Diversity of Living Things and Taxonomy

Vocabulary flashcards covering the Three Domains of Life, principles of taxonomy, binomial nomenclature, microscopy, and cellular characteristics.

Taxonomy

The art and science of categorizing organisms into taxa or groups with similar features.

Three Domain System

A categorization system proposed by Carl Woese in 1990 that places all life into one of three Domains: Eukaryotes, Bacteria, or Archaebacteria.

Taxon

An identified group of organisms that share common anatomical and physiological characteristics; the plural form is taxa.

Species

A group of organisms that can breed with each other to produce offspring, which can, in turn, breed with each other to produce offspring.

Binomial Nomenclature

A naming system developed by Carl Linnaeus where every species is described by its genus (capitalized) and species (lowercase) in italics.

Viable

A term meaning offspring are born alive, do not fail to develop, and are not miscarried or stillborn.

Fertile

A term meaning offspring are able to have offspring of their own when they reach sexual maturity.

Dichotomous Key

A series of questions or tests with only two possible outcomes at each level used to identify organisms based on physical features.

Phylogeny

The study of how organisms are related to each other.

Cladogram

A qualitative diagram illustrating the relationships between species, common ancestors, and the order of divergences.

Divergence

The point in phylogenetics at which different species arise from a common ancestor.

Total Magnification

The product of the magnifications of the ocular lens and the objective lens (e.g., $10\left(ocular\right)\cdot40\left({objective)}=400\right.\left(totalmagnification\right)$ ).

Field of View

The circle of light or surface area seen when looking through the ocular lens of a microscope.

What is 1 Micrometre equal to in millimetres?

1 micrometer = 0.001 millimetres
Moved decimal three places to the left.

Characteristics of living things: Motility

The ability of an organism to use metabolic energy to move around or change position.

Mobility

The ability of an object, whether living or non-living, to be moved around.

Characteristics of living things: Respiration

The process where organisms break down substances to produce or release energy used in biological processes.

Eukaryotic Cells

Cells characterized by an organized nucleus, membrane-bound organelles, and linear DNA organized into chromosomes.

Nucleoid

The central part of a prokaryotic cell where the genetic material (DNA) is found.

Prokaryotic Cells

Cells that lack an organized nucleus and membrane-bound organelles, typically ranging from $0.1$ to 5 microns in diameter.

Archaeabacteria

Unicellular prokaryotic heterotrophs often called extremophiles because they live in extreme environments like volcanoes or acidic lakes.

Characteristics of living things: Sensitivity

the ability of an organism to detect changes to its environment.

Characteristics of living things: Growth

all organisms grow throughout their lives.

Characteristics of living things: Reproduction

the ability of an organism to pass on its genetic material to viable offspring.

Characteristics of living things: Excretion

the ability of an organism to get rid of waste.

Characteristics of living things: Nutrition

all organisms use energy created from the intake of materials from their environment.

Archaeabacteria

unicellular organisms that are heterotrophs. Archaeabacteria are also known as extremophies.

Eubacteria

unicellular organisms that can be either heterotrophs or autotrophs.

Animalia

multicellular organisms that are heterotrophs.

Plantae

multicellular organisms that are autotrophs.

Fungi

can be multicellular or unicellular organisms that are absorbative heterotrophs.  Fungi are also decomposers.

Protista

mainly unicellular organisms  that can be either auto- or hetereotrophic.

Heterotrophic

A hetereotrophic organism obtains the energy they need to sustain life by consuming other organisms.

Autotrophic

An autotrophic organism produces the energy they need to sustain life from their surroundings.

Absorptive Hetereotrophs

An absorptive hetereotroph obtains the energy it needs to sustain life by digesting food externally, then absorbing the products of digestion.

Characteristics of Eukaryotes (Name 5)

• The presence of membrane-bound organelles

• The genetic material, or DNA, is organized into linear structures called chromosomes

• The DNA is bound to proteins

• Each cell contains more than one copy of a chromosome (i.e. diploid, triploid, tetraploid)

• The average size of the cell is in the range of 10–100 microns in diameter

Characteristics of Prokaryotes (Name 5)

• The lack of an organized nucleus and membrane-bound organelles

• The genetic material, or DNA, is found in a central part of the cell called the nucleoid

• The DNA is not bound to proteins

• The presence of a cell wall

• The average size of the cell is the range of 0.1–5 microns in diameter

Binary Fission

A process similar to mitosis in which a parent cell (typically prokaryotic) divides into two daughter cells.

Conjugation

The process by which one prokaryotic cell transfers genetic material to another by direct contact.

Chemical Composition of Cell Wall: Eubacteria

Sugars and proteins, including peptidoglycan (a chemical made up of sugars and proteins).

Chemical Composition of Cell Wall: Archaebacteria

Sugars and proteins, excluding peptidoglycan

Chemical Composition of Cell Wall: Protist

Cellulose

Chemical Composition of Cell Wall: Fungus

Chitin (A chemical found in the cell wall of fungi that is made up of sugars)

Chemical Composition of Cell Wall: Plant

Cellulose

Chemical Composition of Cell Wall: Animal

There is no cell wall in animals.

Ribosomes (Prokaryotes)

Prokaryotes have simplistic, small ribosomes that float freely throughout the cytoplasm of the cell. 

Ribosomes (Eukaryotes)

Ribosomes are bigger, more complex (membrane-bound), and can be found throughout the cell. Some ribsomes are attached to the nuclear membrane and others are attached to rough endoplasmic reticulum.

Genetic Material (Prokaryotes)

The genetic material is often organized into a circular chromosome. 

Genetic Material (Eukaryotes)

The number of linear chromosomes varies among organisms, with the majority of organisms having more than one copy of each chromosome in their nucleus (diploid, triploid, tetraploid).

In which 6 kingdoms is sexual reproduction possible.

Sexual reproduction is possible in protist, fungus, plants, and animals:

• Eubacteria: No, Conjugation is possible

• Archaebacteria: No, Conjugation is possible

• Protist: Yes

• Fungus: Yes

• Plant: Yes

• Animal: Yes

In which 6 kingdoms is asexual reproduction possible.

Asexual reproduction is possible in eubacteria, archaebacteria, protist, fungus, and plants:

• Eubacteria: Yes

• Archaebacteria: Yes

• Protist: Yes

• Fungus: Yes

• Plant: Yes

• Animal: No

What are plasmids?

Plasmids are small, circular pieces of genetic material found in some prokaryotes. They are separate from the main chromosomal DNA and can carry extra genes.