Which of the following is true regarding extinction? a. single events or several causes working together to produce extinction in a short period is referred to as mass extinction. b. extinction that occurs in a relatively short period of time is referred to as background extinction. c. if the rate of speciation in a clade is equal to or less than the rate of extinction, the clade will survive. d. the rate of extinction is steady from clade to clade as are the number of species contained within a clade.

Study the diagram of a cell. which structure is found only in plant cells and functions in the process of photosynthesis? w x y z

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.

Every early childhood education program should develop a