Each unit of a nucleic acid consisting of a sugar, attached phosphate group, and base is a
a) nucleotide
b) histone
c) nucleolus
d) nucleosome

Which part of the neuron below is indicated by the arrow, and what is its function? hormones send chemical signals throughout the body to regulate other body processes. hormones are chemical signals that are sent throughout the body to regulate other body processes. hormones send electrical signals throughout the body to regulate other body processes. hormones are electrical signals that are sent throughout the body to regulate other body processes.

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

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above