The protist group believed to be the most closely related to animals is the Choanoflagellida, also known as choanoflagellates. This group is composed of unicellular, aquatic, single-celled organisms.
They are some of the simplest multicellular organisms, and they share several features with animals, including a collar made of protein microvilli and the presence of flagellum around the cell. This highly structured protist group is thought to be a direct ancestor of animals and is considered a key piece of evidence when studying the origin of animals and early eukaryotic evolution.
The choanoflagellate habitat is typically limited to areas of freshwater and marine environments, where they feed on bacterial prey they can capture with their modified microvilli and their flagella.
They are an important member of the planktonic community and provide a food source for filter-feeding animals such as copepods. As a result, understanding the population diversification of choanoflagellates can aid in understanding the history of metazoan evolution.
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Which groups of protists were the ancestors of plants fungi and animals?
The ancestors of the plants, fungi, and animals were a group of single-celled eukaryotes, or protists, known as the sarcomastigophora. Within this group, three distinct lineages formed the basal root for all modern lineages of plants, fungi, and animals.
These three lineages are known as the Rhizaria, Excavata, and Opisthokonta.
The Rhizaria were the first group to branch off from the main protist group and are some of the oldest fossils of eukaryotes ever discovered. They are characterized by cells that contain a single axostyle, a long protoplasmic extension of the cell membrane, which is used to move and feed.
The Rhizaria includes well-known organisms such as amoebas, radiolaria, and foraminifera.
The Excavata evolved after the Rhizaria and includes organisms that contain organelles known as mitosomes and hydrogenosomes, organelles thought to be the key to the development of animal and plant cells.
Some of the organisms within this group are Giardia, a parasitic protozoan found in fresh waterways, Entamoeba, which causes amoebic dysentery, and Trichomonas, another parasitic protozoan responsible for trichomoniasis.
Lastly, the Opisthokonta, the last lineage to form, is characterized by having an anterior flagellum and posterior flagellum that are used for locomotion. This is the group that gave rise to the modern fungi and animals and includes many organisms like yeast, sea urchins, and humans.
By looking back into the history of single-celled eukaryotes or protists, we can see the origins of the plant, fungi, and animal lineages that are around us today. It is clear that the Rhizaria, Excavata, and Opisthokonta all played key roles in the evolution of these modern lineages.
What protist is both animal like and plant like?
The protist known as Euglena gracilis is both animal-like and plant-like. This single-celled, green-pigmented organism is facultatively heterotrophic, meaning it can exist either as a producer of its own food using photosynthesis or a consumer of other organisms as its food source.
The Euglena has several animal-like features. It can move around by means of a whip-like flagellum, which looks like a tail and helps the organism swim. Its mode of nutrition is also more animal than plant-like.
It requires organic compounds such as proteins, carbohydrates, and lipids. Moreover, Euglena can survive in various environments, which gives it some additional animal-like traits.
The Euglena also possesses several plant-like features. Its primary method of obtaining energy is photosynthesis, and it contains chloroplasts which enable it to absorb energy from the sun. It also has rigid cell walls which provide support, just like in plants.
All of these characteristics make Euglena gracilis an interesting organism. It has both plant- and animal-like characteristics, making it unique and the perfect example of a protist that exhibits both types of traits.
What are the 4 animal-like protists?
The four animal-like protists are ciliates, sporozoans, forams, and radiolarians.
Ciliates are the most abundant group of protozoans and are characterized by an outer membrane, known as an epithelium, which is covered in tiny tentacles called cilia. These cilia help ciliates to move, gather food, and regulate the protozoan’s environment by creating a current of water to bring food and oxygen to the cell.
Furthermore, ciliates often have a contractile vacuole which helps to expel water from their cell and maintain an appropriate water balance.
Sporozoans are another group of animal-like protists which are known for their asexual reproductive pattern. These organisms reproduce through something called sporulation which is when they form a hard shell around themselves and divide into several clones within the same shell.
Sporozoans are usually parasitic in nature, living and feeding off of larger animals such as humans and animals.
Forams are single-celled organisms that are classified as protozoans and are found mainly in marine environments. The most common type of foram is a testate amoeba which has a hard, usually shell-like structure that serves to protect its inner cell.
Forams are also known for their ability to use pseudopods (false feet) to quickly move around, as well as their unique pattern of reproduction which involves a combination of asexual and sexual reproduction.
Finally, radiolarians are protozoans that are characterized by their radial symmetry and spiny, bullet-shaped shells made of cellulose or silica. These organisms feed on a variety of small organisms including bacteria, algae, and small crustaceans.
Radiolarians are also capable of rapidly moving thanks to their long and thin pseudopods which they use to navigate through the water.
What do protist share with animals?
Protists and animals share many similarities in their physiology and behavior, as they are both members of the eukaryotic domain. This means that the cells of protists, like those of animals, contain a nucleus that houses their genetic material while surrounded by a membrane.
Further, both protists and animals have the capacity to move around their environment and actively search for food, water and other resources necessary to their survival.
Protists, like animals, are also capable of producing and sensing various types of signals and stimuli in their environment, which helps them to communicate with others of their species. This can be observed in the behavior of protists such as amoebas and ciliates, which will retract their pseudopods and cilia in the presence of a harmful chemical or predator in order to protect themselves.
Lastly, protists and animals have evolved very similar solutions to the problem of living in their respective environments. Both have developed a wide range of body forms and internal processes that have enabled them to survive and thrive in their environments.
For example, both groups have developed methods of respiration, excretion, and regulation of their internal temperature in order to survive in their environment.
Which of the listed examples is a characteristic shared by Diplomonads and Parabasalids?
Both Diplomonads and Parabasalids are examples of protists, or eukaryotic organisms that are not classified into any of the other major groups of living things, such as animals, plants, fungi, and bacteria.
As such, they share many characteristics, the most notable of which is that they are both unicellular organisms. Both Diplomonads and Parabasalids reproduce asexually by undergoing binary fission, meaning they divide into two new organisms through cell division.
Additionally, both Diplomonads and Parabasalids lack mitochondria, which is a critical organelle present in many other organisms. Both groups of protists also possess a type of flagella known as undulipodia, which is used for locomotion and food ingestion.
Finally, Diplomonads and Parabasalids are both covered by a trilaminar cell wall for protection.
What feature is shared between Diplomonads and parabasalids?
Both diplomonads and parabasalids are remarkable for their possession of a complex interior body structure which are not seen in other protists. Both are characterized by the unusual presence of an anaerobic, hydrogenosomal respiratory system, which is based on enzymatic processes and generates the gas hydrogen.
Furthermore, both have a primitive, highly reduced form of flagellum which is located inside a double cell membrane, a feature which gives rise to their characteristic pear-shaped morphology. Additionally, both lack mitochondria and instead possess several round organelles called hydrogenosomes, which are responsible for generating ATP through anaerobic glycolysis and are considered as ancestral to modern mitochondria.
In terms of reproduction, both group of organisms reproduce through transverse binary fission, which creates two new daughter cells that are identical to the parent cell.
Which of the following describes the similarity between Diplomonads and parabasalids the best?
The best way to describe the similarity between Diplomonads and parabasalids is that they are both restricted to anaerobic habitats and are both single-cell eukaryotes. They have extremely simple internal structures and lack mitochondria and other organelles.
Both groups do have some forms of Golgi complex that are used mainly for food storage, as well as a rudimentary cytoskeleton. Both groups also have specialized features to allow them to move in their restricted environment, such as the growth and folding of cell membranes in the Diplomonads and the flagellar root in the parabasalids.
All of these shared features indicate a close evolutionary relationship between the two groups.
Which of the following are features of parabasalids?
Parabasalids are a group of primitive, single-celled protozoans found primarily in the human gastrointestinal tract. As with other protozoa, parabasalids are classified in the kingdom of Protoctista.
Some of the key features of parabasalids include:
• They have a single, oval nucleus and lack organelles that are present in other protozoa.
• All parabasalids bear one or several energy-producing organelles (mitochondria) at the base of their flagella.
• Parabasalids are heterotrophic, meaning they obtain their nutrients by digesting organic material.
• They are capable of movement and use their flagella to propel themselves through their environment.
• They typically occur in pairs or small clusters and are associated with mucus-lined surfaces, such as those found in the digestive system.
• They possess a protective outer membrane, known as a pellicle, which aids in anchoring the protozoan to surfaces.
• They are primarily anaerobic, meaning they do not depend on oxygen for their energy production.
• All parabasalids reproduce asexually through binary fission.
• Some species can exist in both a motile and a non-motile form, allowing them to adapt to different environmental conditions.
• Some species of parabasalids are capable of forming spores, allowing them to survive in hostile environments.
Which of the five monophyletic supergroups is closely related to fungi and animals?
The supergroup Opisthokonta, which contains fungi and animals, is the group that is most closely related. It is a monophyletic supergroup, meaning that all of its members are descended from a single common ancestor, and is classified as one of the five major monophyletic supergroups of eukaryotes.
The other four supergroups are Amoebozoa, Rhizaria, Archaeplastida, and Excavata. Opisthokonta includes the protists, such as slime molds, but the clade is mostly composed of the animals and fungi, which share a common ancestor distinct from other eukaryotic groups.
Animals have been the most studied members of this supergroup, but there is still much that is unknown about the evolutionary history and relationships between the groups in Opisthokonta.
Which feature is unique to diplomonads?
Diplomonads are a group of parasites which are unique and distinct from other parasitic organisms due to their features. For example, they possess two flagella and a unique form of binary fission called “scissorotomy,” which involves the simultaneous splitting of both of the flagella.
This results in the formation of two daughter cells. In addition, their mitochondrial genome, which is not found in other eukaryotes, is more similar to bacterial genomes than other eukaryotes. Furthermore, diplomonads have an unusually large mitochondrial genome with more than 2000 genes.
Finally, the unusual structure of the diplomonad maternogonium is also a distinguishing feature – it is an longitudinal line-shaped organelle associated with a specific gene, which is known as the maternogonium-associated gene.
That gene encodes a large protein that is essential for the formation of the maternogonium and is not observed in other eukaryotes.
Why are the mitochondria of diplomonads and parabasalids sometimes described as highly reduced?
The mitochondria of diplomonads and parabasalids are sometimes described as highly reduced because they have a degraded set of metabolic pathways and decreased complexity compared to the mitochondria of other eukaryotes.
The inner membrane of the mitochondrion is less stratified, and many metabolic pathways have been lost or drastically reduced. For example, these mitochondria lack the TCA cycle, electron transport chain components, and oxidative phosphorylation pathways that are typically present in other eukaryotes.
Additionally, these organelles lack essential genes and proteins associated with core metabolic components such as ATP synthase, lipoic acid synthetase, and aconitase, which are necessary for normal energy production.
Furthermore, the two membranes of the mitochondria are connected to one another, which is evidence of a simplified system. This reduced complexity is likely the result of specialization by the organisms to their anaerobic environment and its reliance on glycolysis for energy.
What supergroup do diplomonads parabasalids and Euglenozoans belong to?
Diplomonads, parabasalids, and Euglenozoans are microorganisms that all belong to the supergroup Excavata, a recently-proposed taxonomic group. This supergroup comprises of organisms that all share certain key characteristics, such as being heterotrophic, flagellated, and possessing mitochondria with flattened cristae.
Diplomonads, for example, are characterized by having two undulating flagella, as well as two nuclei located within its single-celled body. Parabasalids also possess two flagella, but they have a single nucleus, while Euglenozoans have a single undulating flagellum and a single nucleus.
Aside from their shared characteristics, members of the Excavata supergroup also possess some unique features that sets them apart from other similar organisms.
What type of mitochondria do parabasalids have?
Parabasalids are single-celled eukaryotes that are part of the group diplomonadida. These organisms typically contain a single, spindle-shaped nucleus and two kinds of mitochondria: hydrogenosomes and mitosomes.
hydrogenosomes are organelles that lack an outer membrane, but contain an inner membrane, where they produce ATP and other metabolites. Mitosomes are smaller and lack cristae, but are thought to be involved in iron-sulfur cluster metabolism and the glycosome pathway.
While both organelles are thought to be descended from mitochondria, hydrogenosomes have lost more of the metabolic and genetic features associated with classical mitochondria than mitosomes.
Do diplomonads have 2 nuclei?
Yes, diplomonads have two nuclei. These organisms belong to a group of flagellate protozoa known as the diplomonads, and they are characterized by having two nuclei which are situated side-by-side. Each nucleus contains a single, circular DNA molecule, and the two nuclei are connected together in some way.
The reasons behind this two-part nucleus arrangement are not completely understood yet, but it is believed that it could help the protozoans to exchange genetic material more easily. Additionally, the dual nuclei are thought to help diplomonads deal with rapid environmental changes, as each nucleus can function independently and adapt to different conditions.
The two nuclei also work together to produce cell structures such as mitochondria and Golgi bodies, which are essential for the protozoans’ survival.
