WorksheetsMendelian Genetics
Total questions: 14
Worksheet time: 16mins
Name
Class
Date
1.
In pea plants, the trait for tall stems is dominant over the trait for short stems. If two heterozygous tall plants are crossed, what percentage of the offspring would be expected to have the same phenotype as the parents?
a)
100%
b)
75%
c)
50%
d)
25%
2.
One of the parents of a child has phenylketonuria (PKU), which is caused by recessive alleles. The other parent does not have the PKU alleles. What is the chance that the couple will have a child with phenylketonuria?
a)
0%
b)
50%
c)
75%
d)
100%
3.
The observable traits of an organism are known as its
a)
allele
b)
dominance
c)
phenotype
d)
genotype
4.
Each parent contributes one of the genes for a particular trait. The genes of the pair are called:
a)
variables
b)
gametes
c)
hybrids
d)
alleles
5.
Chromosomes that carry genes that code for the same products, such as hemoglobin or eye pigment, are said to be:
a)
homologous
b)
heterozygous
c)
heterogeneous
d)
homozygous
6.
In snapdragons, Tallness (T) is dominant to dwarfness (t). In a cross between two plants that are heterozygous for this trait, the percent of offspring expected to exhibit dwarfness is
a)
25%
b)
100%
c)
50%
d)
0%
7.
In dragons, large scales (S) are dominant and small scales (s) are recessive. A dragon that is heterozygous for the trait is crossed with a dragon that has small scales. What should be the ratio of large-scaled dragons to small-scaled dragons among the offspring?
a)
1:2
b)
1:1
c)
2:1
d)
3:1
8.
In snapdragons, Tallness (T) is dominant to dwarfness (t). In a cross between two plants that are homozygous for the recessive allele, the percent of offspring expected to exhibit tallness is
a)
25%
b)
75%
c)
100%
d)
0%
9.
The color black is dominant in guinea pigs. The phenotypes of homozygous black guinea pigs and heterozygous black guinea pigs are:
a)
black
b)
gray
c)
BB and Bb
d)
white
10.
Cystic Fibrosis (CF) is a genetic disorder that is controlled by a recessive allele. If a person suffering from CF were to marry an individual who is heterozygous for the trait, what % of their children could be expected to unaffected carriers of the trait? Ignore issues of sterility in persons with CF.
a)
0%
b)
25%
c)
75%
d)
50%
11.
Tay Sachs disease is a fatal genetic disorder. Children born with this disorder generally die before they are five years old. A couple has had three children who died of Tay Sachs. About this couple it can safely be assumed that:
a)
any children they have in the future will also die from this disease
b)
they are both heterozygous for the Tay Sachs trait
c)
they are both homozygous for the Tay Sachs trait
d)
one is heterozygous and the other is homozygous for the Tay Sachs trait
12.
Mendel discovered principles of inheritance because he:
a)
observed simultaneously all of the characteristics in which the parents differed
b)
ignored all characteristics except a few markedly contrasting ones which he studied carefully
c)
studied only the offspring obtained from a single mating
d)
was smarter than any other scientist of his time
13.
The gene makeup of an organism for a particular trait is known as its
a)
dominance
b)
phenotype
c)
allele
d)
genotype
14.
In pea plants, the allele for green pods (G) is dominant and the allele for yellow pods (g) is recessive. A researcher crosses two green pea plants, and the in F1 generation, all of the offspring exhibit green pods. Can you determine the genotypes of both parents
a)
No, they could be Gg and GG OR GG and GG
b)
Yes, they are Gg and GG
c)
Yes, they are GG and GG
d)
No, they could be Gg and Gg OR GG and Gg
100 %
