Study the graph below. At what depth does the thermocline begin? A line graph relating ocean depth to water temperature. At 0 me
ters, temperature is approximately 27°C. At 100 meters, temperature is approximately 24°C. At 200 meters, temperature is approximately 11°C. At 300 meters, temperature is approximately 8°C.
The thermocline in an aquatic ecosystem presents a layer of water which has a steep decline in temperature. In this layer, the temperature of the water drops much faster than in the layers above. This happens because this layer is a ''buffer'' zone between the warm water of the surface layers and the cold layers of the deep. So, in this case, in the zone between 100 and 200 meters, there is a sharp decline from 24 degrees to 11 degrees.
A segment of the DNA that is non-functional but its sequence resembles that of a functional gene is known as a pseudogene.
Pseudogenes can arise in the genome due to several reasons such as DNA duplication, reverse transcription of the mRNA, mutation, etc.
The reason why these genes are nonfunctional is that either they lack regulatory sequences or they have frameshift mutations.
Therefore, in the given case the ancestral gene that is carrying a mutation that makes it non-functional and thus, makes it unable to carry out the conversion of simple sugar into vitamin C is an example of a pseudogene.