Name: __________________________
Guided Reading
Introduction to Genetics
Chapter 11-1
Using your text – NOT THE GLOSSARY - define the following terms on your own paper. Include the page
number on which you find each definition.
 Allele
 Fertilization
 Gamete
 Gene
 Hybrid
 Principle of dominance
 Segregation
 Trait
Answer the following on your own paper. Include the page number on which you find each answer.
1. Every living thing has a set of __________ inherited from its parents.
2. After becoming a ___________, Mendel spent several years studying _________ and mathematics at the
University of Vienna.
3. During sexual reproduction, male and female reproductive cells join, a process known as ______________.
4. Pea flowers are normally ______________________________, which means that sperm cells in pollen
fertilize the egg cells in the ________________ flowers.
5. When Mendel crossed plants with _________________________ characters for the same trait, the resulting
offspring had only one of the characters.
6. A __________________________ is a specific characteristic, such as seed color or plant height, that varies
from one individual to another.
7. Filius and filia are the Latin words for _______________ and _______________.
8. The offspring of crosses between parents with different traits are called ______________________.
9. To Mendel’s surprise, all of the offspring had the character of only __________ of the parents.
10. Mendel’s first conclusion was that biological inheritance is determined by _______________ that are
_______________ from one generation to the next.
11. Scientist calls the chemical factors that determine traits ______________________________.
12. Define an allele: ___________________________________________________________________.
13. Mendel’s second conclusion is the ______________________ _____ ______________________.
14. The principle of dominance states that some alleles are __________ and others are _________.
15. When Mendel allowed the F1 plants to reproduce by self-pollination the traits controlled by
_______________ alleles reappeared in about _________ of the F2 plants in each cross.
16. A gamete is a __________ cell.
17. A capital letter T represents a __________________________________ allele.
Section 11-2 Probability and Punnett Squares
1. Mendel realized that the principles of probabilities could be used to ___________________ the results of
genetic crosses.
2. The likelihood that a particular ______________ will occur is called ______________.
3. That individual probabilities are _______________ together illustrates an important point – past outcomes
do not affect _______________ ones.
4. Punnett squares can be used to _______________ and compare the genetic variations that will results from a
cross.
5. Organisms that have two identical alleles are called __________________________________
6. Organisms that have two different alleles for the same trait are called __________________________
7. A _________________________________is a physical characteristic.
8. A plant with the genotype Tt will have what phenotype? __________________________
9. A plant with the short phenotype will have what genotype? __________________
10. Probabilities predict the _______________ outcome of a _______________ number of events.
11. Probability cannot predict the _______________ outcome of an individual event.
11-3 Exploring Mendelian Genetics
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A two-factor cross follows two different _______________ as they pass from one generation to the next.
All the F1 offspring from the cross RRYY x rryy were _____________ and _____________
The genotypes of the F1 offspring were ______________________
4. Mendel’s F2 generation showed that the alleles for seed shape segregated independently of those for seed
color – a principle known as _______________________
___________________
When a RrYy plant was crossed with an RrYy plant, what ratio was shown in the punnet square?
The principle of independent assortment states that genes can segregate _______ during the formation of
______________.
Independent assortment helps account for the many genetic __________________________ observed in
plants, animals, and other organisms.
Copy and fill out the diagram below as it pertains to Mendel’s crosses and independent assortment.
A summary of Mendel’s Principles:
9. The inheritance of biological characteristics is determined by individual units known as _______________.
Genes are passed from parents to offspring.
10. In cases in which two or more forms ( ________________ ) of the gene for a single traist exist, some forms
of the gene may be dominant and others may be __________________________.
11. In most sexually reproducing organisms, each adult has ____________ copies of each gene – one from
each parent. These genes are _______________________ from each other when gametes are formed.
12. The alleles of different genes usually segregate ______________________________ of one another.
Beyond Dominant and Recessive Alleles
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Some alleles are neither dominant nor _________________________, and many traits are controlled by
_______________________ alleles or by multiple genes.
In the F1 generation of Mirabilis plants, a red flower crossed with a white flower will produce
___________ flowers.
Cases where one allele is not completely dominant over another is called _________
_________________________________ occurs when both alleles contribute to the phenotype.
Describe the “erminette” color in chickens: ________________________________________________
The best known example that illustrates multiple alleles is _____________________________________
The gene for coat color in rabbits is controlled by 4 different alleles. List and describe them: (fig 11-12)
Traits controlled by two or more genes are said to be ____________ traits.
What human trait is polygenic?
Applying Mendel’s Principles
10. What animal did Thomas Morgan choose to study?
11. Why was this animal an ideal organism for the study of genetics?
Genetics and the Environment
12. Genes provide a plan for __________________________________, but how that plan unfolds also
depends on the ______________________________________________