Plant Biology Unit 1

Introduction

What is science? - It;s the study of the natural world through observations and experiments and the knowledge obtained from the process. What is biology? - The scientific study of life (living organisms) and interactions with one another and their environment. Natural sciences consists of physical and life sciences. Anarobic: without oxygen. Avoid using question marks in hypothesis and avoid using the word "proved" in lab reports.

Properties of Living Things

All living things are composed of cells Ordered complexity - all living things are complex and highly ordered Sensitivity - responds to and/or produces stimuli Growth and development Reproduction - sexual or asexual Energy utilization and manipulates matter Regulation and homeostasis - coordinate internal processes and maintains internal conditions different from the environment Evolutionary adaptation - genetic change in a population over time

Classification

Classification - the sorting of objects into groups based on their similarities and differences Taxonomy - the science of identifying, naming, and classifying organisms. Phylogeny - the evolutionary history of an organism. Used to create evolutionary trees. Domain>Kingdom>Phylum(divisions)>Class>Order>Family>Genus>Species

Binomial Nomenclature

Binomial nomenclature - a scientific name contains two parts, the genus and species name. The first letter of the genus is capitalized, all other letters are lowercase. Underlined in notes but italicized in text.

Three Domain System (Current)

Bacteria > Archaea > Eukarya (Fungi, Protista, Plantae, Animalia) Old system, Five Kingdom System:  Monera > Protista > Plantea > Fungi > Animlia

Photoautotrophs

Photoautotroph - an organism that makes its own food (organic compounds) using light energy. (Bio 6) photo = light auto = self troph = feeder Heterotroph - an organism that gets its food (organic compounds) from other organisms. (Bio 4) hetero = other troph = feeder

Photosynthesis

Photosynthesis is used by plants, algae (protists), and some bacteria, organisms that use photosynthesis are –photoautotrophs and the producers for most ecosystems. Photosynthetic Autotrophs: Plants (mostly on land), forest plants Photosynthetic Protists (Aquatic), Kelp Photosynthetic Bacteria (Aquatic), Cynobacteria

Plants are photosynthetic or originated from Photosynthetic ancestors. These plants are not photosynthetic, but had ancestors who were photosynthetic. PLANTS ARE MULTICELLULAR Plants consist of multiple cells and have structures that are specialized for different functions. Cyanobacteria and algae have simpler body structure. PLANTS CONTAIN CHLOROPHYLLS A & B. Cyanobacteria and algae other than green algae utilize other photosynthetic pigments. Plants are adapted to life on land or descended from organisms adapted to land -advantages: more light and CO2 -disadvantages: desiccation, need for structural support, mutagenic radiation and sperm need new strategies to get to egg PLANTS ARE SESSILE AND TERRESTRIAL Plants are anchored in place at their bases. Plants provide protection to the embryo, the protection is the seed.

Photosynthesis (Chemical Process)

Transforms light energy into chemical energy Uses carbon dioxide and water as starting materials. The chemical energy produced via photosynthesis is stored in the bonds of sugar molecules Carbon Dioxide + Water = Glucose + Oxygen Glucose can be made into: Complex carbohydrates, lipids, proteins, nucleic acid, ATP (ATP is the primary energy molecule for the cell)

Chloroplasts

Chloroplasts- the site of photosynthesis (for plants and algae only, cynobacteria do not have chloroplasts.) When light strikes a chloroplast, it can can be reflected, absorbed, or transmitted. The color of an object is determined by the wavelength of light it reflects. Chloroplasts contain several pigments: Chlorophyll a absorbs mainly blue-violet and red light Chlorophyll b absorbs mainly blue and orange light Carotenoids absorb mainly blue-green light absorb and dissipate excessive light energy that might damage chlorophyll The spectacular colors of fall foliage are due partly to the yellow-orange light reflected from carotenoids. Stomata - tiny pores in leaves where carbon dioxide enters and oxygen exists. Water is taken up by roots.

Aerobic Cellular Respiration

- A chemical process that: Primarily occurs in mitochondria Harvests energy stored in organic molecules Uses Oxygen Generates ATP Animals perform ONLY cellular respiration. Plants perform photosynthesis AND cellular respiration

Ecology

Ecology: the study of the interactions between organisms and their environment. Ecology is the study of interactions between organisms and their environments. It can be studied at many levels, including: INDIVIDUALS - Individual organisms POPULATIONS - Groups of individual organisms that interbreed with each other COMMUNITIES - Populations of different species that interact with each other within a locale ECOSYSTEMS - All living organisms, as well as non-living elements, that interact in a particular area A population ecologist may study and describe a population in terms of size, age structure, density, distribution, reproduction rate, survival rates, behavior etc.

Population

Population: An interbreeding group of organisms that occupies a defined geographic area at a particular point in time. Range: area which a population occurs. (Most species have limited geographic range) Population size: total # of individuals in the population Population density: # of individuals per unit area. Individuals in populations exhibit different spacing patterns: Random Spacing: individuals do not interact strongly with one another. (Not random upon closer inspection) Uniform Spacing: behavioral interactions; resource competition. Clumped Spacing: uneven distribution of resources; common in nature.

Survivorship

Survivorship - % of an original population that survives to a given age. Populations often remain the same size regardless of the number of offspring born; environmental resistance controls population growth. Carrying capacity - number of individuals the environment can support over an extended period

Population Size

Density-dependent, factors that affect the population and depend on population size. Examples: Food supply, habitat for living and breeding, parasite and disease risk, predation risk. Density-independent effects Rate of growth of a population at any instant is limited by something unrelated to the size of the population External environment aspects: cold winters, droughts, storms, volcanic eruptions. Populations display erratic growth patterns because of these events

Life History Adaptations

r selected: Opportunistic life history- population grows exponentially when conditions are favorable (many wildflowers) Climate: Relatively unpredictable Maturation time: Short Life span: Short Death rate: Often high Number of offspring produced per reproductive cycle: Many Number of reproductions per lifetime: Usually one Timing of first reproduction: Early in life Size of offspring or eggs: Small Parental care: None K selected: Equilibrial life history (many large mammals) Climate: Relatively predictable Maturation time: Long Life span: Long Death rate: Usually low Number of offspring produced per reproductive cycle: Few Number of reproductions per lifetime: Often several Timing of first reproduction: Later in life Size of offspring or eggs: Large Parental care: Often extensive

Human Population Growth

K-selected life history traits: Small brood size, Late reproduction, High degree of parental care Changes since the 1700s allowed humans to escape logistic growth Human populations have grown exponentially- death rate has fallen faster than birthrate Ecological Footprint: amount of productive land required to support an individual at the standard of living of a particular population through the course of his/her life. Consumption in the developed world further depletes resources: Wealthiest 20% of the world�s population accounts for 86% consumption of resources and produces 53% of CO2 emissions. Poorest countries: 20% is responsible for 1.3% consumption and 3% CO2 emissions.

Community Ecology

Community: all of the populations occurring in a designated geographic area at a particular point in time. Ecological niche: an organism’s “role” in the environment- all of the ways the organism influences the physical environment and interacts with other organisms. Examples: Space utilization, food consumption, Temperature range, mating conditions, requirements for moisture, ect.

Competition

Competition: individuals rival each other for a limited resource. Intraspecific competition: between individuals of the same species (population level) between individuals of different species (community level) Interference competition: physical interactions over access to resources Exploitative competition:consuming the same resources

Fundamental niche vs Realized niche

Fundamental niche: entire niche that a species is capable of using Realized niche: actual set of environmental conditions in which the species can establish a stable population

Principle of Competitive Exclusion

Principle of competitive exclusion: if two species are competing for a limited resource, the species that uses the resource more efficiently will eventually eliminate the other. Example: Population growth of three species of Paramecium grown individually in the laboratory. When P.caudatum and P.aurelia were grown together P.caudatum became extinct. When P.caudatum and P.Bursaria were grown together they coexisted because they have different realized niches. Resource partitioning: subdividing a niche to avoid direct competition

Species Interactions

Predation: one organism kills and feeds upon another Coevolution: Predator and prey populations evolve together  

Chemical Defenses

Chemical defenses in plants: Plants adapt to predation (herbivory) by evolving mechanisms to defend themselves Chemical defenses- secondary compounds: Leaf hairs Thorns/spines Leaf collapse. Herbivores coevolve to continue eating the plants Chemical defenses in animals: Example: Monarch butterfly caterpillars feed on milkweed and dogbane families Monarchs incorporate cardiac glycosides from the plants for protection from predation. Butterflies are eaten by birds, but the Monarch contains the chemical from the milkweed that makes the birds sick.

Defensive Coloration

Insects and other animals that are poisonous use warning coloration. Camouflage or cryptic coloration help nonpoisonous animals blend with their surroundings. Example: Poison-dart frogs produce toxic alkaloids in the mucus that covers their brightly colored skin.

Mimicry

Mimicry: one species mimics another to capitalize on defensive strategies of the second. Batesian mimicry: mimics look like distasteful or harmful species. Müllerian mimicry: several unrelated but poisonous species come to resemble one another.  

Symbiosis

Symbiosis: 2 or more kinds of organisms interact in more-or-less permanent relationships - coevolution. Commensalism benefits one species and is neutral to the other species, Example: Spanish moss, an epiphyte hangs from trees. The moss benefits and tree is thought to be not affected positively or negatively. Mutualism benefits both species. Example: Ants and acacias, Acacias provide food and hollow thorns to live in Ants provide protection from herbivores And organic nutrients. Parasitism benefits one species at the expense of another. Ectoparasites: feed on exterior surface of an organism Endoparasites live inside the host

Succession

Succession: natural changes in a community over time. Primary succession occurs on bare, lifeless substrate where a community did not previously exist: open water, newly formed volcanic land, rock exposed by receding glaciers, sand dune. Lichens are the first organisms to inhabit an area, followed by mosses. Soil slowly forms allowing other plants to colonize area. Rock>Litchen/Moss>Grass>Low shrub>High shrub> Shrub-tree>Low tree>High tree (The entire phase is primary succession, secondary succession begins at grass) Succession happens because species alter the habitat and the resources available in ways that favor other species entering the habitat Secondary succession: occurs in areas where an existing community has been disturbed (field left uncultivated, forest after a fire, clearcut forest)

Flow of Energy

 The Sun provides Earth with 40 million billion calories/sec. 1st Law of Thermodynamics: energy is neither created nor destroyed; it changes forms. Energy exists as: Light Chemical-bond energy Motion Heat 2nd Law of Thermodynamics: during every energy transfer some high quality energy (ex. chemical bond energy) is converted to low quality energy (ex. heat.)(Order -> Disorder [entropy]) Earth functions as an open system for energy: the sun inputs energy which is stored as chemical bond energy (photosynthesis) which flows through the ecosystem and is eventually converted to heat. Energy flows and nutrients cycle through the ecosystem.

Feeders

Autotrophs: “self-feeders” synthesize organic compounds from inorganic precursors Photoautotrophs: light as energy source. Chemoautotrophs: energy from inorganic oxidation reactions (prokaryotic) Heterotrophs: obtain organic molecules from other living things (animals, fungi, bacteria)

Trophic Levels

Trophic levels: stage of energy flow. Primary producers: autotrophs Consumers: heterotrophs Herbivores: eat producers Primary carnivores: eat herbivores Secondary carnivores: eat primary carnivores or herbivore  Detritivores: eat decaying matter Decomposers: microbes that break up dead matter (bacteria and fungi)

Productivity

Productivity: the rate at which the organisms in a trophic level collectively synthesize new organic matter. Gross primary productivity (GPP): raw rate at which primary producers synthesize new organic matter (photosynthesis) Net primary productivity (NPP): (photosynthesis - respiration producers Secondary productivity: amount of energy ingested by heterotrophs that is assimilated into body tissue. (Example: 17% growth, 33% cellular respiration, 50% feces) Amount of chemical-bond energy decreases as energy is passed from one trophic level to the next. As a rule of thumb, the amount of chemical-bond energy available to a trophic level over time is about 10% of that available to the preceding level over the same period of time. Only about 1/1000 of the energy captured by photosynthesis passes all the way through to secondary carnivores. Trophic cascade in a large-scale ecosystem: along the West Coast of North America, the sea otter/sea urchin/kelp system exists with low or high sea otter populations

Nutrient Cycling

Biochemical Cycles: Nitrogen & Phosphorus Bioeochemical Cycle: the recycling of inorganic matter between living organisms and their environments. (energy flows and nutrients cycle through the ecosystem.)

Nitrogen Cycle

Nitrogen is an important component of protein and nucleic acids. Atmospheric Nitrogen (N₂) > Nitrogen-fixing bacteria living in legume root nodule(back into atmosphere from here)> Nitrogen-fixing soil bacteria> Ammonification (NH₄) > Nitryifiing bacteria changes nitrites to nitrates>Denitrifying bacteria release N₂ back into atmosphere. Fertilizers have artificially raised the availability of nitrogen and groundwater contamination. Excessive phosphorus and nitrogen promotes eutrophication, the premature aging of a water body. Low nutrients and high oxygen result in a clear body of water High nutrients and low oxygen result in a cloudy body of water Watershed: The entire region draining into a river, river system, or other body of water. Eutrophication: A process whereby nutrient runoff causes the excess growth of microorganisms, depleting dissolved oxygen levels and killing ecosystem fauna. Dead Zone: An area within a freshwater or marine ecosystem where large areas are depleted of their normal flora and fauna; these zones can be caused by eutrophication, oil spills, dumping of toxic chemicals, and other human activities.

Plant Nutrition

Soil: A mixture of minerals, organic matter, living organisms, air, and water that together support plant life. 45% inorganic mineral matter, 25% water, 25% air, 5% organic matter (microorganisms and macroorganisms) Burrowing animals (prairie dogs, ground squirrels and badgers burrow; owls, snakes, lizards and rabbits use holes made by other animals) mix soil, facilitates water movement and reduces flooding. Living organisms (arthropods: ants, termites, spiders, mites, centipedes, millipedes) aerate soil, breakdown organic matter and disperse microbes. (Nematodes: round worms) Mix and aerate soil, breakdown organic matter and disperse microbes. (Protozoa) eat bacteria and release nutrients. (Bacteria) Releases nutrients through nitrogen-fixation and decomposition. (Fungi) release nutrients though decomposition, mutualistic associations with plant roots and help hold soil together. (Earthworms) Aerate soil, break down organic matter and disperse microbes. (Mollusk: slugs, snails) Break down organic matter and disperse microbes. (Plants) Reduce soil erosion. Organic matter provides food, water, shelter, and air for the living soil.

Rock Particles

The texture and composition of rock particles determines water holding capacity. Gravel > 2,0 millimeters Sand 0.5-2.0 millimeters Silt 0.002-0.05 millimeters Clay < 0.002 millimeters Low water retention: sandy soil has such large spaces between its particles that it cannot hold water well; it dries quickly after rain. High water retention: clay soils have poor drainage, few air spaces an cracks when dry.

Carbon Cycle

Greenhouse Effect: heat energy comes to the Earth as sunlight and leaves in the form of infrared radiation. Gases in the atmosphere trap some of the radiation preventing its escape. The result is the warming of the earth, much like the warming of a greenhouse. CO₂ (carbon dioxide) comes from burning fossil fuels and deforestation. (82% of greenhouse gas emissions as of 2015) CH₄ (Methane) comes from livestock and landfills. (10% of greenhouse gas emissions as of 2015) NO (Nitrous oxide) comes from fertilizer production (5% of greenhouse gas emissions as of 2015)