Question 1

The work of Beadle and Tatum not apply to every gene.Why not?

Accepted Answer

A)   Genes never encode polypeptide sequences
B)   Some genes encode RNA sequences that do not lead to the formation of polypeptides
C)   Some genes encode other DNA sequences that do not lead to the formation of polypeptides
D)   All of these are correct
E)   None of these B

Question 2

When a heterozygous organism shows characteristics found in each of the associated homozygote states because the different alleles contribute equally to the phenotype,the gene exhibits:

Accepted Answer

A)   Simple dominance
B)   Semi-dominance
C)   Codominance
D)   Incomplete dominance
E)   Partial dominance C

Question 3

In a mating between individuals with the genotypes I?I? X I?I?,what percentage of the offspring are expected to have the O blood type?

Accepted Answer

50%

Question 4

When two or more genes influence a trait,an allele of one of them may have an overriding effect on the phenotype.When an allele has such an overriding effect,it is said to be:

Accepted Answer

A)   Dominant
B)   Recessive
C)   Penetrant
D)   Epistatic
E)   Expressive

Question 5

Polypeptides are macromolecules comprised of what monomer subunit?

Accepted Answer

A)   Nucleic acids
B)   Amino acids
C)   Micromolecules
D)   Enzymes
E)   Proteins

Question 6

In maize,overall kernel color is controlled by both the endosperm and the aleurone colors.The Y allele produces a yellow endosperm while the homozygous recessive (y/y)state produces a white endosperm.Endosperm color is masked by the presence of a colored aleurone.The R and Pr genes control aleurone color.The combination of Pr and R alleles lead to a purple aleurone.The combination of pr and R alleles lead to a red aleurone.A homozygous recessive (r/r)produces a colorless aleurone,allowing the endosperm color to be expressed.Which allele is epistatic?

Accepted Answer

A)   Y
B)   R
C)  Pr
D)   Y and R
E)   R and Pr

Question 7

The trait of wavy flowers in petunias is determined by the genetic condition PP'.Plants with flat flowers are PP,while plants with curly flowers are P'P'.A cross is made between two plants each with wavy flowers.If they produce 200 seedlings,what phenotypes and in what numbers would you expect? What is the term for this allelic relationship?

Accepted Answer

The answer of The trait of wavy flowers in petunias...

Question 8

A medical technician is analyzing a blood sample in a clinical lab.It is determined that the red blood cells have both A antigens and B antigens present on their surface.In this case,the red blood cells are exhibiting a genetic characteristic known as:

Accepted Answer

A)   Simple dominance
B)   Incomplete dominance
C)   Partial dominance
D)   Semi-dominance
E)   Codominance

Question 9

A woman who is blood type A has a child who is blood type O.Which of the following individuals could not be the father of this child?

Accepted Answer

A)   Type A
B)   Type B
C)   Type AB
D)   Type O
E)   All of these could be the fether

Question 10

Summer squash color is determined by the interaction of more than one gene.The presence of CC or Cc allele combinations produces a squash that is white in color,and the C allele is epistatic to the G allele.The presence of GG or Gg produces a squash that is yellow in color,and ccgg produces a squash that is green.After two fully heterozygous squash are crossed give the phenotypes,and frequency of occurrence,of the F2 offspring.

Accepted Answer

The answer of Summer squash color is determined by the...

Question 11

If an allele has the same phenotypic effect in heterozygotes as in homozygotes-that is,the genotypes Aa and AA are phenotypically indistinguishable then the allele is:

Accepted Answer

A)   Recessive
B)   Dominant
C)   Incompletely dominant
D)   Codominant
E)   Partially dominant

Question 12

The inbreeding coefficient can be defined as the:

Accepted Answer

A)   Probability that two gene copies in an individual are identical by descent from a common ancestor
B)   Probability that two gene copies in an individual are different by descent from a common ancestor
C)   Probability that two gene copies in an individual are identical by descent from two different ancestors
D)   All of these
E)   None of these

Question 13

If a mutation occurs and it impairs a vital function of an organism the mutation is known as a:

Accepted Answer

A)   Lethal mutation
B)   Sterile mutation
C)   Visible mutation
D)   Non-visible mutation
E)   Polymorphic mutation

Question 14

A mutation that actually interfere with the function of the wild-type allele by specifying polypeptides that inhibit,antagonize,or limit the activity of the wild-type polypeptide is known as:

Accepted Answer

A)   Loss of function mutation
B)   Partial loss of function mutation
C)   Recessive mutation
D)   Gain of function mutation
E)   Dominant negative mutation

Question 15

The coefficient of relationship is represented by which of the following:

Accepted Answer

A)   (1/2) n
B)   n(¹/²) 
C)   (1/2) n * 2
D)   (1/2)  + n
E)   n - (1/2)

Question 16

In Drosophila that exhibit the Lobe eye mutation,some heterozygous flies have tiny compound eyes,whereas others have large,lobulated eyes and between these extremes,there is a full range of phenotypes.This mutation is said to have:

Accepted Answer

A)   Incomplete penetrance
B)   Complete penetrance
C)   Complete expressivity
D)   Variable expressivity
E)   None of these

Question 17

When one gene influences many phenotypic expressions it is said to be:

Accepted Answer

A)   Incompletely penetrant
B)   Variably penetrant
C)   Pleiotropic
D)   Epistatic
E)   Polygenice

Question 18

Most,but not all,loss of function mutations can be attributed to a:

Accepted Answer

A)   Dominant allele
B)   Recessive allele
C)   Codominant allele
D)   Partially dominant allele
E)   Incompletely dominant allele

Question 19

Mutations that alter some aspect of morphology are known as:

Accepted Answer

A)   Lethal mutations
B)   Sterile mutations
C)   Visible mutations
D)   Non-visible mutations
E)   Polymorphic mutations

Question 20

Mutations that limit reproduction are known as:

Accepted Answer