chapter 14

Stanley Miller’s experiment

Stanley Miller’s experiment

He sent an electrical charge through a flask of a chemical solution of methane, ammonia, hydrogen and water. This created organic compounds including amino acids.

Harold Urey’s experiment

Electric sparks were passed through a chemical solution of methane, ammonia, hydrogen, and water, which resulted in the formation of four amino acids, the building blocks of life.

origin of organic molecules

most of these organic molecules come from the reduction of carbon dioxide (CO2) through several carbon-fixation pathways, such as photosynthesis in plants.

Structural traits

represent the physical capabilities of an organism

diversity of Domain Archaea

The majority of archaeal diversity is composed of two kingdoms: the Crenarchaeota and Euryarchaeota.

diversity of Domain Bacteria

contains 5 major groups: proteobacteria, chlamydias, spirochetes, cyanobacteria, and gram-positive bacteria.

Oxygenation of earth by Photosynthetic Cyanobacteria.

responsible for changes in the earth's atmospheric composition, the rise of aerobic metabolism and, ultimately, the evolution of multicellularity.

how do bacteria reproduce genes

reproduce by binary fission. In this process the bacterium, which is a single cell, divides into two identical daughter cells. Binary fission begins when the DNA of the bacterium divides into two (replicates).

how does Archaea reproduce genes

reproduce asexually by binary or multiple fission, fragmentation, or budding; meiosis does not occur, so if a species of archaea exists in more than one form, all have the same genetic material.

how does bacteria and archea exchange genes

horizontal gene transfer of genes from the archaea to the bacteria

Archaean Traits and Diversity

Most closely related to eukaryotes, Live in extreme environments

Domain Eukarya

third domain, Eukarya, consists of organisms whose cells have a nucleus. It's also the only domain that contains multicellular and visible organisms, like people, animals, plants and trees.

Origin of the first eukaryotes

1.8 billion years ago: Eukaryotes \n first (protists) appeared in fossil \n record, 570 mys old: the earliest animal \n fossils found in water, less than a millimeter \n across, shared oceans with fungi, \n protists, bacteria and archaea

Endosymbiotic theory

states that the mitochondria and chloroplast in eukaryotic cells were once aerobic bacteria (prokaryote) that were ingested by a large anaerobic bacteria (prokaryote)/ photosynthetic bacteria were acquired (by endocytosis) by early eukaryotic cells to form the first plant cells.

Origins of chloroplasts

Chloroplasts were originally established in eukaryotes by the endosymbiosis of a cyanobacterium

Origins of Mitochondria

Mitochondria originated by permanent enslavement of purple non-sulphur bacteria.

Diversity of Protista

protists represent the vast bulk of eukaryotic diversity, they live in virtually all environments on Earth

diversity of Protozoa

are incredibly diverse in terms of physiology and lifestyle, which has enabled them to colonise a wide range of moist environments, including marine, freshwater and extreme habitats. Many species have evolved specialised anatomical structures for feeding, motility and exchange of genetic material

diversity of algae

Algae can be divided into three ecological groups, namely phytoplankton, benthic microalgae, and macroalgae in mangrove ecosystems, which play important roles in organic carbon production and nutrient cycle.

diversity of slime molds

There are two types of slime mold: cellular and acellular (plasmodial). During the life cycle of cellular slime molds, they remain as single cells.

Foraminiferans

Foraminifera are amoeba-like, single-celled protists (very simple micro-organisms). They have been called 'armoured amoebae' because they secrete a tiny shell (or 'test') usually between about a half and one millimetre long.

Secrete calcium carbonate

Massive reef structures are formed when each individual stony coral organism—or polyp—secretes a skeleton of calcium carbonate.

Dinoflagellates- Bioluminescent

Single-celled, aquatic with cellulose and two \n flagella, Some are photosynthetic

Choanoflagellates - Most closely related to animals

Choanoflagellates are among the closest living single-celled relatives of metazoans. This relationship means that choanoflagellates are to metazoans — all animals, from sponges to flatworms to chordates — what chimpanzees are to humans.

Apicomplexans

It is a special organelle that appears as a conical structures on the tapered end (or the apical end) of the cell. It contains rhoptries, micronemes, polar rings, and conoid. Most of the apicomplexans are single-celled, spore-forming, and parasitic

Plasmodium

Plasmodium is a type of protozoa, a single-celled organism that is able to divide only within a host cell

Balantidium coli

an intestinal protozoan parasite that causes the infection called balantidiasi

Flagellated protozoa

protozoans with one or a small number of long whip-like hairs called flagella that are used for locomotion

Giardia lamblia-Giardiasis

Giardia is a tiny parasite (germ) that causes the diarrheal disease giardiasis.

Diatoms

single-celled algae, are algae that live in houses made of glass. They are the only organism on the planet with cell walls composed of transparent, opaline silica

Trichomoniasis

a common sexually transmitted infection caused by a parasite

Trypanosoma (African related)

also known as “sleeping sickness”, is caused by microscopic parasites of the species Trypanosoma brucei.

Origin of Viruses

Viruses may have arisen from mobile genetic elements that gained the ability to move between cells

Bacteriophage

also known as phages, are viruses that infect and replicate only in bacterial cells

Entamoeba

a protozoan that causes intestinal amebiasis as well as extra-intestinal manifestations

Viral Multiplication

Attachment.Penetration.Uncoating.Replication. Assembly.Maturation, Release. To multiply, a virus must first infect a cel

Lysogenic replication pathway

The lysogenic cycle is a method by which a virus can replicate its DNA using a host cell.

Lytic replication pathway

the virus introduces its genome into a host cell and initiates replication by hijacking the host's cellular machinery to make new copies of the virus.