Question

Temperature during embryonic development determines sex in reptiles like turtles and alligators.

A. True
B. False

Answer 1

The statement is true; reptiles like turtles and alligators have sex determined by the temperature during embryonic development, known as temperature-dependent sex determination.

Step-by-step explanation:

The statement 'Temperature during embryonic development determines sex in reptiles like turtles and alligators' is true. This process is known as environmental sex determination, specifically temperature-dependent sex determination.

For example, in many turtle species, cooler temperatures during egg incubation tend to produce males, whereas warmer temperatures often lead to female hatchlings. In contrast, for American alligators (Alligator mississippiensis), eggs incubated at 30ºC produce females and those incubated at 33ºC produce males. It's important to note that for some reptile species, the ideal or pivotal temperature will result in a mixed sex ratio of offspring.

Answer 2

The sex of reptiles such as turtles and alligators can be determined by the temperature during their embryonic development, which is known as temperature-dependent sex determination (TSD). Conditions of the incubation environment influence whether the embryos become male or female. Thus, the statement is A. True.

Step-by-step explanation:

In reptiles like turtles and alligators, sex determination is indeed influenced by the temperature during embryonic development. This process is known as temperature-dependent sex determination (TSD). Unlike mammals whose sex is genetically determined by sex chromosomes, in TSD species, environmental temperature during a critical period of incubation influences whether an embryo will develop as male or female.

For instance, in many turtles, cooler incubation temperatures tend to produce males, while warmer temperatures often result in females. Conversely, some species of turtles and alligators have the opposite pattern, with moderate temperatures producing males, and both warmer and cooler temperatures producing females.

Specifically, research on the American alligator, Alligator mississippiensis, has found that eggs incubated at 30°C mostly produce females, while those incubated at 33°C generally produce males. Loggerhead sea turtles also exhibit TSD, with sex ratios dependent on the warmth of the nest: warmer temperatures favor female development, cooler temperatures favor males, and intermediate, or pivotal, temperatures yield a roughly equal sex ratio.

Therefore, the correct answer to the question of whether temperature during embryonic development determines sex in reptiles like turtles and alligators is: A. True.