Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Many reptiles, including sea turtles, do not have their sex determined by genes at fertilization. Instead, their sex is influenced by the temperature at which their eggs develop in the nest.
This phenomenon is known as temperature-dependent sex determination (TSD). Biologists have studied this pattern extensively in green sea turtles (Chelonia mydas). The findings show a clear environmental effect on the trait of hatchling sex.
Nest Temperature (°C) | % Female Hatchlings | % Male Hatchlings |
|---|---|---|
26 | 10 | 90 |
28 | 30 | 70 |
30 | 70 | 30 |
32 | 95 | 5 |
Eggs incubated in cooler nests (around
This study provides strong evidence that traits can be influenced by the environment. The turtles inherit genes for both male and female potential, but environmental temperature determines which trait is expressed. This phenomenon has become especially important in conservation biology because rising global temperatures may cause imbalanced sex ratios in some sea turtle populations.
Make a claim, provide the evidence, and explain your reasoning for the statement:
“The sex of sea turtle hatchlings is influenced by the nest temperature.”
Respond with three parts labeled clearly:
Claim:
Evidence:
Reasoning:
Refer to the table and graphs in the Turtle Hatchling Sex and Nest Temperature resource.
Describe the relationship between nest temperature and the percentage of female hatchlings.
Which statement best describes how nest temperature affects sea turtle sex?
What does this study show about the relationship between inheritance and environment?
Explain how changes in global temperatures might affect the survival of sea turtle populations.