respond to light by switching on signal transduction

results in suntracking, phototropism, flowering, and seed germination

Process in which a cell percieves a signal, switching on an intercellular pathway that leads to cellular response.

results in sun tracking, phototopism, flowering and seed germination

-involved in the timing of germination and flowering

- flips back and forth between 2 conformations

- main blue light sensor in photropism

- becomes phosphylated when exposed to blue-light signal to a chemical signal

1. select for adaptions that help aquisition

2. trigger adaptive changes that aid in nutrients aquisition

Water is essential to plants for 4 reasons:

1. as a nutrient/source of most hydrogens and some oxygens in organic compounds
2. important for metabolic biochemical reactants 
3. solvent for other mineral nutrients
4. main transport medium

1. nitrogen
2. potassium
3. calcium
4. magnesium
5. phosphurous
6. sulfer

1. chlorine
2. iron
3. mangese
4. boron
5. zinc
6. sodium
7. copper
8. molybdenum
9. nickel

1. N2 (form as it exists in the atmosphere)
2. "fixed" (ammonia (NH3), ammonion ions (NH4+), or nitrate ion (NO3-))

1. may involve sudden changes in the number of sets of chromosomes in plants
2. may occur with a population that occupies the same geographic range
3. has been observed in recent centuries

• Highly branched roots increases the surface area for the absorption of nutrients
• more or longer root hair (maturation)
• fungal symbiotic associations 
• bacterial symbiotic associations 
• capture of animals by carnivorous plants
• parasitic associations 

Flowering plants make up the most diverse plant division. 

T/F ?

True

There are more flowering plant species than all others combined

microscopic in flowering plants

produce gametes by mitosis

1. cell division
2. growth
3. cell specialization
4. apoptosis (programmed cell death)

The 'woody' part

surround the established stem of a plant and cause it to grow laterally 

- variations of the ideal, "real" form

- Evolution would not ocur in a world of perfectly adapted creatures

• British naturalist born is 1989
• developed a theory of evolution and published in the the infamous book "The Origin of Species"

• Creator's plan could be understood by studying nature
• adaptions of organisms were evidence that creatures were designed fro particular purpose 
• clssifications allowed an appreciation of hte heriarchical steps inthe ladder of life

• Father of taxonomy (1707-1778)
• He was the primary designer of the classification system, which were not attempts to establish evolutionary relationships

developed the theory that profound geological change due to slow, continuous processes that continue to operate the world

suggested old earth

• developed an early evolutionary model (1809)
• organisms have the tendency to adapt and change in response to the environment 
• a continuous line of descent from simple ancient organisms to more complex modern organisms
• adaptive changes in an organism are heritable

• an anglican minister 
• suggested that unchecked population growth would inevitably lead to famine, disease and a ceaseless struggle for existence. 

Darwin's conceptual framework:

Observation 1

Darwin's conceptual framework:

Observation 2

Darwin's Conceptual Framework:

Observation 3

Darwin's Conceptual Framework:

Observation 4

Much of the variation is heritable

survival is not random

populations will gradually change under the influence of natural selective pressures, 

• natural variation exists that is caused by random changes in the genetic material
• genetic changes may be advantages, disadvantageous or neutral
• natural selection may increase the prevalence of that trait in future generations

Much of what we know about the history of life on earth comes from the study of fossils

Broad patterns = simpler forms in the lower strata and more complex forms in the upper strata, although there are many exceptions to this general rule. 

- suggested to be a "transitional form between fish and tetrapods; provides link between earlier and later forms

- had broad skull, flexible neck, eyes on top, primitive wrist and 5 fingers

- eye position would allow peeking above water to look for prey

study of the geographical distribution of extinct and modern species

Anatomical homology:

1.4 million

estimates of unidentified species range from 2-100 million

each species occupies a unique ecological niche

within their own ecological "niche", members of a given species compete with each other of survival

prevent formation of zygote

Caused by habitat isolation (geographic barrier prevents contact), temporal isolation (reproduce at different times of the day or year), behavorial isolation, mechanical isolation (size or incompatible genitalia prevents mating), or gametic isolation (gametes fail to unite successfully).

block development of viable, fertile individuals

caused by either hybrid inviability, sterility, or breakdown

proposed to be the most common source of cladogenesis 

occurs when some members of a species become geographically seperated, and then diverge

can also occur when small population moves to a new location that is geographically seperated: 'founder effect'

Autopolyploidy:

monocot

vascular bundles are scattered throughout 

light, atmospheric gases, temperature, tough, wind, gravity, water, rocks, and soil stimuli

herbivores, pathogens, organic chemicals from neighboring plants, and beneficial or harmful soil organisms

agricultural chemicals including hormones

• support for the plant body
• carries nutrients throughout plant
• defense system to protect against predators and infection
• produce leaves, branches, anf flowers
• holds leaves up
• may function in storage and photosynthesis

Epidermis encloses region of ground parenchyma

primary vascular system includes enclosed phloem 

pericycle encloses root vascular tissue 

woody roots produce primary vascular tissue followed by secondary vascular tissues

root cells differentiation and cell specialization

identified by the presence of root hairs

about a dozen small molecules synthesized in metabolic pathways

eg. auxins, cytokinins, gibberellins, ethylene, abscisic acid, and brassinosteroids

one hormone 

one hormone may have multiple effects

may enter cells by diffusion

PIN proteins transport auxin out at basal or lateral surfaces of cells 

Polar transport- auxin flows down in shoots and into roots

seedless fruit production

retardation of premature fruit to drop

used as commercial rooting compound

pinching topmost shoots alters outgrowth, produces bushy plants

• plant responses to jasmonic acid and can cause the synthesis of chemicals that repel the herbivores
• can aslo cause the release of chemicals that attract predators of their attackers and/or cause defensive reponse in neighboring plants

Thigmotropism:

touch responses

eg. grasping behavior of vine tendrils, roots moving around rocks and such...

not partitioned into smaller cells

multinucleate

nuclei divides without cytokinesis