Pl Sc 221 Part 2

Life cycle where there are at least two multicellular generations (gametophyte and sporophyte) linked by unicellular reproductive stages (gametes and spores)

Life cycle in which the main form is haploid, with a diploid zygote formed briefly.

Having a life cycle in which the main form, except for the gametes, is diploid.

The diploid (2n) spore-producing phase of the life cycle of an organism exhibiting alt. of gen.

Haploid (n) gamete-producing phase of the life cycle of an organism exhibiting alt. of gen.

a sex cell: one of two cells that unite to form a zygote

A haploid reproductive cell capable of developing directly into a gametophyte without uniting with another cell (asexual reproduction)

Nuclear division where the chromatids of chromosomes separate and form two genetically identical daughter cells.

Process of two nuclear divisions where the segregation of genes occur and a single diploid cell (2n) becomes 4 haploid cells.

Structure where spores are produced, can be unicellular or multicellular

Non-vasular plants: mosses, liverworts, hornworts

Seedless vascular plants w/ microphylls (leaves with only single vascular vein)

Seedless vascular plants with "true" leaves (megaphylls)

The gametophyte of ferns and their relatives

Any cell or structure in which gametes are produced

Male gametangium of certain algae, fungi, bryophytes, and vascular plants other than gymnosperms and angiosperms

The multicellular female gametangium of brophytes and most vascular plants other than angiosperms

A cluster of sporangia, usually used for ferns

Latin for "naked seed", has secondary growth, vascular system, seeds and pollen grain.

(fern) development of a single kind of asexual spores

Complete development of female gametophyte in original megaspore

• Cells in megasporangium that undergo meiosis (megasporocytes (2n) or megaspore mother cell) reduced to one.
• Megasporocyte gives 4 haploid megaspores during meiosis.

• Megaspore stays in sporangium.
• Integument grows from base of sporophyte and sporangium wall forms OVULE (immature seed)

Part of a female cone, a modified leaf

Part of a female cone, a modified lateral shoot system

the pollen sac

The production of both microspores and megaspores

A spore that develops into a female gametophyte

A spore that develops into a male gametophyte

A sporangium in which megaspores are found

A sporangium in which microspores are produced

Arrangement of leaves around the stem

• Greek for "vessel" and "seed". 2 major groups are monocots and dicots. Features are flowers.
• Endosperm
• No archegonia
• Second integument
• Vessels

Include sepals, petals, stamens, carpels.

Beginning of resumption of growth of seed after dormancy

Deoxyribonucleic acid

What genetic info is organized into

Ribonucleic acid. Sequences consist of same nucleotides of DNA but thymine replaced with uracil.

Genetic material carrying the info that contributes to the phenotype

Total of the observable features, result of the interaction of the genotype with the environment.

The variability of the phenotype depending on the given genotype and the environmental conditions.

A distinct characteristic of a phenotype

Each trait has two alleles, if they're the same it's homozygous, if they're different it's heterozygous.

Separate genes for separate traits inherited differently from each other in gamete formation

Recessive alleles always masked by dominant alleles

• 1. Traditional breeding experiments
• 2. Genetic engineering techniques
• 3. Other techniques like "assisted migration"

Different reproductive success of different phenotypes due to favourable trait combinations

Random process that eliminates part of the gene pool (ex. natural disasters)

Evolution of similar structures that occured at different points of origin due to environmental or other factors (ex. wings for birds, fins for sharks)

Evolution of morphologically different structures derived from a common ancestor (ex. limbs of tetrapods, horses, reptiles, humans share same bones).

Studies evolution below a species level (ex. population).

Studies evolution above species level, all the way back to common ancestors.

new species formed by geographically isolated populations

New population formed from small population isolated at edge of larger population

Continuously distributed population

New speciation formed within the range of the ancestral population

Kingdom, phylum, class, order, family, genus, species

Introduced by Carl Linnaeus, Genius first Species second.

A valid grouping

Invalid grouping, groups of organisms that include descendants from more than one common ancestor

Invalid grouping, groups of organisms that share the most common common ancestor but not all its descendants

binds to promoter region in gene and initiates gene transcription

with morphological and molecular data

Random movement of molecules from regions of higher concentrations to lower concentrations

the random movement of molecules

Made of solvent and solute mixed together

Solvent (in this case water) moving across a semi-permeable membrane to an area of lower concentration

Water-selective pore in the cell's plasmamembrane

Plasmolyzed

Flaccid

Turgid

0

Water always moves from areas with higher water potential to areas of lower water potential

solute potential + pressure potential +gravimetric potential

Always negative, expressed in MPa

• Can be positive or negative, expressed in MPa
• Aka "turgor pressure"

• Mass movement of water in response to a pressure gradient
• >99.5% of water movement in xylem occurs this way

Attraction of water molecules to each other

Attraction of water molecules to non-water molecules (wood, glass, etc)

• Result of adhesion and surface tension 
• Attractive forces b/w wood and water stronger than cohesive forces of water molecules

• Water absorbed through fine roots
• Water enters cells via osmosis
• Travels along negative water potential gradient to center and enters xylem

• Bulk of water absorbed + moved through plants by negative pressure
• Able to function b/c water is cohesive - sticks to itself through hydrogen bonding
• Tension part of this theory generated by transpiration - water evaporates and pulls more water up from roots

6 CO₂+6 H₂O -> C₆H₁₂O₆ + 6 O₂

Sugars, amino acids, other nutrients, hormones, mRNA

• Phloem loading is active and requires energy
• Sugar translocation from source to sink
• Movement in phloem sap is bi-directional

• Phototropism (light)
• Gravitropism (gravity)
• Thigmotropism (touch)

• Growth hormone, promotes elongation
• Production mainly in apical meristems
• Involved in tropisms (phototropism)

• Promote cell divisions
• Delay of ageing in leaves

• Increases stem growth dramatically
• Breaks dormancy of seeds and buds

• Synthesized in plastids
• Slows growth
• Induces dormancy
• Induces stomatal closure

• Gas naturally produced by fruits, flowers, seeds, leaves, and roots
• Promotes fruit ripening and ageing

Fixing CO₂ from the atmosphere via photosynthesis in organic compounds (CHO) then releasing CO₂ via respiration

Water vapour, carbon dioxide, methane, ozone

• Increased wildfire
• rising sea levels
• warmer winters
• more frequent and intense storms
• oceans acidification

Relationships between organisms and their environment and each other

Members of the same species in a given location

All the organisms in a given area or space

• A community and their physical environment interacting as a system
• Biotic and abiotic factors

• Bare rock
• No competitors 
• Pioneer species
• ex. Lichens, mosses
• Weathering/erosion breaks down rock and turns it into soil

• Soil is present
• Grasses and shrubs
• Woody pioneers
• More and more trees occupy area
• Climax forest

Distribution of vegetation types as a function of mean annual precipitation and temperature

Average pattern of temperature and precipitation over a long period of time

Short term patterns of variables like temperature and precipitation

• Tundra
• Taiga
• Temperate deciduous forest
• Grassland
• Desert
• Savanna
• Rainforest

Study of terrestrial biosphere by integrating human and ecological systems

• Growth determining factors (genetics)
• Growth limiting factors (environmental)
• Growth reducing factors (crop pests)

• Weeds
• Insects
• Diseases

Cause global losses of $300 billion US each year

A plant growing where it's not wanted

Any deviation from the normal state of a plant due to irritation by a pathogen or environmental factors

Infectious = transmissible

Non-infectious = non-transmissible

• Government level, aimed at exuding pests from a particular area or minimizing their spread
• Pest Management Act of Alberta

• Involves manipulation of the environment in order to make conditions unfavorable for the pest 
• Should be considered first line of defence
• ex. Crop rotation, sanitation, tillage

• Control of pests by other organisms
• Sometimes occurs naturally
• Potential for improvement by introduction/application of antagonistic microorganisms

Establishing one or more species of biocontrol agent(s) to regulate pest populations

• Biological agents mass produced and formulated: "biopesticides"
• Applied where and when they're needed

Enhancing existing populations of biological control agents

Use of compounds that are toxic to plant pathogens (fungicides), insects (insecticides), and weeds (herbicides)

Genetically modified crops, often for resistance against certain pathogens

Integration of all available genetic, cultural, biological, and chemical methods for pest control in a way to maximize their benefits and minimize their risks for producers, consumers, and the environment

Type of land that is unsuited for continuous cultivation and receives limited management inputs

The management of rangelands for the production of goods and services seemed desireable by society in general

The sum of evaporation and plant transpiration from the Earth's land surface to the atmosphere

• Agriculture potential? basic rangeland characteristic
• ex. 0.5 means double the water can evaporate from the land than is absorbed
• P:E ratio of 1 will support forests/continuous crop cultivation

The science, business, and practice of conserving and managing forests to provide sustained supply of forest products, forest conditions, or other values

Canadian Council of Forest Ministers

Managing forests to meet current needs without prejudice to their future productivity, ecological diversity, or capacity for regeneration

• Spatial arrangement of plants (horizontal + vertical)
• Amount of canopy gaps, dead logs, size differences, etc

• Diversity in a single place
• Community structure (number of size classes represented)

• Across a local landscape, series of different biological communities
• results from diff soil moistures, variation in disturbance history
• differences in dominant species, structure, age

• "Landscape" diversity
• diversity of multiple communities
• Major landscape features (mountains, large lakes, oceans) that result in life-form and species composition

Ecological succession

ex. trembling aspen, cutting of trees reduces auxin supply from shoot, stimulates growth of "suckers" on roots that will grow into shoots

• Art of producing and tending stands to achieve management objectives 
• Site preparation
• Regeneration practices/methods
• Vegetation Management
• Tending

• 1. Cultivation: deliberate sowing or management of plants
• 2. Domestication: human modification of a plant or animal that makes it obviously different than its wild ancestors

• 1. China (tea, soybean)
• 2. India (cucumber, nutmeg)
• 3. Central Asia (rice, sugar cane)
• 4. Near East (wheat barley, rye, oats, flax)
• 5. Mediterranean (canola, cabbage)
• 6. Ethiopia (yam, coffee)
• 7. Mesoamerica (maize, beans)
• 8. South America (potato, pepper, tomato)

• Parts of modern Iraq, Iran, Syria, Lebanon, Israel, Jordon
• Wild crops of many important crops still found in this area today

• Father of the Green Revolution
• Wiped out stem rust disease of wheat through selective breeding
• Helped increase crop yield in developing countries such as China and Africa

• Mechanized
• Economies of Scale
• Monocultures
• High inputs of pesticides, fossil fuels
• Environmental Costs?

• Less mechanized
• small scale
• High labour, low inputs
• multi-cropping

• 1. Conventional agriculture
• 2. conservation agriculture, minimum-till or no-till
• 3. Organic agriculture
• 4. sustainable (integrated) agriculture

• High yields
• tillage
• high inputs of fertilizer, pesticides
• limited crop rotations

• ~1985 on
• no till, planting crop on the untilled plant rubble from previous crop w/ little or no soil disturbance
• economically and environmentally friendly

• No synthetic fertilizers, pesticides, GMOs, etc
• greater use of rotations of legumes, animal manure, etc
• tillage for weed control (erosion)
• lower yields

• Minimum tillage + integrated crop management
• knowledge based
• minimize pesticides through: crop rotation, management, trap crops, etc