Today, which of the following ethnic groups has the biggest impact on australia’s culture?
asian
african
hispanic
european

The correct answer is - European.

Australia is a country that is considered as part of the so called Western World. The country has been conquered and settled mostly by people from the British Empire. Because of that, Australia has its basic cultural traits connected with the British, with some unique changes over time as the country developed of course. Also, there's a slight French influence in the culture as well, so we can easily say that the culture in Australia is primarily European based culture.

In the past century there has been migration from multiple other countries, but most of those countries were European countries too, so there's just a mixture of European influences.

fertilization is the union of an egg and a sperm cell i believe.