Why do viruses only infect specific types of cells?

An organism has the following features: diplontic life cycle, protostome development, segmentation, a septate coelom, closed circulatory system, and setae. To which phylum does this organism belong?

In the vascular bundles of most dicot stems, primary phloem differentiates toward the ________of the stem, while primary xylem differentiates toward the ________of the stem.

The closest extant relative of the Tyrannosaurus rex is the _____

*In fungi, plasmogamy results in _____.

*Adult echinoderms display radial symmetry. What evidence suggests that echinoderm ancestors evolved from bilaterally symmetrical ancestors?

The first stage in the gametophyte generation is  _____.

A small island has stable populations of plants and animals, including one species of hawk as the only predator. The removal of the hawks could cause ____________ population size.

Many indicators show that temperatures are increasing, and climate patterns are changing on a global scale.  What is NOT a likely result of these changes?

Considering that the scientific method includes making observations, formulating a hypothesis to explain the observations, testing the hypothesis with experimentation, analyzing data from experiments, and drawing conclusions about the meaning of the data, which of the following statements about a species of flowering plant represents an experiment?