Chapter 4, Problem 14AQP

Summary Introduction

To determine:

Whether the unusual cold weather during breeding season of bearded lizard has any effect on the sex ratio.

Introduction:

The sex chromosome in males is generally XY and in females it is XX but in case of bearded lizard the male sex chromosomes are homozygous ZZ and in females, the sex chromosomes are heterozygous having ZW chromosome

Explanation of Solution

The sex in bearded lizards is dependent on both the environment and genetics. Sex in the newborn bearded lizard was highly affected by the atmospheric temperature. When the temperature of the surrounding is less than $32\text{°C}$, it promotes hatching of eggs and having a male lizard. The decrease in temperature did not have an effect on sex ratio though it only promoted hatching eggs having male dragon lizard.

Summary Introduction

To determine:

The effect of unusual warm temperature on the sex ratio of dragon lizard.

Introduction:

In bearded lizard, the male sex chromosome is ZZ and in females, it is heterozygous having ZW chromosome. The sex in newborn bearded lizard is highly affected by the atmospheric temperature

Explanation of Solution

The sex ratio in bearded lizard is highly affected by increasing temperature. The lower temperature below $32°\text{C,}$ only promoted hatching the eggs containing male bearded lizards. This did not change the male and female ratio. But increase in temperature above $\text{36°C}$ results in the conversion of sex from males to females and increases the sex ratio in favor of female bearded lizards.

Conclusion

In bearded lizard, the male sex chromosomes are homozygous ZZ and in females, the sex chromosomes are heterozygous having ZW chromosome. The lower temperature below $32°\text{C}$ only promoted hatching the eggs containing male bearded lizards, and temperature above $\text{36°C}$ results in the conversion of the sex of eggs which did not hatch, from males to females and increases the sex ratio in favor of female bearded lizards.