BIO 102 Exam 1

Supergroup Stramenophiles (SAR) and 3 groups we study

the most diverse of the exclusively protistan eukaryotic supergroups named for the 3 related lineages: stramenopiles, alveolates, and rhizarians The affinity between members of this group is not readily apparent, but gene sequencing studies indicate that they are relatives. 1. Stramenopiles - diatoms - brown algae - water molds 2. Alveolates - ciliates - dinoflagellates - apicomplexans 3. Rhizarians - foraminiferan - radiolaria

Alveolates

the second major lineage in the Stramenophile SAR supergroup Defined by sacs beneath their plasma membrane - depending on the group, can be empty or contain cellulose 3 major groups are ciliates, dinoflagellates, and apicomplexans

Precambrian history is...

the story of life in the seas

Astrobiology

the study of life's origin and distribution of the universe

Rhizaria

the third lineage in the Stramenophile SAR supergroup Nearly all are single-celled, marine heterotrophs with a protective shell capture prey using cytoplasmic extensions that protrude through small holes in their shell 2 main lineages: Foraminifera and Radiolarians

Gram positive

thick walled Stain purple with gram staining Most are chemoheterotrophs and some are decomposers Lactobacillus and species of Streptococci

Gram negative

thin walled Stain pink with gram staining Have an additional layer of LPS lipopolysaccharides outside the cell wall Makes them more resistant to antibiotics

Diatoms

Diploid, can be single-celled or colonial, photosynthetic, secrete a protective silica shell Silica test (SiO2) in various shapes Composed of two perforated parts that overlap like a pill box Contain a large amount of oil Helps them float and stores energy Ancient diatom oil transformed into petroleum Produce gasoline and potentially biofuels When they die, their shells accumulate on the ocean floor, resulting in "diatomaceous earth" This silica-rich material is used in filters and cleaners, and as an insecticide that is nontoxic to vertebrates. Diatomaceous earth kills crawling insects by nicking their outer covering, causing them to dry out and die. Considered a Stramenopile, part of the Supergroup Stramenophile SAR

Tetracyclines and streptomycins

Discovered in actinomycetes (soil bacteria) Disable bacterial ribosomes UTIs, Acne, intestines, etc Used less now due to resistant strains of bacteria

Protein capsid

Consists of protein subunits that typically assemble in a repeating pattern to produce a helical or many-sided (polyhedral) shape Protects the viral genetic material and facilitates its delivery into a host cell In all viruses, some components of the viral coat bind to proteins at the surface of a host cell

Exotoxin

A substance that bacteria secrete into their environment Binds to and directly harm our body cells

Define retrovirus. Example? How does it replicate?

A virus bearing an RNA genome that is used as a template to produce double-stranded DNA example: HIV to infect - attaches to white blood cells Viral enzymes and RNA are released into the cell and reverse transcription makes the DNA copy of the viral genome DNA enters the nucleus and inserts the viral DNA into the host's DNA - The viral DNA is replicated and transcribed along with the host genome Viral RNA and proteins are synthesized, and HIV particles assemble at the plasma membrane, budding out of the host cell and incorporating its plasma membrane as the envelope

4 Types of Bacterial lineages

Cyanobacteria Proteobacteria Spirochetes Chlamydias

______________________ oxygenated Earth through the process of ______________________

Cyanobacteria, Photosynthesis

Which characteristics suggest that protocells were ancestors of cellular life? Select all that apply. a. They could take up fatty acids from the environment. b. The ability to grow c. The ability to divide into smaller spheres d. They could take up nucleotides from the environment.

ALL of the above! a. They could take up fatty acids from the environment. b. The ability to grow c. The ability to divide into smaller spheres d. They could take up nucleotides from the environment.

What is the main energy-releasing pathway in eukaryotes?

Aerobic respiration

Structures of protists (varies between species)

All protists are eukaryotes so they will all have a nucleus most will have an endoplasmic reticulum, Golgi bodies, mitochondria a. Protective layer Most single-celled protists have this at their cell surface - Green algae and dinoflagellates: cellulose-containing cell wall - Radiolaria and diatoms: hard-mineral shell (silica "test") - Euglena: flexible pellicle - plasma membrane with elastic proteins just under it b. Movement Flagella - the long tail-like structure Cilia - hairlike extensions you see around a cell Pseudopods (extended lobes of cytoplasm) - pseudo means resemble / imitation and poda means feet ... "imitated feet" c. Chloroplasts Many protists have chloroplasts Some have an eyespot to detect light i. Primary endosymbiosis ii. Secondary endosymbiosis iii. Eyespot/stigma **Some have contractile vacuoles that expel excess water from the cytoplasm Basically helps inside of cell environment match its outside

Evolution of chloroplasts

Arose through endosymbiosis with cyanobacteria, resulting in photosynthetic algae (protists)

Early Earth environmental conditions (i.e. Precambrian):

Around 4.6 billion years ago, Earth and other planets formed did not lead to conditions we would recognize today! As gravity increased, collisions of debris made the surface molten a. Oxygen evidence? Volcano eruptions led to an atmosphere of water vapor, carbon dioxide, nitrogen, and hydrogen (toxic and unbearable for us!) Iron in the oldest rocks is not oxidized (rust); so the early atmosphere was oxygen-free Any oxygen would have oxidized organic molecules as soon as they formed b. Water evidence? When Earth's crust cooled, water condensed on its surface Zircon crystals 4.4 billion years old provide the earliest evidence

Sandstones

Australian sandstone (3.4 billion years ago) rocks contain spherical fossils with pyrite (iron sulfide) surrounding them Suggests similar metabolism to modern sulfur bacteria Supports the geothermal vent hypothesis

The two prokaryotic domains are:

Bacteria and Archaea Bacteria - modern bacteria, more well known and widespread Archaea - ancient bacteria, more recently discovered; many live in extreme habitats Bacterial and Archaea have separate domain classifications, though they share many structural and functional similarities

How do bacteria and archaea reproduce?

Bacteria and archaea replicate most often by binary fission, a type of asexual reproduction Reproductive rates in prokaryotes are high; some species reproduce every 20 minutes They also carry out horizontal gene transfers

Define pathogenic

Bacteria that causes disease Can be an exotoxin or an endotoxin

Transduction

Bacteriophages move genes between cells horizontal gene transfer

Formation of organic monomers:

Chemists originally thought - organic molecules had a special "vital force," - and only living organisms could make them Then, began to think about how simple organic compounds could have formed on early Earth - How did we get here in the first place? Organic molecules must have formed from inorganic molecules Early experimentation demonstrated nonbiological mechanisms for producing organic molecules (like amino acids)

Supergroup Excavata (Excavates) and 2 types

Metamonads - diplomonads - parabasalids Euglenozoans - euglenids - kinetoplastids

Which of the following terms can be used to describe Plasmodium? Choose all that apply. Parasitic Photoautotroph Heterotrophic Primary producer

Parasitic Heterotrophic

Define and state the function of endospores.

Some bacteria can enter a state of suspended animation when conditions are unfavorable for growth, forming a spore or cyst Endospore - some soil can form an especially resilient resting structure Consisted of a stripped-down bacterial cell within a thick, protective covering Can withstand heating, freezing, drying, and exposure to UV radiation; surviving in a dormant state for many years

What kinds of resistance mechanisms do bacteria use against antibiotics?

Some bacteria use an enzyme to break down the antibiotic. In others, the structure of the drug's target has been modified so the drug cannot bind to the target or is no longer effective when it does bind. Some bacteria actively transport the antibiotic out of their cytoplasm. In others, the drug cannot enter because the structure of proteins in the cell membrane has been altered.

Cyanobacteria and Lichens

Some cyanobacteria partner with fungi to form lichens and others grow on the surface of soils, but most are aquatic

Alveolates:

Some examples of protists within this group are alveolates (dinoflagellates, ciliates, and apicomplexans) and stramenopiles (water molds, diatoms, and brown algae). Many members of this diverse group are important photosynthetic organisms that function as primary producers at the base of ecological food chains. This group also includes Plasmodium, the pathogen known to cause malaria. Structural characteristics -This group includes unicellular and multicellular protists -Some (alveolates) contain membrane-enclosed sacs or alveoli -Many within this group have chloroplasts -Members of this group use different methods of locomotion (cilia, flagella, or pseudopodia) -Some (diatoms) form glass-like shells Primary habitats -Marine environments -Fresh-water environments -Terrestrial environments

Unikonts:

Some examples of protists within this group are amoebozoa (amoebas and slime molds) and opisthokonts (choanoflagellates). This group also includes animals and fungi. Some protists from this group (amoebas) are parasites known to cause potentially fatal infections. Structural characteristics -This group includes unicellular and multicellular protists -Many use pseudopodia for locomotion Primary habitats -Marine environments -Fresh-water environments -Terrestrial environments

The Human Microbiota

The human microbiota are all of the microbes living in your body - Between 30-50 trillion bacteria, also archaea, fungi, protists, and viruses - Greatest amounts in the gastrointestinal tract; also skin, mouth, respiratory and urogenital tracts When microscopist Antoine van Leeuwenhoek discovered bacteria, scientists realized that microbes can cause disease and called them pathogens Most of the human microbiota are either harmless or helpful

Describe the proposed characteristics of LUCA.

The last common universal common ancestor probably lived between 4 billion and 2.5 billion years ago Believed to be prokaryotic and anaerobic Believed to have lived in a high-temperature environment rich in metal ions and produced energy from hydrogen Supports the hydrothermal vent hypothesis, but life could have migrated there from shallow waters

Paramecium

a common freshwater Ciliate Food enters the cell through an oral groove at the cell surface then pushes food to the gullet uses cilia to sweep water with food particles into an oral groove Found in Ciliates, an Aveolate, part of the Supergroup Stramenophile SAR

Which of the following macromolecules may be found within viruses? Select all that apply. a. Nucleic acids b. Carbohydrates c. Proteins d. Lipids

a. Nucleic acids

Eukaryotes have mitochondria. What does the endosymbiont hypothesis say about the origins of mitochondria? a. A prokaryote capable of photosynthesis was engulfed by an early eukaryote and became an endosymbiont. b. An organelle capable of cellular respiration evolved within the cell from organelles capable of photosynthesis. c. A prokaryote capable of cellular respiration was engulfed by an early eukaryote and became an endosymbiont. d. A eukaryote capable of cellular respiration was engulfed by an early prokaryote and became an endosymbiont.

c. A prokaryote capable of cellular respiration was engulfed by an early eukaryote and became an endosymbiont.

Mixotrophs

can be photosynthetic or heterotrophic depending on conditions Example: Euglena

Many protists form the base of ecological food chains because they _____.

can carry out carbon fixation

Autotrophs

carry out photosynthesis

The endosymbiont hypothesis states that early eukaryotic cells engulfed prokaryotes capable of _____________________________ which explains why all modern eukaryotes have mitochondria, and later some eukaryotes engulfed prokaryotes capable of ________________________________ which explains why a limited number of eukaryotes have chloroplasts.

cellular respiration photosynthesis

The earliest eukaryotes were ______________________. These eventually led to the evolution of what eukaryotic organisms?

chloroplasts photosynthetic algae (protists)

Before binary fission is complete, the prokaryotic cell must replicate its _____.

circular genome

Heterotrophs

feed on various sources in the environment; some form symbiotic relationships; some are parasitic

Pili

hairlife filaments on the cell surface that some bacteria have... used in different ways To stick to surfaces As grappling hooks to help a cell glide along In gene exchange with other bacteria

The origin of _________________________ and _________________________ organelles in eukaryotes explained best by ________________________________ hypothesis.

mitochondria and chloroplasts endosymbiosis

Heterotroph and 2 Types

obtain carbon by taking up organic molecules from the environment - Not capable of making their own carbon (food) i. Photoheterotroph - harvest energy from light and carbon from organic compounds ii. Chemoheterotroph Not capable of making their own carbon (food) Obtain energy and carbon by breaking down organic compounds All pathogenic bacteria are of this type Beneficial bacteria in the digestive tract Some are decomposers

Chemoautotroph

obtain energy from chemicals

Photoautotroph

obtain energy from light

Cellular slime molds

"Social amoebas" Especially common on the floor of temperate forests Spend most of their time as individual haploid, amoeba-like cells that can aggregate to form a "slug" Very important in nutrient recycling and are common in leaf litter and soils of forest

Supergroup Opisthokonta and 1 type

(Opisthokonts) sister group to the Amoebozoans include fungi, animals, and the protistan relatives of both groups the closest living relatives of fungi are a group of amoeba-like cells (nucleariids) that live in soil and freshwater 1 type we study: Choanoflagellates

Phytoplankton are (autotrophic/heterotrophic) and zooplankton are (autotrophic/heterotrophic).

****Phytoplankton are autotrophic while zooplankton are heterotrophic.

Protists are (obligate/non-obligate) (aerobes/anaerobes).

***Protists are obligate aerobes (need oxygen), some are anaerobic

What does it mean when Arachaea are called thermophiles or halophiles?

- Extreme thermophiles Live only at very high temperatures, near hydrothermal vents and in hot springs - Extreme halophiles Live in extremely saltwater, in brine-filled lakes such as the Dead Sea and the Great Salt Lake

Zika virus

- RNA virus discovered in Africa during the 1950s - spread primarily by mosquitoes, but can also be transmitted sexually - traveled to Asia, South America, and then north - By 2016, small outbreaks had occurred in Florida and Texas Most have only mild symptoms, but some develop a temporary paralysis Infection during pregnancy raises the risk of miscarriage - can also cause microcephaly (an unusually small brain and head) - or other neurological defects in the developing child.

Describe what makes the ancestry of eukaryotic organisms complicated to understand: How would you tell a eukaryotic fossil from a prokaryotic fossil?

- are more complicated than prokaryotic cells so they need to be bigger - have a nucleus enclosing the DNA, and membrane-bound organelles that perform metabolic functions Although nuclei and organelles are not preserved in fossilization, cell size and wall composition can provide clues that a cell is eukaryotic Oldest agreed-upon eukaryotic fossils are about 1.8 billion years old Whether the first Eukaryotes descended from a bacteria or archaeal ancestor is still a question - Eukaryotes share similarities with both bacteria and replication processes - Eukaryotic chromosomes and DNA transcription and replication processes are similar to those of Archaea - Many Eukaryotic genes involved in metabolism are more similar to those of Bacteria

Toxoplasmosis.... an apicomplexan disease

- caused by Toxoplasma gondii - Infected people typically have no obvious symptoms. - fatal in immune-suppressed people and an infection during pregnancy can cause miscarriage or result in neurological birth defects - most often arises after ingestion of cysts in undercooked meat - Cats that spend time hunting outdoors can shed T. gondii cysts in their feces, so pregnant women should avoid contact with cat feces

Ebola virus

- caused by an enveloped RNA virus - discovered in Africa in 1976 Until recently, outbreaks had occurred only in limited regions of Africa and had affected fewer than 500 people. - However, an outbreak that began in Guinea in 2013 killed more than 11,000 people before ending in 2016 - Sporadic African outbreaks have occurred since and are likely to continue Within 3 weeks of infection by the virus, a person develops flulike symptoms, followed by a rash, vomiting, diarrhea, and bleeding from all body openings. About 50% die. transmitted by contact with body fluids, so caregivers must wear protective gear

Tobacco mosaic virus

- infects tobacco plants - has a virion with a helical structure - Its coat proteins assemble in a tight helix around the genetic material, a single strand of RNA Plant viruses usually enter their host through a wound made by an insect, pruning, or another mechanical injury Symptoms of viral infection typically include stunting and curling, yellowing, or spotting of leaves

Toxoplasma Gondii How they alter their host's behavior

- reproduces asexually in rodents, but must enter a cat to complete its life cycle - Parasite-induced changes in the rat's behavior facilitate the parasite's movement from rat to cat - Unlike healthy rats, those infected by T. gondii do not avoid cat-scented areas but rather show a preference for such areas - Exactly how the parasite alters the rodent's behavior is not clear, but we do know that T. gondii infects the amygdala, the region of the brain that governs fear and anxiety

How are new flu strains produced?

- viral reassortment - the swapping of genes between viruses that infect a host at the same time - Direct contact between people and infected birds These viruses mutate, and the coexistence of many viral strains raises the possibility of a potentially disastrous gene exchange. If an easily transmissible strain were to pick up genes from a deadly one, the result could be a virus that is easily transmissible and deadly.

5 Major Groups of Protists We Study

1. Exacavates 2. Alveolates 3. Rhizarians 4. Archaeplastids 5. Unikonts

Two types of viral replication in bacteriophages

1. Lytic cycle Viral genes expressed immediately after quickly accomplishing steps 1-4 then causes the cell to rupture (lysis), spilling contents and virus 2. Lysogenic cycle Viral genes undergo steps attachment and penetration, but then remain dormant inside the host cell Viral genes become integrated into host DNA and replicates Resume destructive actively later Examples - HIV, chickenpox = shingles

Transformation

A cell takes up DNA from its environment and integrates it into its genome horizontal gene transfer

Habitats of Protists

A majority of protists are free-living and aquatic, forming plankton Tiny, drifting, and swimming organisms found in lakes and seas Example - phytoplankton Some protists live in moist soil or inside organisms (parasites)

Origin of cellular properties: Origin of genome

Aka duplication All modern cells have a genome of DNA - Pass copies to descendant cells - Cells use DNA instructions to make proteins RNA world hypothesis - RNA may have been first molecule to store genetic information Evidence of an RNA world has accumulated since the 1960s - RNA still serves as enzymes called ribozymes in cells - rRNA catalyzes protein formation - Self-replicating ribosomes have been synthesized in the lab How DNA entered the picture is not quite clear...

Water molds

Aka oomycetes - Heterotrophs - form a mesh of nutrient-absorbing filaments Once believed to be fungi because - they have a similar growth habit but have differences in cells - Fungi are haploid and use chitin in their cell walls while water molds use cellulose Most decompose organic matter in aquatic habitats, but some are parasites - Include important plant pathogens that cause an estimated $5 billion in crop losses each year Examples - saprolegnia and phytophthora Considered a Stramenopile, part of the Supergroup Stramenophile SAR

Common properties of cells:

All cells have a plasma membrane, DNA, RNA and ribosomes They replicate and pass on copies of their genetic material to their descendants Processes such as duplication and metabolism point to a common ancestor Although no early cells exist, scientists use modern chemistry to try out various hypotheses Hypothesis: the earliest cells formed in a stepwise beginning with inorganic materials 1. Inorganic molecules - self assemble on Earth and in space 2. Organic molecules - self assemble in aquatic environments on Earth 3. Organic polymers - interact in early metabolism, self assemble as vesicles, become the first genome 4. Protocells in an RNA world - are subject to selection that favors a DNA genome 5. DNA based cells

Which of the following pieces of evidence support the endosymbiont hypothesis? Select all that apply. a. Structures like thylakoids are found in both photosynthetic bacteria and in chloroplasts b. Double membrane of chloroplasts and mitochondria c. Chloroplasts and mitochondria have to reproduce themselves in a manner similar to prokaryotic fission d. Mitochondria and chloroplasts have their own DNA

All of the above! a. Structures like thylakoids are found in both photosynthetic bacteria and in chloroplasts b. Double membrane of chloroplasts and mitochondria c. Chloroplasts and mitochondria have to reproduce themselves in a manner similar to prokaryotic fission d. Mitochondria and chloroplasts have their own DNA

All living things are made of the same 4 organic subunits

Amino acids Fatty acids Nucleotides Simple sugars

Which of the following structures do many animal viruses acquire when exiting a host cell? HIV is an example of this.

An envelope made of phospholipids

Exaptation

An evolutionary process by which a trait that evolves with one function later takes on another Example - Choanoflagellate adhesion proteins are similar to those of animals, and even solitary choanoflagellates have these proteins. By one hypothesis, these proteins helped a solitary common ancestor of animals and choanoflagellates to catch prey. Later, these proteins helped choanoflagellates stick together to form multicelled colonies. Later still, the proteins allowed animal cells to adhere to one another in multicelled bodies.

Green algae

An informal group of photosynthetic species belonging to 2 lineages: chlorophyte algae and charophyte algae range in size from microscopic cells to multicelled filamentous or branching forms more than a meter long Like plants: have chloroplasts with both chlorophyll a and chlorophyll b, store sugars as starch type of Archaeaplastid

Archaea and bacteria are often...

Anaerobic, meaning they can survive without oxygen Some can even survive in oxygenated environments, making them facultative anaerobes

Charophyte algae

Ancestors of land plants, which share many of their characteristics Like plants, and unlike other green algae, they divide their cytoplasm by cell plate formation and have plasmodesmata (cytoplasmic connections between neighboring cells) type of Green algae, an Archaeaplastid

Common antibiotics

Antibiotics first developed in the 1940s a. Penicillin First isolated from fungus Inhibits synthesis of bacterial walls b. Tetracyclines and streptomycins Discovered in actinomycetes (soil bacteria) Disable bacterial ribosomes UTIs, Acne, intestines, etc Used less now due to resistant strains of bacteria

Describe the characteristics of Archaea that differ from Bacteria.

Archaea are very ancient bacteria that live in hostile environments distinctive features were discovered in the 1970s by Carl Woese Are prokaryotes that differ from other bacteria in their ribosomal RNA and cell walls; they also resemble eukaryotic cells by sharing the same start codon for transcription Archaea differences from bacteria Lack peptidoglycan in their cell walls Cell membrane contains lipids not found in bacteria

Which major group of protists includes red and green algae?

Archaeplastids

The one ciliate known to be a human pathogen

Balantidium coli

Explain how bacteria become resistant to antibiotics and what it means for medical science advances.

Bc of widespread antibiotic Can arise through mutation or horizontal gene transfer Eventually this bacteria will become a superbug if we can't create stronger antibiotics

What animals have methanogens in their stomach?

Cattle have methanogens in their stomach and they release methane gas primarily by belching

Hypothesis 2:

Delivery from space = Many meteorites fell on the early Earth - Carried organic monomers that had formed in space Modern-day meteorites sometimes contain amino acids, sugars, and nucleotide bases Similar compounds discovered in gas clouds surrounding nearby stars ALL OF THESE HYPOTHESES HAVE SHOWN THAT ORGANIC COMPOUNDS CAN COME FROM INORGANIC FORMS

Synonym for Genome

Duplication

Evolution of mitochondria

Endosymbiosis began - when bacteria capable of aerobic respiration were taken up by an archaeal cell - or early eukaryote descended from archaea These endosymbionts divided along with the host cell Evolved together for many generations, lost genes made redundant by the other Eventually became dependent on each other when endosymbionts had become mitochondria

Which are most closely related to Archaea?

Eukarya

HIV

Evolved from a similar immunodeficiency virus that infects chimpanzees in west central Africa A person may have become infected after butchering an infected chimpanzee or being bitten by one - probably arose by the 1900s - spread from Africa to Haiti in the mid-1960s - diversified in Haiti and acquired distinctive mutations not seen in Africa By 1969, these mutations had been introduced to the United States - spread quietly until AIDS was identified as a threat in 1981 Since then = > 35 million deaths. An estimated 37 million people are currently infected.

Which major group of protists is named to reflect the fact that many members have an oral groove used for feeding?

Excavates

Plasmodial slime molds

Exist as one large single-celled multinucleate mass called a plasmodium (never goes through cytokinesis) forms when a diploid cell divides its nucleus repeatedly by mitosis but does not undergo cytoplasmic division Creeps along the ground and engulfs food particles

Differentiate between exotoxins and endotoxins

Exotoxin - a substance that bacteria secrete into their environment Binds to and directly harm our body cells Endotoxin - the LPS of Gram-negative bacteria that are not secreted but released when the bacteria cell dies and fragments Do not directly harm cells but do cause an immune response in the host that results in fever and aches

Process of Science

Experimentation and the collection and analysis of scientific evidence Hypotheses supported by experimental evidence provide a natural explanation for the origin of life Simulations show that chemical and physical processes can produce the building blocks of life and assembly into more complex molecules

Chlamydias

Extremely small Can live inside cells of vertebrates Chlamydia trachomatis causes the common sexually transmitted disease Chlamydia

Spirochetes

Extremely small Look like stretched out spring Some live in the stomach of cattle and sheep; help break down cellulose Others are aquatic decomposers, fix nitrogen, are parasites, or are human pathogens Some cause lyme disease and syphilis

T / F: Prokaryotes are always single celled organisms

FALSE

T/F Methanogens, or methane makers, are aerobic

FALSE Methanogenic archaea are strict anaerobes, meaning they cannot live in the presence of oxygen

T/F Cyanobacteria are SOME OF MANY bacteria that carry out photosynthesis by the oxygen-reducing pathway as chloroplasts do

FALSE The only!!!

Describe fossil evidence for early cellular life

Few ancient rocks that could hold early fossils still exist Cells have no hard parts to fossilize so they would be wiped out Structures formed by nonbiological mechanisms, such as crystals sometimes resemble fossils Oldest cell microfossils - From Canadian rocks at least 3.77 billion years old - Contain tiny tubes and filaments resembling those formed by cells near modern deep sea hydrothermal vents examples - sandstones and stromalites

Define virus

First discovered in the late 1800s Not considered living because they do not have all of the organelles and they cannot function without a host Are non cellular infectious particles that consist of nucleic acid surrounded by a coat of capsid proteins and, in some cases, an envelope derived from membrane of its host 1. are obligate intracellular parasites (need a host) 2. To replicate, must insert their genetic material in a specific host cell 3. are free viral particles called "virions" and can be RNA or DNA 4. can have different shapes and can affect different organisms The tobacco mosaic virus has a cirion with a helical structure tightly assembled around a single RNA strand; they enter the host through a would and cause stunting and leaf deformation Bacteriophages are specialized viruses that infect bacteria The HIV virus is an RNA virus with an envelope derived from the host

Penicillin

First isolated from fungus Inhibits synthesis of bacterial walls

Describe and state the function of the prokaryotic structural features

Flagellum - rotates like a propeller, does not contain microtubules, does not bend side to side Pili - hairlife filaments on the cell surface that some bacteria have... used in different ways To stick to surfaces As grappling hooks to help a cell glide along In gene exchange with other bacteria

Define methanogens

Generate methane In sewage, marsh sediments, and mammalian gut Make ATP anaerobically by converting CO2 and H2 to methane Some reside in humans - In the mouth, archaea may encourage gum disease - In the large intestine, may facilitate the extraction of calories from food - abundance of them is correlated with obesity

Dinoflagellates

Have 2 perpendicular flagella - cause forward movement and rotation **Most are photosynthetic and part of the ocean's plankton as major primary producers - Group name means "whirling flagellates" - Source of bioluminescence in tropical water - Especially abundant in warm climates - some are endosymbiotic with reef-building corals Responsible for algal blooms and red tide (eutrophication) - When population size increases dramatically (via the increase in what they eat) - If it gets really bad where the waves are, it will aerosolize... and you will breathe in the toxin as if it were maize - can cause respiratory problems - causes a lot of fish deaths... clogs their gills and suffocates them Example - Zooaxanthellae Considered an Aveolate, part of the Supergroup Stramenophile SAR

Kinetoplastids

Have a single large mitochondrion and a kinetoplast (clump of DNA) Example - Trypanosoma, parasitizes plants or animals However, the most diverse kinetoplast subgroup, the trypanosomes are long, tapered cells with an undulating membrane Considered an Euglenozoan, part of Supergroup Excavata (Excavates)

Parabasalids

Have an undulating membrane in addition to several freely beating flagella Squiggly membrane allows it to move through viscous fluids Example - trichomonas vaginalis (causes infection of human urinary tract) An antiprotozoal drug will provide a quick cure Considered a Metamonad, part of Supergroup Excavata (Excavates)

Herpes viruses

Herpes simplex virus 1 (oral) and 2 (genital), aka their taxonomical names Human alphaherpesvirus 1 and Human alphaherpesvirus 2 2 members of the human Herpesviridae family, a set of new viruses that produce viral infections in the majority of humans Both 1 and 2 are common and contagious Typically associated with blisters and sores when they break Can go through dormant and outbreak periods

Orythromyxoviruses

Influenza viruses... consists of 3 types: A, B, and C Cause influenza, an acute respiratory disease with prominent systemic symptoms This family represents enveloped viruses the genome of which consists of segmented negative-sense single-strand RNA segments known for periodically giving rise to pandemic outbreaks in humans The infectious agents of bird flu are any of several subtypes of type A influenza virus

What is the most common mechanism of antibiotic action?

Inhibiting synthesis of bacterial cell walls example - Penicillin

Origin of cellular properties: Origin of metabolism

Iron-sulfur world hypothesis Metabolic pathways evolved at Hydrothermal vents Porous rocks that formed around them are rich in iron sulfides Easily donate electrons to inorganic gases, which react and form organic molecules Reactions proceed quickly in the warm environment = being in the earth's mantle Heat, minerals, and pressure combined could have created conditions sufficient to induce organic compounds like ATP Metabolism (monomers → polymers)

Proteobacteria

Largest and most diverse bacterial group Include about 1/3 of all known bacteria - Rhizobium are nitrogen fixing bacteria that live inside plant roots - E. coli is the most studied prokaryote; lives in the mammalian gut; easily grown in labs - Argobacterium infects plants and causes tumors; used to make GMOs - Myxobacteria, or slime bacteria, have a collective behavior as they glide about as a swarm and eat other bacteria (they hunt!) - when food is scarce, 100s - 1000s of cells find each other to form a multicelled fruiting body

Apicomplexans

Largest line of parasitic protists; - all are animal parasites - single-celled protists that spend part of their life cycle inside their animal hosts - Name = complex of microtubules and secretory vesicles at the apex of the cell - Used to secrete toxins - Complicated life cycle, involving both asexual and sexual reproduction Includes Plasmodium = causes malaria Toxoplasma gondii = causes toxoplasmosis - causes bad diarrhea / is very bad for pregnant women Considered an Aveolate part of the Supergroup Stramenophile SAR

Hypothesis 1:

Lighting fueled atmospheric reactions tested by Miller and Urey in 1953 - wanted to mimic earth's atmosphere Filled a reaction chamber with methane, ammonia, hydrogen gas - Zapped with sparks from an electrode Within a week, a variety of organic molecules formed, - including amino acids which are important = building proteins Although the mixture of gases they used is now known not to accurately represent early Earth's atmosphere, variations have also produced amino acids ALL OF THESE HYPOTHESES HAVE SHOWN THAT ORGANIC COMPOUNDS CAN COME FROM INORGANIC FORMS

Stramenopiles and 3 types we study

Means straw-haired and refers to a short anterior flagellum with shaggy hairlike extensions Many have two flagella at some point during their life cycle, the short, shaggy one denoted by the group name, and a longer, smooth one 3 types we study: - diatoms - brown algae - water molds Part of the Supergroup Stramenophiles (SAR)

Protocell

Membrane-enclosed collection of interacting molecules that can take up material and replicate

Rhinovirus

Most common viral infectious agent in humans Predominant cause of the common cold Lives in the nose May also cause sore throats, ear infections, and infections of the sinuses... and pneumonia and bronchiolitis in more serious and rare causes Easily spread from person to person through indirect contact belong to the genus Enterovirus in the family Picornaviridae

Chlorophyte algae

Most diverse group Include freshwater and marine, single celled (Chlamydomonas), colonal (Volvox), multicellular, filamentous (Spirogyra) Many seaweeds are this type of Green algae, an Archaeaplastid

Possible ways for viruses to spread from organism to organism:

Most infections from viruses, bacteria, or fungi are transmitted from person to person via blood or body fluids (mucus, blood, or other pathogen containing body fluid) Some infections are spread via a vector (an organism that transmits the disease) - a disease vector, an animal that carries the pathogen from host to host - Biting insects and ticks - most common vectors for human pathogens Washing your hands regularly is the best defense against such diseases

Describe the life cycles of protists

Most protists reproduce asexually when conditions favor growth - switch to sexual reproduction when not - Asexual is #1 way for them - Sexual reproduction when resources are limited... it costs them more energy to do it this way Many protists' life cycle is dominated by haploid forms; others, like animals, have a life cycle dominated by diploid forms Like plants, multicellular algae undergo alternation of generations between haploid and diploid bodies

Further explanation of Haploid and Diploid life cycles

Most protists reproduce asexually when conditions favor growth, but switch to sexual reproduction when they do not. Some protists have a cycle dominated by haploid forms. Other protists, like all animals, have a cycle in which diploid forms dominate. Some multicellular algae (and all plants) have an alternation of generations, in which both haploid and diploid bodies form.

Viral replication steps:

Most viral replication processes involve the same steps when there is a chance to encounter with a host cell 1. Attachment The virus recognizes and becomes attached to a host cell 2. Penetration DNA or RNA, alone or whole virus, enters cytoplasm 3. Replication and synthesis Viral genes direct the host cell into replicating viral nucleic acids, synthesizing viral enzymes and capsid proteins 4. Assembly Synthesized components are put together into new infections particles 5. Release New virus particles are released from the infected cell 6. Two types of viral replication in bacteriophages a. Lytic cycle Viral genes expressed immediately after quickly accomplishing steps 1-4 then causes the cell to rupture (lysis), spilling contents and virus b. Lysogenic cycle Viral genes undergo steps attachment and penetration, but then remain dormant inside the host cell Viral genes become integrated into host DNA and replicates Resume destructive actively later Examples - HIV, chickenpox = shingles

Stromatolites

Mounded, layered structures that form in shallow sunlit water Mat of bacteria traps minerals and sediment Increases in size over time as new layers cover the old Oldest undisputed fossils date back to 3.7 billion years ago Oldest layers at the bottom, newest at the top

Conjugation

Movement of genes in a plasmid, a small circle of DNA separate from the chromosome horizontal gene transfer

Brown Algae

Multicelled, some appear plant-like Range from microscopic filaments to kelp 30 meters tall; show alternation of generations like plants Example(s): - Giant kelp bends are important ecosystems, supporting vast numbers of microorganisms, protists, and fishes along with other animals - The kelp life cycle is an alternation of generations - The large, spore-bearing seaweed is a long-lived diploid body. Gametes form on a microscopic shorter-lived, haploid body. - Have commercial uses, including as food and source alginates which can be used to thicken foods, beverages, cosmetics, and body lotions Considered a Stramenopile, part of the Supergroup Stramenophile SAR

Why is it important that some archaea and bacteria can undergo nitrogen fixation? Ecological importance?

Nitrogen fixation - incorporating nitrogen from air (N2) into ammonia (NH3) Photosynthetic eukaryotes need and use ammonium Plants can't exist without this... thus all life on Earth would not be possible!!

Are Archaea human pathogens?

No archaea are known to be human pathogens, although some may foster the presence of pathogenic bacteria.

Common characteristics between Bacteria and Archaea:

No nuclear envelope; chromosome in nucleoid Typically a single chromosome (a circular DNA molecule); many species also contain plasmids Cell wall (in most species) - made of peptidoglycan Ribosomes distributed in the cytoplasm Asexual reproduction by binary fission Capacity for gene exchange among cells by way of conjugation, transduction, and transformation 3 cell shapes that are common: bacillus, coccus, and spirillum Cannot be seen without a light microscope Most have a semirigid, porous cell wall around their membrane - Bacteria may also have a slime layer or capsule around their cell wall Single circular chromosome of double-stranded DNA in a cytoplasmic region called the nucleoid

Protists are not part of a single clade because....

No single trait can define all of them Currently, a classification system that distributes the eukaryotes among six supergroups is widely used For this class, protists will be grouped in three categories: plant like, animal like, and fungi like

Chemoheterotroph

Not capable of making their own carbon (food) Obtain energy and carbon by breaking down organic compounds All pathogenic bacteria are of this type Beneficial bacteria in the digestive tract Some are decomposers

The endosymbiont hypothesis states:

One species becomes resident inside another cell to benefit the both Aerobic bacteria could have become the mitochondria Cyanobacteria could have become chloroplasts

Origin of cellular properties: Origin of plasma membrane

Organic molecules need to be able to come together and work together Something is needed to enclose the molecules of the first synthetic reactions - Tiny rock chambers may have acted as an initial boundary (hydrothermal vents) - Plasma membrane serves this function today

Pathways of Transformation

Organisms exchange matter and energy with the environment in order to grow, maintain themselves, and reproduce Life first evolved in an oxygen-free environment and relied upon anaerobic energy-releasing pathways The evolution of oxygen-producing photosynthesis favored organisms capable of aerobic respiration The evolutionary transformation of aerobic bacteria into mitochondria provided eukaryotic cells with an energy advantage over prokaryotes

The lack of _____ in Earth's early atmosphere favored the formation and accumulation of organic molecules.

Oxygen!

Papillomaviruses

Part of the family, Papillomaviridae, of non-enveloped DNA viruses Includes several hundred species Can infect mammals and also other vertebrates such as birds, snakes, turtles and fish Aka HPV the most common sexually transmitted infection in the United States Some health effects can be prevented by the vaccine Some types can cause genital warts and cancers

Cyanobacteria

Photosynthesis good examples of chloroplast-containing bacteria release free oxygen by noncyclic photosynthesis Believed to be responsible for the Earth's 1st atmospheric oxygen and for the evolution of chloroplasts Some partner with fungi to become lichens Aquatic cyanobacteria grow as single cells or as filaments of cells end to end within a mucus sheath

From what source(s) do mixotrophic protists obtain nutrients?

Photosynthesis and absorbing nutrients from the environment

Which of the following factors is most responsible for increased levels of oxygen in Earth's early atmosphere?

Photosynthetic cyanobacteria

Red algae

Photosynthetic, typically multicelled, live in warm currents at great depths Pretty much the only algae that grow at great depths because blue / green light penetrates the furthest than any other color... they absorb this light Most grow as thin sheets or in a branching pattern Chloroplasts contain chlorophyll a and red pigments (phycobilins) - Absorbs blue-green light, which penetrates deeper into water, so red algae can live in deeper water than other algae Help make up coral reefs Used in many food products - Nori, sheets of seaweed used to make sushi, are derived from red algae - Carageenan used as stabilizer in ice cream, chocolate, and cosmetics - Gracilaria used to make Agar (thickener in foods) - When mixed with appropriate nutrients, agar can be used to form a semisolid culture medium for growing bacteria or fungi... used a lot in microbiology Porphyra type of Archaeaplastid

Supergroup Archaeplastida

Plural: Archaeaplastids - members of the eukaryotic supergroup Archaeplastida - All have cells with cellulose walls Their chloroplasts have two membranes that evolved from cyanobacteria by primary endosymbiosis in the ancestor of this group Include red algae, 2 lineages of green algae, and the land plants The land plants evolved from one lineage of the green algae after the red algae and green algae diverged from their common ancestor

Virus in Latin:

Poison

Hypothesis 3:

Reactions at hydrothermal vents Underwater geysers - mineral-rich water (mainly Hydrogen Sulfide) - heated by geothermal energy Heat, carbon dioxide, and potassium cyanide may have formed amino acids Simulations have produced amino acids and other organic compounds Geothermal energy produces a lot of things like plates shifting ALL OF THESE HYPOTHESES HAVE SHOWN THAT ORGANIC COMPOUNDS CAN COME FROM INORGANIC FORMS

_____ remove significant amounts of CO2 from marine environments to generate a shell-like covering.

Rhizarians

Micronucleus

Sexual reproduction (meiosis) Found in Ciliates, an Aveolate, part of the Supergroup Stramenophile SAR

Amoebas

Single, free-living cells - use their pseudopods to engulf prey - most are predators in soil or freshwater - some are marine and a few are parasites Entamoebas live in the human intestine where they can cause a severe form of dysentery, which is bloody diarrhea Naegleria fowleri - a species of freshwater amoeba can enter the sinuses and feed off brain tissue, giving it the name, the brain-eating amoeba

Rhizarians:

Some examples of protists within this group are forams and actinopods. Some of these protists (forams) play an important role in the carbon cycle. They remove significant amounts of CO2 from the ocean and incorporate it into their shell-like covering. Structural characteristics -Almost all unicellular -Contain a shell-like covering -Many use pseudopodia for locomotion Primary habitats -Marine environments

Archaeplastids:

Some examples of protists within this group are red algae and green algae. This group also includes land plants. Many protists within this group also function as primary producers at the base of food chains in many ecosystems. The organisms classically referred to as seaweeds belong to this group. Structural characteristics - this group includes unicellular and multicellular protists - have chloroplasts - many have flagella used for locomotion Primary habits -Marine environments -Fresh-water environments -Terrestrial environments

Excavates:

Some examples of protists within this group include diplomonads, parabasalids, euglenoids, and trypanosomes. The name of this group comes from the presence of an "excavated" side used for feeding. This is often referred to as an oral groove. Additionally, this group includes some protists known to cause disease in humans. Specifically, Trichomonas vaginalis can cause a sexually transmitted disease in humans called trichomoniasis. Giardia intestinalis is a protist within this group known to cause diarrhea in individuals who drink from contaminated waters. Structural characteristics -Unicellular -Multiple flagella used for locomotion -Many members of this group contain an oral groove used for ingesting nutrients -Some (euglenoids) have chloroplasts Primary habitats -Stagnant water -Within the digestion system of hosts -Fresh water -Marine environments

T/F Monomers are the building blocks of polymers

TRUE

T/F Methanotrophic (methane-feeding) bacteria among the closest relatives of mitochondria

TRUE m = m

T/F Parasites sometimes alter their host's behavior in a way that increases their chances of transmission to another host.

TRUE! Examples: - Mosquitoes that spread malaria - apicomplexan parasite: Toxoplasmosis

T/F Microbiota diversity varies among human populations

TRUE! To date, the most diverse microbiota known is that of the Yanomami people

2 Antibiotics that disable bacterial ribosomes

Tetracyclines and Streptomycins

Endotoxin

The LPS of Gram-negative bacteria that are not secreted but released when the bacteria cell dies and fragments Do not directly harm cells but do cause an immune response in the host that results in fever and aches

Be able to differentiate between Gram positive and Gram negative bacteria

The difference in external cell structure and color Gram positive - thick walled Stain purple with gram staining = crystal violet Most are chemoheterotrophs and some are decomposers Lactobacillus and species of Streptococci Gram negative - thin walled Stain pink with gram staining = safranin Have an additional layer of LPS lipopolysaccharides outside the cell wall Makes them more resistant to antibiotics

How did aerobic respiration and the ozone layer change life on Earth (current and later species)?

The evolution of oxygen-releasing pathway of photosynthesis in cyanobacteria resulting in the oxygenation of Earth's atmosphere and waters Oxygen was toxic to many specifies that evolved in its absence The rise of oxygen favored organisms that could detoxify oxygen or use it in aerobic respiration Increasing oxygen concentration led to the formation of the ozone layer, which blocks UV radiation... and allowed life to move onto land

Haploid dominant

The multicellular (or sometimes unicellular) haploid stage is the most obvious life stage and is often multicellular. In this type of life cycle, the single-celled zygote is the only diploid cell. Fungi and some algae have this type of life cycle.

Diploid dominant

The multicellular diploid stage is the most obvious life stage, and the only haploid cells are the gametes. Humans and most animals have this type of life cycle. ... In this type of life cycle, the single-celled zygote is the only diploid cell.

Define the Big Bang theory:

The universe began in a single instant approximately 13.7 billion years ago All existing matter and energy suddenly appeared, exploded outward from a single point Gravity drew gases together and they condensed to form stars Earth and other planets in the solar system formed from dust and asteroids orbiting the Sun

Origin of cellular properties: Origin of Protein

Tidal flat hypothesis Nonbiological process concentrated organic subunits, forming proteins on clay-rich tidal flats Clay has a slight negative charge, so positively charged molecules would stick to clay Energy from the sun might have triggered polymerization (proteins) Simulated tidal flat conditions show short chains of amino acids can form

Mosquitoes that spread malaria How they alter their host's behavior

To facilitate speedy feedings and quick getaways, mosquitos inject their host with apyrase, an enzyme that impairs blood clotting. An injection of apyrase before a meal helps ensure that blood will flow smoothly up the insect's proboscis, rather than turning chunky and clogging it. After Plasmodium (the apicomplexan that causes malaria) has replicated in a mosquito's gut, it moves to the insect's salivary glands. Here, it inhibits production of the anticlotting enzyme. A mosquito with infectious Plasmodium in its saliva has to bite more often because blood clots as it feeds. This is bad for the mosquito, but good for Plasmodium. A mosquito that is forced to eat many small meals, rather than a single large one, is more likely to deliver sporozoites to many new hosts. Thus = very contagious

3 Mechanisms of Horizontal Gene Transfer

Transformation A cell takes up DNA from its environment and integrates it into its genome Transduction Bacteriophages move genes between cells Conjugation Movement of genes in a plasmid, a small circle of DNA separate from the chromosome

Kinetoplastids: Trypanosoma Brucei

Transmitted to humans and animals via the tsetse fly and causes African Sleeping Sickness - is fatal without treatment and has two stages 1st stage - Trypanosomes multiply in tissues, blood and lymph (fluid that contains white blood cells) which brings about fever, headaches, joint pain and itching 2nd stage - when Trypanosomes cross the blood-brain barrier to infect the central nervous system - Causes changes in behavior, sleep cycle disturbances, confusion, sensory disturbances, and poor coordination *** what causes African Sleeping Sickness: Trypanosoma Brucei *** what carries African Sleeping Sickness: Tsetse fly Known as Chagas Disease in Central and South America and rarely in US, spread by blood sucking bugs

Diplomonads

Two identical nuclei, live in animals Several freely beating flagella have only nonfunctional remnants of mitochondria, so they make their ATP by way of reactions in their cytoplasm Example - parasite Giardia lamblia (causes hiker's fever - contracted from drinking dirty water) Considered a Metamonad, part of Supergroup Excavata (Excavates)

Euglenozoans and 2 types

Type of flagellate Free-living flagellated protists that have mitochondria All are heterotrophs, some are mixotrophs 2 major lineages - euglenids or kinetoplastids part of Supergroup Excavata (Excavates)

Metamonads and 2 types

Type of flagellate Lack mitochondria and have multiple flagella Anaerobic mechanisms of ATP production - do not need oxygen 2 types - diplomonads - parabasalids part of Supergroup Excavata (Excavates)

Euglenids

Typically freshwater, free-living, with multiple mitochondria - can function as heterotrophs when conditions prevent photosynthesis - Some lack chloroplasts and are always heterotrophs Example - euglena Considered an Euglenozoan, part of Supergroup Excavata (Excavates)

Evolution

Underlies the unity and diversity of life Shared core processes and features observed among modern and fossil organisms provide evidence of life's common origin Divergences from shared ancestors and adaptation to different environments produced the diversity of life

Organization of Protists: 3 Types

Unicellular vs. colonial vs. multicellular 1. Unicellular Meaning single celled Some protists are single celled but NOT all 2. Colonial organisms Live in groups and behave in an integrated manner, but remain self-sufficient 3. Multicellular organisms Cells have a division of labor and depend on one another for survival

General Structure of Viruses

Viral genome Protein Capsid Viral envelope

Define bacteriophage and its structure

Virus that infects bacteria Head and Tail The "head" of the virus is a polyhedral capsid that encloses the viral DNA. A hollow helical "tail" extends from the head. During infection, the DNA will pass through this tail and into the host cell. At the base of the tail, six leglike tail fibers attach to a baseplate. During infection, the tail fibers bind to the surface of the host cell.

What is the most abundant infectious agents on the planet?

Viruses

Oxygen evidence of Early Earth environmental conditions (i.e. Precambrian)

Volcano eruptions led to an atmosphere of water vapor, carbon dioxide, nitrogen, and hydrogen (toxic and unbeatable for us!) Iron in the oldest rocks is not oxidized (rust); so the early atmosphere was oxygen-free Any oxygen would have oxidized organic molecules as soon as they formed

Water evidence of Early Earth environmental conditions (i.e. Precambrian)

When Earth's crust cooled, water condensed on its surface Zircon crystals 4.4 billion years old provide the earliest evidence

Why do dinoflagellates bioluminesce?

When disturbed, they produce a blue or blue-green glow by an oxidation-reduction reaction The light may protect the protist by startling a predator that was about to eat it Or, the flash of light may function like a car alarm, attracting the attention of predators that pursue the would-be dinoflagellate eaters

Choanoflagellates

a group of aquatic, heterotrophic protists - closest known protistan relatives of animals. - flagellum surrounded by a "collar" of threadlike projection - flagellum movement sets up a current that draws food-laden water through the collar - Most live as single cells, but some form colonies Colonies arise by mitosis, when descendant cells do not separate after division; Instead, stick together with the help of adhesion proteins Only type of Opisthokonts we study

One reason viruses are considered nonliving is because they _____.

are unable to replicate without a host cell

Although archaea and bacteria are different domains of life, they share a lot of characteristics. Which characteristics do they share? Select all that apply. a. Archaea and bacteria are both single-celled. b. Archaea and bacteria both have a single chromosome. c. Archaea and bacteria have nearly identical cell wall and cell membrane structures. d. Archaea and bacteria are both prokaryotes. They both lack a nucleus.

a. Archaea and bacteria are both single-celled. b. Archaea and bacteria both have a single chromosome. d. Archaea and bacteria are both prokaryotes. They both lack a nucleus.

Which of the following are differences between archaea and bacteria? Select all that apply. a. Archaea and bacteria have different lipids in their cell membranes. b. Bacteria are single-celled, while archaea are multi-celled. c. Only archaea have a single chromosome d. Archaea does not have peptidoglycans in the cell wall, but bacteria do.

a. Archaea and bacteria have different lipids in their cell membranes. d. Archaea does not have peptidoglycans in the cell wall, but bacteria do.

Nutritional methods used:

a. Autotrophs - able to make their own food using CO2 as a carbon source i. Photoautotroph - obtain energy from light ii. Chemoautotroph - obtain energy from chemicals b. Heterotroph - obtain carbon by taking up organic molecules from the environment - Not capable of making their own carbon (food) i. Photoheterotroph - harvest energy from light and carbon from organic compounds ii. Chemoheterotroph Not capable of making their own carbon (food) Obtain energy and carbon by breaking down organic compounds All pathogenic bacteria are of this type Beneficial bacteria in the digestive tract Some are decomposers

3 Modes of Nutrition

a. Autotrophs - carry out photosynthesis b. Heterotrophs - feed on various sources in the environment; some form symbiotic relationships; some are parasitic c. Mixotrophs - can be photosynthetic or heterotrophic depending on conditions Example: Euglena

Morphology

a. Coccus - round i. Diplococcus - 2 round ii. Tetrad - 4 round iii. Streptococcus - chain of rounds iv. Staphylococcus - cluster of rounds b. Bacillus - rod c. Spirillum - rigid spiral

Which of the following characteristics did the first cells NOT share with prokaryotes? a. They had the ability to thrive in anaerobic environments. b. There was the presence of a membrane bound-nucleus. c. They had the ability to divide. d. They contained self-replicating polymers.

a. They had the ability to thrive in anaerobic environments.

During the last stages of binary fission, which structure(s) begin to fold inward separating the cell into two distinct sections? Choose all that apply. a. cell wall b. plasma membrane c. circular chromosome d. nucleus

a. cell wall b. plasma membrane

The first cells likely survived in Earth's early atmosphere because they _____. a. were anaerobic b. were similar to eukaryotic cells c. had a membrane-bound nucleus d. were aerobic

a. were anaerobic

Autotrophs and 2 Types

able to make their own food using CO2 as a carbon source i. Photoautotroph - obtain energy from light ii. Chemoautotroph - obtain energy from chemicals

Algal bloom

aka red tide Free-living photosynthetic dinoflagellates or other photosynthetic cells sometimes undergo great increases in population size Can cause aquatic animals to suffocate and some also produce toxins

If life exists on Mars, it is almost certainly: Why?

anaerobic Mars is only about half the size of Earth - has less gravity than Earth and is less able to hold on to atmospheric gases - The relatively small amount of atmosphere that remains consists mainly of carbon dioxide, some nitrogen, and only traces of oxygen

Viral Genome

are very diverse, since they can be DNA or RNA, single- or double-stranded, linear or circular, and vary in length and in the number of DNA or RNA molecules The viral replication process begins when a virus infects its host by attaching to the host cell and penetrating the cell wall or membrane

Prokaryotic cells divide _____ in a process called _____.

asexually; binary fission

Which of the following factors is common to all protist habitats? a. Saltwater b. Water c. Soil d. Leaf litter

b. Water

Systems - Concept

complex properties arise from interactions among components of a biological system Protists interact with one another and with other lineages They can be predators, prey, beneficial partners, or harmful pathogens These interactions influence the structure and properties of the diverse communities that include protists

Macronucleus

controls daily function and divides by mitosis during asexual reproduction Found in Ciliates, an Aveolate, part of the Supergroup Stramenophile SAR

Which of the following protists is exclusively heterotrophic? a. A protist that is a primary producer in an ocean b. A protist that can carry out the process of carbon fixation c. A protist that has chloroplasts d. A protist that acquires its nutrition from the food within an insect's gut

d. A protist that acquires its nutrition from the food within an insect's gut

Where do the greatest number and diversity of microbes reside in humans?

gastrointestinal tract, especially in the colon

Photoheterotroph

harvest energy from light and carbon from organic compounds

Early anaerobe life-forms were most likely _____.

heterotrophs!

12. The origin of the nucleus and endomembrane system in eukaryotic organisms was likely through __________________________ in __________________________ (archaeal/bacterial?) ancestors. Advantages in ancestors?

in folding archaeal The nucleus probably began in archaeal ancestors when portions of the plasma membrane folded inward In-folding is beneficial bc it increases surface area for membrane-bound enzymatic / metabolic activity Infoldings could have surrounded the DNA to become the nuclear envelope that serves to protect the cell from invasions of foreign DNA

Botulism exotoxin

is released by Clostridium botulinum ... one of the most poisonous substances known to man Enters the body through improperly canned food; it damages nerve cell communication and can cause paralysis and death if left untreated Same exotoxin that has been purified for medical use for BOTOX Shigella species and some E. coli release an exotoxin; ingestion of food containing the bacteria results in abdominal cramps and bloody diarrhea Food poisoning

Radiolaria

planktonic, secrete a glassy silica SiO2 shell Have 2 cytoplasmic layers Abundant in nutrient-rich tropical waters Second gas-filled cytoplasmic layer keeps cells afloat Considered a Rhizaria, part of the Supergroup Stramenophile SAR

Ciliates

presence of short motile structures called cilia Lives just about anywhere there is water Heterotropic Some are colonial, but many live as single cells **only protist we talk about with 2 types of nuclei 1. Macronucleus - controls daily function - divides by mitosis during asexual reproduction 2. Micronucleus - sexual reproduction (meiosis) Considered an Aveolate, part of the Supergroup Stramenophile SAR

Some protists stretch out cytoplasmic extensions along their leading edge and retract their trailing end as a method of locomotion. These cytoplasmic extensions are called _____.

pseudopodia

Flagellum

rotates like a propeller, does not contain microtubules, does not bend side to side

Many archaea thrive in ____________________________

seemingly hostile habitats

Supergroup Amoebozoa (Amoebozoans)

shape-shifting heterotrophic cells that typically lack a wall or pellicle move about and capture smaller cells by extending thick lobes of cytoplasm called pseudopods 2 major groups of protists: amoebas and slime molds

Foraminiferan

shell made of calcium carbonate - consists of multiple secreted chambers - Including its shell, can be as big as a grain of sand - Most live on the seafloor - others are members of marine plankton Planktonic ones often have smaller photosynthetic protists - such as diatoms or algae living on or in them **White Cliffs of Dover in England made of CaCO3 shell **giant blocks of limestone used to build the great pyramids of Egypt consist largely of their shells that fell to the seafloor about 50 million years ago Considered a Rhizaria part of the Supergroup Stramenophile SAR

Process of Science - Concept

the field of biology consists of and relies upon experimentation and the collection and analysis of scientific evidence Determining the relationships among the various protists groups remains a work in progress Use of gene comparisons now makes it possible to trace the ancestry of chloroplasts and to determine how protist groups are related to each other and to the plants, animals, and fungi

The endosymbiotic hypothesis can explain why....

the information-processing traits of eukaryotes resemble those of archaea, while traits related to energy metabolism resemble those of bacteria

Evolution - Concept

underlies the unity and diversity of life All protists are eukaryotes Their diverse structure and metabolic processes are adaptations to different environments Protists live in freshwater, saltwater, damp places on land, and inside other organisms Most are aerobic, some are anaerobic Some are heterotrophs, others have chloroplasts Fungi, plants, and animals all have protists ancestors

Viral envelope

viruses that infect animals usually have an outer viral envelope consists of membranes from the cell in which the virus formed

Only after the ozone layer formed...

was it possible for life to move onto land