WorksheetsMonohybrid and dihybrid cross
Total questions: 13
Worksheet time: 7mins
Name
Class
Date
1.
When a person has two different alleles for a gene, they are said to be
a)
heterozygous
b)
homozygous
2.
A __________ allele always shows up in an organism when the it is present.
a)
dominant
b)
hybrid
3.
In a dihybrid cross
a)
one trait is crossed.
b)
two traits are crossed.
c)
four boxes are needed for the punnett square.
d)
mom's alleles are dominant.
4.
Which of the following genotypes is heterozygous?
a)
Bb
b)
BB
c)
bb
d)
B
5.
What allele combination should go in the missing box?
a)
AA
b)
Aa
c)
aa
d)
none of these
6.
What is the dominant trait?
a)
yellow pea seeds
b)
green pea seeds
c)
there is no dominant seed
d)
Jolly green giant
7.
This image shows a...
a)
Punnett Square
b)
Phenotype
c)
Genotype
d)
Dominant allele
8.
An organism’s genetic makeup or allele combination.
a)
Genotype
b)
Phenotype
c)
Beanotype
d)
Notype
9.
In guinea pigs, the allele for short hair is dominant over the allele for long hair.
B = short
b = long
What would the cross be for two heterozygous guinea pigs?
B = short
b = long
What would the cross be for two heterozygous guinea pigs?
a)
BB X BB
b)
BB X Bb
c)
Bb X Bb
d)
bb X bb
10.
Tomato plants usually have hairy stems. Hairless stems are present in tomato plants that are homozygous recessive for this trait. If the stem characteristics are determined by a single gene, what are the expected phenotype percentages for the offspring of a heterozygous hairy plant and a hairless plant?
a)
100% hairy, 0% hairless
b)
75% hairy, 25% hairless
c)
50% hairy, 50% hairless
d)
25% hairy, 75% hairless
11.
Cross Two Homozygous plants
(RRYY x rryy)
R = round seeds, r = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds?
(RRYY x rryy)
R = round seeds, r = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds?
a)
0%
b)
25%
c)
50%
d)
100%
12.
Cross Two Homozygous plants
(RRYY x rryy)
R = round seeds, r = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds?
(RRYY x rryy)
R = round seeds, r = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds?
a)
0%
b)
25%
c)
50%
d)
100%
13.
In guinea pigs, black hair is dominant to white hair and short hair is dominant to long hair. What would be the phenotype of a guinea pig with the genotype Bbss?
a)
Black hair, long hair
b)
Black hair, short hair
c)
White hair, long hair
d)
White hair, short hair
100 %
