BIOL 1002 / Pomarico / Exam 1

Organisms are arranged or grouped by the science of....

taxonomy

Taxonomy

the branch of biology concerned with naming and classifying the diverse forms of life

Binomial Nomenclature

modern classification naming system

Hierarchy

smaller groupings

The lowest two categories of the taxonomic hierarchy

genus and species

Make up the scientific name for an organism

genus and species

the genus name is________

capitalized

the species name is _____

lowercase

the scientific name is usually________

underlined or italicized

taxonomic categories (big to small)

domain

kingdom

phylum/division

class

order

family

genus

species

Systematics

the field of biology that uses phylogeny to categorize the diversity of living organisms

Phylogeny

the perceived evolutionary history of an organism

Systematists depict evolutionary relationships in branching______

phylogenic trees

Each branch point in the tree is a ________represents the divergence of species

node

Shared characters are used to construct phylogenic trees and _____ to show phylogenic relationships

clades

Clades

are groups of species that includes the ancestral species and all its descendants

Taxonomy is an_______

inexact process

In 1969 Robert Whittaker proposed a replacement for the plants vs animals system that had as its largest grouping

5 kingdoms

The ability to examine the DNA sequences and genes of different organisms resulted in the kingdom Monera being separated into two distinct groups which are_________

polyphyletic

Polyphyletic

refers to a grouping which contains organisms with different immediate ancestors.

Three main branches are called________

Domains

two prokaryotic domains

bacteria and archaea

eukaryotic domain

eukarya

Species Categories include:

biological, morphological, ecological, phylogenetic

Biological species

group which includes all the organisms which are interbreeding

Morphological species

the group which includes all the organisms which have the same structure and shape

If two organisms look alike then....

they must be the same species

Biological species

based on the ability to reproduce

Ecological species

defined in terms of its ecological role and is determined by the habitat occupied

Phylogenetic species

the smallest group of individuals that shares a common ancestor sharing an evolutionary history

Biodiversity

the incredible number of species and the ways that they all interact form the basis

One main distinction between the Bacteria and the Archaea is the type of a semi-rigid permeable

cell wall

The bacterial cell wall is composed of:

peptidoglycan

Peptidoglycan

is a complex of structural polysaccharides cross-linked by peptides

The cell wall of a bacterium gives characteristic_________

shapes

Shapes of bacteria

bacilli, cocci, spirilla

bacilli

rod-shaped

cocci

spherical

spirilla

helical or corkscrew shaped

The peptidoglycan cell wall of bacteria can be stained by a specific stain called

gram stain

Gram positive

bacteria have the cell wall exposed to the environment

Gram negative

bacteria not stained by gram stain

flagella

are filaments that extend from the membrane of a cell and are used for cellular locomotion

Taxis

the orientation or movement of an organism either toward or away from the stimulus

Positive taxis

movement toward the stimulus

Negative taxis

movement away from the stimulus

Chemotaxis

movement toward food or away from a chemical substance

Phototaxis

movement toward or away from light

Magnetotaxis

movement toward or away from the Earth's magnetic field

Capsules or Slime layers

surrounding the cell walls of some prokaryotes

Capsules and Slime layers are composed of

polysaccharides and/or proteins

The capsule or the slime layer both function to:

attach the prokaryote to a surface and may also act as protective covering

Capsule

highly organized structure that is firmly attached to the cell wall

Slime layer

much less organized and more loosely attached to the cell wall

Pili

how prokaryotes can attach themselves to a surface

Bacilli can form a protective endospore in response to

environmental conditions

Endospores

protective resting structures in which the bacterial chromosome is surrounded by a durable wall

Halophiles

salt loving-- inhabit the extremely salty Dead Sea and Great Salt Lake

Thermophiles

heat loving-- including thermoacidophiles which live in acidic hot springs or in the hot water surrounding deep-sea volcanic vents

Chemosynthesis

some prokaryotes grow using autotrophic methods and derive their energy from inorganic chemicals

Cyanobacteria

obtain energy from sunlight via photosynthesis

Anaerobic

without oxygen

Binary Fission

prokaryotes use this asexual reproduction

Conjugation

the transfer of genetic information between two prokaryote via a special sex plus

Plasmid

a double-stranded ring of DNA that carries extrachromosomal genes in some prokaryotes

Symbiotic relationship

rely on each other for an exchange some commodity

Pathogenic

harmful and not beneficial to humans

Diseases caused by pathogenic bacteria include:

gonorrhea, syphilis, tuberculosis, lyme disease

Antibiotic Resistance

because of widespread use or misuse this is developed

Viruses

takes control of a host cell to produce more virus particles

Genome

the genetic information can either be DNA or RNA

Capsid

a protein coat that surrounds and protects the genome

Envelope

a membrane (phospholipid bilayer) that surrounds the capsid

Bacteriophage

bacteria are susceptible to viral infection from this

Viroids

small fragments of ssRNA with no protein coat

Viroids infect:

citrus, potatoes, and other crops

Prions

protein particles with no genetic material

Kingdom Protista contains

eukaryotes and most are single celled for most of the life cylce

Eukaryotic differences

contain nucleus (double membrane), organelles, 2 or more chromosomes (DNA + proteins)

Plant-like protists

autotrophic (photosynthetic)

Fungus-like protists

heterotrophic (decomposers)

Animal-like protists

heterotrophic (hunters and symbiotic)

Phytoplankton or algae

are the photosynthetic eukaryotes at the base of most aquatic food webs

Protozoans

heterotrophic protists which actively seek and ingest their food (either food particles or other organisms)

Excavates

move via flagella

have a feeding groove

heterotrophic and lack mitochondria

Larger subgroups of excavates

diplomonads and parabasalids

Diplomonads

both free living and symbiotic species

have two nuclei

multiple flagella

Giardia

infection resulting from drinks untreated water causing diarrhea

Parabasalids

anaerobic

all known species are symbiotic and some are parasitic

Trichomanas vaginalis

sexually transmitted member--males can often be asymptomatic

Euglenozoans

have distinctive mitochondria

move via flagella

mixed nutritional methods

Euglenids

most are freshwater

have 1-3 flagella

primarily photosynthetic

lack a rigid cell wall

named after Euglena

Kinetoplastids

one flagellum, both free living and symbiotic species

Trypanosoma

causing sleeping sickness

Stramenopiles (Chromists)

have many different forms some living as multicellular colonies

mixed nutritional methods

Major groups of stramenopiles

water molds, diatoms, brown algae

Water molds

division oomycota -- form a small division

cells can form aggregated colonies

filamentous bodies

heterotrophic decomposers

mobile flagellated gametes

Diatoms

division chrysophyta -- may be freshwater or marine

photosynthetic

have glass-like shells

Brown algae

division phaeophyta--

marine

deep water to tidal

cell wall has added polysaccharides

large aggregated colonies

giant kelp forest

gas-bladders to keep the plant extending toward the surface

Alveolates

most live as single cells

mixed nutritional methods including parasitic forms

varied forms of motility