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Biology Term 2 > Animal Diversity > Flashcards

Flashcards in Animal Diversity Deck (50):
1

Role of invertebrates in agriculture and ecosystems

- act as pollinators
- decompose dead matter
- aerate the soil

2

Pollinators: role and examples

- mainly insects in farmlands and orchards (e.g. honeybees and butterflies)
- essential for fertilization and formation of seeds and fruit.

3

Insects that help w aerating soil

Insects such as termites, ants and earthworms.

4

How soil aeration works

Insects dig underground tunnels. This loosens the soil and traps air between soil particles, making it easier for water to flow through. Because soil is loose, the plant roots can penetrate deeper into the soil to get water and nutrients.

5

Organisms responsible for decomposition

- bacteria
- fungi
- flies
- worms
- beetles

6

How decomposition occurs

Earthworms live in rotten plant material, which they draw into underground tunnels. The food is ingested and digested together with the soil. Their faeces are rich in nutrients (calcium and phosphorus) which makes the soil more fertile. When food is digested, it mixes with the microorganisms, and the faeces have more microorganisms than food. This increase in microorganisms increases decomposition in soil.

7

Coelom

Internal body cavity formed by the splitting of the mesoderm tissue layer.

8

Body Plans

A set of characteristics of an animal's body which scientists use to classify it.

9

Which common features of an animal's body are important for classification?

- symmetry and cephalization
- number of tissue layers
- presence or absence of coelom
- number of openings in digestive tract

10

Asymmetry

No symmetry. An example would be a sponge.

11

Radial symmetry

- Can be cut through more than one vertical plane to retain a mirror image.
- Have a definite aboral and oral side, but no left or right side.

12

Disadvantage of radial symmetry

Slow and inefficient locomotion.

13

Types of animals that are radial symmetry

Sessile and free floating, such as jellyfish.

14

Bilateral symmetry

Can only be cut in one vertical plane through it's centre to form two mirror images.

15

Aboral side

away from mouth

16

Oral side

side with mouth

17

Bilateral symmetry animals have ?

definite dorsal and ventral side.
a left and right side.
an anterior and posterior end.

18

dorsal and ventral sides

dorsal is top
ventral is bottom

19

Cephalization

The concentration of nerve cells at the anterior end of the body. A central nervous system is formed and is an advantage for locomotion.

20

Methods of locomotion made possible by cephalization

- crawling
- swimming
- running
- flying

21

What does bilateral symmetry go w ?

It goes with the development of a specialized, sensitive area, the head, at the anterior of the body.

22

What does the developing animal embryo consists of ?

It consists of a mass of cells that are in the shape of a ball.

23

Germ layers

different tissue layers

24

Three types of tissue layers

ECTODERM - outer layer
ENDODERM - inner layer
MESODERM - layer between ecto and endoderm

25

Diploblastic

two germ layers, the ecto and endoderm, separated by a jelly layer, the mesoglea

26

Triploblastic

Three layers
ectoderm/mesoderm/endoderm

27

Bilateral symmetry animals tissue layers ?

- triploblastic
- an organ level of organization

28

Tissues that develop from endoderm

lining of digestive tract

29

Tissues that develop from ectoderm

outer protective layer
nervous system
sense organs

30

Tissues that develop from mesoderm

organs that form part of blood system
muscular, reproductive system
skeleton and connective tissue

31

Acoelomate

No coelom in mesoderm.

32

Pseudocoelomate

has a coelom, but not a true coelom, bc it's not only surrounded by mesoderm tissue.

33

Coelomate

has a coelom

34

Biological importance of a coelom

- separates the digestive tract and the body wall -- ensuring that each functions independently.
- A fluid filled coelom can act as a hydrostatic skeleton.
- Presence of coelom allows animals to reach a considerable size and become more complex by providing space for organs to develop.
- Coelomic fluid can transport substances such as gases, nutrients and wastes.

35

Blood system

developed in most triploblastic animals for the transport of oxygen, carbon dioxide and nutrients, as well an excretory system to transport waste products.

36

Digestive tract in acoelomates

- only one opening to outside through which ingestion and egestion takes place.
- new food can only be taken in once all food already ingested is digested and the remains are egested.
- digestion in these animals are a discontinuous process.

37

Digestive tract in coelomate animals

- are more complex and have two openings -- mouth and anus.
- known as a through gut

38

Advantages of the through gut

- incoming food does not mix with outgoing undigested remains
- different regions in digestive tract become specialized to improve efficiency (stomach for digestion and intestine for absorption)
- digestion is a continuous process
- due to presence of coelom, food can move by peristalsis through the digestive tract, independently of muscles in body wall.

39

Porifera examples

sponges

40

Porifera body plan

- asymmetrical
- no cephalization
- cellular (loose cells)
- acoelomate
- no blood system
- no gut

41

Cnidaria example

polyp

42

Cnidaria body plan

- radial symmetry
- no cephalization
- diploblastic
- acoelomate
- no blood system
- no gut, one opening

43

Platyhelminthe examples

tapeworms

44

Platyhelminthe body plans

- bilateral symmetry
- cephalization
- triploblastic
- acoelomate
- no blood system
- no gut, one opening

45

Annelid examples

leeches and earthworms

46

Annelid body plans

- bilateral symmetry
- cephalization
- triploblastic
- coelomate
- closed blood system
- through gut

47

Arthropoda examples

spider, crab, locust

48

Arthropoda body plans

- bilateral symmetry
- cephalization
- triploblastic
- coelomate
- closed blood system
- through gut

49

Chordata examples

mammal, Bird, fish, reptiles

50

Chordata body plans

- bilateral symmetry
- cephalization
- triploblastic
- coelomate
- closed blood system
- through gut