1
2
3
4
5
100
probably the oldest living thing
bacteria
100
an animal without a backbone
invertebrate
100
microscopic
too small to be seen with the eye alone
100
nonvascular
without tubes or channels
100
a living thing
organism
200
algae and protozoans
protists
200
having tubes or channels
vascular
200
an animal with a backbone
vertebrate
200
the building blocks of life
cells
200
controls the functions of a cell
nucleus
300
most numerous organisms on earth
bacteria
300
humans are classified as
a vertebrate and a mammal
300
bacteria cells are different from any other cells because
they have no nucleus
M
e
n
u