B1b 5 Adaptation for Survival 5.1 Adaptation in animals

Lesson objectives Understand how animals adapt to their environment Understand the relationship between body size and surface area

Variety of conditions The Earth has a massive variety of conditions Arctic wasteland Desert Tropical Rainforest Moorland Deep ocean Extreme conditions – all have life Adapted to the conditions

Extreme cold Arctic animal are adapted to deal with it Biggest problem – keeping warm The amount you lose depends on how much skin you have Surface area/volume ratio (SA/V) Lower the ratio – less you lose

Polar Bear

Polar Bear Small ears help to reduce heat loss. Thick fur and a thick layer of body fat insulate from the cold. White fur acts as camouflage?????? Large feet spread the body’s weight. The wide paws act as good paddles and snow shoes.

Polar Bear Eyes have brown irises to reduce the glare from sunlight reflection. Greasy fur repels water and keeps the bear dry. Skin is actually black to absorb any heat transmitted through the hairs. Body surface area is small compared to volume to reduce heat loss.

Hot climate Very difficult Very dry Scorching during day Freezing during night Body temperature must be stable Best way is sweating Lose water Need other adaptations

How is a camel adapted? Brown coat for camouflage. Fat is stored in the hump. There is no other body fat to prevent overheating. Loses little water through sweating or urine. Long, thin legs mean the body surface area is large compared to volume to increase heat loss. Wide feet for spreading body weight over soft shifting sand.

Adapting to a desert environment Ears are lined with fur to prevent sand and dust from getting in. Nostrils can close when needed to protect the camel in sandstorms. A very varied diet, ranging from grass and bark to thorns and bones, is eaten. Long eyelashes protect the eyes from sand and dust.

How are leaves adapted? Broad and flat Veins carry water to the leaf and take food from the leaf help to support the leaf. Plant cells contain chloroplasts with chlorophyll. Small holes called stomata in the underside of a leaf allow gases in and out Water evaporates from leaves

Prickly customers Thick, waxy surface to reduce water loss - succulents Leaves are narrow spines that reduce water loss and protect from predators. Stores water in fleshy stem. Plant surface area is small compared to volume to reduce water loss. Some have shallow, spreading roots for surface water, others have deep roots.

Learning outcomes How are animals adapted to their environment? Why is SA/V ratio important? What adaptations do plants have?