10.Regulation in plants and animal cells

Question 1

how does water get into a plant

Answer 1

Osmosis has occurred. Water has moved from the hypotonic environment in the soil surrounding the root hair cell, through the partially permeable plasma membrane of the root hair cell, to the hypertonic cytosol of the root hair cell. The root hair cell becomes turgid.

Question 2

how does water get out of a plant

Answer 2

after moving up the xylem, plants lose water by transpiration

Question 3

use of water in plants

Answer 3

photosynthesis
hydrolysis
maintain turgidity

Question 4

what hormone controls water loss

Answer 4

abscisic acid

Question 5

how are stomata closed

Answer 5

-stimulus eg decreased water levels
-abscisic acid hormone is released
-abscisic and binds to specific guard cell receptors
-chloride ions and potassium ions are pumped out of guard cells
-guard cells cytosol is now hypotonic and the environment surrounding is hypertonic
-water moves out of guard cell
-guard cell becomes flaccid
-stomata is closed

Question 6

when would stomata close and open

Answer 6

Close in response to:
low CO2 concentration
low light intensity
low water availability

open in response to:
high CO2 concentration
high light intensity
high water availability

Question 7

how are stomata opened

Answer 7

-stimulus eg increased light intensity
-triggers specific receptor
-chloride ions and potassium ions are pumped into guard cells
-the cytosol of guard cell is now hypertonic and surrounding environment is hypotonic
-water follows and moves into guard cells
-guard cells become turgid
-stomata open

Question 8

define homeostasis

Answer 8

the maintenance of a constant internal environment, within narrow limits, in the face of external change

Question 9

what is negative feedback

Answer 9

when response opposes the original stimulus

Question 10

normal body temperature

Answer 10

37 degrees celsius

Question 11

what is metabolism

Answer 11

all of the chemical reactions in your body or cell

Question 12

receptor for maintaining body temperature (thermoregulation)

Answer 12

thermoregulatory centre in hypothalamus

Question 13

coordinator for maintaining body temperature (thermoregulation)

Answer 13

thermoregulatory centre in hypothalamus

Question 14

what responses does your body make when its too cold

Answer 14

-shivering
-vasoconstriction
-goosebumps/piloerection
-huddle
-increased metabolism
-behaviours-jumping, physical activity

Question 15

how can sweat glands help when body temperature decreases

Answer 15

sweat glands stop releasing sweat, decreasing heat loss due to evaporation and increasing body temperature

Question 16

how can arteries help when body temperature decrease

Answer 16

blood vessels/arteries vasoconstrict, decreasing blood flow to surface of body, decreasing heat loss by radiation

Question 17

how can shivering help when body temperature decreases

Answer 17

shivering (rapid muscle contractions) increase of excess heat produced, increase body temperature

Question 18

how can piloerection help when body temperature decreases

Answer 18

goosebumps, more air trapped between hairs, increasing insulation

Question 19

how can thyroid gland help when body temperature decreases

Answer 19

thyroid gland can increase thyroxine production, increasing metabolism (chemical reactions), increased heat produced as by-product, increasing body temperature

Question 20

what responses does your body make when its too hot

Answer 20

-sweating
-vasodilation
-reduced metabolism
-behaviours- reduce physical activity, showering/swimming, increase SA:V

Question 21

how can sweat glands help when body temperature increases

Answer 21

sweat glands produce more sweat, increasing heat loss via evaporation

Question 22

how can arteries help when body temperature increases

Answer 22

blood vessels/arteries vasodilate, increasing blood flow to surface of body, increasing heat loss by radiation

Question 23

how can thyroid gland help when body temperature increases

Answer 23

thyroid stops releasing thyroxine, slowing metabolism, decreasing chemical reactions, decreasing heat being produced as byproduct and decreasing body temperature

Question 24

what is glucose needed for by all cells

Answer 24

needed for aerobic cellular respiration

Question 25

receptor for blood glucose levels

Answer 25

pancreas

Question 26

coordinator for blood glucose levels

Answer 26

Pancreas

Question 27

what cells produce insulin

Answer 27

beta cells

Question 28

what cells produce glucagon

Answer 28

alpha cells

Question 29

what happens when blood glucose levels are high

Answer 29

beta cells release insulin, that causes glucose to be stored as glycogen in liver and muscle cells

Question 30

what happens when blood glucose levels are low

Answer 30

alpha cells release glucagon, that causes glycogen stores to be broken down into glucose in liver and muscle cells

Question 31

define osmoregulation

Answer 31

osmoregulation is the process of maintaining a stable water and salt content in the blood

Question 32

receptor for osmoregulation

Answer 32

osmoreceptors

Question 33

coordinator for osmoregulation

Answer 33

hypothalamus

Question 34

effector for osmoregulation

Answer 34

pituitary gland

Question 35

effectors for maintaining BGL

Answer 35

beta or alpha cells of the pancreas

Question 36

how does the body respond to low water levels

Answer 36

-low water levels (dehydration)
-increase ADH released
-increased permeability of convoluted tubules and collecting ducts of nephrons in kidneys
-increased water absorption (back into the bloodstream)
-more concentrated urine is produced (more water retained)

Question 37

how does the body respond to high water levels

Answer 37

-high water levels (hydrated)
-decreased ADH released
-decreased permeability of convoluted tubules and collecting ducts of the nephrons in the kidney
-decreased water absorption
-diluted urine produced (more water lost)

Question 38

what is a stimuli

Answer 38

change in environment

Question 39

what is a hormone

Answer 39

chemical messenger