Exam 4

Classification of viruses has 2 parts

1st part divides viruses into 1 of 4 groups (I-IV) based on structure of genome, ex whether DNA or RNA (cant be both) or whether either one is single or double stranded. Group 1: viruses have double stranded DNA, chicken pox and cold sores virus. 2nd part is taxonomy of viruses: order, family, genus and species. Since viruses mutate (so they evolve) so rapidly they cant classify them into higher order taxonomic groups like domain or kingdoms. They are categorized by their size and shape and their type of nucleic acid and the presence or absence of an outer envelope.

ascomycota or sac fungi

2 main groups: sexual sac fungi and asexual sac fungi. Can be unicellular but most are multicellular. sexual sac fungi; yeast-unicellular fungi. Neurospora, morel mushrooms and truffles.fruiting body-reproductive structure where spores are produces and released. asexual sac fungi; yeast candida, molds apsergillus and penicillium. Budding, candiospores.

lycophytes also called club mosses

3 groups: ground pines (lycopodium) are homosporous, spike mosses (selaginella) and quilworts (Isoetes) are heterosporous. Microspores male gametophytes and megaspores develop into female gametophytes. They have dominant sporophyte generation.

5 phyla of fungi

Chytrids, zygospore fungi, AM fungi, sac fungi and club fungi.

3 genetic recombination of Prokaryotes.

Conjugation- 2 bacteria are temporarily linked together usually by conjugation pilus. while linked the donor cell passes DNA to recipient cell. Transformation- when cell picks up free pieces of DNA from its surrounding medium; this DNA has been secreted by live prokaryotes or released by dead prokaryotes. Transduction- bacteriophages carry portion of DNA from 1 bacteria cell to another. Viruses have also been found to infect archael cells and so transduction may play important role in gene transfer for both domains of prokaryotes.

Cyanobacteria

Gram negative bacteria, they can be unicellular, colonial, or filamentous. common in fresh and marine water, in soil and on moist surfaces.

Microphylls and megaphylls

Microphylls have single stand of vascular tissue. megaphylls have several branches of vascual tissue and are more broad.

Liverworts, Marchantia

Reproduce both sexually and asexually. gemmae can detach and start a new plant. antheridia are present in disk shaped structures. archegonia are present in umbrella-shaped.

Which of the following is incorrect

all flatworms are parasitic. All the correct answers; sponges are simplest animals, all jellyfish, sea anemones and corals have stinging cells called cnidocytes, roundworms have psuedocoelom, trichinella is a parasitic roundworm contracted by humans by eating undercooked infected pork.

All land plants exhibit

alternation of generations- 2 alternating forms in course of its life cycle.

Protists include all of the following organisms except

answer is plants and yeast. All protist include: algae, slime molds, protozoans, water molds, Paramecium, volvox, diatoms, spirogrya, amoeba.

halophiles

archaea require high salt concentration, few organisms are able to survive like Great salt lake, dead sea, solar salt ponds and hypersaline soils. these organisms are aerobic chemoheterotrophs. instead of chlorophyll they use bacteriorhodospin to capture solar energy.

Retroviruses

are animal viruses with an RNA genome that is converted into DNA within the host cell by special enzyme called reverse transcriptase. 1st reverse transcriptase synthesizes from its RNA genome a single DNA strand (cDNA) because it is DNA complement of viral RNA the single strand of cDNA is used to template to make double stranded DNA. then new viruses are produced.

thermoacidophiles

are isolated from extremely hot, acidic environments. they are chemoautotrphic anaerobes that use hydrogen as electron donor and sulfur as terminal electron acceptors for their electron transport chain.

bacteria called photoautotrophs

are photosynthetic, they use solar energy to reduce carbon dioxide to organic compounds. 2 types of these kind of bacteria. One evolved first and do not give off oxygen, the 2nd evolved later and do give off oxygen.

archaea (domain Archaea)

are prokaryotes with biochemical characteristics that distinguish them from both bacteria and eukaryotes. The plasma membrane of archaea contain unusual lipids that allow many of them to function at high temperatures.

bacteriophages

are viruses that parasitize bacteria. their are 2 alternative life cycles of bacteriophages; lytic and lysogenic cycles. either to 1 or the other or both at same time. lytic cycle- viral reproduction occurs right after virus enters the cell and host cell undergoes lysis, a breaking open of cell to release new viral particles. viruses that are highly virulent enter directly to this cycle. Ex Ebola lysogenic cycle- viral reproduction does not occur right away, but reproduction may take place sometime in the future. and enter lytic cycle. Ex HIV.

Viruses

associated with a number of plant, animal and human diseases. they are biological enigma. have characteristics of living organisms, like DNA or RNA(cant be both) genome and the ability to evolve and replicate, yet not considered living organism. They do not have metabolism and do not respond to stimuli. They are a small packet of genetic instructions for making copies of itself inside living cells.

facultative anaerobes

bacteria are able to grow in either the presence or absence of gaseous oxygen.

mutualism

both species benefit from association. this bacteria live in human intestine, where they release vitamin K and B12, also live in root nodules

The growth of microbes themselves does not cause disease

but the poisonous substance they release (toxin) are the pathological portion.

Lichens

can reproduce asexually by releasing fragments that contain hyphae and algal cell. In fruitcose lichens that sac fungus reproduces sexually. 3 types of lichen: compact crustos, fruitcose and foliose. they are efficient at acquiring nutrients and moisture, can survive in areas of low moisture and temperatures and areas with poor or no soil. cannot survive where air is polluted. Lichens can serve as air pollution sensors.

bacteria called chemoautotrophs

carry out chemosynthesis. they oxidize inorganic compounds such as hydrogen gas, hydrogen sulfide and ammonia to obtain necessary energy to reduce CO2 to organic compound.

Capsid

composed of protein subunits and an inner core of nucleic acid RNA or DNA not both. Viruses vary in shape, however all have same basic anatomy; the outer capsid.

Pteridophytes

consist of ferns, horsetails and whisk ferns. Seedless vascular plants. Have megaphylls- broad leaves with several strands of vascular tissue.

Lichens are

cyanobacterium and fungus, are green alga and fungus, are symbiotic relationships of 2 different organisms, crumble rocks to from soil, prepare the environment for colonization by other organisms and invade hostile environments.

The evidence that mitochondria and chloroplasts were once free living prokaryotes include the fact that they

divide by binary fission, have ribososmes similar to those found in prokaryotes, have circular DNA, have 2 membranes, have inner membrane similar to those found in bacteria.

lytic cycle

divided into 5 stages: attachment, penetration, biosynthesis, maturation and release. Attachment- portion of capsid combine with receptor on rigid bacterial wall in lock and key manner. Penetration- viral enzyme digest away part of cell wall and viral DNA is injected into bacterial call. Biosynthesis- viral components begin after the virus bring inactivation of host genes. virus takes over machinery of cell in order to carry out viral DNA replication and production of multiple copies of capsid protein subunits. Maturation- viral DNA and capsid assemble to produce several hundred viral particles. Lysozyme (enzyme coded for by viral gene) is produced results in bacteria cell dies.

reproduction in land plants

embryophyta- zygote and 2n embryo are retained and protected from drying out. sporophyte- 2n generation produces at least one and perhaps several multicellular sporangia. sporangia-produce spores by meiosis. gametophyte- spores become n generation. male gametangium- antheridium female gametangium- archegonium.

All plants are

eukaryotic, autotrophic, have cell walls made of cellulose, multicellular, ancestors of green algae and photosynthetic.

prions

fatal brain diseases have been attributed to prions. Proteinaceous infectious particles. They are proteins that normally exist in an animal but have different conformation, or structure. like virus, they cannot replicate on their own but cause infection by interacting with normal protein and altering its structure.

Name the plant that does not belong

gymnosperms

Which of the following associations is incorrect

gymnosperms- no gametophyte generation. True answers are: ferns-fronds, mosses- lack seeds, horsetails- cell walls with silica, angiospersm- monocots and eudictos, eudicots- branched veins in leafs.

All of the following are true about animals except that they

have tissues. correct answers are that do belong: are heterotrophic, lack cell walls, are multicellular, are motile during at least part of their life cycle, are eukaryotic, are artificially divided into invertebrates and vertebrates and are mostly invertebrates.

The following are true of all plants except

have vascular tissue. Plants include: make up 98% of biomass on earth, store glucose as starch, have nucleated cells, contain chlorophyll, protect the embryo and have life cycle called alternation of generations.

virus relies on .... to reproduce

host enzymes, ribosomes, transfer RNA, and ATP for its own reproduction

Viruses infect a variety of cells but they are

host specific

dikaryotic

hypha that contains paired haploid nuclei (n+n)

Viroids

in plant cell. are naked strands of RNA (not covered by capsid), like a virus they direct the cell to produce more vitroids.

In mycorrhizae fungi

increase the surface are for water absorption and mineral uptake

A spore

is a haploid reproductive cell that develops into a new organism without the need to fuse with another reproductive cell. In plant life cycle a spore (2n) undergoes mitosis and becomes a gametophyte (n)

Mosses

largest phyla of nonvascular plants. 3 groups: peat, granite and true mosses.

lysogenic cycle

latent, not actively replicating. following attachment and penetration, integration occurs; Viral DNA becomes incorporated into bacterial DNA with no destruction of host DNA. while latent viral DNA is called prophage. Prophage is replicated along with host DNA and all subsequent cells (lysogenic cells) carry a copy of prophage genome. presence of prophage may cause bacterial cell to produce a toxin.

3 main types of archaea (based on unique habitats)

methanogens, halophiles and thermoacidophiles

The simplest plants are the

mosses and liverworts

peptidoglycan

most bacterial cells are protected by cell wall that contains layers of plasma membrane and unique molecule peptidoglycan. it is a complex of polysaccharides linked by amino acids. 2 different kinds in Gram positive and gram negative. gram positive- bacteria have single plasma membrane and thick outer layer of peptidoglycan. Gram negative- bacteria peptidoglycan layer is sandwiched between 2 plasma membranes. most bacteria that are harmful to humans are gram negative, but gram positive bacteria is also responsible for human illnesses.

structure of fungi

most multicellular structure known as mycelium- network of fungal filaments, filaments are hyphae- which give mycelium a large surface to volume ratio. they lack chloroplasts and have cell wall made of chitin. fungi store energy as glycogen, except for chytrids.

Fungi

mostly multicellular eukaryotes. they are heterotrophs and consume preformed organic matter. They are saprotrophs- meaning they absorb food. animals and fungi share more common ancestor than animals and plants and plants and fungi.

Plants

multicellular

spore

nonmotile but normally windblown spores during both assexual and sexual reproduction. it is reproductive cell that develops into a new organism without the need to fuse with another reproductive cell.

there are no parasitic archaea

not known to cause infectious diseases.

Methanogens

obligate anaerobes found in swamps, marshes and intestinal tracts of animals. they have ability to form methane, type of metabolism performed only by some archaea. They are chemoautotrophes, using hydrogen gas to reduce carbon dioxide to methane and couple the energy released to ATP production.

parasitism

one species benefits while harming the other. cause diseases and are called pathogens. deadliest pathogens form endospores when faced with unfavorable environment, they are able to survive the harshest of environments.

commensalism

only one species benefits while the other is unaffected.

prokaryotes include bacteria and archea

organisms lack a membrane-bounded nucleus. on earth alone for at least 1.3 billion years. are adapted to living in most environments because they have wide variety of ways they can acquire and use energy. Move by flagella, adhere to surfaces by fimbriae, lack membranous organelles, have no nucleus instead have nucleoid- single chromosome consisting of circular strand of DNA. have plasmids- accessory rings of DNA. reproduce asexually by binary fission. Mutation happens faster. Are haploid so mutation are immediately subjected to natural selection.

Yeast are

saprophytic

glomeromycota or AM fungi

small group of fungi.most common fungi to form symbiotic relationships with plants. critical role in ability of plants to absorb nutrients with their roots.

obligate anaerobes

some bacteria are unable to grow in the presence of free oxygen. they infect oxygen-free environments in human body. serious illness from this include; botulism, gasgangrene and tetanus.

reproduction of animal viruses

some enveloped viruses process is simple as attachment and fusion of spike studded envelope with host cells plasma membrane Many naked and some enveloped viruses are taken into host cell by endocytosis.

Hornwort

some live on trees, majority live in moist, well shaded areas. they photosynthesize, and can fix nitrogen from the air. can bypass alternation of generations by producing asexually through fragmentation.

Which association is incorrect

spiders- an example of insects. All that are true include; insects- dominant animals on earth in terms of numbers of species. centipedes- arthropods. echinoderms- water vascular system as seen in starfish. chordates- includes humans and some invertebrates. lampreys- lack jaws. amphibians- need moisture or water to reproduce. reptiles- evolved the amniote egg. sharks- cartilaginous skeleton. bony fish- swim bladder and operculum. Mammals- milk producing glands. birds- feathers which are modified reptilian scales.

Bacteria (and archaea) described in terms of shape

spirilli- spiral shaped or helical shaped bacilli- rod shaped cocci- round or spherical.

bacteria called chemoheterotrophs

take in organic nutrients. they are aerobic saprotrophs (decomposers) that decompose almost any large organic molecule into smaller ones that can be absorbed.

In deuterostomes

the blastopore becomes the anus, the echinoderms and chordates are included, the fate of each cell is not fixed in embryological development

protist are

the first to have evolved on earth. A biologically diverse group of organisms. more similar to archaeans than to bacteria. A group of unicellular organisms that do not have a place in any other eukaryotic kingdom. Difficult to classify.

difference between archaea and bacteria

the lipids in archaea contain glycerol linked to branched chain hydrocarbons, lipids in bacteria contain glycerol linked to fatty acids. Cell wall of archaea do not contain peptidoglycan, mostly composed of polysaccharids, others pure protein and in some have no cell wall. Cell wall in bacteria contain peptidoglycan.

As plants have evolved

the sporophyte generation has become prominent

chytrids (fungi)

they are aquatic and have flagellated spores and gametes. may resemble first fungi to evolved. Some are single cells, others form branched nonseptate hyphae. most reproduce asexually through production of zoospores, some have alternation of generations life cycle. play a role in decay and digestion of dead aquatic organisms but some are parasites of living plants, animals and protists.

Viruses are obligate intracellular parasites

they cannot reproduces outside a living cell. a virus cannot duplicate its genetic material or any of its other components on its own. For virus to reproduce it must infect a living cell.

All of the following are true about tracheophytes except

they have seeds. tracheophytes include: have vascular tissue, include ferns, pine trees and flowering plants, mosses are not in this group, they are dominant on earth presently.

All of the following are true about mollusks except

they include ticks, millipedes and mites. all that are true include; have a head, include snails, have visceral mass, have a mantle, they include clams and squid.

zygospore fungi

they live off plant and animal remains in soil or in baker goods. Some are parasites of soil protists, worms and insects. are diploid spores produced during sexual reproduction. - and + attract to each other. sporangium- a capsul that produces haploid spores during asexual phase

All of the following describe fungi except

they only reproduce asexually. All fungi; includes black mold bread, are decomposers, have filaments called hyphae, includes mushrooms and puffballs, includes yeast, cause athletes foot and ringworm, include penicillium, are used to make bread, wine and beer, with cyanobacterium or green alga form lichens. with roots of plants form a symbiotic relationship called mycorhhizae.

Yeast (fungi)

unicellular

club fungi

usually reproduce sexually. basidium- club shaped structure where spores develop. Mushrooms. Smuts and rusts- parasitize cereal crops; corn wheat, oats and rye.

Seed plants

vascular plants that use seeds during the dispersal stage of their life cycle. Seeds conatin sporophyte embryo and store food within a protective seed coat. They are heterosporous (have microspores and megaspores) but retain spores and not release them into environment. 2 groups: gymnosperms and angiosperms.

emerging viruses

viruses that are able to infect large numbers of humans. ex AIDs, ebola, HPS, bird flu