Vascular plants first developed on earth during the period. a. cambrian b. ordovician c. silurian d. devonian

Which statement names a physical property of wood? wood does not rustwood can burnwood can rotwood is softer than coal

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.

2. which of the following statements does not accurately describe stem cells? a. embryonic stem cells make up the inner cell mass of a blastocyst. b. with more research, stem cells may be used to repair or replace damaged cells. c. the use of stem cells is without any objections since it can be used in therapies to humans. d. adult stem cells are multipotent and can differentiate into many types of cells.