Nervous System, Plants, and Water Potential

Question 1

neuron firing steps

Answer 1

sodium channels open, sodium floods cells, potassium channels open, potassium leaves the cell, sodium channels close, potassium leaves the cell still, potassium channels close

Question 2

hyperpolarization

Answer 2

when the potential overshoots caused by the delay of the closing of the potassium channels

Question 3

membrane depolarization

Answer 3

the creation of the action potential due to the sodium channels opening

Question 4

action potential magnitude is due to

Answer 4

sensitivity of receptors and stimulus strength

Question 5

neuron summation

Answer 5

subthreshold responses and accumulation of neurotransmitters in a post-synaptic region can help a neuron reach its threshold potential that otherwise wouldn’t have

Question 6

temporal summation

Answer 6

one neuron’s neurotransmitters stimulate another’s

Question 7

spatial summation

Answer 7

multiple neuron’s transmitters stimulate another’s

Question 8

agonist

Answer 8

increases transmitter’s time in the synaptic gap

Question 9

alzheimers neuron problems

Answer 9

low acetylcholine, lost myelin sheath’s impact

Question 10

dopamine impacts

Answer 10

low: decreases ability to focus, Parkinson’s; high: addiction pathways

Question 11

how did plants evolve?`

Answer 11

from algae; we know because they share cellulose and chlorophyll a and b

Question 12

purpose of roots

Answer 12

anchor plants in soil, absorb minerals, absorb water, store carbohydrates

Question 13

taproot

Answer 13

the main root that provides structure while lateral roots absorb and store nutrients

Question 14

purpose of stem

Answer 14

where leaves attach, hold multiple buddings,

Question 15

purpose of leaves

Answer 15

photosynthesis, gas exchange, dissipates heat

Question 16

dermal system

Answer 16

the plant’s skin; root hairs developed for desert plants to reduce water loss and reflect excess light

Question 17

vascular system

Answer 17

structure and transport

Question 18

xylem

Answer 18

brings water and minerals up from roots

Question 19

phloem

Answer 19

transports sugars and chemicals

Question 20

layers of the leaf

Answer 20

top: epidermis (with pores called stomata); palisade mesophyll; spongy mesophyl (photosynthetis cells); lower epidermis

Question 21

xylem and water flow

Answer 21

xylem sap moves water up the plant; when water is lost by transpiration xylem sap is forced to move up more and more water is taken up by roots

Question 22

sugar flow

Answer 22

phloem sap moves both ways depending on where there are sugar/chemical needs; sugars produced in leaves and are moved throughout the plant

Question 23

in plants, membrane potential is created by

Answer 23

hydrogen ions

Question 24

cotransport in plants

Answer 24

hydrogen ions take solutes into the cell because of the gradient

Question 25

water potential

Answer 25

the indicator for which direction water will flow flow, takes into account concentration and pressure; moves high to low

Question 26

water potential equation

Answer 26

solute potential and pressure potential sum

Question 27

solute potential

Answer 27

based on molarity, moves from high concentration to low concentration

Question 28

pressure potential

Answer 28

in a closed container, pressure moves from high concentration to low pressure

Question 29

turgor pressure

Answer 29

when the cell expands and pushes the cell membrane to the cell wall which creates pressure

Question 30

plasmolysis

Answer 30

when a flaccid cell loses a lot of water and the membrane pulls away from the cell wall

Question 31

hypertonic solution

Answer 31

a hypertonic solution sucks water towards it because it is higher in concentration