BSC 111: Chapter 20, 21, 23, 25 Definitions and Key Concepts

Virus

noncellular parasitic agent consisting of outer capsid and innercore of nucleic acid

Obligate Intracellular Pathogens

replicate using the metabolic machinery of host cells

Outer layer of a virus

protein capsid contains genetic material that will attach to a host cell through tissue specificity, lock and key fit, or target immune response

Outer Membranous envelope

outer layer of a virus is derived from the host cell's plasma membrane

Attachment Step(Lytic Cycle )

virus gains based on proteins on a cell and virus (must match) within the cells of specific living Organisms -> determined by the structure of proteins in the naked capsid in the spikes of an enveloped virus

Penetration step (Lytic Cycle)

host cell engulfs virus or injects genome into cell

biosynthesis step (lytic cycle)

viral component synthesized using host cell

Released step(Lytic Cycle)

new viruses exit the host cell through lysis or budding to infect new host cells

Lysogenic Cycle

After penetration, bacterial cell is integrated into bacterial DNA and is passed on when bacteria reproduce. Causes the bacteria to go dormant and will be activited with the chnages in the enviroment

lytic cycle starts immediately

in animal viruses reproduction:

Seasonal FLu (RNA Virus)

-Influenza A-virus: host changes, caused epidhous -Influenza B and C: only in humans Rapid mutation rate

HIV/AIDS

Retrovirus: Animal viruses with an RNA genome that is converted into DNA within the host cell by reverse transcriptase ->AIDS ->Human Immuno Deficiency

Emerging Viruses

Outbreak of previously unknown disease or known disease that increase in occurrence -Mutated from existing RNA -Expanded host range -Antigenic shift -vector born

Viral Diseases in Plants

-Can occur due to varroids > 10,000 known viruses

Viroids

RNA with no capsid

Prions

misfolded proteins that can transmit their misfolded shape onto variants of the same protein

Fatal Neurovegetative Brain Disease

TSEs(transmissible spongiform encephalopathies) caused by prions -Scrapie -Chronic Waste Disease -Kuru -Mad Cow Disease

Prokaryotes

single celled, lacks membrane bound nucleus and the membranous organelles typical of eukaryotes -> Evolved 3.5 BYA

Cell Wall

Provides support and shapes to a prokaryote cell

Capsule(Slime Layer)

helps parasitic bacteria protect itself from host cell defenses

Fimbriac

hairlike bristles that allow adhesion to surfaces

Flagellum

rotating filament that propels the cell

Conjunction Pilus

elongated, hollow appendage used to transfer DNA to other cells

Ribosome

site of protein synthesis (smaller than eukaryotes)

Nucleoid

single chromosome containing a few thousand genes that codes proteins

Plasmids

accessory rings that contain genes for antibiotic resistance

Binary Fission

Prokaryote reproduction where the cell splits and genetically identical sister cells -allows rapid population growth because every individual our reproduce - disadvantage: less genetic variation

transformation

Source of genetic variation where prokaryotes can absorb and express genetic material from environment

transduction

source of genetic variation where the process of transferring genetic material from one cell to another by a plasmid or bacteriophage

conjugation

source of genetic variation where genetic material transmitted by plasmids -Cells connect by conjugation pilus -donor cell passes DNA to recipient in the form of a plasmid

Peptidoglycan

Composition of Domain bacterial cell walls

gram-negative

indicates that a bacteria has a thin peptidoglycan wall and a extra LPS membrane layer

Spirilla

Spiral

Bacillus

rod shaped

coccus

circle

Strepto

chain

Stapho

clump

autotrophic

of or relating to organisms that can make complex organic nutritive compounds from simple inorganic sources by photosynthesis

heterotrophic

requiring organic compounds of carbon and nitrogen for nourishment

Bacterial Photoautotrophs

photosynthetic bacteria

Facultative anaerobes

bacteria is able to growing either the presence of absence of gaseous oxygen

Chemoautotrophs

bacteria that carry out chemosynthesis -oxidize compounds to obtain the necessary energy to reproduce CO2 to an organic compound

Chemoheterotrophic

bacteria that obtain carbon and energy in the form of organic nutrients produced by other living things

Symbiotic relationship

close relationship between two different species

Mutualistic Symbiosis

both species benefit from the association

Parasitic Symbiosis

one species benefit, the other is harmed

Commensalism symbiosis

one species benefits whereas the other is unaffeced

Endospores

formed by pathogens within a cell wall a copy of chromosome and cytoplasm shriveled into a dormant state, are encased by a heavy coat

Antibiotics

treatment that targets prokaryotes cell wall production in humans

cyanobacteria

Gram-negative bacteria that photosynthesize-> produces oxygen Contains chlorophyll Common in fresh and marine waters, soil, and on moist surfaces Form lichens that can grow on rocks

Roles of Bacteria

Producers: Responsible for the oxygen revolution An important part of marine phytoplankton (food and oxygen production)

Domain Archaea

bacterial cells with pseudopeptidoglycan cell walls Extremophiles: live in conditions of acidity, pressure, temp, salinity that would kill most other cells

Extreme Halophiles

archaea that live in extreme salt conditions

extreme thermoacidophiles

archaea that thrive in hot acidic environment

Methagenes

archaea that generate methane -> exist in swamps and animal intestinal tracts

Protists

eukaryotes that are not animals, fungi, or plants Single-celled, but some exist as colonies of cells or are multicellular

Endosymbiotic theory

proposes that eukaryotic cells acquired mitochondria and plastics(including chloroplasts) by engulfing a free-living bacterium that developed a symbiotic relationship within the host cell -Mitochondria derived first from the endosymbiosis of an aerobic bacterium

mitosis

protists will reproduce asexually by

sexually

protists reproduce how when environmental conditions are unfit

giardia

protist parasite causing serious disease

dinoflagellate

Single celled phototrophs important component phytoplankton Cellulose plates surround two flagella Causes Algae blooms: population explosion cause tides -water turns red or brown due to pigments

plasmodium

protist that causes malaria performs antigen switching

inside the insect vector

the sexual stage of plasmodium occurs

in human blood cells

the asexual stage of plasmodium occurs

Diatoms

A type of algae Single-celled phototrophs Part of phytoplankton as a source of oxygen and food in aquatic ecosystems

Diamtaxous earth

fossilized diatoms used in abrasives

brown algae

true algae -Multicellular phototrophic -Kelp -Homoplastic with plants due to convergent evolution

oomycetes

fungus like protists water molds with a filamentous body, chitin cell walls instead of cellulose

Entamoebas

-parasite Used pseudopods to ingest cells-> uses a temporary arm like projection of a cell to move organisms Acquired through contained water and soil Causes amoebic dysentery

Slime molds

Important decomposer of dead plant material, fungi, and bacterial Reduce spores but homoplasy with fungi is due to convergent evolution Amoeboid movement using cytoplasmic streaming

red algae

Multicellular photoautotrophs (seaweed) Red and blue accessory pigments in addition to photosynthetic chlorophyll Pigments allow for us of the wavelength of light present in deep water

green algae

algae Phototrophs Most are multicellular, but some are unicellular Contain chlorophyll, scratch, and a cell wall with cellulose Charophytes: first closet relatives to modern land plants

Algae

photosynthetic organisms in freshwater habitats that re most closely related to land plants Transition between protist and landplants

Aquatic

the vast majority of green algae are

green plants (virdiplantae)

green algae + land plants

-water cuticle -stromata -Vascularity

Land Plant adaptions to water loss

Stromata

pores in land plants that open and close to regular water and gas exchange

vascular tissue

tissue that conducts water and nutrients through the plant body in higher plants

tracheid

long tubular cell peculiar to xylem, conduct water upward from roots

Flavonoids

An adaption land plants made through pigments that absorb UV rays

Dominate diploid generation

Shift to this minimizes the effect of genetic mutation in plants due to UV rays by having two copies of the same gene

Haplodiplontic life cycle

multicellular haploid and diploid life stages

alternation of generations

a life cycle that alternates between two distinct multicellular haploid and diploid stages

Haploid (n)

cell condition in which only one of each type of chromosome is present,

gametophyte generation

haploid generation of the alternation of generations that produces gametes that unite to form a diploid zygote ->al spores divide by mitosis to produce the gametophyte -> produces gametes by mitosis

Diploid (2n)

cell condition in whcih two of each type of of chromosome are present

sporophyte generation

diploid generation that produces haploid spores that develop into the haploid generation ->produces 4 haploid spores

sporangium(2n)

organ containing or producing spores

spore(n)

asexual reproductive cell capable of developing into a new organism without union with another cell. Within the gametocyte part of alteration of generation

gametangia

male and female gamete producing regions

Antheridia

male gametangia; produce sperm

archegonia

female gametangia; produces eggs

Gametophyte Dominant

What generation is dominnst in mosses

microscopic

When a sporophyte gains dominance the gametophyte is

Sporophyte dominance

In Vascular plants, what is the dominate generation

non-tracheophytes

all non-vascular plants -> Dominant gametophyte generation -> restricted to living in a wet environment

Phlyum Bryophyta(non-tracheophytes)

Mosses -> typically low laying -> superficial leaves, roots, and stems -> multicellular gametangia form at the tips of gametophytes

Phlyum Marchantiophyta (non-tracheophytes)

Liverworts -> flattened gametophytes with liver like lobes -> microscopic sporophyte -> can produce sexually or asexually

Gemma cups

Asexual reproduction done by liverworts; contain a fragment of parent plant. When water fills the cup, the fragments spread tne reproduction occurs

Phylum Anthocerotophyta(non-tracheophytes)

Hornworts -> Sporophytes are photosynthetic and embedded in the gametophyte tissue

Tracheophytes

All Vascular Plants Dom. Sporophyte Generation: gametophyte reduced in size relative to sporophyte

Cooksonia

the first vascular plants No roots or leaves Oldest known plant to have stem with avscular tissue

xylem

tissue that conducts water and dissolved minerals upward from roots, develop in sporophyte -> one way flow

phloem

conducts sucrose and hormones throught the plant two way flow

Stems

first to evolve in early tracheophytes

roots

provide transport and support for plants

Microphyllis

leaves with a single vascular strand -> found in lycophytes

Megaphyllis(true leaves)

leaves that contain branches of vascular strands -> found in ferns and seed plants

Leaves

increase surface area for photosynthesis -> evolved twice

Pteridophytes

Spore Plants ->Lycophyta -> Pteriophytes

Phlyum Lycophyta

Seedless Club mosses, spike mosses, quillworts contain microphyllis leaves

Phlyum Pteridophytes

Spore plants Ferns and friends Require water for flagellated sperm

Ferns(Pteridophytes)

most abdudant group of seedless vascular plants closest living relative to seed plants Have distinct sporangia in cluster that are on the back of fronds (sori)

Fronds

leaves on ferns that develop at the top of the rhizome as tighlty rolled up coils (fiddleheads)

Horsetails (Pteridophytes)

One Genus= Equisteum Sporophyte consists of ribbed jointed photosynthetic stems

whisk fern

chiefly tropical clump-forming plants of skeletal appearance resembling whisk brooms w/o true leaves

Spermatophytes

Seed Plants

Functions of the Seed

-> Facilities dispersal of embryo -> allows developmental clock to be paused in inhospitable environment ->protects and provides food for the embryo -> plants no longer dependent on water for reproduction

seed

contain a sporophyte embryo and stored food with a protective coat. Once the coat forms, most of the embryo’s metabolic activities stop. Germination Can't take place until water and oxygen reach the embryos

Serotiny

seed release occurs in response to an environmental trigger rather than at seed maturation ex: seeds release in wild fires

Reproduction in Seed Plants

Game gametophytes= pollen grains -Dispersed by wind or pollinator -No need for water Female gametophytes= embryo sack -Develop within an ovule in the ovary -Enclosed within diploid sporophytic tissue in angiosperms -Angiosperm ovaries develop into a fruit Angiosperms: enclosed within diploid sporophyte tissue

Gymnosperms (Naked Seeds)

-Ovule exposed on a scale ->All lack flowers and fruit

Phylum Coniferophyta (gymnosperm)

-Largest and most familiar gynosperm division ->Pines, spruces, cedars, firs, cypress Male gametophytes(pollen grains) develop micropsores> air sacs Female gametophytes (larger): form on the upper branches of a tree, Develop 2 ovules on each scale develop spores which develop into haploid diploid Produce cones that carry seeds

Dry Cones

open, wildfire

Wet cone

damp, less prone to wild fires

Cycadophyla- cycads( gymnosperm)

slow growing in tropical and subtropical regions dioecious largest sperm cell of all organisms

dioecious

having male and female reproductive organs in separate plants or animals

Gnetophytes(gymnosperms)

Contain Vessel elements (w/ trachedis) in xylem 3 genera -only gymnosperm with vessel elements ex: Welwitschia

Gingokophyta (gynmosperm)

-Out dated ecology -Dioecious

Angiosperms

all flowering plants Unclosed seeds

Antophyta(angiosperms)

Largest and most abundant group of plants Ovules enclosed in diploid sporophyte tissue at the time of pollination

Ambroella

Most closely related to earliest angiosperm

Archaefructus

oldest known angiosperm in fossil record lacked sepals and petals extinct

-Insect pollination -flowers -braod leaves with thick veins

Adaptions of Angiosperms

Sepals

Outer most whorl Protects budding flower and supports leaves and petals

Petals

second whorl typically colored attracts pollinators

Stamens (Androecium)

male gamephyte produced

anther

the part of the stamen that contains pollen; usually borne on a stalk

filament

the stalk of a stamen

Carpels (gynoceium)

innermost whorl house the female gametophyte

stigma

the apical end of the style where deposited pollen enters the pistil within the carpel

style

neck or stalk of the carpel, connects stigma to ovary

ovary

the organ that bears the ovules of a flower within carpel

pollination

transfer of pollen from the anther to the stigma of a plant -mediation by insects -petals attract animal pollinators

Double fertilization

unique to angiosperms Each pollen grain contains two sperms One sperm unites w/ egg to form diploid zygote The other sperm unifies with 2 polar nuclei to form triploid endosperms (nutrients for the embryo)

fruit

mature ovaries of angiosperms during seed formation, ovary begins to develop into fruit Adaption for seed dispersal

Vessel elements

long tubular formations with perforation plates at each end. Placed end to end to form a completely hollow pipeline from the roots to leaves

Essteintial nuritents

Vessel elements trancheids

Conducting cells in the xylem

Essential nutrients

elements or compounds that plants cannot synthesize -has identifiable role no other nutrient can sub. for deficiency of nutrient disrupts plant function

Carbon, Hydrogen, Oxygen

3 main essential nutirents of a plant

soil, water, and air

How nutrients is obtained by a plant

soil

a dynamic mixture of living and non living components

Macronutrients

nutrients required in large amounts; significant components of nucleic acid, proteins, and phospholipids. ex: nitrogen, phosphorus, potassium

micronutrient

nutrients required in small amounts; act as cofactors for specific enzymes Vital for plant health even though they're only required in a tiny amount ex: copper

humus

partially decomposed organic matter; the organic component of soil

weathering

gradual wearing down of solid rock by rain, running water, and wind. transforms rock into soil -> creates gravel, silt, and clay

soil texture

determined by the relative proportions of gravel, sand, silt, and clay ->Affects the ability of roots to penetrate the soil to obtain water and nutrients and to anchor and support plants ->Affects the soil’s ability to hold water and make available to plants ->Affects the inability of oxygen for cellular respiration

Ionic charge of nutrients -soil texture -Soil pH

Factors affecting nutrient availability

Anions in Soil

negative charge readily avaliable for plants can leach->very quickly washed out by rain causing the loss of nutrients

Cations in soil

positive charge not immeditaley avlaible interact with negative charges found on ogranic matter and clay particles

positive

charge of cations

Cation Exchange

protons and other cations bind to the negative charge on soil particles. Causing the release of bound nutrient cations (Mg2+. Ca2+) Nutrients are then available for uptake. Hydrogen ions switch places with a positively charged mineral ion, and the root takes up the nutrient

Negative charged soil

retain nutrients because cations stay attached to it

tracheid

in vascular plants, type of cell in xylem that has tapered ends and pits through which water and minerals flow

grow to large sizes

development of tracheids helped land plants to:

cations

must be exchanged for H+

obliagte anaerobes

bacteria that cannot survive when oxygen is present

facultative anaerobes

can survive with or without oxygen

aerobes

must have oxygen to survive

hemagglutinin and neuraminidase

proteins that are in influenzas viruses

chronic wasting disease

TSE(prion disease) that affects deer

mad cow disease(Bovine spongiform)

TSE that affects cows

kuru

TSE disease marked by increasing lack of coordination and advancing to paralysis and death within a year of the appearance of symptoms

transmissible spongiform encephalopathies

TSE

negative charge

charge of clay