Midterm 1 Flashcards
What are plant tissues composed of?
Eukaryotic cells (contain a nucleus)
What is the area between cells called and what is it made of
Plasmalemma aka the plasma membrane, composed of pectates (complex set of polysaccharides) – plant glue/cement
What aids in fruit ripening and why
the middle lamella – uses the enzyme pectinases to break down pectins which it is made of to produce a softer fruit
What is the Flavr Savr gene and why is it important
It decreases pectin produced in fruit (started off with a tomato) and allows farmers to harvest fruit later, therefore resulting in something with fuller flavour components and fully developed sugars. Never went to market due to consumer acceptance
How does the plasmalemma aka plasma membrane work
It is semi permeable meaning it is covered in pores that allow smaller things such as water through but not larger things such as organelles (has limitations)
What are the continum of living/non living organisms through the plasmalemma called?
Living: symplast (biotic)
Nonliving: apoplast (abiotic)
What are the 3 components of the plasmalemma called and what are their compositions
lipids: 40%
proteins: 40%
carbs: 20%
What are lipids composed of
They are bilayers with polar heads and nonpolar fatty acid tails (heads out tails in) that are chemically stable - called a unit membrane
What are phospholipids and what do they look like?
They are the most common type of membrane lipid that contain a charged polar head with 2 hydrophobic hydrocarbon tails.
- unsaturated: not all H’s present, creates kinks (crooked)
- saturated: straight tail with all H’s present
What are the 2 most common glycolipids
glucose and galactose
Why are lipid molecules unique
Not covalently linked together so they are able to move around (bob, flex, rotate, flip flop)
What do enzymes do
They act as catalysts and transport metabolites (something made/used when body breaks down stuff) across the cell membrane
What is the optimal temperature for most plants
20 degrees
What occurs during chilling injury and how does it affect the plasma membrane?
When the temperature gets too cold, the inside of the membrane goes from a fluid liquid crystalline state to a solid gel phase. This in turn causes the membranes to leak, causing it to lose its ability to catabolize reactions and creates an imbalance in the organism
- primary mechanism of injuring plant tissues
Why is fluidity important for membranes?
Enzymes no longer work (tertiary and quaternary structures are altered and can’t bind) when its not fluid enough causing the enzymes and proteins not to be able to move in the phospholipid matrix and to function properly (responsible for transport in and out of the cell and hormone binding and primary hormone effects)
Why is semi permeability important for plant tissues
When it becomes too permeable toxic metabolites (such as ethanol and acetaldehyde) are able to enter the plant, giving it an off flavour and it allows the plant to access what it needs and not what it doesn’t
What kind of bonds do low and high temp plants have
low: unsaturated (double bonds - kinks)
high: saturated (straight tails)
What is the definition of critical temperature
the highest temp at which freezing injury to plant tissues can be detected (closest it gets to being damaged)
What is hardening off?
• plants raised in a greenhouse need to be acclimatized to cooler temperatures, lower humidity and increased air movement for about two to three weeks before they are planted outdoors. This ‘toughening up’ process is known as hardening off.
What is the nucleus?
It is surrounded by a porous, double membrane nuclear envelope containing chromosomes (DNA) and one or more nucleoli (dark masses made up of protein and nucleic acids – involved in rRNA synthesis)
What is the endoplasmic reticulum?
a 3D network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis.
What are the 2 types of ER?
rough: has ribosomes
smooth: no ribosomes
What are mitochondria?
They are organelles surrounded by a double unit membrane that provide energy for the cell.
- centers of respiration
Dictyosomes or Golgi apparatus
collect, process, and deliver proteins out of the cell
What are vacuoles?
Vacuoles are membrane-enclosed saclike structures that store materials such as water, salts, proteins, and carbohydrates.
- LARGE (take up 30-90% of the cell)
What are the 6 vacuole functions?
- Storage: for water and other materials (sugars, proteins, organic acids and pigments) also can be retrieved and used
- Digestion: contains digestive enzymes such as proteases, nucleases, glycosidases and lipases (work to break down and recycle nearly all cellular components)
- Regulation: pH and ionic homeostasis
pH is normally around 5-5.5 (slightly acidic) = -log[H] - Defense: against microbial pathogens and herbivores by accumulating toxic components such as phenolic compounds, alkaloids, cyanogenic glycosides and protease inhibitors (makes it so they can’t digest it properly so they don’t want to eat it)
- Sequestration: toxic components (such as heavy metals and oxalate) (shed leaves due to an accumulation of toxic components stored in vacuoles
- Pigmentation: Contain anthocyanin pigments to attract pollinators and seed dispersers (in saskatoon fruit, what gives it its dark purple colours)
Pigments can also work to screen out UV and visible light, preventing photooxidative damage to the photosynthetic apparatus (flavonols)
What are plastids?
small organelles such as chloroplasts that contain pigment or food
What are the precursors (forerunner) of all plastids?
Proplastids
What are amyloplasts?
unpigmented organelles responsible for synthesis and storage of starch granules
What are leucoplasts?
colourless plastids involved in the synthesis of monoterpenes (found in essential oils), found in secretory cells associated with leaf and stem prichomes (hairs) and citrus peel
- storage of starch, lipids and protein
What are Chromoplasts?
They synthesize and accumulate carotenoid and xanthophyll pigments making them yellow, red and orange (tomatoes, carrots or red peppers)
What are Etioplasts?
where development from proplastids to chloroplasts has been arrested by absence of light or very low light. Contain no chlorophyll but have colourless chlorophyll precursor (protochlorophyllide)
Light triggers them to develop into chloroplasts (which convert light into chemical energy)
- basically plastids that form in darkness that turn into chloroplasts when exposed to light
What are chloroplasts?
photosynthetic plastids responsible for energy capture that are green due to the presence of chlorophyll
Where are chloroplasts located on plants receiving different sunlight and why?
direct sun: on the sides or else they fry/too much heat
shade: on the top to receive as much light as possible
What are stacked grana thylakoids?
discs that are within a chloroplast used to absorb light (more = will absorb more light)
What are light reactions?
Energy capturing reactions of photosynthesis; convert light energy into chemical energy (sugars make ATP)
What are dark reactions?
energy produced in the light reactions is used to reduce CO2 and synthesize cell constituents (uses E to make sugars)
Gymnosperms
A plant that produces seeds that are exposed - cone bearing plants (primative)
Angiosperms
A flowering plant which forms seeds inside a protective chamber called an ovary (vessel seed)
What are the classes for monocot and dicot?
mono: liliopsida class
di: magnoliopsida class
What are some characteristics of monocots
- One cotyledon
- Usually 3 floral parts (can be multiples)
- Parallel array of leaf veins
- One pore or furrow in the pollen grain
- Vascular bundles are distributed among the ground tissue of the stem
- Fibrous root system
- Very few are woody
What are some characteristics of dicots
2 cotyledons
Usually 4 or 5 floral parts (can be multiples)
Netlike array of leaf veins
3 pores of furrows in the pollen grain
vascular bundles are arrayed in a ring in the stem
Primary taproot
Over 50% are woody
What is a meristem?
a tissue that contains actively dividing cells
vascular cambium
A cylinder of meristematic tissue in woody plants that adds layers of secondary vascular tissue called secondary xylem (wood) and secondary phloem.
- adds to girth of the stem
Protoderm
The outermost primary meristem, which gives rise to the epidermis of roots and shoots
ground meristem
the part of an apical meristem that gives rise to the ground tissue (cortex) in the primary root
- Consists of parenchyma (living), collenchyma (living) and sclerenchyma (dead) cells
procambium
A primary meristem of roots and shoots that forms the vascular tissue consisting of xylem (water and nutrients) and phloem (sugars)
What is the role of the apical meristem
to generate new tissue and lengthen the organ
What is the backup system of axillary buds?
a hormone called auxins when the plant breaks off (get activated/released)
- inhibits axillary bud outgrowth
What is the role of the lateral meristem
they add to the stem/root’s diameter/girth
Where is the intercalary meristem located?
at internodes
What are the 4 root functions?
What are the 4 root functions? Anchor plants into the soil Absorb water and minerals from the soil Conduct water and minerals to and from shoots Provide an area for storage
What does the root cap do?
Protects the root (apical meristem) as it grows through the soil and receives/transmits signals from the environment
What is the cell maturation region?
where primary tissues mature into secondary tissues (where root hairs are formed)
What is the root epidermis?
the outer absorbing layer, has no stomata and cuticle which allows it to absorb nutrients and water and uses root hairs produced from the cell maturation region to increase its SA
What is the cortex?
large thin walled parenchyma cells inside the epidermis
- food storage
What does suberin do?
it slows water and nutrient loss from the root
Apoplastic vs Symplastic
Apo: movement through cell walls and intercellular spaces (less resistance)
Sym: movement through living cells (greater resistance)
What is the endodermis?
the innermost layer of the cortex
- casparian strip acts as a barrier
What is the pericycle?
a thin layer of plant tissue around the vascular tissue
- Where lateral or branch roots arise
- Generates the vascular cambium in secondary growth
What is the pith?
ground tissue located in the center of the root
How does the mycorrhizae fungi help plants?
it shares a mutualistic relationship and absorbs phosphorus and nitrogen for the plant while the plant gives it sugars and amino acids
How does Rhizobium bacteria help plants?
mutually beneficial relationships – bacteria provides usable nitrogen for the plant and plant provides food and lodging in the root nodules for the bacteria
What is leghemoglobin and what is its function?
hemoglobin for legumes, produced in the plants nodules
- allows nitrogenase to function and provides the bacteria with oxygen for respiration
Where are the xylem and phloem produced?
in the procambium
Tracheids vs vessel elements (Xylem)
tracheids: thin and elongated with tapered ends
vessel elements: larger, lack end walls and act like a continuous pipeline for transport
What is the pit membrane and how does it use the torus?
a membrane of the pit with openings to allow water to flow through: uses to torus to seal itself off when the pressure is unequal
cork cambium
Lateral meristematic tissue that produces the outer covering of stems (bark)
What is the torus?
a swollen central area of the pit membrane that can seal off the pit
What is transpiration?
the pulling of water up and it evaporating from stomata in leaves(returns to the air)
- due to the opening of the stomata (loss of water)
- allows CO2 intake
- causes a loss of water
Sieve tube cells
Cylindrical cells lacking nuclei and with perforated sides and end walls that allow the movement of phloem sap (made up of water and sugar) between cells
- alive at maturity
What are companion cells?
Phloem cells that surround sieve tube elements (brains of the operation)
Why is grafting great?
- allows us to produce an exact replica
- no need to wait for the juvenile phase
- pest resistance, propagation ease, etc.
What happened during the great french wine blight?
Mid 19th century, destroyed a bunch of vineyards and the grape industry in France
Brought the aphid phylloxera from north america to europe
Grafted the european varieties onto the north american ones so that they were not susceptible to the aphids
What are the 4 above ground stems?
stolons, tendrils, thorns and crowns
What are the 4 below ground stems?
rhizomes, bulbs, tubers and corms
What are runners?
above ground horizontal stems that function in asexual reproduction (only variation in asexual reproduction is by mutation)
What are tendrils?
above ground and can cling or coil around structures to provide additional support to the plant
- modified leaves
What are rhizomes?
below ground horizontal stems that develops roots and shoots from the nodes and functions in storage of food for renewing shoot growth
What are bulbs?
below ground compressed stems with fleshy leaf like structures called scales
- outer scale (papery) acts as damage protection and keeps the insides from drying out
- inner scale acts as a food reserve storage
- large bud
What are tubers?
underground stems that are ribosomes that branch off into accumulations of starch
- have eyes
- modified stem
What are corms?
underground fleshy stems that form from axillary buds and have food reserves
- stack on top of one another: grow from cormels
What is secondary growth?
growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken
Where does secondary growth NOT occur?
in ferns or monocots
What is the ancestors of all gymnosperms
Progymnosperms
What are the 4 stages of xylem development
Cell division in the cambium
Cell expansion
Secondary cell wall deposition (needs thick/tough cell walls)
Programmed cell death (dead at maturity – hollow tube)
What does the procambium become in secondary growth
Fascicular cambium
What plant part is used for ID
leaves
What are veins composed of?
xylem and phloem cells embedded in parenchyma and surrounded by bundle sheath cells
What does the xylem transport?
transports water and nutrients
What does the phloem transport?
sugars
What becomes the midvein/epdermis and how
expansion and cell division from phloem and xylem in the procambium and protoderm that produce a vascular strand which becomes it
What are the 2 functions of leaves?
- manufacture food by photosynthesis (sunlight)
2. maintain water balance through transpiration
How are leaves formed?
auxin (2 dots across from one another - hormone that triggers cell elongation in cells) trigger cell division at the shoot apical meristem that form the lead primordium (originate as primordia)
What is phyllotaxy and what are the 4 types?
the leaf arrangement on a stem
- opposite (same spot, either side)
- alternate (go back and forth side to side)
- whorled (3 around same spot XYZ)
- basal (whole bunch around one spot – like a little skirt at the bottom of the plant)
For how long does the leaf rely on the rest of the plant?
until it reaches 40% of its final size, then it can sustain itself through photosynthesis
What is the extremity of the leaf composed of
the epidermis (a layer of cells) and the cuticle (a thick waxy layer that prevents excess transpiration)
What are the openings in the epidermis called and what do they do?
stomata: they use guard cells to “protect” the opening to allow photosynthesis in and out and water to move out
What happens when a proton pump transfers protons out of the guard cells?
potassium ions moves in, followed by water due to osmosis (causes the shape to change)
What turns off the protein pump and what does it do
ABA - abscisic acid (hormone), causes the stomates to close
What is the internal leaf composed of?
- mesophyll tissue
- intercellular space
- vascular tissue
Do epidermal / guard cells have chloroplasts?
epidermal: no
guard: yes
What are the 2 layers of the mesophyll tissue in a dicot leaf?
- palisade: upper region, 1-2 layers (majority of the chloroplasts located here)
- Spongy: lower region, irregularly shaped cells with air spaces to allow for gaseous exchange (increased SA)
* **mesophyll is where most photosynthesis occurs
Where is the xylem located on the leaf vein?
upper side, conducts water and minerals from the roots to the leaves using tracheids and vessel elements
Where is the phloem located on the leaf vein?
lower side of the vein, conducts organic nutrients from source to sink (using sieve tube cells and companion cells)
C3 photosynthesis
C fixation and calvin cycle performed during the day, more energy efficient and is good for colder climates (no chloroplasts in its bundle sheath)
***CO2 fixation occurs in one place (chloroplasts of the mesophyll cells using RuBP or Rubisco)
C4 photosynthesis
C fixation in mesophyll and bundle sheaths both during the day, water efficient and better in warmer climates
- **CO2 fixation takes place once in the mesophyll cells and once in the bundle sheath cells (with chloroplasts)
- bundle sheath cells help with support for the veins and conduct water to the epidermis
- bundle sheath protects it from O2 buildup
- very few use, all are angiosperms, mostly monocots
- can store CO 2 for use later
- use PEP to fix the CO2
CAM photosynthesis
C fixation during the night, calvin cycle during the day, best for arid conditions (very hot / desert)
What does C fixation mean?
making sugars out of CO2
What is photorespiration?
uses ATP and E from light reactions to prevent photooxidative damage
Allows C3 plants to survive during hot and dry conditions
Burns off extra E
Collects CO2 at night (PEP) and releases them during the day through the calvin cycle
What are pitcher plants and how do they work?
the leaves adapted to trap insects (often found in low nitrogen environments and uses the AA/N from insects in place)
What family has the largest array of veggies?
the brassicaceae aka mustard family
How is a cabbage head formed?
When the inner leaves at the center of the plant begin curling inwards and cupping around a short, thick stem
How are brussel sprouts formed?
when the axillary buds form lateral heads
What is the edible part of a kohlrabi?
a swollen stem
What are cauliflower/broccoli?
inflorescences
What is the fancy name for turnips?
brassica campestris (brassicaceae family)
What is the fancy name for rutabagas and what are they a mix of?
brassica napus – turnip and cabbage
What 3 things are in the asteraceae family?
lettuce, chicory and endives
What is the fancy name for lettuce?
lactuca sativa
How are most flowers produced?
when the apical meristem stops producing vegetative structures and starts producing flowers
What is a complete flower?
contains all floral components including sepals, petals, stamens and carpels
What is an incomplete flower?
missing one or more of the sepals, petals, stamens and carpels
What is a perfect flower?
have both female and male reproductive structures (pistil AND stamen) (also known as hermaphroditic, the most evolutionarily advanced reproductive system)
What is an imperfect flower?
have only female or male (pistil OR stamen)
What is the receptacle?
a region where floral parts are attached
What are the sepals, what do they do and what are they collectively called?
the outermost whorl of flower parts that encase the flower – calyx – can perform photosynthesis
Apetalous
has no petals
Sympetalous
petals are partially or completely fused
Choripetalous
petals are separate
Regular petals
all floral parts are of similar shape and size (can equally divide into parts)
Irregular petals
all floral parts are not of similar shape or size (can only be split down the middle)
What are petals collectively called?
a corolla
What is the stamen, what does it include (x2) and what is the area collectively called?
the male, pollen bearing portion
Includes the anther (contains the pollen) and the filament
Collectively called the androecium (male house)
What is the pistil, what does it include (x3) and what is the area collectively called?
Includes the ovary, stigma and style
Female portion of the plant
Collectively called the gynoecium (female house)
What does the ground meristem produce?
the cortex and pith
What does the protoderm produce?
the epidermis
What do the epidermal cells produce?
root hairs
What does the region of cell division produce?
the root cap
What are pneumatophores?
they go above the surface and enhance gas exhange
Where is suberin often located?
In the phellem layer of the periderm/cork cells (outer layer)
- lipophilic
- dead
Where is lignin often located?
Found in the middle lamella and xylem vessels
- provides water transport, mechanical support and resistance to various stresses
Where is resin often located and why is it produced?
Produced when an injury occurs to the plant, on the bark of a tree
What is the transitional meristem?
composed of the protoderm, procambium and ground meristem
- gives rise to tissue systems
What is the periderm, what is it composed of and what does it give rise to?
it is the outer layer of the stem, composed of phellogen, phellem and the phelloderm – gives rise to the cork cambium in secondary growth
What is the periderm, what is it composed of and what happens to it during secondary growth?
it is the outer layer of the stem, composed of phellogen, phellem and the phelloderm – replaces the epidermis in secondary growth
What is the vascular cambium and where is it located?
main growth tissue in stems and roots
- located between the primary xylem and primary phloem
What are parenchyma cells?
- can undergo cell division at maturity
- thin cell wall
- simple tissue
- living
- ground tissue
What are pavement cells?
found in the outmost epidermal layer of plants, serves as an extra layer of protection
Where do dark reactions occur?
stroma of the chloroplast
Where do light reactions occur?
thylakoid membrane
What are collenchyma cells?
- thicker cell wall than par.
- simple tissue
- living
- provide flexibility
What is sclerenchyma cells?
- thick cell wall, primarily for structural support
- simple tissue
- dead
- provides rigid support
What is the intercalary meristem?
Increases the length of plants
What is a chlorenchyma cell and where is it found?
in the mesophyll of leaves, is a parenchyma cell that is photosynthetic (has chloroplasts)
What are the 5 primary tissues?
epidermis pith primary phloem primary cortex cortex
What is the stele?
composed of primary xylem and phloem and the pith (tissues of the procambium)
What are bulbs?
large buds surrounded by fleshy leaves
What is a corm?
a swollen underground root that stores food for the plant
What is a cladophyll?
flattened stem that functions as a leaf (performs photosynthesis)
What is the axil?
the angle between the petiole and stem
What is a petiole?
stalk that attaches a leaf to the stem
What is an inflorescence?
a group/cluster of flowers
What is a peduncle?
the stalk below an inflorescence
What are pedicels?
the smaller stalks below each individual flower on an infloresence
What does a Spike-unbranched inflorescence look like?
the flowers are directly attached to the central axis
What does a raceme unbranched inflorescense look like
flowers are attached by pedicels to the central axis
Panicle-branched raceme inflorescences
multiple flowers on a pedicel
simple umbel-flowers
attached by multiple pedicels that arise from a common point
Compound umbel flowers
attached by multiple pedicels that arise from a common point but each has multiple flowers on each pedicel
Corymb-unbranched
pedicels of unequal length alternately attached along the central axis (flat top cluster)
What is a head inflorescence?
peduncle with flowers attached directly to a broad receptacle (sunflower)
What does the funiculus do?
connects the ovule to the ovary (stalk) – umbilical cord (supplies with water and nutrients
What does the tube nucleus do?
controls the growth of the tube going down the style towards the ovule (eventually helps to form a zygote)
What happens to the ovary?
it develops into the fruit
What happens to the ovule?
develops into the seed
What are integuements?
they develop into the testa (seed coat)
What is the testa?
the seed coat
What is the zygote/embryo composed of?
the egg nucleus (1N) and sperm nucleus (1N)
What is the endosperm composed of? (3N)
2 polar nuclei and sperm nucleus (2+1 = 3)
What is the definition of a fruit?
a mature or ripened ovary of a flower along with its contents and any adhering accessory structures
- all fruits develop from ovaries so they are produced ONLY by flowering plants
What is foliar theory?
that the ovary is derived from a leaf like structure on which ovules were borne
- leafy structure folded and produced a closed ovary
What does the ovary do? (aka pericarp)
holds the ovule/seeds
What does the ovule do?
when fertilized, it becomes the seed
What does the stigma do and what does it form?
- has sticky polysaccharides for pollen to adhere to (germinates)
- forms the pollen tube
What occurs during microsporagenesis
- formation of male gamete
- 2N (2 chromosomes) then undergoes meiosis (division) so that it can produce 4 cells (microspore) that form a pollen grain (is a pollen grain at maturity)
(*** the formation of microspores inside the microsporangia (pollen sacs) of seed plants – diploid cell undergoes meiosis which results in 4 haploids)
What occurs during megasporogenesis?
- formation of the female gamete
- 2N goes through meiosis and produces 4 1N cells but only 1 survives (3 degenerates)
- then, mitosis division of 1N makes 2 nucleate, then 4 nucleate, then 8 nucleate embryo sac (3 on each side and 2 in the middle)
(***megaspores develop from megasporocyte – undergoes meiosis which results in 4 haploid megaspore nuclei) - ovule (mother cell)
What guides the pollen tube to the ovule?
calcium signals – pollen tube
Meiosis vs Mitosis
TEXTBOOK DEFINITION
What forms the seed coat?
integuments
What does the nucellus do?
inner ovule, contains the megasporocyte/embryo sac
What do antipodal cells do?
provide nourishment to the egg cell (rich in lipids)
If a leaf is said to be sessile, what does that mean?
has no petiole (connects leaf to stem)
What is venation?
the arrangement of veins in a leaf/leaflet blade (pinate / palmate)
What is a pinately veined leaf?
one primary midvein and enlarged midrib with secondary veins branching from the midvein
What is a palmately veined leaf?
several primary veins fan from the base of the blade (parallel in monocots, diverge in dicots)
What is the perianth?
Non reproductive part - consists of the corolla (all petals) and calyx (sepals)
What are parenthocarpic fruits?
fruits that develop without fertilization
What is the endocarp?
the inner boundary around the seed(s)
What is the mesocarp?
fleshy tissue between the exocarp and endocarp
What is the exocarp?
the skin (outside layer)
Simple vs compound ovaries
simple: 1 carpel
compound: 2 or more carpels fused together
What makes up a fleshy fruit?
when all or part of the pericarp is fleshy at maturity
What is the fancy name for peppers and what is their central core composed of?
capsocum annuum: core composed of placental tissues where the seeds are
What is the fancy name for tomatoes and what are they composed of?
solanum lycopersicon (L.) H. Karst. seed bearing placental tissues which produce jelly inside the fruit (germination inhibitors)
Fancy name for peach and what family are peaches/nectarines in?
prunus persica – rosacea family
Freestone peaches
pits separate easily from flesh making them easy to slice
Clinging peaches
mesocarp adheres tightly to the pit
What makes nectarines different from peaches?
they are one gene different which makes their skin fuzzless
What are the layers of an orange and what is the edible part composed of?
edible part is made up of swollen hairs borne on the inside of the endocarp
Rind = exocarp
White = mesocarp
Orange fleshy bit = endocarp
What family are all citrus fruits in and what are they called?
rutaceae family – hesperidium (when the skin is composed of the exocarp and mesocarp)
What does hesperidium mean?
when the skin is composed of the exocarp and mesocarp
What are the 2 things that can cause oranges to go from green to orange?
- ethylene gas (plant hormone)
2. cool temps stimulate orange colour and chlorophyll breakdown
What are bloods and what makes them red?
blood oranges - anthocyanin cause them to be red
What are normal oranges and which type is most common?
produce richly flavoured juice used in orange juice (valencia cultivars is most common)
What are navels and why are they called that?
fresh eating orange (named cause their flower produce an abnormal and small ovary on top of the regular one called a navel – mutation makes seeds sterile making pollen nonfunctional) – are seedless and therefore need to be propagated asexually
What makes up a raspberry, whats their fancy name and what family are they in?
(rubus idaeus): rosaceae, an aggregate fruit with drupelets (75-125) on a receptacle
What defines a dry fruit?
when the pericarp (exo, meso, endo) is dry at maturity
Indehiscent vs dehiscent dry fruits
Indehiscent: non splitting (ovary and pericarp stay together) – maple, grains, sunflower
Dehiscent: splitting – peas, beans (splits along the side exposing the seed within)
What is a strawberries fancy name, family and what kinda fruit is it?
fragaria – rosacea family – achene (base of the seed is attached to the pericarp) aka dry fruit
What is the red part of a strawberry
a receptacle: the expanded tip of a peduncle or pedicel to which the various parts of a flower (calyx/corolla) is attached (base part that leads into flower)
Why are cultivated bigger than wild strawberries?
they are an octaploid (8 sets of chromosomes)
What is the cultivated strawberry a mix of?
fragaria virginiana and fragaria chilensis
Where do berries come from and what part is fleshy?
develop from a compound ovary and often contain more than one seed – pericarp is fleshy (hard to distinguish)
What is an aggregate fruit?
single flower with several to many pistils
What are multiple fruits?
several to many individual flowers in a single inflorescence
What is the hilum?
The part at which the ovule was attached to the ovary wall
What is the germplasm?
The sum total of a plants genes
What are suckers?
reproduce asexually and form on the roots and produce aerial shoots
What does caryopsis mean?
whenn the seed coat is fused to the ovary (looks like the seed is the whole fruit)
What is white flour made of?
endosperm (just starch)
What is brown flour composed of?
the whole grain
What is bran composed of ?
the hard outerlayer of the grain (ovary wall and seed coat)
- high in fiber
What is wheat germ made of?
the embryo from wheat grain
What feeds the embryo?
with starches from the endosperm that have been converted to sugar
What is a superior ovary?
ovary is above the sepals and petals (no accessory tissues)
What is the inferior ovary?
ovary is below the sepals and petals (fleshy part includes the ovary and accessory tissues
What is a carpel?
the ovule bearing unit that’s part of the pistil
What are annuals?
grow vegetatively and complete their reproductive cycle (produce seeds) in one growing season, then die
Weeds, wildflowers, crops
What are biennials?
grow vegetatively for a year then during the second year complete the reproductive cycle (produce seeds) then die – common in areas with a mild winter
Carrots, parsley, foxglove, celery
What hormone triggers the second year of growth for biennials?
vernalization triggers to start (cold for a period of time stimulates initiation)
What are perennials?
they produce vegetative structures that survive for many years
What are herbaceous perennials?
they grow actively during periods of adequate temperature and moisture but die back during unfavorable growth conditions
Stay active/dormant underground until conditions are favourable again
Ex. hosta
What are woody perennials?
they do not die back during unfavourable periods but can become dormant
Ex. trees, shrubs and vines
What are the top and bottom parts of a graft called?
top: scion
bottom: rootstock
* **strongly depends on contact between vascular cambiums
What is micropropagation?
When plants are grown in test tubes to provide a disease free state (for those that perform asexual reproduction cause they don’t have a great “immune system”)
