Questions: Which pedigree symbol is used to represent a female carrier of a recessive X-linked trait?

The answer is the second one: a circle with a dot in the center.

Explanation:

1. A circle is typically used to represent a female in a pedigree chart.
2. A dot inside the circle indicates that the female is a carrier of a recessive X-linked trait. This means she has one normal allele and one allele for the trait, but does not express the trait herself.
3. A square is used to represent a male in a pedigree chart, so it would not be applicable for a female carrier.

In summary, the correct symbol for a female carrier of a recessive X-linked trait is a circle with a dot in the center.