Question

Predict the effect of increasing global temperatures on the continued presence of the W chromosome in this species of lizard. Scientist claims that in this species the W chromosomes is unimportant in sex determination. Instead proteins that are encoded by a gene or genes on the Z chromosome and that are maximally expressed only at certain temperatures are responsible for determining wheatger embryo will develop as female or males

Answer 1

A rise in global temperatures could alter the sex ratios of a lizard species with temperature-dependent sex determination, potentially causing a sex imbalance and affecting population dynamics.

Step-by-step explanation:

In the species of lizard mentioned, it's claimed that the W chromosome is not significant in sex determination. Instead, sex determination is tied to the presence of certain proteins encoded by genes on the Z chromosome, which are greatly influenced by temperature. As global temperatures rise, if the conditions favor the expression of these proteins at warmer temperatures, there could be a skewed ratio of sexes, potentially leading to a predominance of one sex over the other, depending on whether the warmer temperatures promote the development of males or females.

This scenario bears similarity to environmental sex determination observed in some reptiles like alligators and certain turtles where temperature plays a critical role during the incubation of eggs. For instance, in many turtle species, warmer incubation temperatures tend to produce females, whereas cooler temperatures produce males. Bearing this in mind, an increase in global temperatures could result in an imbalance in the sex ratio of such species, emphasizing the importance of temperature-dependent sex determination.

Thus, a continuous increase in global temperature would likely impact the ratios of male to female in this lizard species, with potential long-term effects on its population dynamics and survival.

Answer 2

Step-by-step explanation:

Reptile shows temperature dependent sex determination where the temperature determines whether the reptile such lizard is either a male or female during embryonic development. In America dragon lizard where the ZW chromosome determination is used, at a very high incubation temperature there is a change from a genotypic male with genotype ZZ to a phenotypic female with genotype ZW or ZZ. Hence an increase in temperature will lead to reverse of a male genotype to female phenotype.