Chapter 27 Diversification of Eukaryotes
Eukaryotes are the third domain in the tree of life and are distinctly different from Archaea and Bacteria with larger cells also including mitochondria and chloroplast, a nuclear envelope that only exist in eukaryas, multicellular, and reproducing asexually through mitosis, and sexually with gametes or spores via meiosis.
Protist (“the very first”) are a paraphyletic group (doesn’t include common ancestors) and referred as all the Eukaryotes beside animals, fungi, and land plants and are abundant in aquatic environments and also found in wet soils or even inside other organisms
27.1 Why do biologists study protist?
Biologists study protist for medically, global ecologically, and to understand the evolution of plants, animals, and fungi
# Impacts on Human Health and welfare
Plasmodium lives in mosquitoes and when humans are bitten by them it causes Malaria (which is one of the most chronic diseases)
Dinoflagellates (which is toxic covered photosynthetic protist) causes harmful algae bloom and due to its high toxin shellfish and clams are affected which is harmful to humans who consume them.
There are some human health problems caused by protist
# Ecological importance of protists
Protists play a key role in aquatic food chains by being photosynthetic taking carbon from atmosphere or water and fixing it into sugars that are used by other organisms also known as Primary producers
Marine protists represent half of the earth’s fixed carbon dioxide
Diatoms and other photosynthetic organisms are considered plankton which are small organisms that drift in the open oceans and lakes. The sugars produced by them are the basis of the food chain in the aquatic environment
Researchers are trying to use the global carbon cycle (which is the movement of the carbon atoms from the atmosphere to organisms on land or in water and back to the atmosphere) to help control climate change with trying to keep more of the carbon stored in terrestrial and marine environments and less in the atmosphere
The marine carbon cycle starts with carbon in the atmosphere dissolves in the water and then converted into organic matter by the primary producers also known as photosynthetic plankton. Primary consumers eat the plankton, die then consume by decomposers or scavengers or they die and sink to the bottom of the ocean and become part of the carbon sink
By adding iron to the ocean, it speeds up the carbon cycle and increase the population of protist and other primary producers and therefore the carbon in the atmosphere
27.2 How do biologists study protist?
# Microscopy Studying Cell structure
Scientist use light microscope and transmission electron microscopes to get a more detail look at protist to help classify them in to groups based on cell structure and organelles
from using the light and electron microscopes they discovered that the Irish potato famine had a reproductive cell with an unique hollow hair looking flagellum (which is a feature that whips back and forth helping the organelle swim/move around)
After finding out kelp and other brown algae have the same featured, biologists classify the species in that group as Stramenopiles
Eukaryotes have been broken up into seven major groups by their distinct morphological features and characteristics like cell protection ,movement, support etcc..
# Evaluating Molecular Phylogenies
# Discovering New Lineage via Direct Sequencing
27.3 Major Themes in their diversification
Mitochondria are organelles the generate energy (ATP). Endosymbiosis Theory is that mitochondria originated from a bacterial cell inside another cell 2 billion years ago. Endosymbiosis is when an organism from species lives inside the cells of another species.
27.4 Key lineage of Eukaryotes
DYNAMIC STUDY MODULE
The filamentous extensions formed by some Stamenopila are called flagella.
An advantage of sexual reproduction is that diverse offspring are more likely to survive changing environmental conditions.
Dinoflagellate blooms can be harmful to humans because dinoflagellates produce toxins as a defense mechanism.
A range of habitats is common among protists, Bacteria, and Archaea, as well as many other eukaryote lineages.
Some genes moved from the mitochondrial genome to the nuclear genome.
For symbiosis to occur, two organisms must live in regular physical contact with each other.
A plasmodial slime mold contains thousands of nuclei. The large "supercell," called a plasmodium, moves by streaming its cytoplasm in a regular back and forth motion.
The majority of mitochondrial genes are believed to have been transferred into the nuclear DNA of eukaryotic cells by the process of lateral gene transfer.
Eukaryotes divide their volume into compartments, which allows them to carry out their cellular processes efficiently.
Plasmodium in human red blood cells is haploid and replicates via mitosis
The key point about multicellularity is that not all cells in a multicellular organism express the same genes.
Amoebozoa species lack cell walls and take in food by engulfing it. They move via amoeboid motion and produce large, lobe-like pseudopodia.
The earliest eukaryotes had mitochondria but lacked cell walls.
Some scientists believe that increasing populations of protists could help reduce global warming because the calcium carbonate shells found in some protist lineages act as a long-term carbon sink.
Excavata (which include diplomonads) mostly have cells with a pronounced “feeding groove” where prey or organic debris is ingested. Most species lack typical mitochondria, although genes derived from mitochondria are found in the nucleus.
The best support for the endosymbiotic origin of mitochondria is the finding that mitochondrial gene sequences are more closely related to DNA sequences from bacteria than to eukaryotic gene sequences.
In comparing protists, Bacteria, and Archaea, the method of obtaining energy unique to protists is ingesting other organisms, such as Bacteria, Archaea, and other protists.
All photosynthetic protists have chloroplasts: •Hypothesis: Eukaryotic chloroplast originated when protist engulfed a cyanobacterium
Other photosynthetic lineages came about from secondary endosymbiosis examples: Euglenids, Diatoms, Kelp (Brown Algae), Dinoflagellates
Chapter 27 Diversification of Eukaryotes
Eukaryotes are the third domain in the tree of life and are distinctly different from Archaea and Bacteria with larger cells also including mitochondria and chloroplast, a nuclear envelope that only exist in eukaryas, multicellular, and reproducing asexually through mitosis, and sexually with gametes or spores via meiosis.
Protist (“the very first”) are a paraphyletic group (doesn’t include common ancestors) and referred as all the Eukaryotes beside animals, fungi, and land plants and are abundant in aquatic environments and also found in wet soils or even inside other organisms
27.1 Why do biologists study protist?
Biologists study protist for medically, global ecologically, and to understand the evolution of plants, animals, and fungi
# Impacts on Human Health and welfare
Plasmodium lives in mosquitoes and when humans are bitten by them it causes Malaria (which is one of the most chronic diseases)
Dinoflagellates (which is toxic covered photosynthetic protist) causes harmful algae bloom and due to its high toxin shellfish and clams are affected which is harmful to humans who consume them.
There are some human health problems caused by protist
# Ecological importance of protists
Protists play a key role in aquatic food chains by being photosynthetic taking carbon from atmosphere or water and fixing it into sugars that are used by other organisms also known as Primary producers
Marine protists represent half of the earth’s fixed carbon dioxide
Diatoms and other photosynthetic organisms are considered plankton which are small organisms that drift in the open oceans and lakes. The sugars produced by them are the basis of the food chain in the aquatic environment
Researchers are trying to use the global carbon cycle (which is the movement of the carbon atoms from the atmosphere to organisms on land or in water and back to the atmosphere) to help control climate change with trying to keep more of the carbon stored in terrestrial and marine environments and less in the atmosphere
The marine carbon cycle starts with carbon in the atmosphere dissolves in the water and then converted into organic matter by the primary producers also known as photosynthetic plankton. Primary consumers eat the plankton, die then consume by decomposers or scavengers or they die and sink to the bottom of the ocean and become part of the carbon sink
By adding iron to the ocean, it speeds up the carbon cycle and increase the population of protist and other primary producers and therefore the carbon in the atmosphere
27.2 How do biologists study protist?
# Microscopy Studying Cell structure
Scientist use light microscope and transmission electron microscopes to get a more detail look at protist to help classify them in to groups based on cell structure and organelles
from using the light and electron microscopes they discovered that the Irish potato famine had a reproductive cell with an unique hollow hair looking flagellum (which is a feature that whips back and forth helping the organelle swim/move around)
After finding out kelp and other brown algae have the same featured, biologists classify the species in that group as Stramenopiles
Eukaryotes have been broken up into seven major groups by their distinct morphological features and characteristics like cell protection ,movement, support etcc..
# Evaluating Molecular Phylogenies
# Discovering New Lineage via Direct Sequencing
27.3 Major Themes in their diversification
Mitochondria are organelles the generate energy (ATP). Endosymbiosis Theory is that mitochondria originated from a bacterial cell inside another cell 2 billion years ago. Endosymbiosis is when an organism from species lives inside the cells of another species.
27.4 Key lineage of Eukaryotes
DYNAMIC STUDY MODULE
The filamentous extensions formed by some Stamenopila are called flagella.
An advantage of sexual reproduction is that diverse offspring are more likely to survive changing environmental conditions.
Dinoflagellate blooms can be harmful to humans because dinoflagellates produce toxins as a defense mechanism.
A range of habitats is common among protists, Bacteria, and Archaea, as well as many other eukaryote lineages.
Some genes moved from the mitochondrial genome to the nuclear genome.
For symbiosis to occur, two organisms must live in regular physical contact with each other.
A plasmodial slime mold contains thousands of nuclei. The large "supercell," called a plasmodium, moves by streaming its cytoplasm in a regular back and forth motion.
The majority of mitochondrial genes are believed to have been transferred into the nuclear DNA of eukaryotic cells by the process of lateral gene transfer.
Eukaryotes divide their volume into compartments, which allows them to carry out their cellular processes efficiently.
Plasmodium in human red blood cells is haploid and replicates via mitosis
The key point about multicellularity is that not all cells in a multicellular organism express the same genes.
Amoebozoa species lack cell walls and take in food by engulfing it. They move via amoeboid motion and produce large, lobe-like pseudopodia.
The earliest eukaryotes had mitochondria but lacked cell walls.
Some scientists believe that increasing populations of protists could help reduce global warming because the calcium carbonate shells found in some protist lineages act as a long-term carbon sink.
Excavata (which include diplomonads) mostly have cells with a pronounced “feeding groove” where prey or organic debris is ingested. Most species lack typical mitochondria, although genes derived from mitochondria are found in the nucleus.
The best support for the endosymbiotic origin of mitochondria is the finding that mitochondrial gene sequences are more closely related to DNA sequences from bacteria than to eukaryotic gene sequences.
In comparing protists, Bacteria, and Archaea, the method of obtaining energy unique to protists is ingesting other organisms, such as Bacteria, Archaea, and other protists.
All photosynthetic protists have chloroplasts: •Hypothesis: Eukaryotic chloroplast originated when protist engulfed a cyanobacterium
Other photosynthetic lineages came about from secondary endosymbiosis examples: Euglenids, Diatoms, Kelp (Brown Algae), Dinoflagellates
