Name:
Date:
GENETICS WORKSHEET II
Standard: Genetics 2c, 2d, and 2g
Objectives:
 Students can calculate fusion of male and female gametes
(fertilization).
 Students can generalize the concepts of genetics through
vocabulary.
Review from Genetics Worksheet I;
1. Define “Allele” [Uh-leel]-
Period:
Single Trait Dominance
7. Mendel found that when he crossed purebred plants bearing green peas
with purebred plants bearing yellow peas, the progeny (offspring) all had
yellow peas. (Use “G” and “g” alleles)
P-1 = 1st generation
nd
parents; P-2 = 2 generation
a. P-1
X
P-2
X
F-1
F-2
2. How many alleles make-up one genotypic trait?
3. What genotype would a “hybrid” exhibit?
For the following problems, determine as much of each individual’s genotype
as possible, with the information given. Do NOT put down any alleles that
are not fully complete or accurate. For example if you know that an
individual is dominant, but you don’t know if they are homozygous or
heterozygous…then record “B?”
4. In dogs, black body hair dominates over golden body hair. If two parent
black dogs had just one golden hair puppy, what would the genotype of
the parents be? (Use “B” and “b” alleles)
X
5. Both parents of a blue-eyed
man are brown-eyed (Brown
is dominant). This man
marries a brown-eyed woman
who had a brown-eyed
mother, blue-eyed father, and
a brown-eyed brother. The
man and woman in this
question have a brown-eyed
child. Answer the following;
(Use “B” and “b” alleles)
Provide the genotypes
a. the man
b. man’s mother
c. man’s father
d. the woman
e. woman’s mother
f. woman’s father
g. the child
6. In fruit flies (Drosophila) gray body dominates over black body.
Consider the cross between a hybrid gray fly and a black fly. (Use “G”
and “g” alleles) GAMETES = “SEX Cells (sperm or egg)”
a. Gametes of gray fly
&
b. Gametes of black fly
&
c. List all possible offspring genotypes
b.
c.
d.
e.
f.
g.
F-1 genotypes
F-2 genotypes
F-1 phenotypes
F-2 phenotypes
Chance a homozygous plant will be produced in F-1
Chance a homozygous plant will be produced in F-2
Chance of yellow peas produced by F-1
Chance of yellow peas produced by F-2
8. In horses, the trotting gait is due to a dominant allele “T” and the
pacing gait to a recessive allele “t”. If both parents are trotters and their
first foal (offspring) is a pacer…
a. What are the parents genotype
X
b. If the parents have another foal, what is the
probability that this foal will be a trotter?
c. Chances of having two pacers in a row?
9. In humans, the phenotype “white forelock” (a patch of unpigmented hair
on the front of the head) is dominant. A woman with a white
forelock married a man with white forelock. They had two
daughters…one with a white forelock and one without.
a.
b.
c.
d.
Genotype of parents X
Give the gamete genotype of the father’s sperm
Give the gamete genotype of the mother’s egg
Chance that the next child born to this family has white
Forelock?
e. Chances the child is born without white forelock