Bio 152: Unit 2 Physiology

Set point

physiological value around which normal value fluctuates

feedback mechanism process order

stimulus, variable, receptor, control center, effector (back to variable)

stomata

pores allowing for CO₂ to enter

vasculature

movement of fluids, sugars, ions

seeds

method of reproduction and dispersal

bryophytes (mosses, liverworts, hornworts)

non-vascular, reproduce by spores

vascular plants

ferns, gymnosperms, angiosperms that have tubes for moving water, minerals, and sugar around the plant

ferns

vascular, seedless (reproduce by spores), seeds are multicellular

seeds dispersal process in ferns

fertilize, disperse, germinate

gymnosperms (pine, spruces, cycads)

vascular, reproduce by seeds that develop on scale of cones

angiosperms

most diverse vascular plant, flowering plants with seeds that develop in fruits

guard cells

open and close based on turgor pressure, water moves in and out of cells based on osmotic pressure

osmotic pressure

diffusion of water

turgor pressure

pressure exerted by fluid on the cell membrane

guard cells opening (swollen) is what kind of process?

active process

guard cells closing (shrunken) is what kind of process?

passive process

light-dependent reactions

light and water → O₂

calvin cycle

rubisco and carbon fixation

C3 photosynthesis

regular photosynthesis; no adaptations to avoid photorespiration or water loss, involves rubisco that attaches to 5C sugar and cuts new sugar chain in 1/2

photorespiration

rubisco binds with oxygen instead of glucose

C4 photosynthesis

increases CO₂ concentration around rubisco and avoids photorespiration, has spatial separation

CAM photosynthesis (cacti)

reduces water loss and avoids photorespiration, has temporal separation

C3 plants thrive in what environment

cool, wet environment because it is normal photosynthesis

C4 plants thrive in what environment

warm, sunny environments because it can prevent photorespiration

CAM plants thrive in what environment

very hot, dry environments because it has temporal separation

xylem

transports water and minerals (ions - smaller molecules)

phloem

transports sugar and hormones (bigger macromolecules)

movement in xylem

one-way creates turgor pressure (high to low pressure)

movement in phloem

two-way movement from sources to sinks

cephalization

concentration of nervous system, components at one end of the body “the front”

segmentation

axon

carries electrical signals to the next neuron/muscle

action potential is initiated here

axon hillock

dendrites

receive incoming signals

node of ranvier

area of high density of ion channels

axon terminal

releases neurotransmitters

chemical driving force

the difference in energy (such as concentration or chemical potential) between products and reactants

electrical driving force

the force exerted by the difference in voltage (charge) across the cell membrane, pulling charged ions toward opposite charges

resting membrane potential

negative value around -70mV

sodium-potassium pump

generates an electrochemical gradient by the difference in chemical concentration and charge across membrane

K+ leak channels

K+ flows down its electrochemical gradient

action potential

temporary change in membrane potential

depolarization (rising phase)

voltage-gated Na+ channels open, Na+ rushes into neuron, voltage-gated Na+ channels close at top of action potential

repolarization (falling phase)

lags before voltage-gated K+ channels open, then K+ ions rush out of neuron

hyperpolarization

K+ ions rush out of neuron that it drops below resting membrane potential

inhibitory postsynaptic potential

dendrites receive a signal that decreases the membrane potential in postsynaptic neuron (hyperpolarizes); makes it less likely to fire action potential

excitatory postsynaptic potential

dendrites receive a signal that increases the membrane potential in the postsynaptic neuron (depolarizes); makes it more likely to fire action potential

fish circulatory system

two-chambered heart and single circulatory system

amphibians circulatory system

three-chambered heart and partially divided double-circuit system

mammals circulatory system

four-chambered heart and true double-circuit system