The chart shows information about three different embryos early in their development.

Which is best supported by the information in the chart?

Species X and Y are not related to humans.
Species Y and Z are not related to humans.
Species X and Z are related to humans.
Species X and Y are related to humans.

Glutamic acid: hydrophilic or hydrophobic? positive, negative, or neutral? valine: hydrophilic or hydrophobic? positive, negative, or neutral?

Abnormal softening of a gland is known as

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.