SCIENCE CHAPTER 8 SUPPORT & MOVEMENT

The Support System In Animals

The support system of humans and land vertebrates is an endoskeleton (internal skeleton)

The functions of the endoskeleton is to :

1. Support the weight of the body2. Give the body its structure and

shape3. Produce blood cells4. Produce soft organs of the

body such as the heart and the kidneys

Support System In Land Vertebrates

Land vertebrates are also supported by endoskeletons

The land vertebrates ‘ endoskelton :

1. Give them shape2. Support their weight3. Protect their soft tissues

and organs of the body

Support System In Aquatic Vertebrates

The body weight of aquatic vertebrates is supported by the buoyancy of water

Their pectoral and pelvic girdles are very small and weak compared to those of land vertebrates

Aquatic vertebrates like the whale can grow to enormous sizes. This is because their body is supported by water so their bones do not have to support all of their weight

Support System In

Land Invertebrates

Exoskeleton (external skeleton)

Hydrostatic skeleton

(fluid-filled skeleton)

Exoskeleton

Some invertebrates have hard external structures for :

1. Maintaining their shape2. Supporting their bodies 3. Protecting their internal body

organs4. Aiding movement The hard external structures

are called exoskeletons The exoskeletons consists of

a hard substance called chitin

Hydrostatic Skeleton

Invertebrates with soft bodies have body fluids to provide them with shape and support

The body fluids exert a pressure on their body walls to form a hydrostatic skeleton

The hydrostatic skeleton has the following functions :

1. Provides support2. Maintains body shape3. Aids movement

Support System In Aquatic

Invertebrates

ExoskeletonHydrostatic

Skeleton

Exoskeleton

Aquatic invwertebrates such as prawns, crabs, cockles and snails are supported by hard exoskeleton

The exoskeletons are very hard because they contain calcium

Hydrostatic Skeleton

Aquatic invertebrates such as the starfish and the jellyfish are supported by a hydrostatic skeleton

The fluid pressure in their bodies gives them support and shape

Support System in Plants

Support System in Land Plants

Support System in Aquatic Plants

Support System in Land Plants

There are 2 types of support system of land plants, which are :

1. Woody plants2. Non-woody plants (herbaceous plants) Woody plants are supported by woody

tissue. Woody tissue is hard and provides the shape and strength of the stem to hold itself erect

Woody plants are also supported by special structures such as thorns, buttress roots or clasping roots

Various Support Systems Of Woody Plants

WOODY TISSUE THORNS

Woody tissues enables the plants to grow tall and erect in order to obtain sunlight

Plants such as the rattan, rose and bougainvillea have thorns to help them climb and obtain support by clinging onto other plants

Various Support Systems Of Woody Plants

BUTTRESS ROOTS CLASPING ROOTS

Plants such as the casuarina tree have buttress roots to give them additional support

Plants such as the money plant have clasping roots to help them climb on other plants for support and to obtain sunlight

Support System In Herbaceous Plants

Turgor Pressure Special Structures

Turgor Pressure

Herbaceous plants such as balsam, mustard and water convolvulus are supported by turgor pressure

The water in the cells presses against the cell walls and keeps the stem hard and erect

Herbaceous plants will wilt if there is insufficient water

Special Structures

PROP (ADVENTITIOUS) ROOTS

TENDRILS

Plants such as corn and sugar cane have prop (adventitious) roots to provide additional support for plants

Plants such as bitter gourd and cucumber plants have tendrils that twine around the stems of other plants in order to climb and grow upwards

Support System in Aquatic Plants

Water provides support to the aquatic plants such as water lily, hydrilla, water hyacinth and duckweed

Aquatic plants have lots of air sacs in their stems and leaves that make them light and buoyant (able to float) or suspend in the water

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