SUPPORT AND MOVEMENT IN PLANTS AND ANIMALS

Support-Is the ability of organisms to bear their weight and maintain their body forms. 

Movement- Is the displacement of parts of the body of an organism e.g. growth Movements of plants and limbs of animals.

Locomotion- Is Movement of the whole organism.

Necessity for support and Movement in plants

Movement and support enable plants to 

💠Adjust to the environment e.g. growth of pollen tube to bring about fertilization.

💠Obtain resources from the environment Eg. light, water and nutrients facilitate tropic and nastic movements.

💠Escape or avoid harmful stimuli such as high temperature.

💠Supportive tissues enable a plant to hold delicate organs like leaves and flowers where they can most efficiently carry out their functions.

💠Supportive tissues enable a plant to maintain its correct posture.

💠Withstand external forces such as strong winds and animals climbing on them

Arrangement of tissues in stems

A stem plays an important role in support in a plant. This is due to the presence of support tissues which provide mechanical support. These tissues are;

Parenchyma

 💠Are spherical or elongated. They form the major component of the cortex and pith.

When turgid they become tightly packed and rigid, thus enable a plant to attain an erect posture.

Supportive tissues enable a plant to hold delicate organs like leaves and flowers where they can most efficiently carry out their functions.

Supportive tissues enable a plant to maintain its correct posture.

Enables plants to withstand external forces such as strong winds and animals climbing on them

Arrangement of tissues in stems

A stem plays an important role in support in a plant. This is due to the presence of support tissues which provide mechanical support. These tissues are;

Parenchyma

They are spherical or elongated. They form the major component of the cortex and pith.

When turgid they become tightly packed and rigid, thus enable a plant to attain an erect posture.

(iii) Sclerenchyma

Their walls are thick and lignified. The Sclerenchyma cells are often long fibres in stems such as hibiscus.

Sclerenchyma consists of dead cells thickened by lignin. Lignin.is a complex polysaccharide.

Its the main constituent of wood.

Xylem vessels

They are thick walled tubes with lignin deposited unevenly in rings, spirals or patches on their walls.

Their main function is transport but because their walls are thick and