Structural Adaptations Summary Questions

Read through the notes below and be prepared to answer the following questions

1. What is a structural adaptation and give an example.
2. What is an endoskeleton and list some advantages?
3. What is an exoskeleton and list some advantages?
4. List some advantages to egg laying.
5. List some advantages to live birth.
6. Give an example how an adaptation might be an advantage in one environment, but a disadvantage in another environment.

ARE YOU BUILT TO SURVIVE?

Structural Adaptations

All organisms have adaptations - traits or characteristics - that help them to survive and reproduce in a particular habitat.

Structural adaptations are physical features of an organism, such as shape, color, size.

• Not every physical trait of an organism, or every use of a trait by an organism, is an adaptation, however.

For the aquatic mammal, the buoyant effect of water tends to offset the effect of gravity.

• As a result, the whale requires less structural support than the elephant, despite its massive size.

An adaptation is any kind of inherited trait that improves the chances of survival and reproduction for an organism.

• These adaptations can occur over long periods of time.
• Adaptations are indeed changes, and change is a characteristic of evolution.

The environment is the selecting force that chooses the best and most useful inherited characteristics.

• There are many types of adaptations.
• Structural adaptations are adaptations that involve the body of the organism.
• The wings of birds, for example, are structural adaptations for flight.
• The bones in birds are also hollow, which makes them lighter and better adapted for flight.
• Physical adaptations involve the metabolism of organisms.
• Other adaptations are behavioral and some provide protection like camouflage (chameleon) and warning coloration (poisonous frogs).

An internal skeleton is one that is inside the body of the animal.

• It is made of bone and cartilage, and its function is to protect the soft organs, tissues, and other parts of the vertebrate organisms.
• It gives something for muscles to attach to and pull against.
• The internal skeleton also stores mineral reserves and provides a site for blood cell formation.

An external skeleton is an outer covering on an invertebrate such as a spider, sea anemone, clam or lobster; very few vertebrates have an exoskeleton except the turtle.

• Some exoskeletons are made of chitin, calcium or silica.
• They have two advantages.
• They can protect the organism against their environment and danger, and they protect their wearer from drying out.

Egg-laying occurs in animals of all kinds including mammals (just a few - the duck-billed platypus and the spiny anteaters), birds, reptiles, amphibians, and fish.

• An advantage to egg-laying is that the female does not have to continue to give the embryo nutrients and energy.
• Once the egg is laid, it has all the nutrients it needs until hatching.
• Eggs can be buried or protected until the animal hatches.
• In general, organisms can lay more eggs than carry live young.

Live birth is when a mother gives birth to her baby or babies alive.

• She carries them inside her body until they are fully developed.
• An animal that carries her babies can protect them from predators.
• She can also maintain a constant temperature to keep them alive and healthy.

Structures Adapt to Help Survival

All living things have adaptations that increase their chances for survival.

• Living in a desert area such as Utah, many of the plants that are native to this area have structural adaptations that help them to survive.
• Have you ever tried to dig a weed out of the ground?
• Chances are it was not an easy task.
• Desert plants grow roots that are either very deep in the ground or extremely dense.
• Sometimes there is more root material underground than there is plant material above the ground.
• These extensive root systems allow the plant to obtain as much water as possible from the soil.

The leaves on many desert plants are another example of an adaptation to a dry environment.

• Some leaves have a tough leathery coating that helps them to conserve water.
• Other leaves are so different that many people do not even realize they are leaves.
• The spines on a cactus are one example.
• Cactus spines are leaves that are modified to conserve water where it is very scarce.

Many structures that are useful in one environment can be used somewhere else if a change takes place.

• Size and speed are advantages that would help an organism regardless of where it lives.
• Whatever of the type of adaptation an organism has, all adaptations have one thing in common; they give the organism a better chance to survive in its environment.