Support & Movement

CHAPTER 8

CHAPTER 8

UNIT 8.1 Understanding the support system in animals

Support & Movement

Explain the various support system in vertebrates and

invertebrates

Compare and contrast the support system between land and

aquatic vertebrates

Compare and contrast the support system between land &

aquatic invertebrates

The reasons for animals to have a support system is :-

to support the body

to provide body shape

to assist body movements.

SUPPORT SYSTEMS IN ANIMALS

VERTEBRATES

ENDOSKELETON

INVERTEBRATES

EXOSKELETONHYDROSTATIC

SKELETON

The 3 basic types of skeletons in animals

ENDOSKELETON(a) Also known as the internal skeleton.

(b) Located inside the body of all vertebrates includes

human beings.

(c) Made up of bones or cartilages.

Functions: -

(a) Supports body weight

(b) Maintains body shape

(c) Protects soft internal organs

(d) Provide points for the attachment of muscles

(e) Allows free movement

EXOSKELETON(a) Also called the external skeleton

(b) Hard outer skin or shell of invertebrates

(c) Made of cuticle or calcium carbonate

(d) Examples of animals: Centipede, ant, crab

Functions: -

(a) Maintain body shape and support body weight

(b) Protects internal organs

(c) Provides places for the attachment of muscles

(d) Allows movement of body parts

HYDROSTATIC SKELETON(a) Consists of a muscular wall which encloses a body

cavity that is filled with fluid

(b) This body fluid pushes out and exerts pressure in all

directions

(c) This body fluid pressure, called hydrostatic pressure

gives support and shape to the animal.

(d) A type of support system for some invertebrates like

earthworm, leech, jellyfish and caterpillar.

Functions: -

(a) Support & maintains body shape as well as rigidity

(b) Supports & protects internal tissues & organs

(c) Allows invertebrates to bend, straighten & move

Comparison of the Endoskeleton betweenAquatic Vertebrates and Land Vertebrates

Land Vertebrates Aquatic vertebrates

Similarities

•Have endoskeleton

•Have pectoral & pelvic girdles

•Have flexible bones

Differences

Endoskeleton

Pectoral & pelvic girdles

Support

Small & weak

Small

Body weight supported

by the buoyancy of water

Big & strong

Small

Body weight supported

by the buoyancy of water

Comparison of the Support systems in land & aquatic invertebrates

Land Invertebrates Aquatic Invertebrates

Similarities

•Both are supported by either exoskeleton or hydrostatic skeleton

Differences

Structure of exoskeleton

Support

Hard & made of calcium

carbonate

Body weight supported

by the buoyancy of water

Hard & made of cuticle

except for shells of snails

which are made of

calcium carbonate

Body weight supported

by external skin or shell

CHAPTER 8

UNIT 8.2 Understanding the support system in plants

Support & Movement

Explain the various support system in plants

Classify plants based on their support systems

Various Support Systems in Plants

Buttress roots

Prop roots

Prickles

Stilt roots

tendrils

Clasping rootsThorns

Buttress roots

• Thick support roots that grow from the stem

above the ground

• These roots hold the tree firmly to the ground,

giving it extra support

• Examples :

Angsana tree,

casuarina tree,

durian tree

Prop roots

• Roots which grow from the stem or branches

into the ground for support

• Examples :

Banyan tree

Pandan plant

Maize plant

Prickles

• An outgrowth of the epidermis and

can be easily removed from the stem

• Examples :

Rose shrub

Tendrils

• Curly string-like structures modified

from stems and leaves.

• Curl and twine round parts of other

plants or objects to help the plant to

climb

• Examples :

Cucumber

Bitter gourd

pumpkin

Clasping roots

• Roots that grip onto other plants or

structures to get support.

• Examples :

Money plant

Betel vine (sirih)

Thorns

• Sharp modified branches that cannot

be easily removed

• Act as hooks to hold on to supports.

• Examples :

Bouganvillea shrub

Crown of thorns plant

Stilt roots

• Roots that develop from the main

stem and grow into the ground for

support.

• Examples :

Mangrove tree

Buoyancy - (Aquatic Plants)

• Aquatic plants cannot stay upright on land because their stems are non-woody & soft

• Aquatic plants can stay upright in water because their weights are supported by the buoyancy of water

• Some aquatic plants have many air sacs in their stems & leaves. These structures make them light so that

they can float on water.

• Some aquatic plants have tiny leaves to ensure that they are not disrupted by the flow of water.

Examples :

Lotus

Water hyacinth

Water lettuce

Hydrilla

Support Systems in Plants

Features Herbaceous Woody

Structure of stem

Little woody tissue with

few xylem cells

Little woody tissue with

few xylem cells

Support

Supported by the turgidity

of cells

Cannot support a heavy

weight

Supported by woody

tissues

Can support a heavy

weight

Examples- Balsam plant

-Spinach

-Durian tree

- Angsana tree

Scattered

wooden

tissues

Rings of

woody

tissues

Support Systems in Woody Plants

The wood tissues provide stronger support. Normally on taller plants.

Durian Tree Bougainvillea

Rambutan tree

Support Systems in Non-woody Plants

Non-woody plants depend on the water stored in the cells of the stem for support.

Adequate water in plant

Inadequate water in plant

CHAPTER 8

UNIT 8.3 Appreciating the support system in living organisms

Support & Movement

Explain why support system is important to living things

Appreciating the Support System in Living Things

Without support system, many living things will not be able to live

Support system provide an organism:-

Proper shape and posture

Support the weight of body

Protect organs from injury

Additional support system

A crippled person may use a cane, crutches or a walking frame for support.

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