Donaldson Study Guide - Mendelian Genetics

Which of the following crosses would always result in offspring that display only the dominant phenotype? 

A) TTx tt

B) Tt x Tt

C) Tt x tt

D) Both Tt x Tt and TT x tt

A) TTx tt

What aspect of Mendel's background gave him the necessary tools to discover the laws of inheritance? 

A) He was a monk.

B) He was a teacher.

C) He lived in Austria.

D) He had studied mathematics and probability.

D) He had studied mathematics and probability.

What is the blending theory of inheritance?

A) Mendel's theory of how the traits of parents are passed to offspring through the gametes 

B) Darwin's theory of how traits are passed from all parts of the parent's body into the

gamete to be transmitted to the offspring

C) the modern theory of how genetic information is passed from parents to offspring

D) an old theory stating that offspring show traits intermediate between those of the parents

D) an old theory stating that offspring show traits intermediate between those of the parents

An individual with a dominant phenotype is crossed with an individual with a recessive phenotype, four of their nine offspring show the recessive phenotype. What is the genotype of the first parent?

A) AA

B) Aa

C) aa

D) AA or Aa

B) Aa

If you had two guinea pigs of opposite sex, one homozygous black and one homozygous brown, but you didn't know which the dominant characteristic was, how would you find out the dominant color?

A) Mate them together and see what color the offspring are-that will be the dominant color.

B) Mate them together and see what color the offspring are the other color will be the

dominant color.

C) Mate them together, and then mate their offspring to see what color the grandchildren are that will be the dominant color.

D) Mate them together, and then mate their offspring to see what color the grandchildren are the other color will be the dominant color.

A) Mate them together and see what color the offspring are-that will be the dominant color.

Unattached earlobes (EE or Ee) are dominant over attached earlobes (ee). A couple both have unattached earlobes. They notice that each of them has a parent with attached earlobes (ee). Therefore, they correctly assume that they are carriers for attached earlobes (Ee). The couple proceeds to have four children.

A) They can be certain that three will be heterozygous and one homozygous recessive.

B) If the first three are heterozygous, the fourth must be homozygous recessive.

C) All children must have unattached earlobes, because both parents possess the dominant gene for it.

D) Two heterozygous, one homozygous recessive, and one homozygous dominant is a likely outcome, but all heterozygous, or two, three, or all four homozygous are also possible.

D) Two heterozygous, one homozygous recessive, and one homozygous dominant is a likely outcome, but all heterozygous, or two, three, or all four homozygous are also possible.

Of the following, which is an autosomal dominant disorder?

A) Huntington's disease

B) Cystic fibrosis

C) Muscular dystrophy

D) Sickle-cell anemia

A) Huntington's disease

A classical example of incomplete dominance is

A) ABO blood groups in humans

B) height in garden peas

C) pink flowers in heterozygous snapdragons

D) coat color in rabbits

C) pink flowers in heterozygous snapdragons

Individuals in the 1800s (when hunger and childhood diseases were common) averaged slightly over five feet tall, but their offspring in the 1900s were substantially taller on average. This reflects the influence of 

A) polygenic inheritance

B) epistasis

C) gene linkage

D) environmental factors on the ability of genes to express themselves

D) environmental factors on the ability of genes to express themselves

Which disease results in deformed red blood cells, poor circulation, anemia, and an increased resistance to malaria?

A) Hereditary spherocytosis

B) Sickle-cell disease

C) Huntington disease

D) Hemophilia

B) Sickle-cell disease

Which of the statements below is true regarding the pattern of inheritance in the pedigree? A) It is autosomal recessive; the children of the affected son are not affected.

B) It is X-linked dominant; the daughter of the affected son is also affected. 

C) It is X-linked recessive; all the sons of the affected daughter would be affected. 

D) It is autosomal dominant; the children with one affected parent have a 50% chance of inheriting the allele.

D) It is autosomal dominant; the children with one affected parent have a 50% chance of inheriting the allele.

A gene locus is

A) a recessive gene.

B) an unmatched allele. C) a sex chromosome.

D) the location of an allele on a chromosome.

E) a dominant gene.

D) the location of an allele on a chromosome.

Various forms of a gene at a given locus are called

A) kinetochores.

B) alleles.

C) autosomes.

D) loci.

E) chromatids.

B) alleles.

Which of the following genotypes is homozygous?

A) AaBB

B) GABB

C) aaBB

D) aaBb

E) AaBb

C) aaBB

Which organism did Mendel utilize to work out the laws of segregation and independent assortment?

A) the fruit fly

B) the rose

C) the garden pea

D) the chicken

E) E. coli

C) the garden pea

In a Punnett square, the letters within the little boxes represent

A) offspring genotypes.

B) parental genotypes.

C) gametes.

D) offspring phenotypes.

E) parental phenotypes.

A) offspring genotypes.

If short hair (Z) is dominant to long hair (I), animals LL and LI have the same

A) parents.

B) genotypes.

C) phenotypes. 

D) alleles.

E) genes.

C) phenotypes. 

If all offspring of a cross have the genotype Aa, the parents of the cross are most likely

A) AA x aa.

B) Aax Aa.

C) Aax aa.

D) AA x Aa.

E) none of these

A) AA x aa.

Who proposed the law of independent assortment?

A) Morgan

B) Mendel 

C) Darwin

D) Cuvier

E) Flemming

B) Mendel 

Blood types (A, B, and O) are controlled by

A) sex-linked genes.

B) linked genes.

C) incompletely dominant genes.

D) multiple alleles.

E) none of these

D) multiple alleles.

The ABO blood types are controlled by

A) pleiotropy.

B) multiple alleles.

C) incomplete dominance.

D) codominance.

E) multiple alleles and codominance.

E) multiple alleles and codominance.

Multiple effects of a single gene is

A) expressivity.

B) penetrance.

C) codominance.

D) pleiotropy.

E) multiple alleles.

D) pleiotropy.

In genetic analyses, researchers know that linkage of genes will introduce exceptions to the principle of 

A) dominance.

B) segregation.

C) recessiveness.

D) independent assortment.

E) chromosomal inheritance.

D) independent assortment.

A graph of phenotypic variation similar to the illustration below strongly suggests

A) incomplete dominance. 

B) codominance.

C) epistasis.

D) polygenic inheritance.

E) environmental effects on phenotype.

D) polygenic inheritance.

A dihybrid cross uses "true breeding plants" that differ in

A) two traits

B) one trait

C) three traits

D) four traits

A) two traits

Any chromosome other than a sex chromosome (such as a sperm or an egg) is called a(an),

A) android.

B) dichrome

C) autosome

D) polychrome

C) autosome

The following condition is considered an autosomal recessive disorder

A) Tay-Sachs Disease

B) Cystic Fibrosis

C) Phenylketonuria (PKU)

D) All of these

D) All of these

A heterozygote that has a phenotype that is intermediate between that of either homozygote is an example of

A) Epistasis

B) incomplete dominance

C) Pleiotrphy

D) B and C

D) B and C

Sickle Cell Anemia is an example of

A) Epistasis

B) Codominance

C) Pleiotrophy

D) None of the above

C) Pleiotrophy

In the video we watched in class regarding Sickle Cell Anemia, we learned that there is a potenial cure using

A) Gene Therapy

B) Nuclear radiation

C) Blood transfusions and pain medication 

D) Fragrance therapy

A) Gene Therapy

The Himalayan Rabbit is unique in that its phenotype is affected by its environment. When it is grown in a cold climate, it will have darker fur than when it is raised in a hot climate.

A) True

B) False

A) True

Which of the following conditions are considered to be autosomal dominant disorders?

A) C and D

B) Cystic Fibrosis

C) Huntington's Disease

D) Neurofibromatosis.

A) C and D