Download Monohybrid Crosses

Monohybrid Crosses
Name___________________________
MATCHING
A. Dominant
B. Recessive
C. Heterozygous
(hybrid)
D. Homozygous
(pure)
_______1. Tt
_______2. RR or rr
_______3. Having two different alleles for a single trait
_______4. This type of trait is expressed even if the individual only has one copy
of the gene
_______5. Having identical alleles for a single trait
_______6. This type of trait is expressed only if the individual has 2 copies of the
gene
TRUE OR FALSE
_______7. A pea plant with the genotype TT has the same phenotype as a pea
plant with the genotype tt.
_______8. If two people have the same phenotype, they must have the same
genotype.
_______9. An organism with a genotype Bb has a greater chance of passing on
the dominant B gene than the recessive b gene.
10. List the six steps to solving a genetic problem
Monohybrid Cross Problems
PROBLEM KEY:
Tall (T) dominant over short (t)
Black (B) dominant over white (b)
Smooth (S) dominant over wrinkled (s)
Rough hair (R) dominant over smooth hair (r)
Brown eyes (B) dominant over blue eyes (b)
Use the six steps to solve the problems below – show your work!
1. Cross a heterozygous tall pea plant with a homozygous tall pea plant.
2. Cross a pure black guinea pig with a pure white guinea pig.
3. Cross a heterozygous tall pea plant with a short pea plant.
4. Cross a black hybrid guinea pig with a black hybrid guinea pig.
5. Cross a heterozygous smooth pea plant with a wrinkled pea plant.
6. Cross a blue eyed female with a blue eyed male. Can they ever have children
with brown eyes? Prove your answer with problem solving.
7. A woman is pure brown eyed. What color must she find in a man if she wants
to have a blue eyed child? Do a Punnett Square to prove your answer.
8. A man and woman have 2 blue-eyed children and one brown-eyed child.
What is the eye color of the parents?