behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or...

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Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an activity of a defined organism, especially observable activity when measurable in terms of quantifiable effects on the environment whether arising from internal or external stimuli OR = anything that an organism does that involves action and response to stimulation OR = the response of an individual, group, or species

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Page 1: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Behavior = the manner in which a personbehaves in reacting to social stimuli or toan inner need or to a combination thereof;

OR = good manners

OR = an activity of a defined organism, especially observable activity when measurable in terms of quantifiable effects on the environment whether arising from internal or external stimuli

OR = anything that an organism does that involves action and response to stimulation

OR = the response of an individual, group, or species to the whole range of factors constituting its environment

Page 2: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Plant Life Cycle: includes stages of dormancyprocesses of mitosis, cell expansion, differentiation, fertilization (twice!)

Plant Development is flexbile:indeterminate, cells toti-potent

Page 3: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Corn (Zea mays)

produces male flowers(tassel)

and female flowers(many make up the ear)

the plants can ‘self’ oroutcross

a pollen grain germinatingon a style must extend itstube down the length ofthe style (12 inches or so)and fertilize the embryoat the end of the stylein order to make a kernel(ovule) develop

Page 4: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Once and embryo is formed, it can undergomitosis (cell division), and differentiation tomake all the different cell types, tissues andorgans of a plant. This process is calleddevelopment.

Development is regulated at three levels:

Genetic – by control of the pattern of geneexpression, cells determine whichproteins, structures and processesare active

Internal signaling – signals include ‘hormones’other metabolites (sugars, peptides)hydraulic and electric signals

External signalinglighttemperaturewaternutrientbiotic interactions

Page 5: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Plant ‘hormones’ or growthregulators are active at nM levels.

Their activity depends on:

1) rate of synthesis2) rate of transport to active site3) receptivity of target/presence

of receptor4) rate of degradation

Page 6: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Germination:

• dormancy must be broken• seed imbibes water• tissues rehydrate• embryo releases GA• aleuroce cells respond to GA• endosperm digested• embryo begins to grow• root elongation followed by shoot/leaves

Seeds are like tiny space ships, launched from their mother into space, packed fullof food, primed to germinate if or when they land on suitable substrate.

Page 7: Behavior = the manner in which a person behaves in reacting to social stimuli or to an inner need or to a combination thereof; OR = good manners OR = an

Some seeds require light as a cue for germination.The photoreceptor responsible for this sensory process is Phytochrome – red (660 nm)/far red (730 nm) photoreceptor ‘switch’

phytochrome is aprotein with enzymeactivity (kinase), bound to a chromophore;when the chromophoreabsorbs R or FR light,it changes the proteinconformation, thusactivating/inactivatingthe enzyme