The document discusses how scientists classify living organisms. It describes the main categories used in biological classification as domains, kingdoms, and taxa below kingdom. The categories include prokaryotes and eukaryotes, unicellular and multicellular organisms, autotrophs and heterotrophs, and asexual and sexual reproduction. Scientists use characteristics like cell structure and reproduction to systematically classify organisms into domains, kingdoms, phyla, classes, orders, genera and species. Dichotomous keys are also described as tools used to identify organisms based on paired descriptive choices.

1. Classification
Day 6 of 17 Days to STAAR

2. How scientists classify living organisms:
Prokaryotic- lack a nucleus and membrane (ex:
bacteria)
Eukaryotic- have a nucleus and a membrane that
encloses complex structures, such as the nucleus
(ex: plant cell)

3. How scientists classify living organisms:
Unicellular- made up of only one cell (ex: paramecium)
Multicellular- made up more than one cell (ex: humans)

4. How scientists classify living organisms:
Autotroph: make their own food using radiant energy
from the sun into glucose (sugar) (ex: tree)
Heterotroph: eats other organisms to survive (ex: cow)

5. How scientists classify living organisms:
Asexual reproduction: offspring arise from a single
parent, resulting in uniform offspring (ex: bacteria)
Sexual reproduction: offspring arise from the mating
of 2 parents; produces genetically diverse offspring
(ex: dog)

6. Reproduction:
Reproduction is a characteristic of all living organisms.
Inherited traits are governed in the genetic material
found in genes on chromosomes within the nucleus of
the cell.

7. Classification
Scientists classify organisms based on certain
characteristics. They are classified into the following:
 Domain
 Kingdom
 Phylum
 Class
 Order
 Genus
 Species

8. Domains & Kingdoms
The 3 Domains:
 Archaea- a prokaryote that may survive in extreme
environments
 Bacteria- a prokaryote that cannot survive in extreme
environments
 Eukarya- any eukaryote
The 6 Kingdoms:
 Archaea (Domain Archaea)
 Bacteria (Domain Bacteria)
 Prostista (Domain Eukarya)
 Plantae (Domain Eukarya)
 Fungi (Domain Eukarya)
 Animalia (Domain Eukarya)

9. Dichotomous Keys:
 Scientists classify living and nonliving things using a
tool called a dichotomous key.
 A dichotomous key is a system used to identify
plants, animals, rocks, or minerals made up of a
series of paired descriptions to choose between.
 Dichotomous keys are used for identification of
organisms, such as birds, trees, insects,
vertebrates, invertebrates, and flowering plants.

10. Dichotomous Key Example: