Answer:
1. Latitude. Kuala Lumpur is located in the equatorial zone, near the equator, so it receives a lot of sun for the entire year, and this explains its warm climate.
2. The main reason for this difference is the altitude: while Minsk is located at 280 meters over the sea level, Banff is located at approximately 1400 meters over the sea level. As the altitude is higher, the average temperature is lower.
3. Jakarta: in fact, it is located at a similar altitude of Kuala Lumpur (just in the opposite hemisphere), in the equatorial zone, while Baltimore is located much more north, so in a colder region.
4. Because they are located at approximately same latitude (just in the opposite hemisphere), so they are more or less same distance from the equator, and they receive more or less same amount of sun light, therefore they have similar climate.
The most likely explanation for the variation is the offspring were produced from different combination of genes. A single pair of gold fish mentioned in the question means a male and a female gold fish. The two of them mated and contributed different genes to the fertilized fish eggs, this results in production of various body shape and colouration which is known as variation.
