Attached earlobes are a recessive trait in humans. In the tree below, people with attached earlobes are shaded in. Which best describes the person
labeled X in the tree?
A. A female with no recessive alleles
B. A male with no recessive alleles
C. A male with one recessive allele
D. A female with one recessive allele

It would be C

Explanation:

If you look at the tree you can see that one of the male's parents had the recessive allele, and one of the siblings has the ressive allele, the means the male could have the trait but isnt showing it.

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c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."