed of many, similar, ring-like segments; thus, they are commonly called the segmented worms.
-usually have hairs, or at least a few short bristles.
-contain a muscular digestive tract
-contain circulatory system with blood
Ex: Earthwords (Class: Oligochaeta), Leeches (Class: Hirudinea).

24

Mollusca

snails; bivalves; chitons; and cephalopods
-soft body and hard shell
-muscular foot and mantle

25

Echinodermata

starfish; sea urchins; brittle stars; sand dollars
-tube feet; spiny skin; pentra-radial symmetry; water-vascular system