Unit 2 Botany Flashcards
How many cotyledons does a mono it have?
1
What is a cotyledon?
Food storage leaf found in seeds.
How many cotyledons does a dicot have?
2
What is the leaf venation of a monocot?
Parallel
How petals does a monocot have?
Three, or multiples of 3.
What is the arrangement of the vascular bundles in the stem of a monocot?
Scattered, look like faces.
What is the leaf venation of a dicot?
Netted
Flower structure of dicot?
Multiples of 4 or 5.
What is the vascular bundle arrangement in the stem of dicots?
Circular, candy corn.
Deciduous
Lose all leaves at one time
Evergreen
Occasionally shed a few leaves.
Two primary functions of leaves
Photosynthesis and transpiration
What is transpiration?
Evaporation of water from leaves in vapor form.
Three ways leaves vary?
Size, shape, texture
Blade
Main flat portion of leaf
What two plant tissues are found in vascular bundles?
Xylem and phloem.
What are the veins on a leaf?
The vascular bundles.
Petiole
Stalk that supports blade.
What is a leaf with an absent petiole?
Sessile
Axil
Angle between stem and petiole
Axillary bud
Bud that forms in the axil
Stipule
Pair of lead like or scale like appendages sometimes found in the axil.
Node
Area on stem where leaf attaches to the stem.
Simple leaf
One undivided blade.
Pinnate veined
Single main vain that cuts up middle of the blade with little tiny offshoot veins.
Palmate veined
Several primary veins palm out of the base and have little veins shooting off.
Parallel veins
Veins run parallel of each other off the base
Dichotomous venation
Ginkgo leaves, veins fork evenly and progressively from base of blade. Forms a chaotic pattern.
Compound leaves
Blade divided into multiple leaflets.
Pinnately compound
Leaflet in pairs along central rachis (central part of compound leaf)
Bipinnately compound
Leaflets of a pinnately compound leaf subdivided into more leaflets.
Palmately compound
Leaflets attached at the too of the petiole and radiate outward.
Alternate arrangement
Spiral, one leaf per node.
Opposite arrangement
Two leaves per node.
Whorled arrangement
Three or more leaves per node.
Epidermis
Single colorless layer of cells covering the entire leaf
Cuticle
Waxy layer on epidermis
What is the cuticle made of?
Cutin
Stomata
Tiny pores on leaf epidermis. Used for gas exchange.
Dicot stomata distribution
Mainly on lower epidermis
Monocot stomata arrangement
Equal distribution on both surfaces.
Aquatic plant stomata distribution
Trick question, none. Haha loser.
Guard cells
Part of stomata. Curvy, banana shaped, only epidermal cells containing chloroplast. Cell walls are thick but flexible.
Function of stomata
Permit gas exchange
Regulate transpiration
What controls the opening and closing of guard cells
Water content.
What happens when guard cells are inflated.
Stomata opens.
What happens when guard cells are deflated.
Stomata closes.
Bulliform cells
Large thin walled epidermal cells on either side of the midrib. Make lead fold or roll inward.
What triggers bulliform cells
Dry weather
Where are bulliform cells primarily found
Monocots
Glands
Secrete sticky substance.
Occur as a depression or protuberance (sticks off plant) and on hairs or hair tips.
Mesophyll
Literally middle of the leaf
Veins
System of vascular bundles
Types of mesophyll
Palisade mesophyll and spongy mesophyll.
Palisade Mesophyll
Tightly packed chloroplast filled cells. (>80% of leaf’s chloroplast)
Spongy Mesophyll
Loosely arranged parenchyma, has air space between cells, also has chloroplast. Aids in gas exchange.
What happens if the moisture level of the mesophyll cells decreases?
Pores close.
What is special about the mesophyll of monocots?
Only one layer exist
Where are veins located in the leaf?
Mesophyll
Xylem location in leaf
More towards upper epidermis
Phloem location in leaf
More towards lower epidermis
Bundle sheath
Layer of parenchyma and/or fibers that surround veins for protection.
What kind of plant has parallel veins?
Monocot
What kind of plant has branched/netted veins?
Dicot
Chemical formula for photosynthesis
6CO2+ 6 H2O –sun—> C6H12O6 + 6O2
Where do plants get carbon dioxide?
Through stomata.
Where do plants get water?
Through roots and xylem.
What is transpiration?
Water leaving trough the leaves.
What is cohesion?
Water molecules sticking together because they’re all polar.
Brief overview of transpiration cohesion theory.
Water leaves leafs, making leaf empty, pulls water up from the xylem which pulls water up from the roots, which pulls water from earth.
What are the four plastid pigments.
Chlorophyll, carotenoids
What color is chlorophyll?
Green
What are carotenoids?
Carotenes and xanthophylls
What color are carotenes?
Yellow
What color are xanthophylls.
Pale yellow
What are the two kinds of vacuolar pigments?
Anthocyanin and Betacyanin
What color are anthocyanins?
Red and blue. (Red if cell sap is acid, blue if cell sap is alkaline)
What color are beta cyanins?
Reds
What is the stimuli that triggers leaf color change?
Changing of light.
After the stimuli, what happens to the leaf?
The chlorophyll breaks down and disappears.
How come the other colors show over chlorophyll when leaves change color?
The chlorophyll disappears.
What is abscission?
The process of leaves being shed and cut off.
When do deciduous leaves drop in temperate climates?
The fall.
When do deciduous leaves drop in tropical climates?
Dry season.
Why do evergreens never lose all their leaves?
They shed them in small amounts around the year.
What does senescence mean?
Aging of a lead until death.
Why is lead abscission an adaptive advantage?
Can’t use the frozen water, so photosynthesis.
Trees can break from the leaves getting too heavy while being covered in snow.
What causes abscission?
Temperature drop, water drop, or damage to a leaf.
What is the hormone produced in abscission?
Ethylene.
Where do the leaves abscission at?
The node
What are the two layers in the abscission zone called?
Protective layer and separation layer.
What is the area where abscission takes place called?
Abscission zone.
What does the protective layer do?
Acts as a scab, keeps water in.
What is the abscission layer made of?
Suberin
What is the separation layer?
Layer where cells separate.
What does ethylene do?
Triggers production of pectenase.
What does pectenase do?
Eats the pectin from the middle lamella.
What part of the leaf is left holding onto the tree after abscission?
The vascular bundle.
What ultimately breaks the leaf off the tree?
Wind/rain breaks the vascular bundle.
What are tendrils.
Specialized leaves that climb towards the sun quickly.
What kinds of plants have tendrils?
Potato vines, greenbriars, clematis, peas, squashes, melons, cucumbers.
How do tendrils work?
Contact with tendril causes a sudden and rapid growth on the other side of the tendril.
What are spines?
Modified leaves that repel animals and help plants in dry climates not lose a lot of water.
Since plants with spines do not have leaves, where does photosynthesis take place?
In the stem of the plant.
Where are spines found?
In the nodes of cacti and other desert plants.
What are thorns?
Modified stems
Where are thorns found?
On black locust plants.
What are prickles.
They are raised epidermal cells
Where can prickles be found?
On roses and raspberries.
What are the reactants in photosynthesis?
Carbon dioxide and water.
What do leaves meant for water storage have?
Large, thin walled parenchyma cells with extra large vacuoles.
What do specialized leaves that store water NOT do?
Photosynthesize
What are onions, tulip bulbs, garlic, etc?
Specialized leaves that store starch, that are used by the plant in the next growing season.
What are bracts?
Special “floral” leaves found at the base of flowers or a flower stalk to make a flower look bigger.
What is an example of a plant with bracts?
Poinsettias, safe
What are predatory or insect trapping leaves?
What the name says. Come on Elise, get it together.
Why do all carnivorous plants have chloroplast?
They are green, and therefore photosynthesize. Bugs and stuff are just fun vitamins.
What are pitcher plants.
Predatory plants with nectar secreting glands around the rim to attract insects. Insect falls in, can’t get out, and gets digested by enzymes.
Why would the walls of a pitcher plant be coated with wax?
To make it slippery and make the bug heavy.
Sundews
Predatory plants with long, spikey hair structures sticking off the round leaves. Tips of each hair have a sticky fluid oozing off that contains digestive enzymes. The hairs bend inward to trap the prey.
What can sundews do that’s special?
Detect between protein and in edible material.
What other impact do the sticky drops of fluid have other than having digestive enzymes?
Attract bugs.
Venus flytrap
Predatory plant, triggering hairs inside trap cause the bulliforms to stimulate and close.
Bladderworts
Aquatic predatory plant. Leaves have stomach shaped “bladders” with trapdoors that are triggered by the hairs on the end of each door.
What are the three major functions of stems?
Transport, storage, support.
What are the two places ON THE STEM that apical meristems are located?
Apice (tip), axillary buds.
Protoderm
Primary meristem, forms epidermis.
Procambium
Primary meristem, forms vascular tissue, PRIMARY xylem and PRIMARY phloem.
Ground meristem
Primary meristem, forms cortex and/or pith
Pith
Center of stem, made of parenchyma cells
Cortex
Tissue between epidermis and vascular tissue. (Also made of parenchyma)
What two types of meristematic tissue make SECONDARY tissue?
Cork and vascular cambium
Tracheid
Long spongy cell that overlaps with neighbor. No perforations on the ends.
Vessel Elements
Has large hole perforations, stacks on top of one another
Fiber
Long thick walled cell with pointed ends, does at maturity.
What do tracheids, fibers, and vessel elements all have in common?
All in secondary xylem, all conduct water.
Sieve tube elements
Long tapered cells with small sieve plates between connecting cells
Sieve cells
Cell that is connected to an un-nucleared sieve tube element
What forms the inner bark of the tree?
Old phloem
What are sieve tube elements missing
Nucleus
What is cork cambium made of?
Cork and cork parenchyma
What is another name for cork cambium?
Phellogen
What do cork cells get filled with?
Suberin
When do cork cells get produced?
Annually
When do cork cells die?
Shortly after formation
What does the cork make up?
Outer bark of plant.
What are lenticels?
Region of cork cells that allow for gas exchange.
Where do lenticels form?
Beneath stomata.
What are annual plants?
Plants which die after one growing season.
What kinds of plants are usually annuals?
Herbaceous plants
What is wood?
Secondary xylem tissue.
How can you tell the age of a tree?
Count the summer +spring rings together.
Spring wood
Xylem formed early in the season. Large and light in color.
Summer wood
Xylem formed late in the season. Narrow tubes and dark in color.
What is an annual ring?
One year’s growth of summer and spring wood.
What can be discovered about a tree through it’s rings?
Age, insects, injuries, fire history, rainfall
What are rays
Conductors of nutrients and water laterally
What are rays made of?
Parenchyma cells that stay alive for over ten years.
Xylem rays
Carry water laterally
Phloem rays
Carry sucrose laterally
What is shoved into vessels and tracheids to form tylosis?
Protoplasts
What is a tylosis?
Clogged up xylem that’s dead.
What do tylosis do visually?
Make wood appear dark
Heartwood
Found at the center of the stem. Used for support. Dark in color.
Sapwood
Found closer to the vascular cambium, lighter in color, used for conduction of materials.
Resin canals
Tube like, lined with secretory cells that secrete resin
Inner bark
Primary and secondary phloem
Outer bark
Periderm (cork and cork cambium)
Laticifers
Latex secreting cells, remain living and have multiple nucleuses.
Important types of latex
Chewing gum, opium, morphine, gloves
What do monocot stems not make and why?
Don’t make bark because they don’t have vascular or cork cambium.
Why are monocots so small?
No wood means no support
How are vascular bundles arranged in monocots?
Scattered smiley faces
In vascular bundles where is xylem
Towards inside of stem
In vascular bundles where is phloem
Towards outside of the stem
Rhizomes
Specialized stem, grow horizontally below ground
Runners
Horizontal stems that grow horizontally above soil. Produce new plants wherever tips touch the soil.
Stolons
Start below ground and grow in various directions.
Tuber
Swollen tip of stolon. Like potatoes.
What are the eyes of a tuber?
Nodes
Bulb
Stem covered with fleshy leaves
Corm
Fleshy stem with papery scale-like leaves.
Cactus stems
Specialized for photosynthesis. Flat, green, large surface area.
Thorns
Stems that provide protection from potential herbivores.
Tendrils.
Specialized stems that let plants climb
Wood is primarily made of 60-75% of what?
Cellulose
What are knots
Bases of older branches covered in new growths of wood.
Lumber
Used in construction
Veneer
Thin sheets of wood glued to cheap lumber
Pulp
Used as an additive. Ex: ice cream, cereal, paper, and bread
Fuel
<10% of timber in the us is used for fuel.
How do leaves vary?
In size, shape, and texture.
Why does corn have a lot of vascular bundles concentrated beneath the epidermis?
To support the ears of corn.
What are perennials?
Plants that return every year.
Transport
Moves water up from roots and sucrose down from leaves
Support
Holds entire above ground plant
Storage
Stems have lots of parenchyma and vacuoles.
What do roses NOT have?
THORNS
What is special about guard cell walls?
The walls are thickened, but flexible on the sides by the stomata.
Where do glands appear?
As depressions, protuberances (stick out) and on hairs or hair tips.
