Diversity of Life BIO 100 Chapter 16

Organization of Life: Organisms are placed into categories based on their evolutionary relationships

8 major catagories:

  1. Domain4. Order
  2. Kingdom5. Family
  3. Phylum6. Genus
  4. Class8. Species

Each order gets increasingly narrow and specific to groups whose common ancestors is increasingly recently

Each species has a unique 2-part name: Genus & species Species are Identified by features that reveal:

  1. evolutionary relationships
  2. Anatomy (ex: bone structure)
  3. Molecular similarities (DNA, genotype, genetic traits)

EXAMPLE: the bones of the vertebrate forelimb there are similarities in the functional anatomy structure

EXAMPLE: the similarities between the pig and chick embryo. It also appears similar to the human embryo.

Classification of organisms

There are 3 major Domains – this is the largest classification category

  1. Eukarya
  2. Archaea (prokaryotes)
  3. Bacteria (prokaryotes) ** Prokaryotes are single-cell organisms.

The Domain: Archaea

Prokaryotes= theprokaryotes in this category are unicellular organism. These organisms are simple in structure and have a nucleus with no membrane. They have a complex metabolic system. They live in aquatic, salty, acidic, or very hot environments or environments that lack oxygen

Prokaryotes

There are differences that exist among the Prokaryotes. They can live in extreme conditions with variant temperature:

  • Very hot (hot springs) or very cold (Artic)
  • Exreme high pressures
  • Below the deep surface of Earth.
  • Variant pH conditions
  • Acidic (vinegar) – basic(salty waters) conditions

Domain: Bacteria

These are Unicellular Prokaryotes that lack a membrane bound nucleus. They are found almost everywhere – in water soil and atmosphere, in the skin, mouth, andintestines

Some cause disease while others are good for the environment

** The Bacteria & Archaea Prokaryotes are similar in appearance under microscope

  1. Both are very small, measuring 0.2 to 10 m (micron meters)
  2. Both lack organelles: like the nucleus, chloroplasts and mitochondria
  3. They differ in structure & biochemical features
  4. They differ in plasma membrane composition, ribosome and RNA structures

Domain: Eukarya

The Eukarya domain is subdivided into 4 Kingdoms:

  1. Protista – unicellular or multicellular organisms (protozoans)
  2. Fungi - unicellular or multicellular organisms
  3. Plantae – multicellular
  4. Animalia – multicellular

Eukaryotes either Photosynthesize or absorb/injest food

The Eukarya: Protista

  • Most Eukaryotes are single-cell organisms that are either Photosynthetic (photoplankton) ornonphotosynthetic organisms\
  • Some are multicellular organisms: Like the seaweed or brown algae
  • Alveolates: include parasites & predators. Some have flagella and others have celia

The Eukarya: Protista - thePseudopods include:

  • Amoebas (mobile organisms)
  • Fungi (immobile organisms) that grow rapidly to compensate for the lack of mobility. They obtain their nutrients from other organisms. They are surrounded by a cell wall (like the plant cell)

The good, the bad and the ugly side of Fungi:

  • Many antibiotics have derive from fungi: like the Penicillins
  • Yeast ( a fungus) - Makes wine & beer using yeasts
  • Yeasts makes bread rise
  • It is Beneficial to the ecology -- by becoming a decomposers of the forest floor
  • It can produce diseases in humans like:
  • Ringworm, athlete’s feet, jock itch
  • Candidanalbicans: vaginal yeast infections & thrush

Some Protista can produce toxins: like the Aspergillus

The Eukarya: Protista - the Plants

  1. Tracheophytes- vascular plants

They have conductive vessels that provide support to the plant. They are seedless plants: like mosses, horsetails & ferns; and there are seedproducing plants that mostly dominate the land

  1. Bryophytes – are nonvascular plants

These plants have slow diffusion & distribution of water & nutrients. Examples of these plants include the liverworts and moss.

  1. Gymnosperm – the non-flowering seed plants
  2. Angiosperms – flowering seed plants. Flowers attract pollinators. Some plants bare fruits, which encourage the seed dispersal

The Broad leaves in plants capture more sunlight which increases the production of photosynthesis

The Eukarya: Anemalia

Animal s come in a diversity of forms. They are multicellular & Motile (able to move and migrate). Most of the animals in this classification lack backbones, however they obtain energy by consuming other organisms (which is required for cellular respiration)

These species should be able to:

  1. Reproduce sexually – there are variable reproductive styles
  2. Respond to external stimuli
  3. They lack cell walls (which only exist in plant cells)

There are Evolutionary trends among animals.

  1. Invertebrates- lack an endoskeleton of bone or cartilage formation.

All but one animal phylum are invertebrates

  1. Vertebrates- have an endoskeleton of bone or cartilage

Sponges & Cnidarians

Sponges: have simple bodies that lack true tissues & organs

Cnidarians: are well armed predators like the Jellyfish, sea anemone, and Hydra

Annelids & Arthropods: Annelids (worms, leeches). These species are:

  • Segmentation with repetition of body parts
  • EIvolvedCephalization(brains) and specialization of body parts

Arthropods – are the most dominant of animals. They have Jointed appendages, specialized for locomotion

  • Mollusks (shells)
  • Chordates
  • Vertebrates – sea squirt
  • Invertebretes – bony fish

Evolutionary trends are seen and compared within species. For example the Roundworms –(Pseudocoelomates).

  • It is body is a tube-within-a-tube
  • I has 2 openings;the mouth and anus
  • Many forms of these species
  • Some are free-living in soil and water, while others are parasitic and live within a host.

Ascaris- these species move with whip-like motion. Example of these species include intestinal parasites that are found in many animal species.

  • Their eggs enter a host in uncooked vegetables, soil, or feces
  • The Larvae burrow out of the intestine, and migrate to other organs like the heart, lungs or liver.

Arthropods- Anthropods fall into the Phylum Arthropoda

These are the species with jointed appendages: which allows them to walk, swim, reproduce, eat, and respond to sensory reception.

The Exoskeleton of Chitin will undergo molting. These have 3 body regions: head, thorax, abdomen. These organisms have a:

  • Well-developed nervous system
  • Brain and ventral nerve cord
  • Sense organs-compound eyes, antennae

Arachnids –fall under the Subphylum Chelicerata

These include Spiders, ticks, scorpions, mites

Vertebrates

Birds are classified based on beak and foot types; their Habitat, behavior & how they prey

Reptilia: classified by their ability to produce amniote egg: like the Reptile, turtles, snakes, lizards

Mammals: classified by species that havehair and mammary glands

Vertebrates are Endothermic – having a constant internal temperature; and a placental base.

Examples: Marsupials, mammals, primates