Genetics Basics Worksheet #1
Part I.
1. Below each of the following words are choices. Circle the choices that are
examples of each of these words.
a. Dominant gene
D
e
k
L
N
o
R
S
m
b. Recessive gene
M
n
d
F
G
i
k
P
q
c. Homozygous Dominant
AA
Gg
KK
ll
pp
Rr
TT
Dd
ff
d. Homozygous Recessive
ee
Ff
HH Oo
qq
Uu
ww
Bb
vv
e. Offspring combinations in which the dominant gene will show
AA
Dd
EE
ff
Jj
RR
Ss
HH
uu
f. Offspring combinations in which the recessive gene will show
aa
Gg
Ff
KK
Oo
PP
ss
tt
dd
2. Fill in the blanks below using these choices: dominant, genes, genetics,
heterozygous, recessive, chromosomes
 Chromosomes have parts that determine traits. These parts are
_________
 A gene that prevents others from showing is said to be
__________________
 A gene that may not show up even though it is there is said to be
__________
 Long rod-shaped bodies inside a cell’s nucleus are called
_________________
 One who studies how traits are passed on is studying
____________________
 A person with one dominant and one recessive gene for a trait is
___________
Part II.
1) If short hair (L) is dominant to long hair (l), animals with LL and Ll have the
same
a. parents b. genotypes
c. phenotypes
d. alleles
e. genes
2) If all offspring of a cross have the genotype Aa, the parents of the crosses
would most likely be:
a. AA x aa
b. As x Aa
c. Aa x aa
d. AA x Aa e. none of these
3) For each genotype below, indicate whether it is heterozygous or homozygous
AA _________________Bb ________________ Pp__________________
4) For each genotype, determine what phenotype would be possible. Brown eyes
are dominant to blue eyes
BB _________________ Bb ___________________ bb ________________
Round seeds are dominant to wrinkled seeds
RR __________________ Rr __________________ rr ________________