Name:
Date:
Period:
Genetics Test Review
1. Genetics is the study of biological _________________ patterns and variation in
organisms.
2. A man named Gregor ___________________ did early work that is the basis for much of
our current understanding of genetics.
3. Mendel’s views on inheritance differed from the views of many scientists of his time.
Mendel recognized that _____________ are inherited as discrete units.
4. Mendel’s law of segregation has two conclusions:
i.Organisms inherit one copy / two copies of each gene, one from each parent.
ii.
Genes segregate during gamete formation, so organisms donate one copy / two
copies of each gene in their gametes.
5. There is a relationship between genes and proteins: A gene / protein provides
instructions for a cell to make a certain gene / protein.
6. An allele is any of the alternative forms of a gene / genome that may occur at a specific
locus / trait.
7. If a pair of alleles is the same, they are called heterozygous / homozygous. If a pair of
alleles is different, they are called heterozygous / homozygous.
8. Homologous chromosomes are two chromosomes (one from the mother
and one from the father) that have the same length, overall appearance, and
alleles / genes, although the alleles / genes may differ.
9. Genotype and phenotype differ. Use the statements below to fill in the definition and an
analogy for each one in the table.
a. The observable traits of an organism.
b. The underlying genetics of an organism.
c. A person’s thoughts that you can’t read.
d. A person’s words that tell you what they’re thinking about.
Definition
Genotype
Phenotype
Analogy
10. Alleles are represented on paper by letters. Uppercase letters
indicate ______________ alleles, and lowercase letters indicate ______________
alleles.
11. An organism’s phenotype is affected both by alleles and by ______________.
Complete the table by filling in the following terms: dominant, recessive, TT, Tt.
Genotype
Phenotype
homozygous dominant
dominant
Alleles
homozygous recessive
tt
heterozygous
12. An organism with a QQ genotype has ____________________ alleles.
13. An alternative form of a gene is called an _________________.
14. The opposite of homozygous is _______________. The opposite of
dominant is _______________.
Identify what each of the numbered parts represents in the Punnett square below. Then draw
lines from each of the parents’ alleles to the corresponding alleles in the offspring.
2. __________________________________________
A
A
a
AA
Aa
___________________________________________
1. _______________________________________________________________
3. ______________________________________
a
Aa
aa
_______________________________________________________________
______________________________________
15. What is a dihybrid cross?
16. What is the phenotypic ratio that results from a dihybrid cross between two organisms
that are heterozygous for both traits? See Figure 5.5 for help.
17. The exchange of chromosome segments between homologous chromosomes is called
_________________.
18. The tendency for two genes that are located close together on a chromosome to be
inherited together is called __________________.
19. Sex-linked genes are located on the _____________________.
20. Fill in the Punnett square below to show the pattern of inheritance for sex
chromosomes. Write in the phenotype (male or female) for each.
Sex Chromosome Inheritance
X
X
X
Y
21. A karyotype is a ___________________ of all the chromosomes in a cell.
22. A pedigree is a chart that traces phenotypes and ____________ in a family.
23. In pedigree analysis, the _______________ is used to infer the genotype.
24. The prefix in- means “not.” In genetics, the term _____________________ means that
neither allele is dominant.
25. The prefix co- means “together.” In genetics, the term ___________________ means that
both alleles are expressed together.
26. The prefix poly- means “many,” and the term genic means “related to genes.” Traits that
are produced by two or more genes are called ______________________.