Structural Adaptations to

the Environment

TAKS

Structural adaptations to the environment

• Every species is uniquely adapted to its environment

• This ensures the survival of the species

Structural adaptations to the environment

Camels• Heavy insulation of

fur on backs• Long eye lashes to

protect eyes from sand

• Legs long and not fatty

• Walks on two toes protected from heat by pads of tissue

Structural adaptations to the environment

Camels• Kidney reabsorbs

most of the water in urine

• Able to drink rapidly to replenish water losses – but does not store water in body (27 gallons in 10 mins!)

• Tolerates high levels of dehydration of body tissues

Structural adaptations to the environment

Camels• Tolerates wide

range of body core temperatures

• Feces so dry they can be burned immediately

Structural adaptations to the environment

Desert rats• Survive by avoiding

the conditions camels thrive in

• Live underground in burrows only coming out at night

• Rarely if ever drinks water

Structural adaptations to the environment

Desert rats• Water supply

comes from the respiration of its food

• Produces a virtually solid urine

• Virtually no sweat glands

Structural adaptations to the environment

Plants• Mesophytes –

plants living where water is readily available

• Xerophytes – plants living in areas where water is in short supply

• Halophytes – plants living in salty areas

Structural adaptations to the environment

Mesophytes• Includes native

plants of Britain• Can control their

rate of transpiration• Close their stomata

at times of water stress

• Can easily recover from short periods of wilting

Structural adaptations to the environment

Xerophytes• Reduction of leaves to

fine spikes, reducing transpiration

• Stem has hard thick epidermis and a waxy cuticle

• Can fix carbon dioxide at night so stomata remain closed during the day

Structural adaptations to the environment

Xerophytes• Marram grass (see

notes from earlier in course)

• Reduced number of stomata sunk deep into grooves

• Leaves roll up into cylinder shape –trapping moist air within leaf

• Interlocking hairs reduce transpiration

Structural adaptations to the environment

Halophytes• Although often

surrounded by water it is usually salty

• Actively absorb salts into their roots so roots have a lower water potential than surrounding water

• Also have many xeromorphic features to help them conserve water

Structural adaptations to the environment

Adaptations in humans to high altitudes

• Greater depth of breathing, higher lung capacity and larger tidal volumes

• Blood has a higher affinity for oxygen

• Oxygen dissociation curve is shifted to the left

• Darker skins to combat higher UV radiation levels