MYP3 Science Adaptations of Organisms (short notes)

Adaptations of Organisms

Key Concepts

• Adaptations: Adjustments or changes in an organism's structure or function to better survive in its environment.

• Natural Selection: Darwin's theory explaining how organisms adapt over time due to varying characteristics and environmental pressures.

Types of Adaptations

• Structural Adaptations: Physical features that aid survival. Examples include:

  • Giraffe's long neck.

  • Beaver's oar-like tail.

  • Polar bear's fur for insulation in cold climates.

  • Webbed feet in water birds.

  • Waxy leaves on plants to reduce water loss (e.g., mirror bush).

• Behavioural Adaptations: Changes in behavior to enhance survival. Examples include:

  • Remaining still to avoid predators.

  • Desert plants flowering at night to attract nocturnal pollinators.

• Functional Adaptations: Internal changes in how an organism works. Examples include:

  • Ability to sweat.

  • Hibernation (lowering metabolic rate).

  • Release of defensive chemicals (e.g., skunks).

  • Fragrant flowers attracting pollinators.

Adaptations in Bears

• Polar Bears (Ursus maritimus): Adapted for Arctic climate.

  • Sharp teeth for grasping prey.

  • Large paws for weight distribution on ice.

  • White fur for camouflage.

• Brown Bears (Ursus arctos): Omnivorous with adaptations for seasonal diets.

  • Shorter snouts and blunter teeth compared to polar bears.

  • Strong shoulder muscles and claws for tearing logs.

• Spectacled Bears (Tremarctos ornatus): South American bears with flatter faces, diet consists 5% of meat.

• Sloth Bears (Melursus ursinus): Adapted to eat fruit, ants and termites.

  • Long snout and tongue.

• Sun/Honey Bears (Helarctos malayanus): Adapted to live in tropical forests.

  • Powerful teeth to rip leaves and bark.

  • Thin Fur.

• American Black Bears (Ursus americanus): Varying colors depending on their habitat for camouflage.

• Asian Black Bears (Ursus thibetanus): Similar to American Black Bears.

Factors Affecting Adaptations

• Environmental Changes: Organisms must adapt to changes in their habitat (e.g., climate, food availability) or face extinction.

• Human Impact: Human activities can alter habitats, requiring organisms to adapt.

• Extreme Conditions: Some organisms are adapted to survive in extreme environments (e.g., high altitude, extreme temperatures).