What happens during external respiration?

Two organisms that are closely related would have

Natural selection has favored the dark form of the peppered moth in areas subject to severe air pollution, perhaps because on darkened trees, moth-eating birds see them less easily. As pollution went away, the light forms increased in the population because

Study of embryos of various organisms to show a common ancestor because of similarities in development

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are

A bird’s beak changes over time to fit it’s environment. What is this an example of?

Which of the following is evidence of a common ancestor?

_____________is the process of creating mRNA copies from DNA sequences. This is done by an enzyme called__________________.

During DNA replication, each original strand serves as a template for synthesizing a new complementary strand. This replication mechanism is referred to as:

What is the purpose of the leading strand during DNA replication?