Summary Topic 6 - Organisms respond to changes in their internal + external environment

words
key-
Survial + Response Hormonest Homeostatis
Kinesis cascade effect
taxis
AMP
IAA Cyclic
Pholohopism/georopism ADU

nephron
complex organisms d/ is cells

Pascian Corpscle
glycogensis/glucogenesis/glycogelysis
Rods + comes Osmoregulation
SAN/Ara
accelerately centre
-
Cardioregulatory centre-
inhibitory conbre




nerrous coordination

-
depolarisation
-generator potential/threshold
-
shelch - mediated
-

impulses
-
SAN) Sinoahial model
-
AVN (atrioventricular nodel
-
It is bundle/purkyne fibres

, Responses by simple organisms



I
Kinesis
Taxis

Funa
until suitable environment is found
Organism will help moving toward
a
-
either
-
Directed movement of an organism
-non-directed movement
from stimulus
away
a
caused
In response stimulus e g light ↳ in a movement

howardpositivisesingatedalga morvan
-



to
-

-




nearer the favourable by stimulus
Rale of movement will decrease when

conditions/furer hom unfavourable
moving
light gets brighter skys
+
it
E g
.
.
wor will more guide
environment is found
When dark




&
↓




Survival + Response
I
Plant response to Stimuli Phototrogism -

plants bend towards the light as the planks
sideo a
slightly faster he more shady
grow
on




roof/shoot Plant hormones Geotropism by planl, as
a turing or
Crowth of has I distinct movement

growth
-

a



stages :


1 all division at near tip

Auxins Indole acetic acid (EAA) substances that control different Roots show positive geotropism + stems show negative




end
important
-




e
.
g many
-
.




georopism
aspeds of plant growth including hopisms differentation
#
,



tissues
of
+ abscission (leaf + Smit fall)
-

has main

↳
synthesised in
young roof cells at his / Experiments




I
1 Diffuses int
elongating region + attaches t recuples on

sensitive




7
to light
.




which region
Finding
cell is




response onboa.BindingStimulatdirehansmadditionshamalla
membranes -




·
↓
in he cell wall he sensia
in
region
suggest M
spaces is




-
Result
elongate

some of the bonds between microfibrils in the cellmse walls --


easier to shekh by the hugar of the cells
-

can also increase rate of hunscription in cells + speed up
protein synthesis




win
control bending of rooks




7
-
can




1 .
steps
Cells in
in



lip
phototropism
of produce EAA which is hansported
shoot
down t shoet
,
↳
num sugge ratheromon
is

down shoot via diffusion shaded side
2 . IAA
initially hansported evenly it moves shaded :·
as

side
Light of EAA from light >
-




.
3 causes movement

distribution of homone




7
producing uneven
side than light side
on shaded


bending-gone e
builds
light
2 Creater soneEIAA up
no
.




5. == cells on shaded side elongate more
use is dus to

6 .
shaded side elongates faster than light side i. short hip bends unequal distribution of homone
kwards In light

geotropism




I
in
steps the roo
IAA which is hansported along
1. Cells in
lip of roof produce ,


shows
. ZAA
2 is initially hansored to all sides of the roo phototropic response
side to te lower results ham distribution of
of IAA from th upper uneven

3 Gravity influences the movement
.




roo
me amountof chemical dinsa
1
side of thanHe
the lover side of the voor
4. A conc IAA builds up on
greater
upper
sich
of root cells + the conced IAA
. As IAA inhibite the elongation
is a
greater
5
less than th upper side
on the lower side :
My elongah
6 .


Therelativegreater ofalsonuppersidecompandta
longation