How do scientists explain the origin of life on earth?

The earliest know life-forms on earth are putative fossilized microorganisms, found in hydrothermal vent precipitates, that have lived as early as 4.28 billion years ago, relatively soon after the oceans formed 4.41 billion years ago, and not long after the formation of the earth 4.54 billion years ago.

The correct answer is -

genotype: rr

phenotype: black eyes.

As per the information in the question, red eyes is a dominant trait and black eyes is a recessive trait.

Dominant trait (depicted by capital letter allele such as R) is the one that masks the expression of a recessive trait (depicted by small letter allele such as r).

This means that recessive trait is only expressed when its genotype (genetic makeup, represented by gene variants) is homozygous recessive (both alleles are same and recessive, such as rr here) .

Thus, rr represents genotype for black eyes, which is a phenotype (physical trait).