A. B. C. D. - CORRECT ANSWER: D.

Bio 181 ASU exam 3 Latest Update 2025-2026 160 Questions and 100% Verified Correct Answers Guaranteed A+

A dihybrid cross is arranged for two plants with the following genotype:

AaGg x aaGg A = Almond shaped seed a = round seed G = Green seed color g = yellow seed color What proportion of the offspring will be Almond-shaped and green?

A. ½ B. 1/8 C. ¼ D. 3/8 - CORRECT ANSWER: D. 3/8

A dihybrid cross is arranged for two plants with the following genotype:

AaGg x aaGg A = Almond shaped seed a = round seed G = Green seed color g = yellow seed color What proportion of the offspring will be Almond-shaped and yellow?

A. ½ B. 1/8 C. ¼ D. 3/4 - CORRECT ANSWER: B. 1/8

A dihybrid cross is arranged for two plants with the following genotype:

AaGgbbDd x aaGgBbdd

A = Almond shaped seed a = round seed 1 / 4

G = Green seed color g = yellow seed color B= Bright seed coat b= dull seed coat D= Durable seed coat d =fragile seed coat

What proportion of the offspring will be round-shaped, Green, dull, and fragile ?

A. 3/32 B. 9/64 C. ¼ D. 8/64 - CORRECT ANSWER: A. 3/32

A mutant strain of E. coli is found that produces both β-galactosidase and permease constitutively. What are the MOST likely mutations in this strain? (Select all that apply: hint** There are two correct answers.)

• lacOc
• lacI-
• lacP-
• mutation in CRP-cAMP binding site

E) lacZ- and lacY- - CORRECT ANSWER: A) lacOc

• lacI-

A mutation that changes one amino acid codon into another codon (but not a stop codon)

• Nonsense

B) Missense - CORRECT ANSWER: B) Missense

A mutation that results in a stop codon where before there was a normal amino acid is called...

• Missense mutation 2 / 4

• Nonsense mutation
• Synonymous mutation

D. Conservative mutation - CORRECT ANSWER: B. Nonsense mutation

A mutation that you could not pass on to your offspring would occur in the

• germ cells

B) somatic cells - CORRECT ANSWER: B) somatic cells

A purple-flowered pea plant of unknown genotype is crossed with a white-flowered pea plant. Half of the offspring have white flowers. What is the genotype of the purple- flowered parent?A)AA B)Aa C)aa

D)No basis to decide - CORRECT ANSWER: B)Aa

A single gene can produce different proteins.

• true

B) false - CORRECT ANSWER: A) true

A testcross involves crossing with a(n) _____ individual and is used to determine the _____ of the tested parent.

• homozygous dominant; phenotype
• homozygous recessive; phenotype
• homozygous dominant; genotype
• homozygous recessive; genotype

E) F2 offspring; parental genotype - CORRECT ANSWER: D) homozygous recessive;

genotype 3 / 4

A woman who has five children (all boys) is planning to have another child. What is the probability that this child will be a boy?

A) 1/2

B) 1/64

C) 1/32

D) 6/256 - CORRECT ANSWER: A) 1/2

A woman you know has five children - all of whom are boys. What is the probability for a woman to have five boys out of five children?

A) 1/4

B) 1/8

C) 1/32

D) 1/64 - CORRECT ANSWER: C) 1/32

AaBbCc x aabbcc, What proportion of offspring have the same genotype as first parent?

A) 1/4

B) 1/8

C) 1/16

D) 1/32 - CORRECT ANSWER: B) 1/8

An operon is a:

• gene coding for a repressor protein.
• region of DNA consisting of the promoter, the operator, and coding sequences for

structural proteins.

• region of DNA consisting of the operator and coding sequences for structural

proteins.

• region of DNA consisting of the promoter and operator sequences needed to

regulate one or more structural genes.

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