If someone tells you they have a sample of niobium-90, can you tell how many neutrons are in the nucleus

In a cladogram' when does a group of organisms branch off

Which of the following statements about archaea and bacteria is true? a. neither is single-celled. b. they both have nuclear membranes. c. neither reproduces by binary fission. d. they both lack a nuclear membrane.

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.