Sentence Arrange s— Put the steps of DNA replication in order by writing a number in the space before each statement. Two new molecules of DNA are created.

DNA polymerase attach the free-floating nucleotides to the exposed nitrogen bases.

Helicase begins to break the hydrogen bonds between nitrogen bases.

Cell starts into the mitosis phase of the cell cycle.

Free floating nucleotides pair up with exposed nitrogen bases.

Complete the statement guanine, cytosine, and thymine are the four nitrogen bases.

In DNA, always forms hydrogen bonds with guanine.

The sequence of carries the genetic information of an organism

The process of produces a new copy of an organism's genetic information.

The double coiled shape of DNA is called a

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

The bacteria inside a tube worm would be analogous to what organism in the ocean ecosystem near the waters surface? a. photosynthetic algae b. shrimp c. clown fish d. parasitic lamprey

Which example describes a mutualistic relationship between organisms? young wasps prey on caterpillars. crabs eat the remains of dead fish. tapeworms feed on food in the intestines of cats ants protect a tree on which they feed.