Bio II Chapter 23

How much of the world's oxygen comes from phytoplankton?

80 percent

Mitosomes

A mitosome is an organelle found in some unicellular eukaryotic organisms, like in members of the supergroup Excavata. The mitosome was found and named in 1999, and its function has not yet been well characterized. It was termed a crypton by one group, but that name is no longer in use.

Mixotroph

A mixotroph is an organism that can use a mix of different sources of energy and carbon, instead of having a single trophic mode on the continuum from complete autotrophy at one end to heterotrophy at the other. It is estimated that mixotrophscomprise more than half of all microscopic plankton.

What causes red tides?

A red tide is caused by an increase in the population of toxic algae. ... A red tideoccurs when the population of certain kinds of algae known as dinoflagellates explodes, creating what's called an "algal bloom." Scientists sometimes refer to red tides as harmful algal blooms or HABs.

Holdfast (biology)

A root-like structure that anchors aquatic sessile organisms to their substrate.

What is a slime mold?

A simple organism that consists of an acellular mass of creeping gelatinous protoplasm containing nuclei, or a mass of amoeboid cells. When it reaches a certain size it forms a large number of spore cases.

What are dinoflagellates?

A single-celled organism with two flagella, occurring in large numbers in marine plankton and also found in fresh water. Some produce toxins that can accumulate in shellfish, resulting in poisoning when eaten.

What is meant by Symbiosis in this case?

A symbiosis is an evolved interaction or close living relationship between organisms from different species, usually with benefits to one or both of the individuals involved. ... Endosymbiosis is a symbiotic relationship, occurring when one of the symbioticpartners lives within the body of the other.

Pseudopod

A temporary projection of the cytoplasm of certain cells or of certain unicellular organisms, especially amoebas, that serves in locomotion and phagocytosis.

Endosymbiosis

A theorized process in which early eukaryotic cells were formed from simpler prokaryotes.

Pellicle

A thin skin, cuticle, membrane, or film.

Do all current Eukaryotes have the same characteristics?

All eukaryotic cells have a membrane bound nucleus that contains DNA, cell membrane, cytoplasm and organelles.

Rhizaria

Ammonia tepida: Ammonia tepid...

Plant supergroup

Archaeplastida.

Asexual reproduction

Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from a single cell or from a multicellular organism inherit the genes of that parent.

Why do we say Eukaryotes are "Combination Organisms"?

Because they have archaeal and bacterial orgins. The theory that mitochondria and plastids, including chloroplasts, originated as prokaryotic cells engulfed by a host. A relationship in which one organism lives within the body of another organism.

What was the old method of classifying protists?

Biologists used to classify all protists as part of Kingdom Protista

What is Caulerpa?

Caulerpa is a genus of seaweeds in the family Caulerpaceae (among the green algae).

What are diatoms?

Diatoms 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.

Chromalveolata

Diatoms, brown algae, and significant disease agents in animals and plants.

Excavata

Discoba. Tsukubea. Euglenozoa. Percolozoa. Jakobea. Loukozoa. Metamonada. Malawimonas. Ancyromonadida.

How did Eukaryotes evolve?

Endosymbiotic theory They evolved from prokaryotes that engulfed other cells. The chloroplast/mitochondria used to be free-living bacteria but have their own DNA and are double membranes in cells. This is supported in the endo-symbiosis theory.

Which supergroups were produces of primary endosymbiotic events with typical organelles?

Eukaryotic cells arose through endosymbiotic events that gave rise to the energy-producing organelles within the eukaryotic cells such as mitochondria and chloroplasts.

What are the six supergroups?

Excavata, Chromalveolata, Rhizaria, Archaeplastida, Amoebozoa, and Opisthokonta.

What is giardia?

Giardia is a microscopic parasite that causes the diarrheal illness known as giardiasis. Giardia(also known as Giardia intestinalis, Giardia lamblia, or Giardia duodenalis) is found on surfaces or in soil, food, or water that has been contaminated with feces (poop) from infected humans or animals

What is a typical habitat for a protist?

Habitats. Most protists are aquatic organisms. They need a moist environment to survive and are found in places where there is enough water for them, such as marshes, puddles, damp soil, lakes, and the ocean.

What is Trypanosomiasis?

Human African trypanosomiasis, also known as sleeping sickness, is a vector-borne parasitic disease. It is caused by infection with protozoan parasites belonging to the genus Trypanosoma.

What evidence do we have to support the idea that chloroplasts evolved from prokaryotes—and cyanobacteria in particular?

It turns out that many lines of evidence support this idea. ... Membranes — Mitochondria have their own cell membranes, just like a prokaryotic cell does. ... Then, later, a similar event brought chloroplasts into some eukaryotic cells

What is the organism that causes malaria? (you do not need to know details of life cycle; just that it is transmitted by mosquito)

Malaria is caused by the Plasmodium parasite. The parasite can be spread to humans through the bites of infected mosquitoes. There are many different types of plasmodium parasite, but only 5 types cause malaria in humans.

What types are there in protists?

Many have both asexual and sexual reproduction. An example is a protist called Spirogyra, a type of algae, shown Figure below. It usually exists as haploid cells that reproduce by binary fission

Protists as Decomposers

Many of the protist organisms are decomposers, that is, they feed on dead organisms and obtain their nutritional requirements from them. Some examples of decomposer protists are oomycetes, chytrids, labyrinthulomycetes, molds, etc. Oomycetes are fungus-like protists and typically grow on dead animals

Why do we think mitochondria came before chloroplasts?

Mitochondria formed when bacteria capable of aerobic respiration were ingested; chloroplasts formed when photosynthetic bacteria were ingested. They eventually lost their cell wall and much of their DNA because they were not of benefit within the host cell.

What organelles did we likely get through endosymbiosis?

Mitochondria, the result of endosymbiosis in eukaryotic evolution are the energy-generating V8 engines of eukaryotic cells, where oxidative phosphorylation and electron transport metabolism takes place. Plastids, including chloroplasts, are the corresponding photosynthetic organelles of plant and algae cells.

When did the first large multicellular eukaryotes evolve?

Multicellular organisms evolved from unicellular eukaryotes at least 1.7 billion years ago.

Was the ancestor of all Eukaryotes a protist-like organism?

No, it was a prokaryote

What protist is in your sushi?

Nori

Protists as pathogens

Pathogenic protists are single-celled organisms that cause diseases in their hosts. These types of protists enter a host, such as an animal or plant, and live within the organism. ... In addition to living in a host, a protist also causes an organism harm.

What group (i.e. oomycetes) includes the organism that causes potato blight?

Phytophthora infestans, which causes potato late blight, is an oomycete — a type of single-celled organism related to brown algae.

What is phytoplankton made of?

Phytoplankton is made of very tiny--usually one-celled--plants. Since plants make their own food and release oxygen as a byproduct, all the other living things in the ocean depend on them directly or indirectly for food or oxygen.

Primary endosymbiosis?

Primary endosymbiosis refers to the original internalization of prokaryotes by an ancestral eukaryotic cell, resulting in the formation of the mitochondria and chloroplasts. Two membranes surround mitochondria and chloroplasts.

What are some generalizations about protists (e.g. most are microscopic, unicellular organisms that are abundant in soil, and aquatic environments).

Protists are eukaryotes, which means their cells have a nucleus and other membrane-bound organelles. Most, but not all, protists are single-celled. Other than these features, they have very little in common. You can think about protists as all eukaryoticorganisms that are neither animals, nor plants, nor fungi.

Why are protists important for coral reefs? Which protists?

Protists like zooxanthellae have a symbiotic relationship with coral reefs; the protistsact as a food source for coral and the coral provides shelter and compounds for photosynthesis for the protists. Protists feed a large portion of the world's aquatic species and conduct a quarter of the world's photosynthesis.

What is trichomonas?

Protozoan parasite

Chimera-like

Resembling or characteristic of a chimera (fabulous creature with parts of different animals).

Are vampire amoeba Amoebozoans or Rhizarians?

Rhizarians

What is kelp?

Seaweed is a term which can be used to describe many different marine-based species of plants and algae. But sea kelp is more specific. It describes the largest subgroup of seaweed. Seaweed ranges dramatically in size, whilst sea kelp is always quite large.

Secondary Endosymbiosis?

Secondary endosymbiosis is when a living cell engulfs another eukaryote cell that has already undergone primary endosymbiosis. It has happened often enough that it has led to genetic diversity among the organisms on Earth.

How do protists vary in size? Complexity? Cell structure? Metabolism? Motility? Life Cycles?

Single protist cells range in size from less than a micrometer to thousands of square meters (giant kelp). Animal-like cell membranes or plant-like cell walls envelope protist cells. In other protists, glassy silica-based shells or pellicles of interlocking protein strips encase the cells.

Amoebozoa

Some amoebae are harmless commensals in the gut of insects (e.g., Endamoeba blattae in cockroaches and several species of the same genus in gut of termites).

Protists as producers

Some protist species are essential components of the food chain and are generators of biomass. Protists are essential sources of nutrition for many other organisms. In some cases, as in plankton, protists are consumed directly. Alternatively, photosynthetic protists serve as producers of nutrition for other organisms.

What group were the oomycetes previously classified as?

The Oomycota were once classified as fungi, because of their filamentous growth, and because they feed on decaying matter like fungi. The cell wall of oomycetes, however, is not composed of chitin, as in the fungi, but is made up of a mix of cellulosic compounds and glycan.

Opisthokonta

The Opisthokonta also includes some flagellate (choanoflagellates), amoeboid (e.g. Nuclearia) and sporozoan (e.g. Ichthyosporea, Microsporidia) protists.

Alveoili

The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.

Endosymbiont theory

The endosymbiotic theory states that some of the organelles in eukaryotic cells were once prokaryotic microbes. Mitochondria and chloroplasts are the same size as prokaryotic cells and divide by binary fission. Mitochondria and chloroplasts have their own DNA which is circular, not linear.

Blades

The expanded part of a leaf or petal. Especially a leaf of grass or the broad portion of a leaf as distinct from the petiole.

When did the first Eukaryotes likely evolve (chemical vs. fossil evidence)?

The first eukaryotic cells - cells with a nucleus an internal membrane-bound organelles - probably evolved about 2 billion years ago. This is explained by the endosymbiotic theory.

What evidence do we have to support the idea that mitochondria evolved from prokaryotes—and from alpha-proteobacteria specifically?

The first piece of evidence that needed to be found to support the endosymbiotichypothesis was whether or not mitochondria and chloroplasts have their own DNA and if this DNA is similar to bacterial DNA. This was later proven to be true for DNA, RNA, ribosomes, chlorophyll (for chloroplasts), and protein synthesis.

Gas bladder

The gas bladder (also called a swim bladder) is a flexible-walled, gas-filled sac located in the dorsal portion of body cavity. It controls the fish's buoyancy and in some species is important for hearing.

Archaeplastida

The green algae, and the land plants, together with a small group of freshwater unicellular algae called glaucophytes.

Why are dinoflagellates so important?

The main ecological significance of dinoflagellates lies elsewhere, though. They are second only to diatoms asmarine primary producers. As phagotrophic organisms they are also important components of the microbial loop in the oceans and help channel significantamounts of energy into planktonic food webs.

Protists as food sources

The protists act as a food source for coral

The new method?

The protists can be classified into one of three main categories, animal-like, plant-like, and fungus-like. Grouping into one of the three categories is based on an organism's mode of reproduction, method of nutrition, and motility.

What is serial endosymbiosis?

Theory explains the origin of nucleated eukaryotic cells by a merging of archaebacterial and eubacterial cells. The paradigmatic change is that the driving force behind evolution is not ramification but merging.

What was the role of Endosymbiosis?

This major theme in the origin of eukaryotes is known as endosymbiosis, where one cell engulfs another such that the engulfed cell survives and both cells benefit. Over many generations, a symbiotic relationship can result in two organisms that depend on each other so completely that neither could survive on its own.

What is the Ediacaran Biota?

Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The Ediacaran biota may have undergone evolutionary radiation in a proposed event called the Avalon explosion, 575 million years ago.

What supergroup are animals/fungi found in?

Unikonta

What are the major characteristics of Eukaryotes?

Unlike prokaryotic cells, eukaryotic cells have: a membrane-bound nucleus. numerous membrane-bound organelles (including the endoplasmic reticulum, Golgi apparatus, chloroplasts, and mitochondria) several rod-shaped chromosomes

When did novel features (such as multicellularity, sexual life cycles, and photosynthesis) evolve?

We propose that the crucial determinant can be found in internal reactive oxygen species (ROS) formation at the start of eukaryotic evolution approximately 2 × 109 years ago. The large amount of ROS coming from a bacterial endosymbiont gave rise to DNA damage and vast increases in host genome mutation rates.

Why do we say protists are the "catch-all" category?

What do we mean when we say that the term Protista is a "catch-all" Kingdom? -The kingdom protista is called a "catch-all" kingdom because the group in which taxonomists place eukaryotic organisms do not seem to fit into any of the other kingdoms of eukaryotic organisms 2. ... It is considered a "dumping ground" kingdom.

Stipe

a stalk or stem, especially the stem of a seaweed or fungus or the stalk of a fern frond.