What is suggested by similar bones in vertebrate fossils and present day vertebrates

Which of the following is not a main characteristic that scientists focus on when determining which kingdom an organism belongs to

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons

Which is an example of a vestigial structure? a. tail of a monkey b. fin of a fish c. flower of a plant d. tailbone of a human