CHAPTER 36 REPRODUCTION AND DEVELOPMENT
Scientific Skills Exercise
Teaching objective: Students build scientific skills by making inferences based on data from an
experiment on sex development in rabbits.
Teaching tips: A version of this Scientific Skills Exercise can be assigned in MasteringBiology.
In other experiments, Jost transplanted an undifferentiated gonad from a male embryo close to an
undifferentiated gonad in a female embryo. The transplanted male gonad developed into a testis,
and the female gonad near it developed into an ovary. However, the tissues surrounding that
ovary, which would normally develop into an oviduct and other female genital structures, instead
Answers:
1. The normal process that was blocked was the signaling from the gonads to the structures that
2.
Interpret the Data
Figure 36.4
n all go through the
same cycles, but the cycles start and end at different times, resulting in behavioral differences
that are complementary with regard to mating behavior.
Suggested Answers for End-of-Chapter Essay Questions
See the general information on grading short-answer essays and a suggested rubric at the
beginning of this document.
10. Scientific Inquiry
You could collect individual eggs from worms raised apart from one another. If such an egg
11. Focus on Evolution
12. Focus on Energy and Matter
Sample key points:
Female animals invest energy in producing offspring regardless of whether fertilization or
development is external or internal.
Sample top-scoring answer:
Female animals expend energy toward reproductive success in egg production and, in some
cases, in nurturing offspring directly or indirectly. The amount of energy invested varies with the
13. Synthesize Your Knowledge
Since the diploid offspring are homozygous for all genes, a simple hypothesis would be that