Attached earlobes are recessive to free earlobes. What genotypic ratio is expected when an individual with attached earlobes mates with an individual heterozygous for free earlobes?

Which of these crosses will produce only heterozygous offspring?

The type of reproductive barrier that occurs when two species mate but produce sterile hybrids is referred to as ________.

________ is an example of bioremediation.

Read the following scenario to answer the following questions.The earliest cells detectable in fossils were different from the cells in animals, plants, fungi, and protists living today. These first prokaryotic cells gave rise to eukaryotic cells approximately 1.7 billion years ago. The structure of eukaryotic cells today suggests how they might have evolved from their prokaryotic ancestors. Scientists examining mitochondria and chloroplasts now think that these organelles were probably free-living prokaryotes before becoming a part of eukaryotic cells long ago.Which of the following is a characteristic of mitochondria that suggests that they might have evolved from free-living bacteria?

Please read the following scenario to answer the following questions.Widow’s peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. It can be traced back through a family’s history using pedigree analysis.The pedigree shown here is of three generations of a family. Notice that some individuals (shown in gray) have a widow’s peak (W = dominant allele and w = recessive allele).This pedigree supports the fact that widow’s peak is due to a dominant allele, because if it were due to a recessive allele and both parents show the recessive phenotype, then ________.

What is a difference between embryonic and adult stem cells?

Which of these is a characteristic of Type I survivorship?

If seed production had never evolved, which organisms would be missing in today’s landscape?

Consider the following figure. It illustrates that a single amino acid substitution in the hemoglobin gene ________.