UWM BIO 152 EXAM 3 - PLANTS PT 2

Are stomata usually located on the upper or lower epidermis?

Lower epidermis

What is the function of the stomata?

Regulates intake of CO2 and loss of water and O2

What are the two layers of the mesophyll?

Upper/ palisade and lower/spongy

What is contained in the pallisade mesophyll?

Chloroplasts for photosynthesis

What is the function of the spongy mesophyll?

space for gas exchange

What are some properties if veins in leaves?

Vascular Bundles

Continuous

Contain xylem and phloem

Structural support and transport

What are some properties of chloroplasts?

Cellular organelles that conduct photosynthesis

Circular genome - endosymbiotic origin

Which membranes in chloroplasts contain chlorophyll?

Thylakoid membranes

What is stroma?

Dense fluid in chloroplast

What are the inputs and products of photosynthesis?

In: Solar energy, CO2, H2O

Out: Glucose and Oxygen

What types of light does chlorophyll absorb?

Blue and red light

Reflects green

In which membrane does photosynthesis occur?

Thylakoid membrane

What is the light independent reaction that occurs in plants called?

The Calvin Cycle

Where does the Calvin Cycle occur?

Stroma

How are the light dependent and the light independent (calvin cycle) reactions of photosynthesis related?

Light dependent produces Glucose which is used by the Calvin Cycle as a source of energy

What does rubisco do?

Catalyze carbon fixation

What does the Calvin Cycle produce?

Sugars

How are sugars stored in plants?

As starch

What are the differences between photosynthesis and respiration?

Photosynthesis: Occurs in chloroplast

Uses CO2 and H2O

Produces O2 and Glucose

Requires solar energy

Respiration: Occurs in mitochondria

Uses O2 and glucose

Produces CO2 and H2O

Produces energy (ATP)

How does aerobic respiration work?

Releases energy in the chemical bonds of glucose

Uses oxygen

CO2 and Water are byproducts

What is diffusion?

Movement of solutes from area of high concentration to area of low concentration

What is passive transport?

Transport that does not require energy

Diffusion and osmosis

What is active transport?

Transport that requires energy

Membranes are impermeable to ______ and ________.

Ions and large organic molecules

What is the difference between passive and facilitated diffusion?

Passive - through lipid bi-layer

Facilitated - Through protein channels, attached to carrier protein

What does active transport take place?

Pumping of solutes through a membrane against the concentration gradient, from low to high concentration

How does a sodium potassium pump work?

Moves sodium ions out of cell and potassium ions into cell

1 ATP = 3 sodium out 2 potassium in

What does isotonic mean?

Equal solute concentration on both sides of membrane

What does hypertonic on the outside mean?

Higher concentration of solutes on outside of membrane

What does hypotonic on the outside mean?

Lower concentration of solutes on outside of membrane

What is a turgid cell?

A cell in a hypotonic solution

What is a plasmolyzed cell?

A cell in a hypertonic solution

What is the equation of water potential?

Solute potential + Pressure potential

How does mineral uptake in root hairs work?

H+ pumped out of cell

Cations (Na+ and K+) are attracted to negatively charged cytoplasm

Anions couple with H+ as they re-enter the cell

Where are the epidermis and endodermis located in a plant root?

epidermis on the outside of the root

Endodermis around the vascular tissue in the middle of the root

What is the cortex?

Part of the root between epidermis and endodermis

What is the difference between the apoplast pathway and the symplast pathway?

Apoplast - carries water through cell. Moves water between cells.

Symplast carries water through cytoplasm

What is the casparian strip?

Layer of suberin in endodermis that is impermeable to water

Prevents water from crossing endodermis between cell walls

What two mechanisms move xylem sap?

Root pressure pushes from below

Transpiration from leaves pulls from above

_____% of herbaceous plants are water. Stored in ______.

80-85%

Vacuoles

What are the most abundant elements of a plant (dry weight)

C, H, O

What is a hydroponic culture?

Growth with roots in a liquid nutrient solution

What are the 9 macronutrients for most plantsand what is a macronutrients?

C, H, O, N, S, P, Ca, K, Mg

Nutrients needed in large supply by a plant

What are NPK fertilizers?

Nitrogen Phosphate, Sodium

5 - 10 - 15 ratio

What is the function of N in plants?

Proteins

Base pairs for RNA/DNA

Chlorophyll

Chemical Defenses

What are the functions of P as a macronutrient?

ATP/ADP Transport and Storage

Phospholipids of membranes

Sugar phosphates DNA and RNA

What are the functions of S as a macronutrient?

Amino-Acids

Chemical Defense

What is the function of Ca as a macronutrient?

Middle lamella pectin

What is the function of K as a macronutrient?

Regulating stomata

What is the function of Mg as a macronutrient?

Important component of chlorophyll

What are the 8 micronutrients?

What are they mostly used as?

Fe, Cl, Cu, Mn (Manganese), Zn (Zinc), Mo (Molybdenum), B (Boron), Ni (Nickle)

Co-factors in enzyme reactions

What is the function of Fe as a micronutrient?

Essential in electron transport chains in chloroplast and mitochondria

What is the function of Boron as a micronutrient?

Cofactor in chlorophyll synthesis

What is the function of Molybdenum as a micronutrient?

Nitrogen assimilation enzymes

What is the underlying rock type around Milwaukee?

Dolomite and Shale

Where does soil originate?

Weathered rock

What are the three sections of soil?

A horizon - Topsoil (nutrient-rich)

B horizon - Subsoil

C horizon - Weathering parent rock

How do the sizes of Sand Silt and Clay compare?

Sand is largest, Silt is smaller, and clay is invisible to naked eye

What are aggregates?

Clumps of silt and sand held together by clay and organic material

What is the cation exchange mechanism?

Cations adhere to surface of clay particles in soil. Plant roots discharge H+ which displace cations from soil to be taken up by plant

What are the most common mineral deficiencies in plants?

N, P, and K

Characteristics of low pH soils and high pH soils

Low pH - Acid soils, Clay, wet soils

High pH - Alkaline soils, often limestone base (along Lake Michigan)

What is phytoremediation?

Using plants to suck up harmful toxins in soil

Physical vs Biological Stimuli

Physical: Abiotic stimuli

Light, temperature gravity etc.

Biological: Hormones.

Herbivores, pathogens, organic chemicals emitted by other plants etc

What are tropisms?

Growth responses resulting in curvature toward or away from a stimulus

What is thigmotropism?

Response to a mechanical stimuli

AKA Touch. Seen in vines

What is thigmorphogenesis?

Change in form which results from mechanical vibrations or wind

Increases ethylene production which inhibits elongation, making it short and sturdy

What are tugor movements?

Leaves move/close when you touch them

What is photoperiodism?

Plants changing seasonally

Response to varied day length

How do plants measure the length of night?

Phytochrome - Hormone that is activated by red light and far red light. Germination occurs with red light, not with far red light

What are the main plant hormones?

Auxin, Gibberellins, Ethylene, Abscissic Acid

What is auxin?

Indoleacetic Acid - Natural Hormone

Hormone that stimulates cell elongation

Produced in apical meristem

Low concentrations required

Is auxin drawn toward light?

No, moves to shaded side of the plant and elongates that side more, so that the plant grows toward the light

How do gibberellins work?

Stimulate cell elongation and division

Produced in leaves and stems

Used to initiate growth in seeds

What is ethylene?

Gaseous hormone

Interacts with auxin

Involved in fruit ripening by stimulating loss of chlorophyll

How is the apical hook of eudicot seedlings maintained?

Asymmetrical production of ethylene, which inhibits elongation of cells on the inner surface

Ethylene production stops after seedling breaks thru soil

What is abscisic acid?

Produced in buds - induces dormancy of apical growth in winter buds

Regulates guard cells, closing stomata during dry periods

What are the two types of plant defenses?

Physical: Cell walls, bark, etc.

Chemical: Constitutive - Present at all times

Inducible - Plant activates defense when needed

What are some examples of constitutive physical defenses?

Trichomes, silicates on blade of grass

What are primary and secondary metabolites?

Primary - Chemicals necessary for growth, development, and reproduction

Secondary - Related to defending plant tissue

What are the three main classes of chemical defenses in plants?

Terpenoids

Phenolics

Alkaloids

What are terpenoids?

Type of chemical defense

Classified by # of isoprene units

Used in essential oils

Cardiac glycosides

What are phenolics?

Chemical plant defense

Inhibitors, animal toxicants, and pesticides against invading organisms

What are alkaloids?

Chemical plant defense

Contain nitrogen

Affects central nervous system

Caffeine, morphine, cocaine, etc.

What are cyanogenic glycosides?

Plant toxin that releases cyanide upon breakdown

What are some ways plants can sense attack/induce defense?

Disruption of cell membrane polarity

Insect saliva chemicals

Jasmonic Acid

Created from jasmonate that is used to send signals through a plant that it is being attacked.

What is general immunity?

A response to damage from bacteria or fungi

What is specific immunity?

A response to a specific pathogen (gene)

What is a hypersensitive reaction?

Localized cell death to limit spread of the pathogen

What is systemic acquired resistance?

Heightened state of readiness throughout a plant after exposure to pathogen

Can spread to other plants by insects

What are the types of diversity?

Ecosystem Diversity

Species Diversity

Genetic Diversity

What are the four main causes of species extinction/decreased biodiversity?

1. Habitat Loss

2. Invasive Species

3. Pollution

4. Over-exploitation

Is there more solar energy per unit of area in the tropics?

Duh

About _____% of all species that ever existed are now extinct.

90%

How great is the current rate of extinction?

100-1000 times greater than expected

What is the rule of tens in terms of invasive species?

1 in 10 non-native plants will become naturalized and 1 in 10 naturalized plants will become invasive

What is EICA?

Evolution of Increased Competitive Ability

Natural selection favors plants that allocate resources to growth and reproduction as opposed to defense

How many millions of acres of lawn is there in the USA?

32 Million acres, more than any other crop

Herbicides (Roundup) are linked to ________

Lymphoma