Test 1 Flashcards
The study of plants
Botany
A tentative unproven explanation for an observation
Hypothesis
A test to determine if a hypothesis is correct
Experiment
Results from an experiment
Data
Useful generalization derived from experimental data
Principle
Grouping of related principles
Theory
The study of internal plant structure (tissue and cell structure of plant organs)
Plant Anatomy
The study of plant function (physical, chemical and biological functioning of plants)
Plant Physiology
The study of defining, describing and classifying plants.. Also developing methods to classify plants (plant systematics)
Plant Taxonomy
The study of plant distribution
Plant Geography
The study of plant-environment interaction
Plant Ecology
The study of the form and structure of plants
Plant Morphology
The study of the hereditary of plants
Plant Genetics
The study of cell structure and function
Plant Cell Biology
The study of the practical uses of plants
Economic Botany and Ethnobotany
The study of food, fibre and oil production of plant products
Agronomy
Cultivation of plants for human use
Horticulture
When were cells discovered and by who?
1665, Hooke
All living organisms are composed of cells and cells form a unifying structural basis of organization
Cell Theory
Who discovered the nucleus?
Brown 1831
Who first argued against spontaneous generation in 1858?
Virchow
Who disproved spontaneous generation by boiling broth and cooling in sealed and unsealed flasks?
Pasteur
Increase magnification as light passes through a series of transparent glass
Light Microscope
In this light microscope, light passes through thinly sliced material and can distinguish organelles 2mm in diameter or larger. Can magnify to 1500x
Compound Microscope
This light microscope allows for 3-D viewing of opaque objects and can magnify up to 30x
Dissecting Microscope/Stereomicroscope
These microscopes use a beam of electrons produced when high-voltage electricity is passed through a wire
Electron Microscopes
This type of electron microscope can magnify up to 200,000x but the material must be extremely thin. Living objects can’t be observed.
Transmission Electron Microscope
This type of electron microscope can magnify up to 10,000x. Surface details can be observed on thin objects.
Scanning Electron Microscope
This type of cell lacks a nucleus, a cell wall, plasma membrane, DNA
Prokaryotic Cell
This cell type contains a nucleus, has a cell wall in plants, plasma membrane, nucleus & DNA, membrane-bound organelles and has a cytoskeleton
Eukaryotic cells
Membrane-bound bodies found within Eukaryotic cells
Organelles
The theory that some organelles evolved when a large Eukaryotic cell engulfed independent prokaryotic cells
Endosymbiotic Theory
Cells should have a “blank” to surface to volume ratio for efficient cellular communication. This makes smaller cells more efficient
Large
Main structural component of the cell wall
Cellulose
A part of the cell wall matrix; holds cellulose fibrils together
Hemicellulose
A part of the cell wall matrix; gives stiffness
Pectin
A part of the cell wall matrix; proteins with associated sugars
Glycoproteins
This layer of pectin shared by two adjacent cell walls and is first produced when new cell walls are formed
Middle Lamella
What type of walls are laid down on either side of the middle lamella (they are flexible)?
Primary Walls
What type of walls are produced inside the primary walls of plant cells?
Secondary Walls
Where is Lignin found?
mature and developing Secondary Walls
How do cells communicate
passage of fluid between adjacent cells through Plasmodesmata
Cytoplasmic strands that extend between cells through minute openings
Plasmodesmata
Semi-permeable outer layer of the living part of the cell, regulating movement into and out of the cell
Plasma Membrane
What structures make up the plasma membrane?
Phospholipids (hydrophilic head, hydrophobic tail) as well as hydrophobic glycoproteins and proteins dispersed throughout, come creating channels
Shows the plasma membrane is a dynamic model
Fluid Mosaic Model
What structure provides the selective permeability and osmosis of the plasma membrane?
Protein channels
The diffusion of water across a selectively permeable membrane
Osmosis
Osmosis moves from “-“ to “-“ concentrations
High to Low
The control centre of the cell, containing the DNA
Nucleus
How many membranes does the nucleus have?
2
What are the two membranes of the nucleus called?
Nuclear membrane
What type of fluid is found in the nucleus?
Nucleoplasm
Found within the nucleus and composed primarily of RNA
Nucleolus
Found within the nucleus, composed of DNA and proteins which coil into chromosomes
Chromatin Strands
What comes before the Hypothesis in the scientific method?
Observations unexplained by previous theories or principles
Which organelles are NOT bound by membranes and therefore not correctly classified as organelles?
Ribosomes
An enclosed space of flattened sacs and tubes throughout the cytoplasm
Endoplasmic Rectilium
What cell structure facilitates cellular communication, channelling of materials, membrane synthesis and modifies proteins?
Endoplasmic Rectilium
Studded with ribosomes, associated with protein synthesis and storage
Rough ER
Devoid of ribosomes, associated with lipid secretion
Smooth ER
Where are the two subunits of the ribosomes assembled?
Nucleolus
What are Ribosomes made of?
2 subunits of Protein and RNA
What cell component links amino acids to construct complex proteins?
Ribosomes
Where can ribosomes be found?
Rough ER, chloroplasts, mitochondria and cytoplasm
Stacks of flattened discs or vesicles which modify carbs attached to proteins and collect polysaccharides into vesicles?
Dictyosomes
What happens when vesicles are pinched off from Dictyosomes?
Travel to plasma membrane, fuse with it and discard contents outside the cell.
What can be contained within vesicles from Dictyosomes for disposal?
floral nectars, polysaccharides, essential oils
Most conspicuous plastid
Chloroplast
Found within cloroplast, a stack of coin-like thylakoids
Grana
A single coin within a stack of Granum, contains chlorophyll
Thylakoid
What is the matrix of enzymes found within chloroplast?
Stroma
A type of plastid that synthesizes and accumulates carotenoids (yellow/orange/red)
Chromoplasts
Colourless plastids are known as
Leucoplasts
What organelle releases energy from cellular respiration?
Mitochondria
What is found within the Mitochondria’s matrix?
DNA, RNA, ribosomes and proteins
What organelles have double membranes as well as their own DNA and ribosomes, suggesting the endosymbiotic theory?
Mitochondria and Chloroplasts
What is the vacuolar membrane called?
Tonoplasts
An organelle that takes up 90% of the cell at maturity and is filled with watery cell-sap
Vacuoles
What is the function of vacuolar cell sap?
maintain cell pH, pressure and storage
What red/blue/purple pigment is found within the vacuole?
Anthocyanins
A structure involved in movement and strength within the cell
Cytoskeleton
The cytoskeleton is a network of…
Microtubules and Microfilaments
What do microtubules do?
Control the addition of cellulose to cell walls, flagella and cilia movement, and are found in fibres of dividing cells (hollow)
What do microfilaments do?
Cytoplasmic Streaming
The orderly series of events when cells divide, comprised of two phases
Cell Cycle
Takes up 90% of cell cycle when cells are NOT dividing
Interphase
Interphase phase when cells increase in size
G1 Phase
Interphase phase when DNA replicates
S Phase
Interphase phase where mitochondria and organelles divide and microtubules are produced
G2 Phase
Process of nuclear division
Mitosis
Where does mitosis occur?
Meristems of plants
What is the result of mitosis?
Two identical daughter cells
Chromosomes are made up of two identical … held together by …
chromatids, centromere
Mitosis phase, chromosomes condense, spindle fibres attach to kinetochore of centromere. Nucleolus disintegrates and nuclear envelope is dissociated
Prophase
Mitosis phase, chromosomes align at centre of cell
Metaphase
Mitosis Phase, sister chromatids are pulled apart, spindle fibres shorten and pull chromatids to poles
Anaphase
Mitosis Phase, daughter chromosomes uncoil, nucleoli reappear, phragmoplasts and cell plate form at centre cell
Telophase
phragmoplast trap dictyosome-derived vesicles, guiding them towards the equator, fuse and form a
Cell Plate
What forms the plasmodesmata in cell plates?
trapped portions of ER
What structure is formed of RNA and associated proteins inside the nucleus?
Nucleolus
a group of cells performing a similar function
Tissue
a collection of tissues that form a specialized unit for a specific function
Organ
Permanent regions of growth and active cell division
Meristems
Meristems found at root and shoot tips
Apical meristems
Growth in length
Primary Growth
Growth in girth
Secondary Growth
What three primary meristems develop from the apical meristem
procambium, ground tissue and protoderm
Type of meristems responsible for secondary growth
Lateral meristems
A lateral meristem that produces tissues that function in support and conduction, extending the length of roots and shoot
Vascular Cambium
A lateral meristem that produces bark and lies outside the vascular cambium
Cork Cambium
Special meristems that have cells dividing at the base of leaf blades and/or nodes adding to stem length to plants without a vascular or cork cambium
Intercalary Meristems
A tissue that consists of one type of cell
Simple tissue
A simple tissue cell that is thin, flexible, living, with spaces between cells
Parenchyma Cells
What is the most common simple tissue cell type?
Parenchyma
What are the three types of Parenchyma cells?
Aerenchyma (connected by air spaces), Chlorenchyma (in chloroplasts) and Transfer Cells (extensions to transfer substances)
A simple tissue cell that is strong and pliable with uneven thickness and is living
Collenchyma Cells
A simple tissue cell with even thickness, dead at maturity, impregnated with lignin for support (secondary walls)
Sclerenchyma Cells
Two types of Schlerenchyma Cells are …
Sclerids (scattered in tissue and as long as they are wide) and Fibers (much longer than they are wide and contain a lumen)
What is a lumen and where can it be found?
a small cavity within sclerenchyma fibers
A tissue composed of two or more cell types
Complex Tissue
A complex tissue responsible for mineral and water conduction from roots
Xylem
What are the 5 cells Xylem is composed of?
Parenchyma, Fibres, Trachieds, Vessels and Ray Cells
long tubes made of vessel elements that stack on top of each other, thick, open at both ends, has a perforation plate
Vessels
Tapered tubes with pairs of pits (no secondary wall to allow water to pass) with thick secondary walls
Tracheids
Function in lateral conduction and food storage, composed of old parenchyma cells
Ray Cells
Conducts dissolved food materials produced by photosynthesis
Phloem
What are the 5 cells Phloem is composed of?
Parenchyma, Fibres, Sieve Tube Elements, Companion Cells and Ray Cells
Lack of a secondary wall and nuclei. Lay end to end and have sieve plates
Sieve Tube Members
What is the function of Sieve Plates?
Form callose plugs to stop flow when plant cells are damaged, preventing loss of food
Aid in food conduction by controlling with nucleus
Companion cells
A complex tissue that is a protective out layer composed of mostly parenchyma cells, guard cells, stomata and hairs
Epidermis
Fatty substance secreted to form a layer over the epidermis to prevent water loss that forms the…
Cuticle
This complex tissue replaces the epidermis when cork cambium starts producing bark
Periderm
Loosely arranged pockets of Parenchyma cells within the Periderm/bark that are responsible for gas exchange
Lenticels
Are Mitochondria larger than plastids?
No
Do mitochondria have circular DNA?
Yes
In roots and shoots, what does the protoderm, ground tissue and procambium give rise to?
epidermis, cortex and pith, primary Xylem and Phloem
Composed of apical meristem
Region of Cell Division
Cells become several times longer and vacuoles emerge
Region of Elongation
Cells differentiate - marked by root hairs
Region of Maturation
In ROOTS, what is the name of the parenchyma cells between the vascular cylinder and epidermis that’s used for food storage?
Cortex
Inner boundary of the cortex consisting of a single layer of cells
Endodermis
Where are Casparian Strips found?
in the Endodermis of Roots
The core of tissues inside the endodermis is…
Vascular Cylinder
Outer boundary of the vascular cylinder, forming lateral roots
Pericycle
In dicot roots, the Xylem and Phloem are arranged as
Xylem is an x with “arms”
In monocot roots, the Xylem and Phloem are arranged as…
rings with xylem just outside the pith and phloem outside the xylem
Xylem is produced … the vascular cambium and phloem is produced …
inside, outside
Growth that stops
Determinate Growth
Growth that does not stop
Indeterminate growth
A specialized root that stores starch and other carbs (sweet potatoes, carrots, radishes)
Food Storage Roots
Specialized root that store water (pumpkin family and plants in arid regions)
Water Storage Roots
Specialized root that have adventitious buds that develop into suckers above ground
Propagative Roots
Specialized root that grows in water with their surfaces above water for gas exchange
Pneumatophores lol pneumonia (let em breathe!)
Specialized Aerial roots are
Velamen Roots, Prop Roots and roots for climbing
Specialized root that pull plant deeper into the soil
Contractile Roots
Specialized root that are tall roots used for stability in shallow soil
Buttress Roots
Specialized root that has no chlorophyll and depends on other chlorophyll bearing plants for nutrition
Parasitic Roots
Plant roots form associations with…
Mycorrhizae (fungi)
What does Mycorrhizae do for plants?
Increases absorption and concentration of nutrients (especially Phosphorous)
Mycorrhizae are susceptible to…
Acid Rain
What do plants provide mycorrhizae?
sugars and amino acids
What do root nodules do for plants?
Convert nitrogen into nitrates for plant absorption
What plant family commonly has root nodules?
the Legume Family
In topsoil the “…” Horizon is dark with more organic material than below and the “…” Horizon is directly below and lighter in colour
A and E
In the Subsoil, the “…” Horizon has more clay and is lighter in colour than topsoil
B
the “…” Horizon the parent material that extends to bedrock
C
the best agricultural soil is…
Loams
What is loam composed of?
40% silt, 40% sand and 20% clay
Does course soil drain water quickly or slowly
Too quickly! Not good
Does clay soil allow water to pass through?
Only in littles, not good!
What are soil aggregates?
coarse-grained soil for human use with pore spaces comprising 40-60% of soil volume
Soil alkalinity happens when … … … become less available
iron, manganese and copper
How do you counteract basic soil?
Add Sulphur
How do you counteract acidic soil?
Add Calcium or Magnesium
The procambium is a precursor of…
xylem and phloem
An area of the stem where leaves are attached
Node
The stem region between nodes is…
Internode
A leaf is attached to a …
Petiole
An alternate leaf arrangement has
One leaf on one node
An opposite leaf arrangement has
Leaves attached in pairs on one node
A whorled leaf arrangement has
Leaves attached in groups of three or more at one node
The angle between the petiole and stem
Axil
“…” bud is located in the axil, will become a branch of flowers in flowering plants
Axillary Bud
Structures that protect buds
Bud Scales
Bud at twig tip, responsible for primary growth of the stem
Terminal Bud
Small, paired, often leaf-like appendages at the base of the leaf/petiole
Stipules
Apical meristems at twig tip are protected by…
scales and leaf primordia
What is the fatty substance secreted to form the cuticle?
Suberin
Flowering plants that develop from seeds from two cotyledons are
Dicotyledons (Dicots)
Flowering plants that develop from seeds from one cotyledon are
Monocotyledons (Monocots)
“Seed Leaves” attached to embryonic stems that store food needed by young seedlings are
Cotyledons
Do herbaceous dicot stems have a vascular cambium?
NO
Do woody dicot stems have a vascular cambium?
Hell YES
If woody dicot stems have ungrained uniform wood, their vascular cambium and cork cambium are active…
all year
How are xylem and phloem arranged in herbaceous dicots?
discrete vascular bundles around the periphery
If woody dicot stems produce wood seasonally they have two types of wood called…
Spring wood (lighter secondary xylem due to longer vessels) and Summer wood (darker secondary xylem)
One annual ring is equal to
One year’s growth of XYLEM
Older darker wood in the centre of a dicot tree is
Heartwood
Lighter, still functioning wood of a dicot tree is
Sapwood
Softwood is
less dense due to no fibers or vessel elements
Hardwood is
denser wood
All tissues outside the vascular cambium including phloem is
Bark
Latex secreting ducts within phloem of dicot trees are
Laticifers
What type of stems are all herbaceous and have no secondary growth?
Monocot stems (dicots are both herb and woody)
Monocot stems have no
Vascular or cork cambium therefore no secondary growth
How are xylem and phloem arranged in Monocot stems?
In vascular bundles, more densely dispersed around the outside. Within the bundle, surrounded by a bundle sheath is the xylem (towards the centre of the stem) and the phloem (towards the outside of the stem)
Specialized stems that grow horizontally below the ground, striking new roots at their nodes
Rhizomes
Specialized stems that grow horizontally above ground and have long internodes
Runners
Specialized stems that grow underground are swollen and fleshy (potato)
Tuber
Specialized stems that grow underground and are filled with fleshy leaves with a small stem at the end (onion)
Bulb
Specialized stems that resemble bulbs but are made entirely of stem tissue with papery leaves
Corm
Specialized stems that are sharp and pointed extensions that save energy from producing leaves that arise from the axils of leaves
Thorns
Specialized stems that climb to get better light exposure are
Climbing Stems
Specialized stems that are flattened and leaf-like
Cladophylls
In a living tree, …% of its weight comes from water content
50%
Do all roots contain a root cap?
YES
The primary root of a particular root system is called the
Taproot
Leaves originate as
Primordia
The flattened blade of a leaf is called the
Lamina
If leaves lack a petiole they are considered
Sessile
A pair of small “…” are at the base of the petiole
Stipules
Without a petiole, leaves form a “…” around the stem
Sheath
A stem attached to the centre of a leaf, like a lilly pad, is called a
Peltate
Simple leaves have a
Single Blade
Compound leaves have a
blade divided into leaflets
What are the two types of compound leaves?
Pinnately Compound Leaves (leaflets in pairs) and Palmately Compound Leaves (all leaves attached at same point like fingers on a palm)
Tiny pores on the LOWER surface of leaves, allowing CO2 to enter and O2 to leave, as well as water to leave
Stomata
Found in pairs beside stomata that control water loss
Guard Cells
The exudation of water from modified stomata at tips of veins is called
Guttation
The arrangement of leaves on a stem is
Phylotaxy
What are the three types of phylotaxy?
Alternate, Opposite and Whorled
The arrangement of veins in a leaf is
Venation
What are the two types of venation?
Pinnately Veined Leaves (one main midvein) and Palmately Veined Leaves (several primary veins fan out from base of leaf)
In Monocot leaves, veins have
Parallel Venation of primary veins
In Eudicot leaves, veins have
Netted or Reticulate Venation (diverge in various ways)
The “…” of the leaf has a single-layered surface with no chloroplasts, is coated with cutin and functions as protection
Epidermis
On what side are stomata found on a leaf?
Lower epidermis
Do guard cells contain Chloroplasts?
Yes
What are the two types of Mesophyll in leaves?
Pallisade and Spongy Mesophyll
Which type of mesophyll contains the most chloroplasts?
Pallisade Mesophyll
Mesophyll that is tightly packed, stacked and barrel-shaped parenchyma cells, commonly in two rows
Pallisade Mesophyll
Mesophyll that is loosely arranged parenchyma cells with abundant air spaces from transpiration and gas exchange through stoma
Spongy Mesophyll
In leaves, veins are contained in “…”
Vascular Bundles
Do monocots have differentiated mesophyll layers?
Usually not!
Monocots often have “…” cells paired along parallel veins that partly collapse under dry conditions, causing the leaf to fold and reduce transpiration
Bulliform cells
A specialized leaf that receives less total light, are larger, thinner with less defined mesophyll and chloroplasts
Shade Leaves
How does a specialized leaf in arid regions differ?
Water retaining (succulent), less stomata, sunken stomata, leathery thick epidermis, less leaves or no leaves, dense hair
How does a specialized leaf in aquatic areas differ?
less xylem and phloem, mesophyll isn’t differentiated, and have large air spaces
Specialized leaves that curl around adjacent objects for support of to climb are called
Tendrils
Specialized leaves that prevent water loss and herbivory are called (found on cacti)
Spines
Modifications/outgrowths from the epidermis or cortex cells, found on roses
Prickles
A specialized leaf modified for water storage
Storage leaf
A specialized leaf with an exposed, transparent end with leaves buried underground are
Window Leaves
A specialized leaf with tiny plantlets produced by asexual production along leaf margin/tips
Reproductive Leaves
A specialized leaf that resembles a petal
Bracts or Floral Leaves
A specialized leaf that grows in nutrient-deficient areas, adapted to consume insects
Insect-Trapping Leaves
What organism co-evolved with the pitcher plant?
Malaysian Tree Frog (lays eggs within the plant and neutralizes it’s digestive enzymes)
The insect trapping plant that has round/oval leaves covered with sticky glandular hairs that coils and traps insects are
Sundews
Insect trapping plants that are submerged or floating that trap insects inside a “trap door” are called
Bladderworts
Why do leaves change colour in autumn?
Chloroplasts break down, revealing other pigments like carotenoids
The process of shedding leaves is known as
Abscission
In monocots, the base of the leaf expanded into a
Sheath
Annual plants complete their cycle in
One Season/Year
Biennial Plants complete their cycle in
Two Growing Seasons
Perennial plants are
plants that take several growing seasons to complete a cycle or persist indefinitely
Dicot flowers are found in multiples of
4/5
Monocot flowers are found in multiples of
3
The arrangement vascular bundles of monocot stems are
scattered
The arrangement vascular bundles of dicot stems are
arranged in rings
Almost like leaves, flowers origniate as
Embryonic Primordium
Flowers grow on specialized branches called
Peduncles
If flowers diverge on many branches, these branches are called
Pedicels
The swollen end of a peduncle/pedicel is known as the
Receptacle
What are the 4 whorls of a flower?
Sepals (calyx), Petals (corolla), Stamen, Pistil/Carpel
What are the structures of the Stamen?
Filament and Anther
What are the structures of the Pistil?
Stigma, Style, Ovary
What are modified leaves with ovules on their margins?
Carpels
A group of flowers on one plant is called an
Inflorescence
All fruits develop from
ovaries of flowering plants
Fruits that develop without fertilization use a process called
Parthenocarpy (why bananas have no seeds!)
What are the three regions of fruits?
Exocarp, Mesocarp and Endocarp ( listed from outside in)
A broad category of fruits that have a mesocarp that is at least partly fleshy at maturity is known as
Fleshy Fruits
A category of fleshy fruits that develop from one single pistil is
Simple Fleshy Fruits
A simple fleshy fruit that has a single pit enclosed by a stony endocarp
Drupe (peaches olives, mangoes, ALMONDS lol, walnuts, pecans, pistachios, cashew)
A simple fleshy fruit that comes from a compound ovary, has more than one seed and has a fleshy pericarp
Berries
What are the 3 types of berries?
True Berry, Pepo, Hesperidium
What is a true berry?
thin skin and soft pericarp (tomato, grapes, blueberries, bananas, peppers)
What is a pepo?
A berry with relatively thick skin (pumpkins, watermelon and cucumbers)
What is Hesperidium?
Berries with leathery, oily skins (lemon, oranges)
A simple fleshy fruit with flesh that arises from an enlarged floral tube/receptacle that grows up around the ovary (core is the ovary)
Pome (apples, pear)
A broad category of fruits that are dry at maturity
Dry Fruits
A dry fruit that splits on its own
Dehiscent Fruits
A type of dehiscent fruit that splits along one side
Follicle (milkweed, peony)
A type of dehiscent fruit that splits along two sides
Legume (peas, beans, lentils, peanuts)
A type of dehiscent fruit that split along two sides but has a central partition that holds seeds
Siliques/Silicles
A type of dehiscent fruit that splits in a variety of ways and has at least two carpels
Capsules (poppies, brazil nuts)
A dry fruit that doesn’t split on its own and has one single seed that’s firmly united with the pericarp
Indehiscent Fruits
A type of indehiscent fruit that’s seed base is attached to the pericarp
Achene (sunflower seeds, buckwheat)
A type of indehiscent fruit that’s similar to an achene but is larger with a thicker, harder pericarp
Nut (acorns, hazelnuts, hickory nuts)
A type of indehiscent fruit with pericarp tightly attached to seed
Grains (rice, corn, wheat, oats)
A type of indehiscent fruit that’s pericarp is extended into wing-like structures for dispersal
Samara (maple seeds)
A broad category of fruit that is derived from a single flower with multiple pistils
Aggregate Fruits (strawberries, raspberries, blackberries)
Derived from several to many individual flowers in a single inflorescence
Multiple fruits (pineapples)
What are the 4 methods of seed dispersal
Wind, Water, Animals, Humans
What are the 6 structures of a seed?
Cotyledons, Plumule, Embryo, Hypocotyl, Epicotyl and the Radicle
Food storage organs that function as seed leaves of a seedling
Cotyledons
Within the seed, the “…” is made up of cotyledons and plantlet
Embryo
The embryo shoot of a seed
Plumule
The stem below the cotyledon of a seed
Hypocotyl
The stem above the cotyledon of a seed
Epicotyl
The tip of the seed embryo that develops into a root
Radicle
What are the two types of seed germination?
Epigeous and Hypogeous germination
What is Epigeous Germination?
the hypocotyl bends, becoming hook-shaped, emerges from the ground and pulls the cotyledons above ground
What is Hypogeous Germination?
Hypocotyl remains short and cotyledons do not emerge from the soil
What is scarification?
artificial breaking of seed dormancy
The seed will not germinate until the “…” develops
Embryo
What is vivipary?
When seeds do not have a period of dormancy
The part of the flower in which ovules are produced is the
Carpel
Modified leaves that form chambers in the ovary
Carpels
The PASSIVE movement of molecules from a region of high to low concentration
Diffusion
Liquid in which substances are dissolved
Solvent
Substance dissolved in liquid
Solutes
Membranes with restricted movement to some substances and allow passage of different substances at different rates
Selectively-Permeable Membrane
Diffusion of water from high to low concentration
Osmosis
Pressure required to prevent osmosis, balance by cell wall resistance
Osmotic Pressure
Pressure that develops against cell walls as a result of water entering cells
Pressure Potential (Turgor Pressure)
A firm cell due to water gained by osmosis
Turgid Cell
The Water Pressure of a cell is equal to the
Osmotic Pressure + Pressure Potential
What is the pathway of water through a plant?
From soil to roots, crosses semi-permeable membrane, cytoplasm of endodermis, into the xylem, up to leaves and transpired through stomata
Loss of water due to Osmosis
Plasmolysis
Large molecules that attract water molecules when wet, resulting in the swelling of tissues. This is the first step in seed germination
Imbibition
Process to absorb/retain solutes against diffusion, requiring energy
Active Transport
Where does the energy for active transport come from?
Proton pump energized by ATP molecules
Loss of water vapour from internal leaf to the atmosphere is
Transpiration
The theory that water transpiration creates a tension to pull water from roots to leaves, also created by cohesion of water molecules to each other by weak hydrogen bonds and the adhesion to tracheid/vessels
The Cohesion/Tension Theory
Transpiration rate is affected by…
humidity, temperature, sunlight and CO2 concentration
During photosynthesis, stomata are
open
How do guard cells open stomata?
Expend energy to absorb K ions, creating a low water potential inside the cells therefore water diffuses in, making cells turgid and opening the stomata
How do guard cells close?
Potassium ions leave the cell (perhaps triggered by abscisic acid) and water follows
Why would some plants have stoma open at night?
Conserves water during the day, converting CO2 into organic acids to be re-converted to CO2 during the day by CAM photosynthesis (desert plants)
Stomata that are within crypts are known as
Recessed stomata where the chambers are filled with hairs.
Hypothesis that organic solutes flow from a source, where water enters by osmosis, to sinks, where food is utilized and water exits
Pressure-Flow Hypothesis
What are sources of organic solutes in plants?
parenchyma tissues of roots, stems, modified organs that store carbs
What are sinks in plants?
meristematic tissues that require energy to increase plant length/girth
What are the stages/flow of the Pressure-Flow Hypothesis?
Phloem loading (sugar enters sieve tubes by active transport from sources), water potential in sieve tubes decrease, water enters, by osmosis. Turgor pressure develops and drives fluid toward sinks. Food substances are actively removed at sinks. Mass flow occurs from higher pressure at source to lower pressure at sink.
essential building blocks for compound synthesized by plants
Essential Elements
Macronutrients required in large quantities are
N, K, Ca, P, Mg (magnesium) and S
Micronutrients required in small amounts are
Fe, Na, Cl, Cu, Mn (manganese), Co, Zn, Mo (molybdenum) and B
The primary force that enables water to move to the top of very tall trees is
Root Pressure
What is the name of the process of water being split in light-dependent reactions of photosynthesis
Photolysis
converts light energy into a usable form
Photosynthesis
The release of stored energy
Respiration
The sum of all interrelated biochemical processed in living organisms
Metabolism
Forming chemical bonds to build molecules (e.g. photosynthesis)
Anabolism
Breaking chemical bonds (e.g. in cellular respiration)
Catabolism
A cycle that involves the transfer of energy via oxidation-reduction reactions
Photosynthesis-Reduction Cycle
Oxidation is the “…” of an electron
Loss
Reduction is the “…” of an electron
Gain
In theory, extra CO2 in the atmosphere may “…” photosynthesis
Enhance
Energy for most cellular activity involves…
ATP
Where within the plant is ATP made using light as an energy source?
Chloroplasts
What are the reactants of photosynthesis?
CO2, H20, light
What are the products of photosynthesis?
O2, H20, C6H12O6
How does CO2 reach chloroplasts?
Diffuse in through stomata to reach chloroplasts in pallisade mesophyll
Less than “…”% of water absorbed is in plants used for photosynthesis
1%
What is the role of water in photosynthesis?
Source of electrons (oxygen is released as a by-product when hydrogen atoms are taken)
About “…”% of radiant energy received on Earth is in the form of visible light
40%
What component of a chlorophyll molecule captures light, acting as a solar panel?
Magnesium
Where does photolysis occur in the light-dependent rxn of photosynthesis?
Before Photosystem 2, replenishing electrons lost
What antenna pigments are found in flowering/higher plants that function in photosynthesis?
Carotenoids and Chlorophyll b
What are antenna pigments that function in photosynthesis?
pigments that do not directly use sunlight and instead pass them on to pigments such as chlorophyll a
What is the longest wavelength of light useful in photosynthesis?
Red
What is the shortest wavelength of light useful in photosynthesis?
Blue
What wavelength of light is reflected from chloroplasts?
Green
What percent of light can leaves absorb?
80%
What does the lipid tail of the chlorophyll molecule do?
Anchors chloroplasts onto the thylakoid membrane
Why do plants contain antenna pigments for photosynthesis?
Makes it possible for photosynthesis to occur across a broader spectrum of light
What are phycobilins?
blue/red photosynthetic pigments in cyanobacteria and red algae
What are the two phases of Photosynthesis?
Light-dependent reactions and light-independent reactions
What are light-independent reactions known as?
The Calvin Cycle
Each pigment has its own “…” which is its own distinctive pattern of light absorption
Absorption Spectrum
Does both Photosystem 1 and 2 produce ATP?
Yes
Can organisms with just one photosystem produce NADPH and Oxygen?
No
What pigments/molecules are found in Photosystem 1?
Chlorophyll a, small amounts of chlorophyll b and carotenoids that pass light energy onto P700 (reaction centre molecule) and Fe-S proteins (primary electron acceptor).
What pigments/molecules are found in photosystem 2?
Chlorophyll a, small amounts of chlorophyll b, B-carotene, P680 (reaction-centre molecule) and Pheophytin (primary electron acceptor)
When light photons absorbed by P680 in Photosystem 2 boosts electrons to a higher energy level, passing on electrons to the primary electron receptor pheophytin, how are the lost electrons replaced?
PHOTOLYSIS: electrons are extracted from water to replace electrons lost by P680
What happens in Photosystem 2?
Electrons gained by photolysis are exctied by light photons delivered/absorbed to P680, boosting them to a higher energy level. These electrons are passed on to pheophytin, PQ and along an electron transport system to photosystem 1.
What happens in Photosystem 1?
Electrons from electron transport chain are excited by light absorbed by P700, boosting them to a higher level and passing them to Fe-S protein (primary electron acceptor). Electrons make their way Fd (ferredoxin) and FAD (flavin adenine dinucleotide). NADP is reduced to NADPH (hydrogen/electrons) added.
How are electrons replaced when lost from P700 in Photosystem 1?
Gained back from photosystem 2
The reaction-centres, P700 and P680, are surrounded by…
Antenna Pigments
Does the 4-Carbon Pathway cost more or less energy than the plain C3 Calvin Cycle?
Yes, 2 extra ATP are required
What is the benefit of the 4-Carbon Pathway if it costs more energy?
More efficient in CO2 conversion
What happens in the Carbon Cycle?
6 CO2 and 6RuBP combine with the aid of Rubisco. This eventually results in 12 3-Carbon molecules called 3PGA (3-phosphoglyceric acid). NADPH and ATP supply energy to reduce 3PGA to GA3P (glyceraldehyde 3-phosphate). 10 of the 12 GA3P are restructured using 6 ATP into 5 Carob RuBP. The net gain of 2 GA3P can be used as carbs or used to make lipids/amino acids
What is Kranz Anatomy?
Tropical grasses and plants in arid regions that use the 4-Carbon Pathway in addition to the Calvin Cycle. This anatomy is marked by small chloroplasts in mesophyll with well-developed grana, whereas the bundle sheath has many chloroplasts and few to no grana.
What happens in the 4-Carbon Pathway?
PEP and CO2 combine with the aid of PEP carboxylase, which requires less CO2 than Rubisco for conversion. This results in 4-Carbon oxaloacetic acid. CO2 is transported to the bundle sheaths as an organic acid and enters the Calvin Cycle.
What percent of plants use CAM photosynthesis?
7%
What is CAM photosynthesis?
Stomata are open at night and convert CO2 to organic acids, converting them back to CO2 in the day for use in the Calvin Cycle.
Do carnivorous plants photosynthesize?
Yes!
Do all plants photosynthesize?
No
What plant doesn’t photosynthesize?
the Dodder which is yellow in colour due to little chlorophyll content. Enter the vascular tissue of photosynthetic plants to steal sugars
