WorksheetsMCAS Practice Genetics
Total questions: 35
Worksheet time: 1hrs 16mins
Tt represents:
homozygous dominant
homozygous recessive
heterozygous
none of these
Define Alleles
Molecule which contains the genetic information for an organism.
Different versions of the same gene.
all the chromosomes/DNA that code for an individual’s traits.
Condensed DNA that is visible during cell division.
Define Gene
Condensed DNA that is visible during cell division.
Different versions of the same gene.
A section of DNA that codes for specific proteins/traits.
Molecule which contains the genetic information for an organism.
Define Chromosome
Condensed DNA that is visible during cell division.
Different versions of the same gene.
all the chromosomes/DNA that code for an individual’s traits.
1. A section of DNA that codes for specific proteins/traits.
During what process does independent assortment and segregation of alleles occur?
Mitosis
Meiosis
Fertilization
A genotype describes the physical characteristics of an individual.
True
False
A phenotype describes the genetic make-up of an individual.
True
False
When Mendel crossed true-breeding tall plants (TT) with true-breeding short plants (tt), all of the offspring were tall because...
The allele for tall plants is recessive.
The allele for short plants is dominant.
The allele for tall plants is dominant
What is the relationship between phenotype and genotype?
The phenotype determines the genotype.
The genotype determines the phenotype.
There is no relationship between phenotype and genotype.
What principle states that during gamete formation genes for different traits separate and are distributed without influencing the distribution of other genes?
Principle of independent assortment.
Principle of recessives alleles
Principle of complete dominance.
Principle of incomplete dominance.
The law of segregation states: Allele pairs separate during gamete formation and randomly unite at fertilization.
True
False
What's missing in this sequence?
DNA -> Genes -> ______ -> Genome
homozygous
chromosomes
allele
RNA
TT is an example of...
Homozygous Dominant
Heterozygous
Homozygous Recessive
Principle/Law of Segregation is defined as...
Some alleles are dominant over others.
Allele pairs separate randomly during gamete formation and randomly unite at fertilization.
During gamete formation genes for different traits separate without influencing each other’s inheritance
Principle/Law of Dominance is defined as...
Some alleles are dominant over others.
Allele pairs separate during gamete formation and randomly unite at fertilization.
During gamete formation genes for different traits separate without influencing each other’s inheritance
A Punnett square shows all of the following EXCEPT
All possible results of a genetic cross.
The possible genotypes of the offspring.
The alleles in the gametes of each parent.
The actual genotypes of the offspring.
Multiple alleles refer to an inheritance pattern that has more than two alleles that control phenotype.
True
False
Which option below best describes polygenic inheritance?
More than one set of genes contributing to the phenotype
A blending of genes getting an intermediate phenotype
A phenotype that has more than 2 possible alleles for a gene
A white rose and a red rose produce a pink rose, which type of inheritance does this show?
incomplete dominance
codominance
Multiple alleles
Polygenic inheritance
A kitten has spots and stripes. The mother has stripes and the father has spots. Which law of inheritance does this show?
incomplete dominance
codominance
multiple alleles
polygenic inheritance
The paired chromosomes of a human male are shown above. The last pair, labeled X and Y, are the sex chromosomes.
Which chromosomes did this man pass down on to his daughter?
All 46 chromosomes from all pairs, including the X chromosome
one chromosome from each of the first 22 pairs, and the X chromosome
one chromosome from the first 22 pairs, but none of the sex chromosomes
all 44 chromosomes from the first pairs, but only one of the sex chromosomes
tt is an example of...
Homozygous Dominant
Heterozygous
Homozygous Recessive
Principle/Law of Codominance is defined as...
Some alleles are dominant over others.
Allele pairs separate during gamete formation and randomly unite at fertilization.
Neither allele is completely dominant over the other, so they blend to make a new phenotype.
Neither allele is more dominant than the other and both show up in the phenotype.
Principle/Law of Incomplete dominance is defined as...
Some alleles are dominant over others.
Allele pairs separate during gamete formation and randomly unite at fertilization.
Neither allele is completely dominant over the other, so they blend to make a new phenotype.
Neither allele is more dominant than the other and both show up in the phenotype.
The feather color of Andalusian chickens is controlled by a single gene with two alleles. A cross between a true-breeding, white-feathered Andalusian hen and a true-breeding, black-feathered Andalusian rooster results in 100% blue-feathered Andalusian offspring.
Which of the following describes the inheritance pattern for feather color in these chickens?
It is a polygenic pattern because more than two phenotypes are possible.
It is a dominant-recessive pattern because both parents are true breeding.
It is a codominant pattern because the heterozygous offspring have a different phenotype than either parent.
It is a sex-linked pattern because the hen and the rooster have different feather colors.
All corn plants contain the ZmLA1 gene. Some corn plants contain a certain mutation in the ZmLA1 gene. The graph below shows the amount of ZmLA1 RNA produced in plants with the normal gene and in plants with the mutated gene.
Based on the graph, what most likely happens in corn plant cells as a direct result of the mutated gene?
Protein production decreases.
Glucose synthesis increases.
Lipid production decreases.
DNA replication increases.
In the plant Brassica rapa, the allele for purple stem color (P) is dominant to the allele for green stem color (p). Students in a biology class cross-pollinated a heterozygous purple-stemmed plant (Pp) with a green-stemmed plant (pp). The 78 seeds produced from this cross were planted to form the F1 generation.
Approximately how many purple-stemmed plants and how many green-stemmed plants are expected in the F1
generation?
0 purple-stemmed plants and 78 green-stemmed plants
39 purple-stemmed plants and 39 green-stemmed plants
58 purple-stemmed plants and 20 green-stemmed plants
78 purple-stemmed plants and 0 green-stemmed plants
In cattle, the allele for no horns (P) is dominant to the allele for horns (p). The allele for cloven hooves (C) is dominant to the allele for mule feet (c). Cattle that are heterozygous for these traits are crossed. The Punnett square for this cross is shown below.
What is the probability that an offspring will have the same phenotype as the parents?
3/16
13/16
11/16
9/16
