SAS/PLS 12 MIDTERM

how plants affect our lives

produce oxygen
renewable source of energy
supply food
pull carbon from the air and reduce climate change
provide medicines
clean water and soil

science

knowledge attained through study or practice

scientific knowledge

proven knowledge acquired through scientific method

scientific method

plan to perform scientific experiments
allows experiments to be duplicated

percent efficiency of energy conversion (food chain)

10%

macronutrients

carbs(glucose, fructose) , proteins, lipids
function in plants
function is humans

micronutrients

vitamins
minerals

why are some amino acids essential for humans

top 3 most widely consumed cereal crops

wheat
rice
corn

legumes are abundant in which macronutrient

protein

modified stems

have nodes and internodes
serve as a protected food reserve
ex: potato tubers

tuberous roots

are a form of modified roots that have become enlarged and fleshy with food reserves
ex: sweet potato and carrots

phytonutrients

major 3 classes: alkaloids, terpenoids, phenolics

examples of phytonutrients

carotenoids, anthocyanins

function of antioxidants

many can stabilizee and deactivate free radicals before they attack cells

examples of plant produced antioxidants

carotenoids (carrot), lutein (spinach), Lycopene (tomato)

function of carotenoids

humans:act as antioxidants and reduce the risk or developing cancers and heart diseases
plants: protect plant from light damage

function of anthocyanin

humans: antioxidant activities
plants: UV screen for plants

function of glucosinolates

humans: may prevent diseases like cancer, high blood pressure, macular degeneration and stomach ulcers
plants:

how did people obtain knowledge on medicinal plants?

trial and error
religious beliefs
doctrine of signatures (if a part of a plant looked like a part of the human body, it would be useful treating a disease in that body part)

traditional and modern medicinal uses of ginkgo and St. John's wort

gingko: traditional

allelopathy

plants secrete toxins from their roots that prevent the germination of other plants in their root zone; reduces competition with other plants

processes that are involved in drug discovery from plants

1. identify potential medicinal plants
2. screen for biological activities
3. chemically analyze the extract
4. large

methods to conserve medicinal plants

in

advantages of using plant

based raw materials for the production of industrial chemicals

plant tissue culture

any part of a plant can be used to start in citro cultures and induce callus tissue

totipotency

the ability of a single cells to develop into a complete plant

advantages of using plant tissue cultures for production of phytochemicals

year round availability of plant material
absence of interfering microorganisms in the soil
the de

bio

pharming

pros and cons of producing pharmaceutical drugs in plants

pros: plentiful and cheaper drugs
cons: environmental impact of the field release of gmo's; levle of protein production obtained within the plants (dosage needs to be carefully regulated)

Life cycle of a flowering plant

seed germinates

3 basic cellular events involved in plant growth

plant cell division
cell elongation
cell differentiation

meristem in plants; where and what

SAM: shoot apical meristem; at the tip of a plant shoot
RAM: root apical meristem; bottom of a plant

totipotency

all living plant cells have the genetic code to produce any kind of tissue or organ

diseases agrobacteria can cause

agrobacteria: soil pathogenic bacterium
crown gall disease: modulate plant growth and development

Ti plasmid

type of DNA in agrobacterium
tumor inducing plasmid

T

DNA

process of Agrobacterium

mediated genetic transformation of plants

process of double fertilization in flowering plants

pollen

advantage of seed dormancy

delay germination until favorable environmental conditions are present for seed germination

methods used to break seed dormancy

stratification (4 deg C in dark)
scarification (mechanical abrasion & Acid treatment)

examples of major seed crops

wheat
rice
corn
barley
sorghum
soybean
common bean
coconut

seed crops abundant in protein

broad bean
garden pea
peanut
soybean

seed crops abundant in oil

castor bean
palm oil
pine
papeseed

seed crops abundant in carbhydrates

barley
maize
oat
wheat

importance of seed banks

save genetic diversity

svalbar global seed vault

250mil seeds
500,000 plant species form 100 countries
arctic circle

recalcitrant seeds; methods to preserve plants that produce these seeds

seeds that don't survive drying or freezing
about 10% of flowering plants produce these
es: cocoa, mango, avocado

why are mineral nutrients important for plant growth and development

nitrogen: amino acids, proteins, nucleic acids (DNA RNA)
phosphorus: ATP, nucleic acids, sugar phosphate, phospholipids
potassium: enzymes
magnesium: chlorophylls

sources of minerals in soils that can be taken up by plants

rocks
natural fertilizers
artificial fertilizers

potential causes of plant mineral nutrient deficiency

mineral nutrients not present in soil
crop competition
unfavorable soil pH

relationship between soil pH and plant mineral nutrition

favorable range for many plants: 5.5

role of fertilizers in agriculture; possible environmental harm

organic fertilizers: from plant and animal residue, slow release, increase the amount of organic material in soil
inorganic fertilizers: inorganic salts of macronut, greater % of nutrient, easier to handle, more uniform, free from odor
harms: eutrophication

biotic stress in plants

caused by living organisms

abiotic stress in plants

caused by non

plant responses to drought stress

control of stomatal openings: pores open up and let in CO2, releases O2 & H2O (g)
stress escape strategy: plants complete their life cycles before the onset of stress (ex sunflowers grow, flower, and die during rainy seasons)

examples how plants interact with other living organisms in their "social networks"

mutualistic and symbiotic interactions
defense against pathogens and pests
competitive and cooperative interactions with other plants
plants and people (food, medicine, anthropogenic climate change)

importance of symbiotic nitrogen fixation for plant nutrition and nitrogen fixing bacteria

plants get nitrogen; helps growth
rhizobia get photosynthetic products; a well controlled and protected environment (plant nodule) to grow in

name and describe different groups of microorganisms that can cause disease in plants

pathogens: host

plant disease triangle; principles of plant disease

susceptible host; host resistance
favorable environment; protection
pathogen; exclusion (prevent introduction of pathogens with seeds treated with fungicides and cleaning equipment) & eradication (eliminating pathogens after it is introduced but before it has become widely spread)

center or triangle: disease

advantages and limitations of monocultures

advantages: more convenient
limitations: susceptible to weather pattern changes an crop diseases

benefits of polycultures

diverse pollen and nectar sources to attract natural enemies of the crop pathogens
provides habitat for more species and increases bio diversity

examples of competitive relationships among plants

plants competing for light
allelopathic chemicals: interferes with growth of nearby plants
some plants parasitize other plants

cooperative relationships among plants

ancient 3 sisters method: corn, bean, squash

environmental issues with deforestation

threatens plant survival
decreases plant diversity

common sources of environmental contaminants

volcanic eruptions: toxic gases
factories
forest fires
oil spills
pesticides
mining
waster water treatment

biotic migration of contaminants in the environment

transfer and concentration of a toxic material along a food chain
ex: DDT

types remediation methods that decontaminate environmental pollutants

physical: soil removal; generally used before bioremediation
chemical: generally used before bioremediation
biological: using living organisms to reduce or eliminate environmental hazards. phyto or bio remediation

plant organs that uptake environmental contaminants

root
plant axis
leaf
phloem
xylem

mechanisms that plants use for remediation of contaminate soil and water

phytovolatilization: uptake and vaporization of contaminants by plants, either at low concentrations or in a modified form
phytoextraction: uptake of contaminants in the soil by the plant roots and translocation into above ground portion of the plants
phytostabilization: immobilization of a contaminant in soil or groundwater through absorption and accumulation by roots, absorption into roots, or precipitation within the root zone and physical stabilization of soil

crop domestication

genetic modification of a wild species to create a new form of a plant that is altered to meet human needs

2 processes that are needed for crop domestication

cultivation (management)
selection (differential reproduction)

natural vs artificial selection

natural: wild plants develop via this to ensure their survival
artificial: done to suit human needs

domestication syndrome

common traits hat distinguish crop plants from their wild progenitors
examples: more compact growth; elimination or reduction in seed dispersal; loss of seed dormancy; gigantism of harvested organs; reduction in fertility; reduction of toxic compounds; change in life span; changes in organ shape and size

irish potato famine causes

low genetic diversity
blight pathogen