Final Study Guide Flashcards
When did plants move to land?
475-430 million years ago
What is the atmosphere currently composed of?
~78% nitrogen
~21% oxygen
~1% argon
>1% CO2
What molecules made up the early atmosphere?
CH4, NH4, SO2, CO2, H2S, and H2
How did the relative proportions of molecules in the atmosphere change over time?
O2 increased while reducing gases (such as CH4 and NH4) decreased
What is the most significant difference between young dicot and monocot stems?
Monocot stems have scattered vascular bundles whereas dicot stems have rings of vascular bundles
What are the two zones of cell division that plants grow from called?
Meristem and cambium
What are the four types of meristems?
Apical
Plate and marginal
Intercalary
Basal
Secondary growth
Growth in width or diameter that gives rise to woody or corky tissues
What are two secondary meristems that give rise to secondary growth?
Vascular cambium and cork cambium
Vascular cambium
Gives rise to secondary xylem on the inside and phloem on the outside
Cork cambium
Gives rise to the periderm (bark)
What are the four types of cells that xylem is made up of?
Tracheids, vessels, fibers, and rays
What do tracheids and vessels do?
Water transport
How is water transported through the xylem, and what drives its movement?
Water is passively transported one-directionally due to evapotranspiration from leaves
Give the order of the system of plant classification
Kingdoms, divisions, classes, orders, families, genera, species
The last 3 are most important
What makes phenotype?
Genotype x environment = phenotype
Genotype
The genetic makeup of an individual
Phenotype
The appearance or traits of an individual
Clone
Identical genotype, phenotype similar
Line
Genotype similar, phenotype similar
What process forms the gametes of an angiosperm?
Pollen and ovule (egg) are formed by meiosis; two 1n polar nuclei and one 1n egg.
What are the products of double fertilization?
Endosperm and zygote
Primitive flower
Radially symmetric
Advanced flower
Bilaterally symmetric
What is special about grass flowers?
They are advanced flowers with no showy petals since they are wind-pollinated
Fruit
A developed ovary of a seed plant with its contents and accessory parts
How does the pH of the vacuole compare to that of the cytosol?
The pH inside the vacuole is lower than the pH in the cytosol
Light-driven/dependent reactions
Use light energy to drive endergonic (energy-requiring) synthesis of ATP and NADPH
Carbon-linked/light independent reactions
Use chemical energy from the light reactions to drive the endergonic (energy-requiring) incorporation of CO2 into carbohydrates
Occur in the stroma
What are the 3 important chemicals in the Calvin cycle?
3-PGA (3-phosphogylcerate)
G3P (glyceraldehyde-3-phosphate)
RuBP (Ribulose-1,5-biphosphate)
How does the Calvin cycle work?
RuBP, CO2, and H2O are used to produce 3-PGA, which is then reduced to form G3P.
For every 3 RuBP molecules, one G3P molecule is produced. Multiple G3P molecules are then synthesized into sucrose.
The rest of the G3P molecules are recycled back into RuBP.
What does the regeneration of RuBP require?
Energy, in the form of ATP
CAM mechanism
Temporal separation of CO2 fixation and the Calvin cycle
CO2 is fixed into malate by PEP carboxylase at night.
Malate releases CO2, which is fixed by Rubisco during the day
Where does each of the 3 stages in aerobic respiration occur?
Glycolysis occurs in the cytosol
The Krebs cycle and ETC happen in mitochondria
How much ATP does a sucrose molecule produce?
60 ATP
Metabolism
The biochemical reactions that create molecules
Primary metabolites
Molecules produced by all plants and that are essential to their growth and survival
These would be things like amino acids, fatty acids, carbs, and nucleotides
Secondary metabolism
The biochemical reactions that create molecules not necessary for plant survival. These molecules are called secondary metabolites and are often unique to one group of plants
What are the 4 primary metabolites?
Amino acids
Fatty acids
Carbohydrates
Nucleobases
What are the 3 main groups of PNPs?
Terpenoids, phenolics, and alkaloids
Terpenoids
Derived from isoprene (5-carbon unit). Mostly multicyclic C structures with oxygen-containing functional groups
Examples of terpenes are carotenoids and menthol
Phenolics
Molecules containing phenol groups
Examples: lignin, flavonoids
Alkaloids
Nitrogen-containing molecules mostly synthesized from amino acids. Usually feeding deterrents and toxic to insects and other animals.
Some examples include cocaine, morphine, caffeine, nicotine
What are the 5 traditional plant hormones?
Auxin, abscisic acid, gibberellins, cytokinin, and ethylene
What are the major functions and uses of auxin?
Synthetic auxins are used as herbicides. Auxins can promote rooting, increase fruit set, and prevent pre-harvest fruit drop
What are the major functions and uses of gibberellin?
Increased malt production by enhancing alpha-amylase production
Order of soil horizons
OAEBC
O horizon
The layer above the A horizon comprised of organic matter in varying stages of decomposition
E horizon
An area that may develop between horizons A and B when there has been significant leaching, leaving a pale layer mostly composed of silicates
How is soil TEXTURE determined?
By its particle-size distribution
How is the timing and amount of water to apply determined?
By measuring water loss from the crop or by directly measuring the soil water potential
What is the most efficient irrigation method?
Drip irrigation
Why is water a universal solvent?
Because it is a molecule that has a polar charge
What is the relationship between Ψw, Ψs, and Ψp?
Ψw = Ψs + Ψp
Ψw: water potential
Ψs: solute potential
Ψp: pressure potential/turgor pressure
What is the optimal pH range for most soils?
pH 5.5 to 7.0; slightly acidic to neutral
What are the 6 macronutrients?
Nitrogen
Phosphorus
Potassium
Calcium
Magnesium
Sulfur
Nitrogen (N)
A vital component of amino acids and nucleic acids.
The most frequently deficient element in crop production
Too much nitrogen can cause excessive vegetative growth and delay flowering/fruiting
Atmospheric nitrogen
Not available to plants until it is fixed
How does symbiotic N fixation occur?
Bacteria associate with plant roots by forming nodules, providing them with nitrogen in exchange for carbohydrates
What is one genus of symbiotic bacteria that helps fix nitrogen?
Rhizobium
What are 5 examples of abiotic stress?
Temperature, moisture (water/relative humidity), solar radiation, atmosphere, nutrient availability
Reactive oxygen species
Highly reactive forms of oxygen that rapidly react with and oxidize a wide variety of cellular components.
They are one of the most common group of toxic molecules
How have global CO2 concentrations increased in the last <200 years?
They have increased by 50%
Pierce’s disease of vines
The bacteria Xylella fastidiosa is carried to vines by insect vectors. The bacteria multiply and block the xylem
How to control Pierce’s disease of vines
Monitor and treat the vector
Remove infected vines
Grow less susceptible varieties
How should methods to control pests start off?
With preventative cultural methods, only using harsher methods when necessary
Cultural and physical/mechanical methods
Crop rotation, companion planting, breeding for pest-resistance, mulches, plowing, cover crop, eliminating vectors or reservoirs
Nucleotide makeup
Nitrogenous base
Sugar
Phosphate group
What are the sugars in DNA and RNA?
Deoxyribose in DNA
Ribose in RNA
How are nucleotides paired?
A-T (or U, in RNA)
C-G
Agrobacterium-mediated plant transformation
The most widely-used method for DNA insertion into dicot plants
Limitations: not all plants are susceptible to agrobacterium transfer, and not all agro-susceptible plants can be regenerated from a single cell
What was the benefit of Bt corn?
Dramatically reduced insecticide use
What are methods of modifying plant genomes?
Traditional plant breeding, genetic engineering, and genome editing
Lignin
Cell wall strengthing
What pumps into the vacuole?
H+ proton
What are the antiports
Mg^+, hexose, sucrose
