Below are experimental and control groups for an experiment that is seeking to d

Question

Below are experimental and control groups for an experiment that is seeking to determine if testosterone has an organizational effect on the production of color in a fence lizard. Critique this experimental design and suggest any changes that might improve the design.

Group 1: Adult male lizards who are castrated

Group 2: Adult male lizards who are castrated implanted with testosterone pellets that release a daily dose of testosterone similar to that in a normal adult male

Group 3: Adult male lizards who received the same surgical procedure as lizards in group 1 except the castration

Explanation / Answer

Adult male fence lizard possess blue and black ventral patches that function in sex recognition and intersexual social signaling but this ventral coloration is absent or reduced in female and juvenile males.Adult male also exhibit relatively uniform reddish brown dorsal coloration and female and juvenile males are cryptically coloured with 2 rows of black or brown chevrons set against background of gray and brown.this suggest sexual diachromatism is regulated by testosterone.

In group 1 development of dorsal coloration is inhibited by castration.

In group 2 dorsal coloration is restored by exogenous testosterone following castration.

In group 3 no castration so dorsal coloration is unaffected.

This experiment support the critical role of androgen in mediation of sexual coloration among lizards.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.