Midterm 2 Flashcards
What kinda tree is the tallest?
redwood
What is the oldest type of tree?
bristlecone pine
What is the biggest tree?
sequoia
What is the green revolution?
When major progress made around the 1950-60’s with fertilizers, irrigation, etc. – worried it maxed out agricultural products
What are the 2 definitions of a seed?
- a mature, fertilized ovule that acts as a dispersal unit for seed plants
- contains an embryo, food source and seed coat (testa)
What is 2n composed of?
diploid, 2 chromosomes each composed of 2 alleles (4 alleles total – allele = version of a gene)
What is n composed of?
haploid, 1 chromosome
What is the sporangia
aka “mother cell”, is a sexual organ where meiosis occurs to produce spores (n)
What is the alternation of generations life cycle?
alternation between a haploid (n) gametophyte phase and a diploid (2n) sporophyte phase in the life cycle of a sexually reproducing plant (circle of gametophyte to sporophyte)
What is a gametophyte?
the haploid gamete producing phase in the life cycle
Formed in sexual organs (antheridia / archegonia) – reproduces sexually – undergoes mitosis
Whats the difference between a gamete and a spore?
spore: germinates and develops into a sporeling
gamete: combines with another gamete to form a zygote
What is a sporophyte?
the diploid spore producing phase in the life cycle – reproduces asexually – undergoes meiosis
Bryophytes (gam/spo dominant, homo or hetero)
small, non vascular plants (mosses, liverworts and hornworts) – gametophyte dominant – homosporous
Ferns (gam/spo dominant, homo or hetero)
sporophyte dominant – homosporous
Gymnosperms aka seed plants (gam/spo dominant, homo or hetero)
sporophyte dominant – heterosporous
What is homospory?
the production of one type of spores asexually (same size and type)
What is heterospory?
the production of 2 different types of spores asexually (2 sizes and 2 sexes)
Conifer characteristics
Seeds are in cones (naked seeds)
Cones = a collection of reproductive structures on a short axis
2 types of cones on the same tree (pollen male cones and seed female cones)
What are pollen cones?
many microsporangia that produce microspores which become microgametophytes (pollen) – have 2 air sacs (air bladders) on either side that help with wind distribution (reduce density) – pollen consists of 4 nuclei and is dispersed only through wind
What are seed cones?
each woody scale on the cone has 2 wings and 2 seeds (ovule = seed before fertilization)
Ovule characteristics
Surrounded by integument (2n - tough) Has 2-5 archegonium, each with their own egg (n) (only 1 seed in total carries on tho) Female gametophyte (n) acts as the food source
What are serotinous cones?
require heat to open and release seeds (resin glues it together)
Clears the landscape so lots of sunlight
Provides lotsa nutrients (ash) in the soil to grow
Yews and juniper berry special characteristics
have individual seeds surrounded by a red fleshy aril (part of the seed coat) // juniper berries are fleshy seed cones, not really berries or fruits
What are the big 3?
wheat, corn and rice
What is the hilum?
basically the belly button, where the ovule was connected to the ovary
What is the cotyledon?
they are food storing organs
What does the coleoptile enclose?
plumule
What encloses the coleorhiza?
radicle
What is the pericarp?
Meso, endo and ecto
What is the endosperm?
primarily composes seed, where food is stored (starchy)
What 3 things does germination require?
temperature, water and oxygen
Why isn’t sunlight important?
only certain plants require it to germinate since they can use the food stored in the seed
What is desiccation and why do seeds do it?
it allows them to stay viable during unfavourable conditions, like a “sleeping” dry stage
What are the 3 stages of germination?
- imbibition (absorb water)
- Lag phase (repairs damage done by desiccation)
- Radicle emergence (when the radicle breaks through the seed coat and concludes germination)
What is dormancy?
a period of growth inactivity in seeds or buds, even when environmental requirements for germination are met – used to assure the seeds will germinate at the proper time, often times in the spring
What are 2 ways to break dormancy?
mechanical breaking of the seed coat (scarification) or by cold temperatures – chilled and moist (scarification)
What is the definition of genetics?
the study of how traits are inherited from one generation to the next
What are genes?
make up chromosomes, they are coding DNA
What is the genetic code
set of rules that translate nucleotide sequence into amino acid sequence
How many codons do humans and plants have?
10 for humans, 20 for plants
What does it mean that plants are polyploid?
they have homologous chromosomes (whereas humans/mammals are diploid)
What is the law of independent assortment
that 2 traits determined by 2 genes are passed to offspring independently of each other (Mendel – not accurate)
What are quantitative traits?
show continuous variation – determined by several genes and are influenced by the environment
What is the definition of adaptation?
the process and the product of natural selection
What is an adaptive trait?
structural or physiological – heritable and maximizes fitness (ex. C4 plant)
What are provenance trials?
common garden experiments (helps pick planting stock that is well adapted to local growing conditions) (when you compare different versions of a plant under the same environmental conditions - shows genetic and environmental variation on the phenotype)
What are 3 ways of modifying plants?
Traditional breeding
Transgenic plants
Genome editing in the future tho
What is plant breeding?
accelerated evolution guided by humans, rather than nature
What is green revolution and who was the father of it?
Norman borlaug was father of it
Stem rust fungus (in Mexico) – find one resistance and cross with a local breed – made them self sufficient in wheat production
What does breeding depend on (for plants)?
genetic diversity
What do gene banks do?
they preserve agricultural diversity (dried seeds or frozen plant parts to provide that genetic diversity)
What are transgenic plants/
produced by inserting genes from virtually any organism into plants (to introduce resistance to insects and herbicides - roundup ready crops that are resistant to round up herbicide that suppresses weeds)
What are the inserted genes of transgenic plants called/
transgenes
What is agrobacterium?
soil bacterium, inserts T-DNA that contains gene of interest from its plasmids into plants chromosomes
What helps to clone a gene (produce a transgenic plant)?
e coli that’ll mass produce the gene of interest
What are particle guns?
shoot DNA on gold particles into plant tissue
What is the definition of taxonomy?
describing, naming and classifying organisms (oldest branch of plant study)
What is nomenclature?
a system of naming objects
What is a taxon?
a taxonomic group at any level in the hierarchical system
What is a monophyletic group?
includes all the descendants of a particular common ancestor and the ancestor itself
What is the language of science?
Latin
What is the binomial system of nomenclature?
all living organisms are given 2 word latin scientific name (a species name – one scientific name in latin, many common names to the same species)
How does the binomial system of nomenclature vary from varieies?
varieties have 3 parts to their name (subspecific – trinomen) whereas binomical naming only ever has 2
Who was Carolus Linnaeus? (x2)
Published species plantarum (the starting point for naming vascular plants)
Developed latin names for organisms
Abbreviated names to 2 parts (binomials)
Little letter at end of name = who named it (if L it’s probably Linnaeus)
What is the starting point for naming vascular plants?
the species plantarum
What are cultivars?
arise from human activity (are created by humans)
What would you use to name wild species?
the international code of botanical nomenclature
What would you use to name cultivated plants?
international code of nomenclature for cultivated plants
What are 2 rules for naming a new species?
A unique name and description must be published (latin + genus)
A type specimen of the new taxon must be deposited in a herbarium and available for study for anyone interested
What is a type specimen?
a preserved (dried) plant that is typically deposited in a herbarium (a collection of preserved plant specimens)
What are some features about taxonomic keys?
they are used to aid in the identification of organisms Mostly dichotomous (presented with a pair of choices for different character states of a character or feature of the organism)
What are closely related species grouped together called?
genera (aka genus)
What is the order from variety to kingdom?
Kingdom - Phylum - Class - Order - Family - Genus - Species - subspecies/variety
What is the most fundamental level of classification and what is its definition?
species: a set of individuals closely related by descent from a common ancestor
What was the most significant event in evolution?
the origin of life 3.5 billion years ago
What are the 6 kingdoms?
animals, fungi, plants, protists, archaea and cyanobacteria
What are the 3 domains?
bacteria, archaea and eukarya
What are protists?
A very broad group (includes lotsa organisms)
Not monophyletic and not a natural kingdom
Probably will be broken down in the future
What are cyanobacteria?
prokaryotes that have chlorophyll, produce oxygen and fix nitrogen
How might chloroplasts have originated?
as cyanobacteria living within other cells
What is a clade?
it shares one common ancestor
What does polyphyletic mean?
derived from more than one ancestor (unrelated) lack a most recent common ancestor
What does paraphyletic mean?
consists of the most recent common ancestor and some of its descendants
What does monophyletic mean?
consists of the most recent common ancestor and all of its descendants
What do phylogenic trees (evolutionary trees) consist of?
monophyletic groups
What do bryophytes include?
mosses, liverworts and hornworts
What do plants have in common with green algae?
chloroplasts a and b, carotenoids, starch and cellulose
What differentiates plants with green algae?
plants grow on land, algae in the water and plants release embryos with a parental tissue surrounding them for protection, whereas algae doesn’t
How do bryophytes reproduce?
sexually but need water for it
What are some features of mosses?
have antimicrobial properties, acidify water around them, damage to peatlands can release a lot of carbon into the atmosphere, increase water retention of soil since they have hollow cells that allow for water storage in between photosynthetic chlorophyll cells
How do gemma cups work?
they allow certain bryophytes to perform asexual reproduction and distribute with rain
What are gemmae?
small discs of tissue growing into new gametophytes
Why are bryophytes often small?
they have no vascular tissue (no xylem or phloem) or roots so no circulatory system
How does coal originate?
it comes from organic plant matter
Features of seedless vascular plants
ferns and their relatives – they have true roots and stems
Features of lycophytes
Can get very tall since they have vascular tissue (KEY)
Heterosporous (2 types of spores)
Features of horsetails
Scale like leaves (whorled)
Stems do photosynthesis
Sporangia at the tip of some stems
Can be a weed
Features of ferns
Fronds are often large and much divided Vascular, free sporing and homosporous The underground stem = a rhizome Most abundant in tropical regions but also found in cooler climates Sporangium act as a catapult
Conifer features
Narrow tracheids so they are freeze resistant
Needles: have thick cuticle, sunken stomata and endodermis
Trees or shrubs (most are evergreen)
Resin canals
Stress tolerant
Susceptible to bark beetles when stressed
What is part of the cypress family?
junipers and redwoods
What is the largest family of conifers?
pine family
Ginkgophytes features
one living species left, living fossils (VERY OLD), male and female trees, deciduous
Gnetophytes features
Grow in very dry conditions Use fog moisture / condensation for water CAM photosynthesis Some are very old Looks old and scraggly
Angiosperm features
Monophyletic (1 common ancestor)
Ovules are enclosed in an ovary (gymnosperms = naked)
Ovary becomes a fruit
Use double fertilization, creates a 3n endosperm
Have flowers that provide lots of interactions with animals
Have sieve elements, companion cells and xylem
Roses features
Flowers attract bees, insect pollination
Many with edible fruits
Many ornamental trees and shrubs
Lilies features
Monocot, herbaceous
Large flowers with their parts arranged in threes
Grow from bulbs
Beautiful ornamental plants
What is the reaction for photosynthesis and respiration?
Energy + Co2 + H2O = C6H12O6 + O2
Going right is photosynthesis, going left is respiration
What is the endosymbiosis theory?
When a free living cyanobacteria was engulfed by a larger cell (also prokaryotic) to form a symbiosis where cyanobacteria does photosynthesis within larger cell (large cell benefits) – cyanobacteria turns into a chloroplast – then to green algae and plants
How do plants sense light?
with photosynthestic pigments (ex. chlorophyll)
How do seeds detect light?
with phytochrome
What are blue light receptors?
located in stomata – sense light in the early morning and take up carbon dioxide from the atmosphere
What light has higher energy?
blue has higher energy than red light
What did einstein state about light?
light is composed of particles of energy called photons
How do pigments work?
they absorb certain wavelengths (colours) and reflect others
What is colour?
what an object or something reflects
Why are carrots orange?
because they absorb green/blue lights but reflect red/orange/yellow lights
What are carotenoids?
accessory pigments in photosynthesis (that help chlorophyll absorb light), absorbing wavelengths that chlorophyll doesn’t (helpers)
Roles in antioxidants
Roles in photoprotection
Bonds are double then single then double then single…. (alternating)
What is the principal pigment of photosynthesis?
chlorophyll
Where is chlorophyll located?
in the thylakoid membranes of algae, cyanobacteria and plants
What 2 fancy elements do chlorophyll require?
nitrogen and magnesium
What is the difference between a and b chlorophyll?
they have different absorption peaks
What is the purpose of hydrophobic tails for chlorophyll?
to help anchor them in the thylakoid membrane
What do chlorophyll rings do?
absorb energy
What are the 3 things that might happen when chlorophyll returns to its ground state?
fluorescence, energy transfer or electron transfer
What is fluoresence?
when excited chlorophyll returns to ground state and emits photon of lower energy and a bit of heat (lower E = longer wavelength)
What is energy transfer?
When it passes energy to a neighbouring chlorophyll molecule (only works when they’re close together) – electron becomes excited in an excited state – occurs in photosynthesis
What is electron transfer?
in photosystems of light reactions (is a chemical reaction), loses electron to an acceptor molecule and starts a light reaction – occurs in photosynthesis
How does a light reaction occur?
starts at photosystem 2 in the thylakoid membrane, then electron transfer to electron acceptor then the light reaction occurs
What do photons do (x3)?
- have energy
- cause electrons to become excited
- excite chlorophyll
What are anthrocyanins?
provide photoprotection during the breakdown of chlorophyll (hypothesis)
Red pigments
Where are chloroplasts located?
in the mesophyll
Where does photosynthesis occur?
in the leaf within the thylakoid membrane
What 2 things are photosystems composed of?
reaction center and antenna pigments
What is the reaction center?
where electrons are passed on (in membrane so they can be packed tightly together so they can transfer the electrons)
What does NADPH do?
its an electron transporter
Where do light reactions occur?
in the thylakoid membrane
How is ATP created in photosystems?
when electrons flow from the thylakoid membrane out into the stroma
Where does the calvin cycle take place?
in the stroma
What is water?
= the molecule of life
Provides structural support / turgor (=pressure within a cell)
Drives growth of cells and tissues
Medium in which nutrients are transported in xylem, and in which sugars are transported in the phloem
- polar
How does water create cohesion/adhesion?
through hydrogen bonds
What does metastable mean?
not being in a stable equilibrium state
What are 3 examples of metastable water?
stretched, glassy and supercooled water
What is stretched water?
liquid under tension
What is glassy water?
below freezing, different molecular arrangement of molecules than ice has
What is supercooled water?
water that remains a liquid below 0 degrees
How is water in the xylem?
it is liquid even though it should be in a vapour phase (under tension = negative pressure)
- prone to cavitation
What is diffusion?
follows concentration gradient from high to low, acts under short distances
What is cavitation?
the static pressure of a liquid reduces to below the liquid’s vapour pressure, leading to the formation of small vapor-filled cavities in the liquid
What is osmosis?
diffusion across a semipermeable membrane from a region where the solvent is more concentrated to a region where it is less concentrated
What is bulk flow?
the movement of water and any solutes together – driven by either a positive or negative pressure difference
What are aquaporins?
Channel proteins that facilitate the transport of water across semipermeable membranes
Valves, not pumps (don’t use ATP)
Narrow and effective, make water transport much faster
Facilitate rapid plant movement, such as in sensitive plants
Why are xylem and phloem in close proximity to one another?
so they can exchange water between the 2 of them
Where is there the highest pressure?
in the phloem
What kinda transport is vascular transport?
bulk flow
What are source cells?
food production (loading of sugars) – leaves
What are sink cells?
store produced food (stems/roots/growing flowers)
What kinda pressure is there in the xylem and what kinda transport?
negative and passive
What is Munch’s pressure flow hypothesis?
states that phloem sap (water and sugar) is moved by a pressure gradient
- Maintained by loading at source and unloading at the sink
What does an increase in solute concentration mean?
an increase in pressure
What is phloem loading?
Creates a high sugar concentration at the source
Water enter phloem by osmosis creating very high pressure
At sink, sugars are unloaded and water exits the cell
What does phloem sap contain?
hormones, amino acids, RNA, viruses and many other molecules
What is the closest thing plants have to a nervous system?
the phloem
What is apoplasmic loading?
Active transport of sugars from apoplast (cell wall bundle sheath) into companion cell
Sugars can’t leak back to the bundle sheath mesophyll
Most herbs do this
What does apoplasmic loading attract?
Attracts water through osmosis
What is symplasmic loading?
Sugar follows a downhill concentration gradient from bundle sheath into the phloem
All cells are well connected via plasmodesmata
Most trees do this
(no pump, most likely why sugar content is higher in the bundle sheath to begin with)
What are p-proteins?
protein filaments that float around however when damage occurs, they surge to the next sieve plate and fill/block it (temporary measure)
What is callose?
blocks pores so phloem don’t leak (polysaccharide – a more long term solution)
How do aphids help scientists?
used to collect phloem sap – they stick their mouth until it reaches a sieve element (phloem) and it rises up through body and out their butt – helps scientists extract it
What is transpiration?
water lost from mesophyll cells in leaves diffuses through stomata into the atmosphere
What kinda transport is there in the phloem?
osmosis and active
What happens when air gets into xylem?
embolisms – ruins the whole vessel
What is guttation and how is it undone?
water drops on leaf tips due to positive rather than negative pressure in the xylem (caused by root pressure) – xylem sap
Early in the morning due to pores on the surface
Undone by transpiration
What kinda root pressure is there in birch?
Strong enough to collect xylem sap at the base of the tree but too weak to refill vessels at heights higher than 2m or so
Only occurs before the leaves emerge in the spring
What is ecology?
it studies the relationships of organisms to each other and to their physical environment
What is a population?
a group of individuals of the same species in the same area
What is a community?
all or some of the organisms in a common environment (may study competition, succession or conservation)
What is an ecosystem?
consists of all the organisms in an area and the physical environment with which they interact (includes plants, animals, soil, water and nutrient cycles)
What is succession?
changes in the composition of a community from the initial development of vegetation to the establishment of a climax community
What is primary succession?
no soil present - on bare rocks and lava - soil forms eventually, no competition at first
What is secondary succession?
soil is present - species become established from existing seeds - disturbances such as fire, logging or abandoned farmland - normally regrowth is from things that have been able to remain below the soil
How do plants change successional stages?
by manipulating their own environment via soil, light or moisture
What is a climax community?
relatively stable communities at the end of ecological succession (subject to change eventually but stable at the moment)
What is a pioneer species?
don’t need soil to grow (ex. Lichens and mosses)
Where is the majority of water found on earth?
97% of all water on earth is in the ocean, 3% is in freshwater (most of which is frozen)
Only 1% of earth’s water is available freshwater (groundwater/aquifers)
How do plants contribute to the water cycle?
via uptake, transpiration and facilitating infiltration
What is the most limiting factor for crops?
water
How much of global water is used for agriculture?
70%
Why don’t farmers just grow drought tolerant plants?
because they’re super slow growing, need water basically for production
How do plants contribute to the environment?
they facilitate infiltration and reduce runoff – they also modify humidity and influence climate
What are biomes?
similar biotic communities considered on a worldwide scale (bigger than ecosystems)
How are biomes classified?
according to dominant vegetation which is determined by its climate
How are biomes usually organized?
as latitudinal belts
Every 1000m decreases the temp by how much?
6 degrees
Characteristics of a conifer forest
medium ish temp, lotsa rain (vancouver)
Characteristics of a desert
high temp, little to no precipitation (vegas)
Dominated by drought tolerant shrubs
Great basin desert
Wide temperature ranges, low precipitation
Vegetation depends on the desert
Plant adaptations (small leaves, drought resistant xylem, water storage tissue, CAM or C4, underground variations, deep roots)
Characteristics of a temperate grassland
similar temp to desert, slightly more rain but still minimal amounts
Characteristics of a tropical rainforest
high temp, lotsa rain
Characteristics of a temperate broadleaf forest
medium-high temp, average rain
Characteristics of an arctic and alpine tundra
little to no precipitation, low temp
Characteristics of a boreal forest (aka taiga)
Contributes to the annual cycling of CO2 levels (important for the C cycle)
Dominated by spruce, fir, pine and larch (not much species diversity)
Long, cold winters and low precipitation
Poor soil due to conifer needles
Characteristics of a mountain forest
Many conifers, broadleaf trees and shrubs
Cooler temp, dry summers (water comes from snow melting since its at low elevations)
Conditions get worse with altitude, lotsa steep slopes
Characteristics of a temperate deciduous forest
Light limited floor
Deciduous (drop leaves in winter) trees (maple, oak, beech)
Distinct seasons
High precipitation, moderate temperatures
Several canopy layers
What is the largest biome?(across eurasia and north america)
the taiga / boreal forest
What is forest ecology?
the study of plants and animals and how they interact with one another and the environment
What forest do we mostly have in canada?
boreal
What is a forest?
an area dominated by trees with at least 25% cover of trees
- Make up 40% of surface in Canada
- Important for watershed protection
What are some examples of disturbance agents?
lightning, fire, wind, insects, etc.
What are natural subregion local differences influenced by?
precipitation, temperature and elevation
What is boreal region dominated by?
aspen, pine and white spruce
What are lowlands dominated by?
black spruce
What is xeric?
dry and poorly irrigated sites (drought tolerant pine and lichen)
What is mesic?
average moisture content and support aspen and spruce
What is hydric?
periods of prolonged flooding (difficult for trees to survive due to the anaerobic conditions for tree roots) support black spruce and tamarack
What are the 3 layers of forest?
Upper layer: canopy
Under layer: shrub/herb layer
Forest floor (mosses, litter, etc.)
What provides light in forests?
canopy gaps
What is shade tolerant?
the ability to establish and grow in shade
What is shade intolerant?
need strong light for establishment (fast juvenile growth)
What is shade tolerant?
can establish and grow at low light (slower juvenile growth)
How does fire/logging affect forests?
it stimulates roots to sprout new shoots (large amounts per hectare – 100,000 is common)
What is partial harvest forestry?
keeps shade on the site at all times, tends to promote shade tolerant trees
50% of light to be transmitted to the lower level
Reduces frost damage in partial areas
Costs more to log but there are always substantial sized trees on site
What is transpiration?
water evaporating from the leaves (through the stomata)
What is sublimation?
the direct transfer of frozen water to water vapour
What is interception?
water held in the canopy of trees
What can interception cause?
sublimation
What prevents erosion?
a physical barrier
What controls nutrient cycling?
the thermal barrier
What are canopies?
Carbon storage factories
Carbon uptake/storage = release back the atmosphere over the long term
Forest fires, insects and disease can speed the cycle of carbon back to the atmosphere
Solid wood products take carbon out of the loop (atmosphere)
Forest floor and deeper soil might store as much or more carbon than in the trees
What is a crown fire?
Massive release of energy and carbon
Consumes fine fuels including soil carbon
Dangerous and fast moving, cannot be fought on the ground by workers
What controls forest type?
temperature and moisture
What is the potential yield?
theoretical, determined by genetics (will grow to the best of its ability, best it can)
What is the attainable yield?
what’s expected due to growth limiting factors (environmental conditions) less than potential, will never have perfect growing conditions
What is the actual yield?
what grower actually ends up harvesting, influenced by growth reducing factors (less than attainable yield)
What does crop protection focus on?
maximizing actual yields and reducing impact of growth reducing factors
What is a weed?
a plant growing where it is not wanted
What is the definition of disease?
any deviation from the normal state of a plant due to irritation by a pathogen or environmental factor
What are the 4 canola diseases?
White stem root
Blackleg
Clubroot
Alternaria blackspot
What 5 things does pest management rely on?
Regulatory Cultural Biological Host resistance (for insects and diseases) Chemical
What are regulatory strategies?
they’re aimed at excluding pests from a particular area or minimizing they spread at a government level
What are cultural management strategies?
involve manipulation of the environment in order to make conditions unfavourable for the pest (first line of defense) – crop rotation, sanitation and tillage
What is biological control?
the control of pests by other organisms (sometimes occurs naturally)
What are suppressive soils?
they contain microorganisms antagonistic to a pathogen
What are classical biological control methods?
involves establishing one or more species of biocontrol agent(s) to regulate pest populations
What are inundative biological control methods?
biocontrol agents are mass produced and formulated (biopesticides) – applied when and where they’re needed – produced in a laboratory
What are augmentative biological control methods?
enhancing existing populations of biocontrol agents
What is host plant resistance
Represents inherent ability of crop plants to restrict, slow down or overcome pest infestations and diseases
Simplest and most convenient method of insect pest and disease control
Plants are bred for resistance by crossing with related plants carrying the desired resistance genes
3 examples of chemical control
Use of compounds that are toxic to plant pathogens (fungicides), insects (insecticides) and weeds (herbicides)
Where are. the majority of pesticides used?
western provinces
What are transgenic crops?
crops containing gene(s) that have been transferred into the plant using recombinant DNA technology
What are the 4 principal transgenic crops?
soybean, corn, cotton and canola
Where does insect resistance come from?
insecticidal proteins from bacillus thuriengis
What is genome (gene) editing?
Insertion, deletion or replacement of DNA at a specific site in the genome of an organism
Why is gene editing great?
it provides tools to create Insertion, deletion or replacement of DNA at a specific site in the genome of an organism plants and allows for elimination of foreign genetic elements
How is genome editing achieved?
by using nucleases (cut RNA/DNA)
What are gene edited plants considered in the US?
not considered as genetically modified
What are gene edited plants considered in Canada?
gene edited organisms will fall under existing regulations (regulated based on novelty of product – premarket assessment)
What are gene edited plants considered in Europe?
top court gave gene edited crops same stringent legal status as GMOs
What is integrated pest management?
Integration of all available methods for pest control in a way to optimize their benefits and minimize their risks for producers, consumers and the environment
What are rangelands?
elands
Includes grasslands, shrublands and barrens 40% (+ forests 30%) = 70% of world covering
Provides forage and habitat for free ranging animals
Native herbivores and/or domestic herbivores
Often support multiple uses (wood, water, wildlife and recreation)
- not suited for continuous cultivation and recieves limited management inputs
- Climate + topography + soils + disturbance (3 abiotic and 1 biotic factors)
Where are rangelands primarily found?
on public land
What is crop land?
smaller than rangelands and are managed to hit maximum output, short term practices
What is energy flow?
the ability of a plant community to convert sunlight into biomass (forage and habitat)
What is nutrient cycling?
the efficiency of nutrient uptake, assimilation and return
What is hydrologic function?
the efficiency of water capture (infiltration), retention by soil and subsequent uptake by plants (ex. water cycling)
What creates vegetation?
= soil + climate +topography + disturbance (fire, herbivory, flooding, drought, disease)
Why is fire important?
it prevents trees and shrubs from overrunning grasslands and is important for the creation of open habitats, control of woody species and vegetation renewal
What is stocking rate?
the intensity of use (too much causes degradation - want moderate levels)
What is the intermediate disturbance hypothesis?
that herbivory often increases species diversity
Removal of grazing may reduce productivity due to litter accumulation and vegetation stagnation
What are the 3 things diffusion depends on?
pressure, temperature and density of the medium
What is the osmotic potential?
the potential of water to move from one cell to another as influenced by solute concentration
Water gained in a cell by osmosis may result in what?
it becoming turgid (turgor pressure)
What is the water potential?
its osmotic potential and pressure potential combined (favours that with higher water potential)
What is the pressure potential?
the turgor pressure that develops against the cells walls as a result of water entering the vacuole of the cell
What is the primary method that water enters plants from their surrounding environments?
osmosis
What is plasmolysis?
the loss of water through osmosis which is accompanied by the shrinkage of the protoplasm away from the cell wall (can be undone)
What is imbibition?
the final step of germination: the absorption of water and therefore the swelling of organic materials because of adhesion of the water molecules to the internal surfaces
What is active transport
when plants absorb and retain solutes against a concentration gradient
What gets produced in leaves when water stress occurs?
abscisic acid (hormone)
What does a loss of potassium from the leaves result in?
leave when photosynthesis is not occurring it causes the stomates to close since water is leaving
What is guttation?
when water gets forced out of the plant by root pressure
What are the mouths of aphids called?
stylets
What are the 6 most common macronutrients used by plants?
N, K, Ca, P, Mg and S
Oxidation vs reduction
oxidation = the loss of one or more electrons reduction = the gain of one or more electrons
What is the difference between chlorophyll a and b?
a = 3x more of it, makes cells more green b = transfers energy to a
What occurs during the calvin cycle?
CO2 mixes with rubisco to produce glucose/sugars/energy
If a plant has both photosystems 1 and 2 what can it do?
they can produce NADPH and oxygen as a consequence of electron flow
What is the reaction center of both photosystems and what can it do?
1: 700
2: 680
it is the only molecule that can use light energy (numbers refer to the peaks in the absorption spectra of light – wavelengths)
What do antenna pigments do?
they function together like an antenna in gathering and passing light energy to the reaction center molecule
What kinda leaf anatomy do C4 plants have?
Kranz
What is respiration?
the release of energy from glucose molecules that are broken down to individual carbon dioxide molecules
What is aerobic respiration?
respiration that requires oxygen – most common form of respiration
How does an increase in temperature affect respiration rates?
it increases them
What is assimilation?
when plants use the products of photosynthesis (ATP)
What is digestion?
the conversion of starch and other insoluble carbohydrates to soluble forms
What is the order of classification?
K-P-C-O-F-G-S
What are Nicolai’s 8 centers of origin?
China India Central asia Ear east (wheat, barley, rye, oats, flax) = fertile crescent Mediterranean (canola/cabbage) Ethiopia (sorghum, yam + coffee) Mesoamerica (maize/beans) South america (potato/pepper/tomato)
What is the fertile crescent?
where agriculture took root (cradle of civilization)
What was one of the first cities?
Uruk
Whats the difference between ancient and modern wheat?
ancient was very stuck to the seed, it needed a lot of manipulation
What is cultivation?
the deliberate sowing or management of plants (does not necessarily differ from wild populations)
What is domestication?
the human modification of a plant/animal – one that is identifiably different from its wild ancestors and its wild relatives (involves genetic change through conscious or unconscious human selection)
What are some effects of agriculture?
Increase in population
Permanent settlements
Development of complex social structures
Increased dependence on fewer plant and animal species
Increased dependence on on stored food
Feast and famine due to crop failure or weather, etc
Problem of disposal of human and animal waste
What does a food surplus become?
fuel for urban life
What was the order of agricultural advances?
Crop rotations with legumes (1200-1300)
Columbian exchange (1492) (back and forth exchange between europe with north america, brought a pandemic and products)
Mechanization – industrial revolution (1750) – seed drill (evenly distributed and put them at correct depth for growth)
Mineral fertilizer (1940)
Pesticides (1950)
Green revolution with norman borlaug (1970) (created semi dwarf varieties with stem rust resistance – prevented lodging (heavy top causes them to fall over))
Biotechnology: genetically engineered crops
Old world of europe to the new world of the americas
What are some traits of developping world agriculture?
Less mechanized Small scale High labour Low level of inputs (manure) Simple equipment Multicropping (at least 2 crops grown in the same field in the same year) Intercropping (2 crops grown at the same time in the same year) Subsistence, sales at local market
What are some traits of modern agriculture?
Mechanized
Economies of scale (large acreages, declining farm populations)
Monocultures: a single crop type and genotype in a field
High inputs of fertilizer, pesticides and fossil fuels
Biotechnology
Soil conservation
Organic agriculture
Sustainable agriculture
What does biotechnology provide?
a massive amount of food production (less land to grow equivalent amounts of food)
When did canada start no/0 tillage?
1985 onwards
What are some benefits of no/0 tillage?
Lower labour costs Increased yields Reduced fuel consumption Carbon sequestration Soil conservation (decline in soil losses) Reduces wind erosion
Organic agriculture has no what?
No synthetic fertilizers, pesticides, herbicides, hormones or GMOs allowed
What is food freedom day?
the date when the average canadian has earned enough income to pay for their food both at home and in restaurants for the entire year (normally takes around 6 weeks and $4100) – anticipated to increase $$$ and time to achieve in the upcoming years
What are some traits of sustainable agriculture?
Minimum tillage and integrated crop management
Knowledge based
Minimize use of pesticides
Reintegration of plant and animal agriculture
More human input
What is a rare plant?
based on the size of the populations and number of stations occupied by a species in a particular region (at risk – defined region)
What is considered a species at risk?
one that faces a high probability of becoming extirpated in a region or extinct in a short period of time (not always rare)
What is the definition of extinction?
a species that no longer exists in the wild
What is the definition of extirpated?
a species that no longer exists in a defined geographical area (but might exist elsewhere)
What are 3 things that natural extinction / extirpation are caused by?
Physical changes in the environment (climate, geologic changes, etc.) Biotic factors are important too: small populations, competition, disease Stochastic event (tsunami, meteorites, hurricanes)
What is human induced extinction / extirpation caused by?
Habitat change/destruction of habitat
Pollution
invasive/introduced species
Exploitation of the species itself for food/medicine etc.
What are 2 things that can make a species susceptible to becoming extinct/extirpated?
Habitat specialization, often combined with habitat rarity (ex. Late snowbed due to global warming)
Life history characteristics (biology of species, ex. Inability to reproduce and disperse)
What is a risk category?
it describes the probability that a species will become extinct or extirpated in the near future – assigns a risk category and assessments are done by a panel of experts
What does COSEWIC stand for?
committee on the status of endangered wildlife in canada
What does IUCN stand for?
international union of the conservation of nature
What is the definition of endangered?
a wildlife species facing imminent extirpation or extinction
What is the highest level of risk?
endangered
What is the definition of threatened?
a wildlife species likely to become endangered if limiting factors are not reversed
What is the definition of special concern?
a wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats
What are the 7 risk categories for COSEWIC?
extinct, endangered, extirpated, threatened, special concern, data deficient and not at risk
What is the classification for endangered species in Alberta?
endangered species conservation committee (ESCC)
What is the classification for endangered species with no legal listing in Alberta?
Alberta conservation information management system (ACIMS)
What are the variables or factors used for assessment?
Declining population size Small population size Extreme population fluctuation Restricted distribution Severe fragmentation
What is the criteria used for assessment?
Declining total population
Small distribution, fragmentation, decline or fluctuation
Small total population size and decline
Very small population or restricted distribution
Quantitative analysis
What are some of the hotspots in canada?
southwestern BC, garry oak ecosystem urban development
Southern okanagan, vineyards urban development
Prairie provinces, agriculture
Southern ontario/quebec, agriculture urban development
What are some defining features of white bark pine?
Grows high up
Alpine rocky slopes or subalpine
Cones covered in tar
Threatened by mountain pine beetle and white pine blister rust (goes into and cuts off cambium to distal portions of the branch, tree cannot reproduce “living dead”)
What are some defining features of soap weed (yucca)?
Small population size
Possible loss of habitat
Consumption of flowers by herbivores may be limiting
Dependence on yucca moth for pollination (moth itself is endangered)
What are some defining features of apple moss?
Tree removal Rock removal Pollution Changes in microclimate because of micro hydro development (diverted water goes down penstock to a powerhouse with turbines and generators) Wildfire Small population size
How do mosses reproduce?
Asexually through fragmentation
What are some functions of peat moss?
incredible water absorbers, antiseptic properties, soil conditioned and fuel
What are groups of sporangia called?
sori (sorus is singular)
What is an annulus?
it catapults spores out of the sporangium (influenced by moisture changes in the cells)
What are petrifications?
uncompressed rocklike materials in which the original cell structure has been preserved
What does gymnosperm mean?
naked seed
What is conifer wood considered to be?
soft (no thick walled cells), whereas broadleaf trees is hard
What does dioecious mean?
the male and female reproductive structures are produced on separate trees
What is eutrophication?
the gradual enrichment of a body of water through the accumulation of nutrients resulting in a corresponding increase in algae and other organisms (accelerated by pollutants and sewage)
