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WorksheetsJAMB Biology Mock Test
Total questions: 20
Worksheet time: 10mins
In a dihybrid cross involving two heterozygous parents (AaBb × AaBb), what is the expected phenotypic ratio?
3:1
9:3:3:1
1:2:1
1:1:1:1
Which of the following best explains dihybrid inheritance?
Inheritance of one gene pair
Inheritance of two independent gene pairs
Inheritance of linked genes
Inheritance of multiple alleles
The genotypic ratio of a dihybrid cross between two heterozygous parents (AaBb × AaBb) is:
9:3:3:1
1:2:1:2:4:2:1:2:1
3:1
1:1:1:1
In dihybrid inheritance, how many different types of gametes can be produced by an organism with genotype AaBb?
2
4
8
16
A cross between two pea plants with genotypes RrYy × RrYy results in which phenotypic ratio?
9 round yellow : 4 wrinkled yellow : 2 round green : 1 wrinkled green
9 round yellow : 3 round green : 3 wrinkled yellow : 1 wrinkled green
9 round yellow : 3 wrinkled yellow : 3 round green : 1 wrinkled green
9 round yellow : 3 round green : 2 wrinkled yellow : 2 wrinkled green
If a dihybrid cross produces offspring with a 9:3:3:1 ratio, the parents must have been:
Homozygous dominant
Homozygous recessive
Heterozygous for both traits
Heterozygous for one trait only
In a dihybrid cross, the probability of obtaining an offspring with both recessive traits is:
1/16
3/16
9/16
12/16
How many phenotypes are possible in a dihybrid cross involving two heterozygous parents?
2
3
4
9
Which of these combinations represents a dihybrid cross?
Tt × Tt
AaBb × AaBb
AA × aa
Bb × Bb
What is the expected proportion of offspring with dominant phenotypes for both traits in a dihybrid cross (AaBb × AaBb)?
1/16
3/16
9/16
12/16
If two heterozygous tall, yellow-seeded pea plants (TtYy × TtYy) are crossed, what fraction of the offspring will be short with green seeds?
1/16
3/16
9/16
12/16
In a dihybrid cross, a 9:3:3:1 ratio suggests:
Codominance
Complete dominance and independent assortment
Linked genes
Incomplete dominance
Which of the following genotypes represents a heterozygous dihybrid organism?
AABB
AaBB
AaBb
Aabb
In dihybrid crosses, the 9:3:3:1 ratio is an example of:
Genotypic ratio
Phenotypic ratio
Mendelian ratio
Monohybrid ratio
In pea plants, round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant to green seeds (y). What is the genotype of a plant that is heterozygous for both traits?
RrYy
RrYY
RRyy
rrYy
A dihybrid test cross involves crossing an organism with an unknown genotype with:
A homozygous dominant organism
A homozygous recessive organism
A heterozygous organism
A hybrid organism
In a dihybrid cross between AaBb and aabb, the proportion of offspring with the genotype AaBb will be:
1/4
1/8
1/2
3/4
How many types of genotypes are expected from a dihybrid cross between two heterozygous parents?
4
9
16
8
In a dihybrid cross, which of the following represents a possible combination of gametes from a parent with genotype AaBb?
AB, Ab, aB, ab
AA, BB, aa, bb
Aa, Bb, AB, ab
AaBb, Aabb, aaBB, AABB
When two heterozygous dihybrids are crossed, the least frequent phenotype is likely to be:
Both dominant traits
Both recessive traits
One dominant, one recessive trait
All traits in the heterozygous form
