activity 1 adaptations · 2011-11-03 · an adaptation is an inherited trait or set of traits that...

Activity 1 Adaptations

610Active Biology

A Highway Through the Past

What Do You Think?

Imagine surviving a temperature of �50°C and a blindingsnowstorm. Imagine surviving a temperature of 50°C in anextremely dry landscape.

• How are plants and animals that live daily in theseenvironments adapted for survival?

Write your answer to this question in your Active Biology log.Be prepared to discuss your ideas with your small group andother members of your class.

For You To Do

Part A: Observing Adaptations

An adaptation is an inherited trait or set of traits that improvethe chances of survival and reproduction of organisms. In thispart of the activity you will look at photographs of animals to

GOALSIn this activity you will:

• Explain the meaning ofadaptation.

• Speculate how adaptationshelp an organism survive intheir environment.

• Distinguish betweenstructural and behavioraladaptations.

CS_Ch10_Evolution 2/28/05 2:54 PM Page 610

611Coordinated Science for the 21st Century


observe and speculate about how thedifferent types of adaptations help theorganism survive.

1. Look closely at the followingphotographs. There is a livingorganism in each picture.

a) Which organisms are exhibitingcamouflage?

b) How could this adaptation help anorganism in capturing prey?

c) How could this adaptation helpprotect the organism frompredators?

d) What other animals can you thinkof that use this type of adaptationfor protection?

2. Some animals are not adapted todisappear into the background, but rather stand out.

Alligator. Praying Mantis.

Snowshoe hare. Chameleon.


612Active Biology


Look at the photographs of thehawk moth and caterpillar.

a) At first glance, of whatanimal does each remindyou?

b) Why would birds avoid ananimal with large eyes atthe front?

c) What advantage does thisadaptation present for themoth and caterpillar?

3. A monarch butterfly storesbad-tasting chemicals in itsbody that birds hate. Theviceroy butterfly also has abitter taste.

a) The monarch butterfly isbrightly colored. Why doyou think that this wouldbe an advantage for themonarch butterfly?

b) Would the bright colorsand bitter taste protect allmonarch butterflies?Explain your answer.

c) Compare the appearanceof the monarch andviceroy butterflies. Canyou distinguish betweenthem?

d) How would the viceroybutterfly’s coloration be anadvantage for its survival?

4. Adaptations are not limitedto animals. Look closely atthe plants or plant partsshown on the next page fortheir adaptations to theenvironment.

Hawk moth.

Hawk-mothcaterpillar.

Monarch butterfly.

Viceroy butterfly.




a) For each plant shown above,explain the adaptation(s) thatyou can see. Consider theenvironment in which the plantslive, how they reproduce, andhow they get their nutrientswhen identifying adaptations.

5. Not all adaptations need to bestructural. Some adaptations canbe behavioral.

a) How is each animal in thephotographs adapted to a changein the environmental conditionsfrom summer to winter?

b) How do other animals adapt to an environmental change?Give at least two examples.

c) What type of behavioraladaptation is the plant at rightexhibiting?


614Active Biology


Adaptation

Diversity is a striking feature of living organisms.There are countlesstypes of organisms on Earth.They are the result of repeatedformation of new species and adaptation.There is a type of organismthat can live in almost every type of environment on Earth. Livingorganisms are unique in their ability to adapt.The accumulation ofcharacteristics that improve a species’ ability to survive and reproduceis called adaptation.Adaptation occurs over long time periods. It isthe environment that “selects” the best and most useful inheritedvariations. In this activity you observed just a few of the large numberof adaptations that exist.

6. Invent an organism with specificadaptations. Consider one of thefollowing:• camouflage• mimicry• warning coloration

Part B: How Well Adapted Are You?

In this part of the activity you will havean opportunity to examine one of yourown adaptations that you probably takefor granted.

1. Using masking tape, have yourpartner tape your thumb to yourindex finger on each hand. Afteryour thumbs are securely taped, tryeach of the following activities. Rankthe difficulty of each activity on ascale of 1 to 5.• picking up and carrying your

textbook;

• writing your name and address ona piece of paper;

• picking up five coins from the floorand placing them in your pocket;

• unbuttoning and buttoning abutton;

• tying up a shoe.

a) Did you find any of the activitiesimpossible?

b) How did your ratings comparewith others in your group and inyour class?

c) Why do you think that anopposable thumb is an importantadaptation for humans? (An opposable thumb is anarrangement in which the fleshytip of the thumb can touch thefleshy tip of all the fingers.)

d) Do any other animals haveopposable thumbs?

Bio Wordsspecies: a group oforganisms that caninterbreed under naturalconditions and producefertile offspring

adaptation: an inheritedtrait or set of traits thatimprove the chance ofsurvival and reproductionof an organism




Animals Adapt to the Demands of Their Environments

Animals cannot make their own food.Therefore, they must usuallyseek food.As a result, adaptations that allow animals to move arefavorable. Movement is easier if the organism is elongated in thedirection of movement. Fish, for example, are streamlined.This reduceswater resistance as they swim. It is also easier to move if the sensoryorgans are concentrated in the head.The organs that detect food,light, and other stimuli should be in a position to meet theenvironment first.An organism can move more easily if it has abalanced body.

Animals have the type of body plan that is best suited to their lifestyle.The symmetry of an organism gives clues to its complexity andevolutionary development. Higher animals, including humans, aresymmetrical along the mid-sagittal plane.This body plan is referred to asbilateral symmetry, in which the right and left halves of the organismare mirror images of each other. Some animals, however, are radiallysymmetric, or symmetricabout a central axis.

How is body symmetryrelated to the speed at whichan animal moves and to braindevelopment? In general,animals that display radialsymmetry are not highlyadapted for movement. Oneexplanation for the slowermovement can be traced tothe fact that no one regionalways leads. Only bilaterallysymmetrical animals have atrue head region. Because the head, or anterior region,always enters a newenvironment first, nerve cellstend to concentrate in thisarea.The concentration of

BODY SYMMETRY

radial symmetry

bilateral symmetryanteriorposterior

ventral

Bio Wordsbilateral symmetry:a body plan thatdivides the bodyinto symmetricalleft and righthalves

radial symmetry:a body plan that issymmetrical abouta center axis

CS_Ch10_Evolution 2/28/05 2:55 PM 15

616Active Biology


nerve tissue at the anterior endof an animal’s body, is anadaptation that enables therapid processing of stimuli suchas food or danger. Notsurprisingly, the faster theanimal moves, the moreimportant is the immediateprocessing of environmentalinformation. Every environmentplaces special demands on theorganisms living there. Seawateris fairly uniform. It poses theleast stress for animal life.Oxygen is usually adequate.Thetemperatures and salt contentare fairly constant.There is littledanger that the organism willdry up. In contrast, the salt andoxygen contents of fresh watervary greatly.

Organisms that live in water have special adaptations. Gills, forexample, allow the organisms to use the oxygen found in water. Onland, oxygen is plentiful. However, the organisms that live there mustprotect themselves from the dangers of drying up.These dangersincrease greatly because air temperatures change daily and seasonally.Air does not provide the same buoyancy as water.Therefore, largeterrestrial, or land-dwelling, animals require good supportivestructures. On the other hand, there is less resistance to movement inair than in water.Arms and legs, which would hinder an animal’smovement in water, may help on land.Thus, long appendagesspecialized for locomotion have evolved in terrestrial animals.

Plant Adaptations

Plants lack the ability to move and must survive in the environment inwhich they are living.A plant must do more than simply survive andgrow bigger. It must grow in such a way that it can take the bestadvantage of the light, water, and other conditions available to it.

The jellyfish is a group of structurally simplemarine organisms.The jellyfish has no headand a nervous system without a brain.Thebody exhibits radial symmetry.




Desert plants are an excellent example of adaptation to anenvironment. Some have a thick waxy coating to prevent them fromdrying out. Some have long vertical roots enabling a plant to reachwater sources beneath the soil. Others develop shallow roots thatextend horizontally.This maximizes water absorption at the surface.Many desert plants have small and narrow leaves.This decreases theheating from the Sun.

Even though plants are not able to move, they are still able to disperse.They produce seeds and fruits or other reproductive structures thatmay be distributed far from the parent plant.

Some plant adaptations are also behavioral.A vine spreads its leavesoutward and receives as much light energy as possible. It sends itsroots downward and receives more water.Tendrils of a vine touch anobject and quickly coil it.This secures the vine in its upward growth.A vine would not live very long if it did not send its roots downwardand its stem upward.The manner ofplant growth is believed to begoverned chiefly by hormones thatare produced within the plant.Thehormones are produced in responseto conditions around the plant suchas sunlight and gravity.Thus, the plantcan fit itself to the environment inwhich it lives.

Some plants have even becomeadapted to feeding on animals. In thisactivity you looked at the Venusflytrap. Its leaves have been adaptedto capture prey.These plants dophotosynthesize. However, theseplants live in bogs where there isvery little nitrogen available.Therefore, they require the nutrientsthey receive from digesting their prey.Of course, the plant must thereforealso be adapted to digest its preywith the secretion of chemicals.

Tendrils are modified stems or leavesthat wrap around a support.They enablethe plant to achieve fairly extensivehorizontal and vertical spread withoutthe use of much energy, since they don’thave to support their own weight.Tendrils seem to respond to touch so ifthe stem or tendril touches an object, itwraps around it.This response is knownas thigmotropism.


618Active Biology


1. Explain the term adaptation.

2. Distinguish between a structural and a behavioral adaptation.

3. a) How can an animal’s structure help it survive in different environments? Give three examples.

b) How can an animal’s behavior help it survive in different environments? Give three examples.

4. Do all animals living in the same environment have similar adaptations? Explain your answer.

5. A cross section represents a cut through the middle of an animal’s body. Beloware cross sections through an earthworm, sand worm, and a primitive insect.

a) The jointed appendages of the insect lift the body from the ground. How doesthis help the insect move?

b) What advantages might the fleshy projections of the sand worm have over thebristle-like projections of the earthworm?

c) Predict which animal would be the fastest and give your reasons.

In this activity you had an opportunityto look at adaptations of differentorganisms. You learned that everyenvironment places various demands onthe organisms living there. Organismshave developed special adaptations forliving in any given environment. Theanimals and plants in the area of the

highway construction have also adaptedto their environment. In anenvironmental study scientists wouldhave assessed the impact the highwaywould have had on the animals andplants. You may need to address thisissue in the town-hall meeting if you arerepresenting a government employee.

Reflecting on the Activity and the Challenge

insectsand wormearthworm

jointedappendages

small fleshyprojections called

parapodia

small bristle-likeprojections calledsetae can be felt




Inquiring Further

1. Animal adaptations to the arctic

Keeping warm is no easy task in thearctic where frigid weather lasts almostnine months of the year and wheretemperatures can plunge to �55°C.Even during the brief summer, whenthe land thaws and the Sun never sets, a sudden snowstorm can freezeeverything. What adaptation haveanimals that live in this regiondeveloped?

2. Animal adaptations to the desert

Lack of water creates a survival problemfor all desert organisms. However,animals have an additional problem.The biological processes of animal tissuecan function only within a relativelynarrow temperature range. Fortunately,most desert animals have evolved bothbehavioral and structural adaptations.Research the adaptations of animalsliving in desert regions.

The desert tortoise retreats to its burrowduring the hottest times of the summer days.In the cold of winter it hibernates in itsunderground burrow.

Seals are well adapted to a cold environment.Their slick fur sheds water, and a thick layer ofblubber beneath the skin keeps them warm in frigid temperatures.


activity 1 adaptations · 2011-11-03 · an adaptation is an inherited trait or set of traits that...

Documents