Kingdoms of Life Quiz

Study Notes

Kingdoms of Life

Domains are the broadest classification of life.
The three domains are: Bacteria, Archaea, and Eukarya.
Life forms within each domain are then categorized into Kingdoms.

Bacteria

Eubacteria.
They are the most abundant organism on Earth.
Bacteria were the first to evolve.
Cell walls are made up of peptidoglycan.
Most are heterotrophs, but some are autotrophs (like cyanobacteria).
Very diverse and live everywhere.

Archaea

Archaebacteria - "ancient" bacteria, which evolved after Eubacteria.
Strong membranes (different structure—no peptidoglycan).
Extremophiles—live in harsh environments.
Some heterotrophs, some autotrophs.
Live in places with no sunlight using chemicals instead.
They are called "extremophiles" because they thrive in extreme conditions like high temperatures, high salt concentration, or low pH.

Eukarya

Eukaryotes - cells with membrane-bound organelles.
Often multicellular.
Larger than bacteria and archaea.
Usually need oxygen.
Cells have outside membranes, RNA, DNA, and ribosomes that make proteins.

Evolutionary Classification

Phylogeny: "evolutionary relationships".
A phylogenetic tree or evolutionary tree is a branching diagram illustrating evolutionary relationships based on evolutionary history, not just physical characteristics.
Biologists now group organisms into categories based on evolutionary history.

How Organisms Evolutionary History Can Be Determined

Homologous Structures: Organisms that have similar structures are likely to have come from a common ancestor.
Embryological Relationships: Organisms that look the same as embryos are likely to have a common ancestor.
Biochemical Relationships: Organisms with the same chemicals (such as proteins) are likely to have a common ancestor.
DNA: Organisms with similar DNA are more closely related.
Molecular Clocks:
- Show mutations in DNA over time.
- The more time that has passed, the more mutations there are.
- These mutations may or may not affect the organism.

Constructing a Cladogram

A cladogram is a branching diagram that shows the evolutionary relationships between different species or groups.
Organisms are placed on the cladogram based on shared derived characteristics.
To construct a cladogram:
- Make a table showing which derived characteristics are present in each organism.
- Identify the organism that is least closely related to others—this will be at the end of the cladogram.
- Use the information to build the cladogram, ending with the organism that has the most derived characteristics.

Domains

Beyond Classification: Carl Woese discovered archaea, some environments that these organisms are found in include: hydrothermal vents, deep inside the earth's crust.
The domain system of classification is a modern way of categorizing all life forms on earth based on their cell structure and genetic makeup.

Description

Explore the fascinating diversity of life in this quiz covering the three domains: Bacteria, Archaea, and Eukarya. Test your knowledge on the characteristics and classifications of different life forms. Perfect for students studying biology or environmental science.