Members of the phylum ____________ characteristically have bodies with three distinct sections: mantle, visceral mass, and foot.

The formation of seeds greatly improved plants’ adaptation to land by:

At which step in the diagram are gametes being formed?

The blastopore is a structure that first becomes evident during:

Which of the following groups has a water vascular system?

When we say that one organism has a greater biological fitness than another organism, we specifically mean that it:

What does the branch point labeled “4” represent in relationship to the brown bear and the Asian black bear?

Cytochrome-c is a protein found in most organisms. The amino acid sequence of this protein varies between species. The numbers of differences in the amino acid sequences of this protein between three species of chordates A, B and C are shown in the table above. Based on this evidence, the phylogenetic tree that best represents the possible evolutionary relationships between the three species is:

_______ are not classified as a gymnosperms.

The rule “like dissolves like” explains why liquids are generally soluble in other liquids and gases are soluble in one another.