Chapter One: Introduction To Genetics
Comprehension Questions
Section 1.1
*1. How Did Hopi Culture Contribute To The High Incidence Of Albinism Among Members
Of TheHopi Tribe?
Solution:
In Hopi Culture, Albino Individuals Were Considered Special And Awarded Special Status
In The Village. Hopi Male Albinos Were Not Required To Work The Fields, Thus
Avoiding ExtensiveExposure To Sunlight That Could Prove Damaging Or Deadly.
Because The Male Albinos Remained In The Village During The Day, They Had Mating
Advantages Over The Males Who Participated In Farming And Other Duties Outside Of
The Village. Albinism Was Considered To Be A Positive Trait Reflecting The Purity Of
The Villagers. Finally, The Small Population Size OfThe Hopi Tribe May Have Helped
Increase The Allele Frequency Of The Albino Gene Due To Chance.
2. Outline Some Of The Ways In Which Genetics Is Important To All Of Us.
Solution:
Genetics Directly Influences Our Lives And Is Fundamental To What And Who We Are.
For Example, Genes Affect Our Appearance (E.G., Eye Color, Height, Weight, Skin
Pigmentation, And Hair Color). Our Susceptibility To Diseases And Disorders Is Affected
By Our Genetic Makeup. Genetics Plays A Significant Role In Researching And
Developing Techniques To Diagnose And Treat These Hereditary Diseases. Genes May
Also Influence Our Intelligence AndPersonality. Genetic Techniques Have Enabled
Scientists To Develop Genetically Modified Crops That Are Resistant To Pesticides And
Herbicides Or That Have Enhanced Nutritional Properties Making It Possible To Produce
Larger Quantities Of Food For The World’s Growing Population. Lastly, Genetic
Engineering Has Made It Possible To Mass Produce Pharmaceuticals And Other
Substances Of Commercial Value.
3. Give At Least Three Examples Of The Role Of Genetics In Society Today.
Solution:
Genetics Plays Important Roles In The Diagnosis And Treatment Of Hereditary
Diseases: InBreeding Plants And Animals For Improved Production And Disease
Resistance; And In Producing Pharmaceuticals And Novel Crops Through Genetic
Engineering.
4. Briefly Explain Why Genetics Is Crucial To Modern Biology.
, Solution:
Genetics Is Crucial To Modern Biology In That It Provides Unifying Principles: The
Genetic Code Is Universal, Meaning That All Organisms Use Nucleic Acid As Their
Genetic Material, AndAll Organisms Encode Genetic Information In The Same Manner.
The Study Of Many Other Biological Disciplines, Such As Developmental Biology,
Ecology, And Evolutionary Biology, Is Supported By Genetics.
5. List The Three Traditional Subdisciplines Of Genetics And Summarize What Each Covers.
Solution:
1) Transmission (Classical) Genetics Is Concerned With The Inheritance Of Genes From
One Generation To The Next. It Also Deals With The Location Of Genes On
Chromosomes And Gene-Mapping. 2) Molecular Genetics Focuses On The Structure,
Organization, And Function Of Genes At The Molecular Level. Molecular Genetics Is
Also Concerned With The Processes By Which Genetic Information Is Transferred And
Expressed. 3) Population Genetics Studies Genetic Variation And Changes In Genes And
Allele Frequencies Within Groups Of IndividualsOf The Same Species Over Time.
6. What Are Some Characteristics Of Model Genetic Organisms That Make Them
Useful ForGenetic Studies?
Solution:
Model Genetic Organisms Have Relatively Short Generation Times, Produce Numerous
Progeny, Are Amenable To Laboratory Manipulations, And Can Be Maintained And
PropagatedInexpensively.
Section 1.2
7. When And Where Did Agriculture First Arise? What Role Did Genetics Play In The
DevelopmentOf The First Domesticated Plants And Animals?
Solution:
Agriculture First Arose 10,000 To 12,000 Years Ago In The Area Now Referred To As
The MiddleEast (I.E., Turkey, Iran, Iraq, Syria, Jordan, And Israel). Early Farmers
Selectively Bred Individual Wild Plants Or Animals That Had Useful Characteristics With
Others That Had SimilarUseful Traits. The Farmers Then Selected For Offspring That
Contained Those Useful Features.
Early Farmers Did Not Completely Understand Genetics, But They Clearly Understood
That Breeding Individual Plants Or Animals With Desirable Traits Would Lead To
Offspring That Contained These Same Traits. This Selective Breeding Led To The
Development Of DomesticatedPlants And Animals.
8. Outline The Notion Of Pangenesis And Explain How It Differs From The Germ-Plasm Theory.
, Solution:
Pangenesis Theorizes That Information For Creating Each Part Of The Offspring’s Body
Originates From Each Respective Part Of The Parent’s Body And Is Passed Through The
Reproductive Organs To The Embryo At Conception. Pangenesis Suggests That Changes
In PartsOf The Parent’s Body May Be Passed To The Offspring’s Body. The Germ-Plasm
Theory, In Contrast, States That The Reproductive Cells (Eggs And Sperm) Possess All
Of The Information Required To Make The Complete Body; The Rest Of The Body
Contributes No Information To The Next Generation.
9. What Does The Concept Of The Inheritance Of Acquired Characteristics Propose And
How Is ItRelated To The Concept Of Pangenesis?
Solution:
The Theory Of Inheritance Of Acquired Characteristics Postulates That Traits Acquired
DuringOne’s Lifetime Can Be Transmitted To Offspring. It Developed From
Pangenesis, Which Postulates That Information From All Parts Of One’s Body Is
Transmitted To The Next Generation. Thus, According To The Theory Of Inheritance
Of Acquired Characteristics, The Development Of Large Bicep Muscles Through
Exercise Would Produce Children With Large Biceps.
10. What Is Preformationism? What Did It Have To Say About How Traits Are Inherited?
Solution:
Preformationism Is The Theory That The Offspring Results From A Miniature Adult That
Is Already Preformed In The Sperm Or The Egg. All Traits Would Thus Be Inherited
From Only OneParent, Either The Father Or The Mother, Depending On Whether The
Homunculus (The Preformed Miniature Adult) Resided In The Sperm Or The Egg.
11. Define Blending Inheritance And Contrast It With Preformationism.
Solution:
The Theory Of Blending Inheritance Proposes That The Egg And Sperm From Two
Parents Contains Material That Blends Upon Conception, Influencing The Development
Of The Offspring. This Theory Indicates That The Offspring Is An Equal Blend Of The
Two Parents. InPreformationism, The Offspring Inherits All Of Its Traits From One
Parent.
12. How Did Developments In Botany In The Seventeenth And Eighteenth Centuries
Contribute ToThe Rise Of Modern Genetics?
Solution:
Botanists Of The Seventeenth And Eighteenth Centuries Discovered That Plants
Reproduce Sexually, Enabling Them To Develop New Techniques For Crossing Plants
And Creating PlantHybrids. These Early Experiments Provided Essential Background
, Work For Mendel’s PlantCrosses. Mendel’s Work Laid The Foundation For The Study
Of Modern Genetics.
13. List Some Advances In Genetics Made In The Twentieth Century.
