Biology 112 Exam 1
RNA viruses
higher mutation rate
Which of the following is not associated with prions? Replicating shapes Mad Cow disease DNA Toxic proteins
DNA
What characteristic is shared by prokaryotes and eukayotes cytoskeleton nuclear envelope DNA-based genome mitochondria
DNA-based genome
Viroids
NO capsid or envelope! Infectious RNA molecules Plant diseases (interfere with plant metabolism) Transmitted like a virus Do not manufacture proteins
Prions
NO nucleic Acids! infectious protein molecule Animal diseases smaller than viruses
Many prokaryotes are able to move around on their own effort within their environment. Which of the following statements is FALSE about its motility?
Negative chemotaxis helps some heterotrophic abcteria to locate food
Eukaryote organelles
Nucleus: membrane bound, genetic material Micro-and Macro-nuclei Mitochondria: energy •Cytoskeleton: microtubules & microfiliments Food vacuole: contains food particles •Contractile vacuole: expel fluids Plastids: contain photosynthetic pigments (Chloroplasts: contain versions of chlorophylls)
Coral Reefs
One of the most diverse ecosystems on the planet Protect coastlines from the damaging effects of wave action and tropical storms Provide habitats and shelter for many marine organisms
Small rings of DNA in bacteria are called Hfr rings nucleoids chromatids plasmids
plasmids
A scientist discovers a new virus with a linear, RNA genome surrounded by a helical capsid. The virus is most likely a member of which family based on structure classification? Rabies virus Herpes virus retroviruses Influenza viruses
Rabies virus
Gymnosperms
Stomata Persistently green sporophyte tracheids (vascular cells), branching independent sporophyte, rooting structures Megaphylls overtopping growth form *Seeds Includes: Cycads, Ginkgo, Gnetophytes, Conifers, Flowering Plants
Excavata
Unicellular, flagella, no cell wall "Cavity" or pocket where flagella are rooted Diplomonads Euglenozoans
Archaeplastida
autotrophic, cell walls with cellulose red algae chlorophytes (green algae) Charophytes (Green algae) Land plants chloroplasts from primary endosymbiotic event aka Kingdom: Plantae
In the life cycle of the malaria parasite Plasmodium, where does fertilization and formation of the zygote occur?
Within the body of a mosquito
Plant Vascular Tissue
Xylem: Transports water and minerals Phloem: Transports sugars, amino acids
Which of the following statements is true? a dikaryotic ascus that forms in the ascocarp undergoes karygamy, meiosis, and mitosis to form eight ascospores a diploid ascus that forms in the ascocarp undergoes karyogamy, meiosis, and mitosis to form eight ascoscpores a haploid zygote that forms in the ascocarp undergoes karyogamy, meiosis, and mitosis to form eight ascospores a dikaryotic ascus that forms in the ascocarp undergoes plasmogamy, meiosis, and mitosis to form eight ascospores
a dikaryotic ascus that forms in the ascocarp undergoes karygamy, meiosis, and mitosis to form eight ascospores
Sporopollenin
(durable, watertight polymer) surrounds spores and allows air dispersal
Which of the following statements is false? In this lytic cycle,new phages are produced and released into the environment In the lysogenic cycle, phage DNA is incorporated into the host genome An environmental stressor can cause the phase to initiate the lysogenic cycle Cell lysis only occurs in the lytic cycle
An environmental stressor can cause the phase to initiate the lysogenic cycle
Megaphylls: Probably only evolved once Are found in all the vascular plant groups Probably arose from sterile sporangia Are the characteristic leaves of club mosses Are the characteristic leaves of ferms and horsetails
Are the characteristic leaves of ferns and horsetails
Fungi Sexual versus asexual
Asexual: Mycelium (1n) -> (mitosis)-> Spores -> (germination) ->Mycelium (1n) Sexual: Mycelium (1n) -> (plasmogamy) -> Heterokaryotic stage -> (karyogamy) -> Zygote -> (meiosis) -> Spores -> (germination) -> Mycelium (1n)
Bacteria versus Virus
Bacteria: prokaryotic cell, larger Virus: Not living, 1/1000 size of bacteria
Virus Entry
Bacteriophage DNA enters the host cell "naked". Viruses may enter eukaryotic cells by (a) endocytosis, or if enveloped, by (b) fusion with the cell's membrane.
Classify Viruses
Baltimore classification According to nucleic acid type and function According to capsid structure Enveloped/non-enveloped Genome structure
The viral _________ plays a role in attaching a virion to the host cell. Core Capsid Envelope Both b and c
Both b and c
Which of the following about Paramecium sexual reproduction is false? The macronuclei are derived from micronuclei Both mitosis and meiosis occur during sexual reproduction the conjugate pair swaps macronuclei Each parent produces four daughter cells
Both mitosis and meiosis occur during sexual reproduction
HIV (Human Immunodefiniency Virus) Retrovirus
Causes AIDS (acquired immunodeficiency syndrome) Is enveloped Is a retrovirus (can reverse transcribe its RNA genome into DNA form.
The disease causing tetanus bacterium clostridium tetani secretes a poisonous protein into the tissues of its host. It lives and grows by absorbing and metaboliing the organic molecules of its hosts tissues but it can only form. All of the following terms, then, apply to this bacterium EXCEPT Chemoautotroph exotoxin endospore pathogen obligate anaerobe
Chemoautotroph
Match the prokaryote classification with the way they obtain energy.
Chemotroph- chemical compounds Phototroph- light Chemolithotroph- inorganic compounds Chemoorganotroph- organic compounds
Members of which group are all endoparasites?
Chlamydias
Which of the following is a correct match of a protist or bacterial group with its description or characteristics?
Chlamydias-- includes sexually transmitted bacterial endoparasites
You observe the gametes of a fungal species under the microscope and realize that they resemble animal sperm. To which of the following groups does the fungus belong?
Chytrids
Chitin is a long chain polymer derived from glucose. It strengthens cell walls of fungi and the outer covering (exoskeleton) of arthropods (including crabs shrimps and insects). The presence of chitin in these groups is likely due to ____:
Convergent evolution
Nitrogen fixation is a process that can only occur in the absence of oxygen. Rhizobium is a nitrogen fixing bacterium that lives off the sugars and water in the plant root nodules it inhabits, while releasing the products of nitrogen fixation for the plant to utilize. Therefore we can conclude that Rhizobium ...?
Converts nitrogen gas to ammonium is an obligate anaerobe is a chemoheterotroph is a mutualist
Baltimore system
Current classification system for viruses double or single stranded DNA, RNA, or retrotranscribing group typeimpacts how mRNA is coded
Protist Supergroups
Excavata Chromalveolata (Stramenopiles & Alveolates) Rhizaria Archaeplastida Unikonta (Amoebozoa & Opisthokonta) (SAR supergroup includes chromalveolata and rhizaria)
Which type of cell does NOT have the ability to transfer part of its DNA to another bacterium through conjugation?
F- cell
The eukaryotic flagella is homologous to the prokaryotic flagella. True/False
False
Hyphae are comprised of individual mycelia
False. It's the other way around
Multicellular, dependent embryo (embryophytes)
Female gametophyte retains embryo resulting from fertilization
Flagella Pseudopodia Cilia
Flagella: few, long, taillike Cilia: Many, short, hairlike Pseudopodia: flowing cytoplasm
Angiosperms - Flowering Plants Phylum Anthophyta
Flowers - structure specialized for sexual reproduction. (protects ovules within ovary) Fruits - mature ovary & other portions of plant surround seeds
Phagocytosis
Food taken into digestive cavity, followed by extracellular digestion Can occur using cytosome or pseudopodia
Amoebozoans: Gymnamoebas
Found in soil, freshwater, and marine habitats Feed on bacteria and other protists
Alternation of Generations
Gametophyte (1n) Sporophyte (2n)
Generative cell, Tube cell Exine Micropyle
Generative cell: makes sperm Tube cell: makes pollen tube Exine: outer protective layer Micropyle: narrow opening in scale providing access to the ovule. Arils: fleshy coverings
In the fungus life cycle
Genetically diverse spores are produced only after a zygote is formed
Euglenozoans
Genus: Trypanosoma Trypano- (borer) soma (body) Many require more than one host for life cycle Intercellular parasite T. cruzi (Chagas' disease) Kissing bug vertebrate T. brucei (African Sleeping Sickness) Tsetse fly vertebrate
Which of the following staements about virus structure is true? All viruses are encased in a viral membrane The capsomere is made up of small protein subunits called capsids DNA is genetic material in all viruses Glycoproteins help the virus attach to the host cell
Glycoproteins help the virus attach to the host cell
3 main virus hypotheses
H1- Devolution or regressive H2-Escapists or Progressive H3- Virus first
Meiosis
Haploid (1n) spores are formed
Byrophytes
Haploid gametophytes dominant of stage of life cycle - Larger and longer-lived Diploid sporophyte present short period of time
Alternation of Generations Land Plants
Haplontic: Most of time in haploid (n) stage Diplontic: Most of time in diploid (2n) stage. Haploid gametes are formed Evolutionary Trend = smaller/less time in gametophyte form
Vascularization
Height increase competition for sunlight increased spore release root evolution to anchor and absorb materials from the soil arranged in continuous, branching bundles of tubular cells connected end -to -end provides bulk flow over longer distances adds support
Decomposers
Heterotrophic Use organic matter to get energy, carbon, nutrients for growth and development Many were incorrectly identified as fungi e.g., slime molds, water molds (oomycetes)
What is the function of the apical complex in an apicomplexan?
It helps the parasitic cell penetrate and enter a host cell
What is the function of the apical complex in an Apicomplexan?
It helps the parasitic cell penetrate and enter a host cell.
What is NOT true of angiosperm pollen It is the male gamete it is haploid it produces a long tube it interacts with the carpel
It is the male gamete
Reproductive structure (fungi)
Part seen above ground Used to characterize fungi
Match the following descriptions with the groups they best describe
Monecious Plants: has a megasporangiate and microsporangiate flowers on the same plant Dioecious plants: has megasporangiate and microsporangiate flowers on different plants Angiosperms: produce flowers and fruits Gymnosperms: produce seeds that are not protected by the ovary
Monocots versus Dicots
Monocots: Sheath (leaf attaches directly to stem) Dicots: Petiole (leaf attaches to stem at node)
Chemoheterotrophic bacteria
Most important decomposers on earth absorptive: monomers enter by diffusion/active transport metabolism releases CO2 & N, P, K, and maybe digestive enzymes
Which of the following is NOT part of the life cycle of a cellular slime mold?
Multicellular feeding form
Viruses
NOT living (acellular) All contain: nucleic acid and a protein capsid Cannot fit into any domain of life Non-cellular, no metabolism, no growth, and no cell division Completely dependent on host for resources to produce progeny Visible with electron microscopes Species and tissue specific
Euphyllophytes
Stomata Persistently green sporophyte tracheids (vascular cells), branching independent sporophyte, rooting structures *Megaphylls overtopping growth form Includes: Horsetails, Ferns, Cycads, Ginkgo, Gnetophytes, Conifers, Flowering Plants
Why do do RNA viruses appear to have higher rates of mutation
Replication of their genomes does not involve proofreading
Plant Pathogens
Rhizaria: Plasmodiophorids Cause substantial damage to crops Infects hosts roots, disrupting nutrient and water uptake Excavata: Phytomonas sp. flagellates in the phloem of coconut palms Chromalveolata: Oomycetes Potato Blight Ireland's potato famine in 1845 Phytophthora infestans
Seed Plant Importance
Seed = embryo and its food supply surrounded by a protective coat When mature, seeds are dispersed from parent to plant by wind, water, animal movement, etc. rapid and distant dispersal from parent
5. Evolution of Seeds
Seeds • Develops from fertilized ovule • Includes: embryo, food supply, seed coat Advantages: Enhanced dispersal, safe from desiccation • Underground germination possible may stay dormant larger/multicellular for protection
Vascular Plants
Stomata Persistently green sporophyte *tracheids (vascular cells), branching independent sporophyte, rooting structures *(Lycophytes possess microphylls) Includes: Lycophytes (club mosses), Horsetails, Ferns, Cycads, Ginkgo, Gnetophytes, Conifers, Flowering Plants
Angiosperms
Stomata Persistently green sporophyte tracheids (vascular cells), branching independent sporophyte, rooting structures Megaphylls overtopping growth form Seeds *Flowers, double fertilization Includes: Flowering Plants
SAR Group
Stramenopiles Alveolates Rhizarians Currently debated whether to group into a single "SAR" supergroup
HIV is inactivated in the labratory after a few minutes of sitting at room temperature but the flu virus is still active after sitting for several hours. What are the practical consequences of these findings?
The flu can be transmitted more easily from person to person than HIV
In the first plants, one reproductive adaptation to land life provided nourishment and protection from dessication directly to offspring, promoting the success of the next generation. This refers to
The growth of the embryonic sporophyte within gametophyte tisssue
Fungi have an extremely high surface-volum ratio. What is the advantage of this characteristic to an organism that gets most of its nutrition through absorption?
The high ratio allows for more material to be acquired from the surroundings and transported through the cell membrane
Virus attachment
Viral receptors on the surface of the host cell bind to virus capsid proteins or virus envelope glycoproteins. Viruses only attach to specific species and tissues
Endotoxins
are toxins within the outer membranes of some Gram-negative bacteria
A bacteriophade can infect ____: The lungs viruses prions bacteria
bacteria
During sexual reproduction, a homothalic mycelium contains:
both mating types
Mutualism -
both species benefit from each other
The Gram stain differentiates between bacteria based on the composition of their _________
cell wall
In protists exhibiting both asexual and sexual modes of reproduction, what factor frequently triggers the shift from asexual reproduction to sexual reproduction?
the onset of unfavorable environmental condition
Nitrogen fixation
converts N2 to NH4 + cyanobacteria in water & soil or symbiotic in plant roots Occurs in heterocyst *Important for Nucleic acids (nitrogenous bases) Used to make amino acids proteins
A significant portion of oxygen production on our planet it attributed to:
cyanobacteria
Oxygen revolution
cyanobacterial photosynthesis produced O2 cyanobacteria today are still a major world O2 source
Match the type of life cycle to its definition 1- only diploid multicellular organisms 2- both haploid and diploid multicellular organisms 3-only haploid multicellular organisms
diplontic- 1 haplodiplontic- 2 haplontic- 3
Oncogenic virus cores can be _____: RNA DNA neither RNA nor DNA either RNA or DNA
either RNA or DNA
Sporangia in Seedless Plants
enclosure where spores are formed • Spores produced meiotically and protected until maturity Evolution of a waxy cuticle to resist desiccation Spores produced in multicellular sporangia
Ectomycorrhizae are well known for:
enhancing growth of plants Fungus remains outside root and between cells
chemoautotrophs
form base of food web in this hydrothermal vent community
When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter?
fungal enzymes
Endomycorrhizae
fungi penetrate cell walls and form haustoria
Plasmogamy
fusion of cytoplasm Haploid cells from two different mycelia fuse to form a heterokaryotic cell with two or more nuclei
Karyogamy
fusion of nuclei The nuclei fuse to form a diploid (2n) zygote
What event is thought to have contributed to the evolution of eukaryotes? global warming glaciation volcanic activity oxygenation of the atmosphere
glaciation
Viral Shapes
head and tail, filamentous helical, isocahedral, enveloped
The members of domain archaea and domain eukarya have this in common:
histone proteins associated with DNA
Amoebozoans: Slime Molds
live in moist terrestrial habitats (rotting wood, etc) use pseudopodia to move & ingest bacteria
What is the function of raphe in diatoms?
locomotion
What statement is not true of viral replication? lysogenic cycle kills the host cell There are six basic steps in the viral replication cycle Viral replication does not affect host cell function Newly released virions can infect adjacent cells
lysogenic cycle kills the host cell
Endosymbiotic theory
theory that eukaryotic cells formed when a prokaryote engulfed but did not consume an aerobic bacterium [mitochondria] and (for plants) a cyanobacterium [chloroplast]
Cytoskeleton components
these assemble & break apart quickly: microtubules (tubulin proteins) microfilaments (actin proteins) more permanent fibers: intermediate filaments cytoskeleton is for cell division, cell support, transport in cell
Vertical Transmission
virus is transmitted from the parent plant May cause hypoplasia (decreased growth and vigor) May cause necrosis of the plant or plant tissue
Horizontal Transmission
virus typically enters by way of damaged plant tissue may come from pollen, another plant, or vectors such as insect bites
The genetic recombination that occurs during conjugation in the ciliate Paramecium most directly involves...?
micronuclei
What are prions?
misfolded versions of normal proteins that can cause disease
Archaeplastida: Green Algae
most are freshwater; many marine many with bi-flagellated cells unicellular forms: Phytoplankton Over 7,000 species Colonial forms: Volvox Spherical colonies in freshwater. Connected to each other with cytoplasmic strands. Asexual and sexual reproduction
Archaeplastida: Red Algae
mostly marine, multicellular seaweeds chloroplasts include unique red phycoerythrin accessory pigment helps absorb light in deeper water some thallose; some filamentous; some make CaCO3 Cellulose + unique cell wall polysaccharides: carrageenan thickener (ice cream) agar (for petri dish cultures, food)
Commensalism -
one sp. benefits w/o any impact (good or bad) on other sp.
An example of carbon fixation is: photosynthesis decomposition phagocytosis parasitism
photosynthesis
At what stage of a basidiomycetes life cycle would reproduction be halted if an enzyme that prevented the fusion of hyphae was introduced?
plasmogamy
obligate anaerobes
poisoned by O2 first cells probably like this
Stomata
pores that allow materials into/out of a plant's leaves (CO2 and O2 )
Opisthokonta
posterior flagella Nucleariids Fungi Choanoflagellates Animals
Most prokaryotes are chemoheterotrophs. You should expect to find chemoheterotrophic bacteria filling all the roles except:
primary producers
Amoebozoa
pseudopodia: Lobopodia Amoeboid movement Phagocytosis Slime molds Gymnamoebas
obligate aerobes
require O2 for cellular respiration Most of life today
In most fungi, karyogamy does not immediately follow plasmogamy, which consequently ____:
results in heterokaryotic and dikaryotic cells
What are the four similarities in cell structure between prokaryotes and eukaryotes
ribosomes, cell wall, cytoplasm, genetic material
Protists with the capabilities to perform photosynthesis and to absorb nutrients from dead organisms are called ____: photoautotrophs mxotrophs saprobes heterotrophs
saprobes
Chromalveolata
secondary endosymbiosis, chlorophyll alveolates: dinoflagellates, apicomplexans, ciliates contain alveolus, membrane-enclosed sac beneath cell membrane stramenopiles: diatoms, brown algae Presence of hairy flagellum
Cuticle
waxy covering to epidermis of many plant species (water tight barrier)
In fungi that produce spores both sexually and asexually, how do these spores differ
sexual spores are genetically diverse and asexual spores are genetically identical
Vaccines ____: Are similar to viroids are only needed once kill viruses stimulate an immune response
stimulate an immune response
Plasmopara vilicola is the causal agent of fowny mildew of grape. This organism produces a fuzzy fungal like growth on the undersides of leaves, and ultimately the fruit. Closer inspection of these fruits reveal several spores that have two flagella, one plain, one tinsel like. This organism would be classified as a:
stramenopile
Prokaryote Motility
taxis = movement directed toward or away from (+ or -) stimulus chemotaxis phototaxis geotaxis (magnetotaxis) flagellum protein fibers Slime-gliding (slime ejected thru pores)
Which of the following statements about the Laminaria life cycle is false? 1n zoospores form in the sporangia the sporophyte is the 2n plant the gametophyte is diploid both gametophyte and sporophyte stages are multicellular
the gametophyte is diploid
biofilms
a surface coating colony of prokaryotic that engage in metabolic cooperation plaque
Which of the following are NOT used to treat active viral disease? vaccines antiviral drugs antibiotics phage therapy
antibiotics phage therapy
Which of these organelles is not found in a fungal cell?
chloroplast
asexual reproduction in fungi
(Most common method) -Fragmentation: bits of mycelium can grow into new individual -Budding: single-cell yeasts--mitosis & asymmetric cytoplasmic division -Asexual spores by mitosis: grow new genetically identical mycelia ("mold")
Bacteria genetic diversity
(Usually asexual through binary fission) Transformation- bacterium takes up a piece of DNA floating in its environment Transduction- DNA is accidentally moved from one bacterium to another by a virus Conjugation- Form a mating bridge to transfer DNA between two bacterial cells with a pilus.
Reduced Gametophytes
*Evolutionary trend away from prevalence of gametophyte during plant evolution Protects gametophyte from environmental stress, UV radiation, desiccation Allows gametophyte to gain nutrition from sporophyte
Sporophylls
*Leaves modified that bear sporangia (Sporangia shift to leaves) [Sporangium: tissue in which meiosis occurs, resulting in the production of spores] Fern sporophylls look like normal leaves but have sori that generate spores on underside Club moss and gymnosperm sporophylls modified into a cone-like structure called a strobilus (i.e., pinecones) strobilus = cone-like group of sporophylls sori = clusters of sporangia on sporophylls
Lichens (mutualist fungi)
-fungi living in close association w/ photosynthetic unicellular chlorophyte or cyanobacteria "gives" framework, moisture, minerals can reproduce as "dual organism" via soredia "pioneers" on bare rock & harsh environments. create soil for plants, food for animals
Active Virus Life Cycle
1- Attachment- The phage attach to specific receptors on the E. coli. 2- Entry- Phage DNA is injected into the bacterial cell leaving the phage coat outside. 3- Transcription-Phage DNA is transcribed producing phage mRNA, which is translated into phage proteins. 4- Replication- phage coat proteins, other protein components, and DNA are produced sepaarately. Host DNA degraded. 5- Assembly- Phage components are assembled into mutated virions 6- Egress (release)- The bacterial cell lyses and releases many infective phages.
Reproductive Adaptations of Seed Plants
1. Reduced gametophytes 2. Heterospory 3. Ovules 4. Pollen 5. Seed
Flowers
1. Sepals - green leaf-like appendages that enclose the rest of the flower 2. Petals - brightly colored appendages that aid in attracting pollinators 3. Stamen - produce microspores that develop into pollen (contain male gametophyte) Filament - stalk that holds up pollen-producing sac Anther - terminal sac that produces pollen 4. Carpel (aka "pistil") - make megaspores that contain female gametophyte Stigma - sticky tip of carpel that receives pollen • Style - long tube leading from stigma to ovary • Ovary - structure at base of the carpel that produces ovules *unisex flowers (only carpels or stamens) promotes outcrossing Groups of flowers can form an inflorescence (attractive to pollinators) Coevolution of plants & their pollinators nectar used as reward over pollen (cheaper)
Fruit types
1. Simple (i.e. peach, apple etc.) • Derived from one singe flower (most common) 2. Multiple (i.e. Pineapple) • Derived from a cluster of flowers whose fruits grow close together 3. Aggregate (i.e. Strawberry) • Derived from one flower with several separate carpels • These carpels are united together to form a single structure (often times by the receptacle) A. Fleshy (thickened ovary wall) • Exocarp • Mesocarp • Endocarp B. Dry • Dehiscent = split open when ripe • Indehiscent = do not split open when ripe
Steps of Virus Infection
1.Attachment 2.Entry 3.Replication and Assembly 4.Egress (Release)
When a single cell protist goes through asexual reproduction, which of these is POSSIBLE? A haploid parent cell gives rise to two haploid daughter cells. A diploid parent cell gives rise to two haploid daughter cells. A diploid parent cell gives rise to four haploid daughter cells. Two haploid cells fuse to form a diploid cell. ALL of these choices are possible in asexual reproduction.
A haploid parent cell gives rise to two haploid daughter cells
Which of the following characteristics is typical of the lytic cycle of a bacteriophage?
A large number of phages are released at a time
Germination
A multicellular mycelium is formed
Fungal hyphae are characterized by?
Ability to secrete hydolytic enzymes and absorb nutrients across a large total surface area
Which statement is not evidence for evolution of land plants from green algae: Both plants and green algae have cellulose in their cell walls Both plants and green algae produce starch as their pricipal storage carbohydrate Some green algae have multicellular sporophyte and multicellular gametophytes All green algae produce large stationary eggs Two groups have the same photosynthetic pigments
All green algae produce large stationary eggs
Regarding the kingdom Fungi:
All multicellular forms have haploid nuclei the main fungus body is called a mycelium cell walls are reinforced with the polysaccharide chitin materials can easily stream through septate hyphae because of large pores
A Gram-negative coccus .... When treated by gram staining, looks pink and spherical under the microscope Has a wall with a relatively thinner layer of peptidoglycan than a gram positive bacterium has a second outer lipid bilayer in addition to its plasma membrane all of the above
All of the above
What is thought to be the origin of mitochondria of eukaryotic cells
An aerobic heterotrophic bacterium
Gymnosperm versus Angiosperm
Angiosperm= Seed surrounded by ovary fruit present flower developed 2 fertilization pollination with wind insects birds etc herbaceous or woody leaves expanded and pendulous gymnosperm= seeds naked fruit absent male and female cones (sporophyll) one fertilization (except for gnetophyta) pollination with wind generally woody leaves needle or scale like and persistent except gnetophyta)
Angiosperms versus gymnosperms:
Angiosperms: 1. Pollen grains form in anthers 2. Ovule(s) enclosed w/in ovary 3. Pollen lands on stigma 4. Pollen tube grows thru style & ovary 5. Double fertilization w/ 2 sperm nuclei Fertilization stimulates ovary wall & other parts to develop into fruit. Ovules develop into the seed
Hyphae (fungi)
Cytoplasmic threads with chitin cell walls Hyphae are made of tubular cells with rigid cell walls containing chitin Cell membranes contain ergosterol, not cholesterol - septate (cross walls) or coenocytic ("common cytoplasm") hyphae .Both allow rapid cytoplasmic streaming Feed by absorbing simple organic compound. secrete hydrolytic enzymes
Fungi importance
Decomposers: Break down dead tissues (including lignin) Mutualists: (Mycorrhizae) fungi living in close association with almost all plant roots (80- 90% of plants!) help plants absorb moisture & minerals, fungus "gets" sugars, etc., from plant pathogens food
Dr. Bio samples some pond water to observe under the microscope. She finds the specimen above, which seems to have a clear shell or wall with yellowish pigmentation within. No flagella or cilia are observed. Recognizing that this is clearly a unicellular organism, Dr. Bio's best guess as to its classification is:
Diatom
Zooxanthellae
Dinoflagellate + Cnidaran Symbiosis
The poisonous "red tides" result from blooms of
Dinoflagellates
Trends in the Evolution of Vascular and Seed Plants
Diversity and density of SVPs caused dramatic drops in atmospheric CO2 Global cooling and glacier formation (ice age results) Fern and lycophyte forests mainly grew in Carboniferous swamps and never completely decayed Coal formations almost all from Carboniferous forests
Animal Viruses
Do not have to penetrate a cell wall Associated with a bunch of human diseases Oncogenic viruses have the ability to cause cancer
Why can't dogs catch the measles? Dog cells don't have the receptors for the virus to attach to Answers: Dog cells don't have the receptors for the virus to attach to Dog cells aren't specialized enough for the virus to take advantage of Dogs don't come in contact with the virus Dogs have an innate immunity to the virus
Dog cells don't have the receptors for the virus to attach to
Characteristics of the 4 gymnosperm phyla
Dominant sporophyte life cycle - Vascular tissue - Seeds - Leaf adaptations to dry environments - Woody stems/bark - Heterosporous - Most are evergreen
Plant Viruses
Due to the host's cell wall, the virus needs a mechanism for entry (e.g., damage from weather, insects, animals)
Which statement is true of viral replication? In the process of apoptosis, the cell survives During attachment, the virus attaches at specific sites on the cell surface The viral capsid helps the host cell produce more copies of the viral genome mRNA works outside of the host cell to produce enzymes and proteins
During attachment, the virus attaches at specific sites on the cell surface
Human Pathogens
Euglenazoa: Trypanosomes African Sleeping Sickness Chagas Disease Leishmaniasis *INTERcellular parasites Apicomplexa: Plasmodium species malaria *INTRAcellular parasites
Match the following groups with the correct definition 1-exhibits alternation of generations and produces both motile zoospores and sperm 2- exists as large plasmodium and sporulates when conditions dry up 3-no cell wall, but have alveoli and a complex life cycle. Some are pathogens of humans 4- are key primary producers. Have silica skeletons and produce oil to maintain buoyancy 5- may be unicellular or colonial. Photoautotrophic and biflagellated 6- No cell wall, but pellicle. Some free living, others are choice parasites.
Euglenozoans-3 Diatoms-4 Brown Algae-1 Apicomplexans-6 Green Algae-5 2 is parabasilids
According to the theory for the origin of eukaryotic cells, a chemoheterotrophic eukaryotic ancestor to the photosynthetic eukaryotes derived photosynthetic organelles from:
Ingestion of a smaller prokaryotic cell
In the fungi, the process that directly produces the zygote stage is called
Karyogamy
Antibiotics
Kill bacterial cells but not eukaryotic cells penicillin affects peptidoglycan wall
nonvascular land plants
Liverworts: basal taxon Mosses: stomata present Hornworts: stomata present, persistently green sporophyte
Apical Meristems
Localized regions of cell division at the tips of roots and shoots Cells grown by meristems differentiate into specific tissues (epidermis, vascular tissue, leaves, etc.) Results in continual growth and complexity of above- an below-ground parts
Mycelium (fungi)
Mat of hyphae underground Reproductive bodies emerge to make spores "fairy ring"
Virus Egress
May involve: lysis and death of the host cell. budding, which does not directly kill the host cell.
2. Heterospory
Megasporangium produces megaspores that give rise to the female gametophyte (One functional) Retained within sporophyte Microsporangium produces microspores that give rise to the male gametophyte (Vast number)
Match the following plant groups with the types of leaves they have
Microphylls= club mosses, spike mosses megaphylls= horsetailss, ferns, seed plants *all seed plant leaves are megaphylls
4. Pollen and Sperm Production
Microsporangium develops into pollen grain that consists of male gametophyte enclosed with a pollen wall Pollination = transfer of pollen to the part of a seed plant that contains the ovules Pollen= microspores retained; mature into pollen grains while w/in microsporangium pollen grains = mature male gametophytes w/ sporopollenin protective coating. Then grows a pollen tube toward egg w/in ovule Pollination ≠ Fertilization
Prokaryote structure
No membrane-bound organelles no nucleus: DNA in nucleoid • ribosomes "free" No microtubules Three major cell shapes 1. Rods (bacillus/bacilli) 2. Spheres (coccus/cocci) 3. Spiral (spirilla or spirochetes) (Unicellular or cells in chains or clusters) Almost all have cell wall lies outside plasma membrane protects & prevents cell lysis (rupture) Bacteria: w/ peptidoglycan (PG) Archaea: w/ other structural polysaccharides Many have a capsule or slime layer Some have hairlike protein fimbriae
Which of the following is FALSE regarding the process of transduction? A virus is involved in the process. Only plasmid DNA enters the recipient cell. The donor bacterium dies. The recipient cell's chromosome is altered. Daughter cells are NOT produced
Only plasmid DNA enters the recipient cell.
Angiosperm Clade:
Phylum Anthophyta
Gymnosperm Clade:
Phylum Cycadophyta Phylum Ginkophyta Phylum Coniferophyta Phylum Gnetophta
Importance of Seedless Plants
Pioneer species in poor soils Mosses are major primary producers in cold and high areas Played an important role as fuel Peat moss
Protista groups
Plant-like autotrophic- (synthesize own food from inorganic substances) Animal-like (Protozoa) -Heterotrophic (eat other organisms) phagocytosis
Micropyle
Pollen tube terminates pore in integument of ovule Two sperm cells discharged 1 fertilizes egg to form zygote Other fuses with diploid cell of female gametophyte to make triploid cell Double fertilization > unique to angiosperms • Zygote develops into sporophyte embryo with 2 seed leaves called cotyledons Triploid cell develops into endosperm that will nourish sporophyte embryo
Rhizaria: Radiolaria
Produce mineral skeletons of silica Mostly marine zooplankton important fossils for relative dating
Which of the following statements is correct?
Prokaryotic life was responsible for a dramatic increase in Oxygen concentration in the earth's atmosphere before the Phanerozoic Eon
A geologist asks you to look at some ocean sediment, knowing this "dirt" contains the remains of dead protists whose hard shells have fossilized. You mix the sediment with water and examine it under the microscope. The "shells" or "tests" you observe will most likely belong to which group(s)?
Radiolarians, Foraminiferans, or Diatoms
An isolated bacterial colony grows into millions of cells from a single cell. Research has shown that even such isolated clones have the ability over time to adapt to a new environment. If such a clone has no gene flow from any other bacterial colony, what best accounts for the new gene diversity needed for adaptation?
Random mutation
One example of horizontal gene transfer is
The acquisition of genes associated with mitochondria from prokaryotes
An apple grower notices that several of his apple trees with fungi growing on their trunks have developed necrotic ring sports, while other trees in the orchard that lack fungi appear healthy. What is the most likely conclusion the farmer can make about the virus infecting his apple trees? The apple trees were infected by horizontal transmission The fungi carry disease The fungi attract disease carrying insects The apple trees were infected by vertical transmission
The apple trees were infected by horizontal transmission
Which statement is true of viroids? They are single stranded RNA particles they reproduce only outside of the cell They produce proteins they affect both plants and animals
They are single stranded RNA particles
How are viroids like viruses?
They both replicate in the cell They both contain nucleic acid
Which of the following characteristics correctly describes retroviruses?
They have single stranded RNA that acts as a template for DNA
Why are fungi important decomposers? They can grow in many different environments. They produce many spores. They produce mycelia. They recycle carbon and inorganic minerals by the process of decomposition.
They recycle carbon and inorganic minerals by the process of decomposition.
DNA Viruses
Viral DNA directs host to synthesize new copies of its genome and to translate and transcribe them into viral genome Less chance for error
RNA Viruses
To replicate in the host, the virus must replicate its own enzymes that can replicate RNA -> RNA or RNA -> DNA More chance for error
Archaeal genomes are typically organized as circular genomes, like bacteria
True
Retroviruses
Type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell.
Excavata: Euglenozoans
Unicellular no cell wall Genus: Euglena Aquatic, free-living Autotrophic Food and Beverages! Eyespot, light detector, pellicle complex pellicle (protein) underlies plasma membrane, allowing "euglenoid movement"
Chromalveolata: Ciliates
Unicellular •Injestive •No cell wall • Aquatic • Cilia for locomotion and feeding Macronucleus: chain of beads. Protein Synthesis Micronucleus: small an densely stained. Reproduction Both macronucleus (polyploid; controls cell functions) & micronucleus (used only for genetic recombination) divide animal-like in function Stentor, Vorticella. This Didinium is a predator on other ciliates! Paramecium
Chromalveolata: Dinoflagellates
Unicellular, Aquatic Two dissimilar flagella Cellulose armor (theca) Important component of plankton Some produce neurotoxins ("blooms" of some species kill fish or create toxic "red tides") cellulose deposited w/in the alveoli photosynthetic mutualists within corals Chemical reaction: luciferin (pigment) to excited state by enzyme luciferase to cause bioluminescence
Seedless Vascular Plants
Until vascular tissue evolved, all land plants were short, ground cover plants Vascular tissue allowed for efficient transport of nutrients (...plants become much larger) Diploid sporophyte dominates life cycle 2. Transport in Xylem and Phloem Evolution of true roots and true leaves
Which of the following statements correctly describes vaccines and how they help preventviral infection?
Vaccines are inactive versions f a virus that stimulate an immune response in a person
Vaccines and Antiviral Drugs
Vaccines= the primary method of controlling viral disease. prepared using weakened live viruses, killed viruses, or molecular subunits of the virus Antiviral drugs=Not usually able to cure a viral disease, but control and reduce symptoms. Inhibit the virus by blocking the actions of one or more of its proteins. Antibiotics will not affect viruses
Angiosperm Life Cycle
Very similar to gymnosperm life cycle with a few exceptions Pollen grain has several cells with specific functions Generative cell - divides into two sperm cells Tube cell - produces pollen tube in ovary Mechanisms to ensure cross-pollination Transfer of pollen from anther of a flower on one plant to the stigma of a flower on a different plant
Which statement is true? A virion contains DNA and RNA Viruses are acellular Viruses replicate outside of the cell Most viruses are easily visualized with a light microscope
Viruses are acellular
Devolution or regressive hypothesis (Virus evolution)
Viruses evolved from more complex free-living organisms that lost genetic material as they adapted to a parasitic lifestyle.
Virus first hypothesis (Virus evolution)
Viruses existed before all life as self-replicating entities that over time became more organized and more complex.
Which of the following statements correctly describes a difference between viruses and prions
Viruses generally cause disease symptoms quicky, whereas prions generally take many years to cause disease symptoms
Escapist or progressive hypothesis (Virus evolution)
Viruses may stem from pieces of RNA and DNA that escaped from a host cell and gained the ability to move between cells.
Bacteriophages
Viruses that only affect bacteria Lytic Cycle= the bacteria cell lyses (shorter). The phage DNA never merges with the host DNA Lysogenic Cycle= the virus DNA gets fused with the host DNA and can go through many asexual replications with the bacteria. (longer) The phage DNA will be excised from the host DNA under stressful conditions and enter the lytic cycle.
3. Ovules and Egg Production
Whole structure, including megasporangium, megaspore, and integument, is collectively referred to as an ovule female gametophyte develops from megaspore and produces one or more eggs Ovule = the megasporangium w/ retained megaspore + surrounding sporophyte tissue
How do yeasts differ from other fungi
Yeasts are unicellular
Which of the following aout seed plants is true all seed plant species are heterosporous seeds are produced only by flowering plants (angiosperms) the sporophyte generation is more reduced in seed plants than in the ferns. The gametophytes of seed plants are independent of the sporophytes The zygote of seed plants divides repeatedly to form the gametophyte
all seed plant species are heterosporous
Alternation of generations describes which of the following? the haploid form can be multicellular; the diploid form is unicellular the haploid form is unicellular, the diploid form can be multicellular both the haploid and diploid forms can be multicellular neither the haploid nor the diploid forms can be multicellular
both the haploid and diploid forms can be multicellular
Pick the correct match Diplomonad- flagellum supported by crystalline rod euglenozoan- cell wall of silica brown algae- multicellular seaweed diatom- ingestive heterotroph parabasalid- chloroplasts derived from secondary endosymbiosis
brown algae- multicellular seaweed
The viral ________ play(s) a role in attaching a virion to the host cell.
capsid envelope
Which polysaccharide is usually found in the cell wall of fungi Starch glucose chitin cellulose
chitin
Which of these protists is believed to have evolved following a secondary endosymbiosis? green algae cyanobacteria red algae chlorarachniophytes
chlorarachniophytes
WHich of these organelles is not found in a fungal cell? chloroplasts mitochondria nucleus golgi apparatus
chloroplasts
Which of these locomotor organs would likely be the shortest? flagellum cilium an extended pseudopod a pellicle
cilium
mycosis
infection due to fungus Many fungal infections are superficial (cutaneous) Antibiotics only target prokaryotic cells Compounds that kill fungi could also harm the eukaryotic animal host cells
In a typical fungus life cycle, plasmogamy
is the fusion of the cytoplasm of genetically different haploid mycelia
Which of the following is true of reverse transcriptase? it is a nucleic acid it infects cells it transcribes RNA to make DNA it is a lipid
it transcribes RNA to make DNA
Characteristics of Fungi
multicellular & terrestrial many Chytrids are aquatic some fungi are unicellular yeasts main fungus body is a mycelium network of filamentous (thread-like) hyphae absorptive heterotrophs
Chromalveolata: Brown Algae
multicellular, mostly marine "seaweeds" major primary producers w/ brownish accessory pigments large thallose form (thallus has blade, stipe, holdfast) cell wall w/ cellulose & algin kelp (Laminaria & other species) alternation of generations
Sexual reproduction fungi
no genders; instead: + or - mating types -three steps to form zygote: 1. plasmogamy = fusion of haploid + & - hyphae 2. heterokaryotic stage = hyphae w/ unfused haploid nuclei of both types 3. karyogamy = fusion of +/- haploid nuclei to form zygote zygote (2n) always does meiosis, making genetically diverse spores (n)
Facultative anaerobes:
normally use O2 but switch to anaerobic processes if no O2 present
Virus components
nucleic acid (DNA RNA) Protein capsid
Secondary compounds terrestrial plant adaptations)
organic compounds created by "offshoots" of the primary metabolic pathways in organisms
Haustoria
penetrate cell walls of host plant without killing cell specialized hyphae
Pigments
protection against mutagenic effects of ultraviolet radiation in terrestrial environments
Protists that have a pellicle are surrounded by: silica dioxide calcium carbonate carbohydrates proteins
proteins
Parasitism -
smaller parasite benefits at expense of other species (host) including pathogens (cause disease)
Gram negative
smaller peptidoglycan wall stains pink more pathogenic because of exotoxins outer lipopolysaccharide layer often toxic
Reproductive structures consisting of one or more photosynthetic cells surrounded by fungal hyphae are called
soredia
In fungal sexual reproduction,
spores are hapliod plasmogamy produces heterokaryotic cells. plasmogamy occurs before karyogamy.
Yeast is a facultative anaerobe. This means that alcohol fermentation takes place only if
the atmosphere does not contain oxygen
The host range of a virus is determined by
the proteins on the surface of the virus and that of the host
Which of the following statements about protists is FALSE? they are important components of plankton they live in very dry environments they can be free living or symbiotic flagella occur in many different protist groups they include the algae
they live in very dry environments
What is true of DNA viruses? they use the host's cell's machinery to produce new copies of their genome they all have envelopes They are the only kind of viruses that can cause cancer They are not important plant pathogens
they use the host's cell's machinery to produce new copies of their genome
Gram positive
thicker peptidoglycan wall stains purple
exotoxins
toxic substances that bacteria secrete into their environment
The difference between vertical and horizontal transmission of plant viruses is that vertical transmission is ___-:
transmission of a virus from a parent plant to its progeny, and horizontal transmission is one plant spreading the virus to another plant
Symbiosis
two species living in close relationship
Chromalveolata: Apicomplexa
unicellular endoparasites of animals no cell wall apical complex helps them penetrate host cells Plasmodium vivax = malaria Intracellular parasite. Transmitted by mosquitoes
Chromalveolata: Diatoms
unicellular phytoplankton ("algae") key primary producers (aquatic) w/ yellow & brown accessory pigments silica walls (glass-like) flagella only in gametes
Rhizaria
unicellular, axopodia, test Pseudopodia emerge through perforations in the test "Hole bearers" External shell = test Chitin Calcium carbonate Forams (Foraminiferans) Radiolarians
Excavata: Diplomonads
unicellular; multiple flagella; no cell wall anaerobic; reduced mitochondria most are parasitic Ex: Giardia intestinalis intestinal parasite durable cysts consumed in water
Bioremediation
using living organisms to clean up pollution, chemicals, sewage, oil spills, etc.
Viruses ______: All have a round shape cannot have a long shape do not maintain any shape vary in shape
vary in shape
Primary Producers
¼ of the world's photosynthesis Primarily marine Mainly dinoflagellates, diatoms, and multicellular algae Internal symbiosis
