BIOL 1102 Exam 3

gyymnosperms

naked seed; no flowers or fruit

angiosperms

sees protected; flowering plants

monocot

one seed leaf. Parallel leaf veins; flower parts in 3 or multiples

eudicot

two seed leaves. Net leaf veins; flower parts in 4, 5 or multiples

indeterminate growth

plants have _______

totipotent

ability to grow a whole plant from one cell

meristematic cell (tissues)

plant stem cells

apical meristem; roots; shoots; xylem; phloem

primary growth occurs by increasing cell number and cell size. Found at tips of *_ And _ and makes primary vascular tissue, __ and __*

apical dominance

apical meristem blocks the growth of lateral meristems

intercalary meristem

in monocots. Meristematic tissues at the internodes or base of leaf blades. Grass, bamboo.

basal meristem

intercalary meristem located underground (grasses) so they can grow after being grazed

lateral meristem (cambium)

in eudicots. Secondary growth. Cylinder of cells around roots and shoots that increases width/thickness

cork cambium

cells found outside vascular cambium with wax and other waterproofing molecules. Cork cells produce a tough secondary cell wall containing lignin. Outermost layers often called “bark”

vascular cambium

ring of cells that makes xylem and phloem. New cells to the inside become xyelm. New cells on the outside become phloem

xylem; protective compounds; heartwood; sapwood

as tree grow in width, the innermost _ *stops functioning in water transport and accumulates _ (resins, gums, etc) that make the innermost parts of the wood _ appear darker than the younger, outermost wood we call the __*

vascular cambium; large, thin-walled; smaller, thick-walled; darker; annual growth rings

in seasonal environments, the *stops growing during the winter. when it becomes active in spring, it produces xylem cells. By summertime, the xylem cells are _ and _ producing* _ when viewed in cross section of wood. Count rings to know age of tree at the time it was cut

vascular tissue

transport of water and dissolved nutrient

xylem

transport water from roots to leaves. xyelm is DEAD @ maturity

transpiration

move water from roots to leaves and stems

>95%

of the water that enters a plant is transpired and is NOT used for growth or metabolism

pholem

holem cells lack lignified secondary cell wallstransports sugar, amino acids, hormones, and other molecules throughout the plant body. most

translocation

moving dissolved nutrients throughout a plant

Medullary Rays; laterally; figure

specialized xylem and/or pholem cells that transport resources _ *across the stem. These rays move plant resources from _ of the stem. Visible in wood that is quarter sawn and creates wood* _ (e.g. bird-eye, medullary spots, tiger striping, etc

cellulose

(C6H10O5) A chain of hundreds to thousands of linked D-glucose units. Hydrophilic, but insoluble in water - undigestible to animals

roots; absorbing water and nutrients; anchoring

major functions are _ *and* _ the plant

pneumatophores

roots that grows above water allowing water plants to respire

root tubers

storage organs for carbohydrates. Examples are sweet potatoes, cassava, taro

gravitroprism

growing toward gravity

leaves; photosynthesis , but often modified to do other things

major function is

tendril

modified shoot or leaf used for climbing/support (e.g., Grape vine, cuscuta, nepenthes)

spines

modified leaf with vascular bundles. Usually for defense against herbivores (e.g. cactus spine)

shoots (stems/ leaves); support; light compeitition

major functions are

stem tubers

underground carbohydrate storage (e.g. Idaho Potato, Yams)

adventitious roots

a root that develops from tissue other than root tissue (prop root of corn)

phototropism

growing toward light

Auxin

many roles in plants, including growth of adventitious roots in tissue cultures and plant cuttings. Causes cell elongation in response to blue light. Overdose kills plants… as the defoliant in “Agent Orange”

Abscisic Acid (ABA)

stops growth. causes dormancy. help plants cope with environmental stresses like drought , salt

ethylene

ripening, senescence, and leaf detachment. Green Bananas often exposed to ethylene to hasten ripening. Apples are stored with high CO2 and low O2 to stop apples from making ethylene, and they last longer

light

electromagnetic energy described as protons/wavelength

shorter wavelengths have more energy than longer wavelengths

what is the relationship between wavelength and energy level?

photopigment molecule

a molecule that can absorb photon energy

chlorophyll

the most abundant plant pigment?

Blue and red light

chlorophyll absorbs?

most green light

chlorophyll reflects?

accessory pigments

capture other wavelengths of light

carotenes

reflect red and orange

anthocyanins

reflect blue, purple

xanthophylls

reflect yellow

pheophytins

reflect gray and brown capture electrons in photosynthesis

photosystem

ring of accessory pigments around a pigment molecule (P680 or P700) light bounces around the accessory pigments until reaches pigment in center

transfer energy to an electron and move it to a higher energy shell

how do photopigment molecules absorb light energy?

1. drop back down and give off energy as heat
2. give off light (bioluminescence)
3. captured by another molecule; pheophytin is the primary electron acceptor

an excited electron can do one of three things

photophosphorylation

using light energy to make ATP

plant uses more ATP than NADPH

why would a plant only run cyclic?

making sugar in the stoma

summary of dark reactions (calvin-benson cycle)

1. ATP energy from light reactions
2. H+ and 2e- from NADPH
3. Carbon and oxygen from CO2
4. combined to make sugar molecules, C6H12O6

Calvin-benson Cycle

rubisco

the enzyme that starts this process _, is probably the most abundant protein on Earth

CO2; carbon; carbon fixation

when plants remove _ *from the atmopshere, split it, and then use the _* to make a sugar molecule, we call this _

green plants, green-algae, cyanobacteria

primary carbon fixers on earth

stoma

holes in the plant, particularly the leaves, that allow the plant to exchange gases (breathe)

oxygen

a problem with photosynthesis is that _ can interfere iwth the plant using CO2 to make sugars

photorespiration

also called C2 photosynthesis. when rubisco acts as an oxygen instead of carbon dioxide. makes photosynthesis less efficent. common if plants close stomata

C3 photosynthesis

most plants use this, they have no special mechanism for keeping oxygen away from rubisco (i.e. can’t stop photorespiration and photosynthesis is less efficient)

C4 photosynthesis

minimize photorepsiration by keeping oxygen away from rubisco in different cell types. oxygen and rubisco are kept separated in space

CAM photosynthesis

desert plants store CO2 at night during the day. allows them to keep stoma closed during day and reduce water loss. separate oxygen and rubisco by time (day/night)

hormone

a chemical produced by one cell that controls other cells

gland

cells organized into organs that secrete hormones

endocrine gland

secrete hormones INSIDE body (blood or interstitial fluid)

exocrine gland

secrete hormones into a duct that leads OUTSIDE the body

target cells

cells that can respond to a hormone. have receptor proteins

receptors

proteins on target cells that recieve chemical signals

true hormone

secreted directly into blood long distance dispersal

paracrine hormone

secreted directly into interstitial fluid, travels short distances

nuerohormone

secreted by neurons. travel in blood stream to distant target cells. ex. oxytocin, ADH

neurotransmitter

secreted by nerve cells into synapse

pheromone

hormone released to influence cells in another individual

females who live together tend to have synchronized menstrual cycles

examples of pheromones

McClintock effect

female control/humans/wellesly

whitten effect

male control/ rats and mice

hypothalamus

(neuroendocrine control center): inside the brain. closely associated with pituitary. secretes eight total hormones. two of these, ADH and oxytocin, are stored in the pituitary

oxytocin

in females during labor contractions. during/after orgasm in humans. known as the “cuddle hormone” for bonding and trust

pituitary gland

right near hypothalamus. stores ADH and oxytocin

endorphins

pain tolerance molecules, sometimes create euphoria

growth hormone (HGH) somatotrophin

biggest peaks during puberty, a half-hour after you fall asleep. decreases with age

1. increase height in children
2. increase bone and muscle mass
3. stimulate growth of organs, except brain

HGH roles in the body include:

increase risk of colon, lung, and breast cancers, enlarged heart

potential problems with HGH

ovaries and testes

produce the sex hormones

testostorne

an anabolic steroid in both males and females

anabolic effects

build muscle and body mass

androgenic effects

facial hair, deeper voice, “maleness”

estrogen

development of breasts and menstruation in females

breast cancer

some cancers rely on estrogen to grow

pineal gland

receptors in your eyes; regulates sleep/wake cycles (circadian rhythms)

Melatonin

goes up in the evening, you get sleepy; goes down in the morning, you wake up

thyroid gland

controls metabolism and blood calcium levels

thyroxine; triiodothyronine

metabolism is regulated by thyroid hormone _ *after its converted to* _

calcitonin; parathyroid hormone

calcium and phosphate levels in the blood are regulated by thyroid hormone _ *and its antagonist,* _

iodine

what is required in your diet to make thyroxine?

iodized foods/sea salt/seaweed/fish

where do you get iodine?

adrenal glands

stress response. salt response in kidneys