Summary Plant and animal responses biology A level OCR revision notes
26 views 0 purchase
Course
Plant and animal responses
Institution
OCR
Book
A Level Biology A for OCR Student Book
In depth revision notes covering the whole of plant and animal responses. The topic is broken down into the individual specification points, shown by the numbers used throughout.
OCR A Biology H420 - 2.1.5 - Biological Membranes (Chapter 5) Short Summary Notes
Respiration notes or OCR biology A level
Biodiversity revision notes for Biology A level OCR
All for this textbook (126)
Written for
A/AS Level
OCR
Biology
Plant and animal responses
All documents for this subject (1)
Seller
Follow
lizziebowles
Content preview
, beaches &
⑤
This helps them
to survive for
longer-greater
chance of them
J
- reproducing
RESPONSES TO ABIOTIC STRESS
Alkaloids-nitrogenous
J
butter tasting
metabolism
S
compounds that interfere with
,
E .
g Caffere toxic to fungit visects
!
.
Tannins-bitter tasting puenoic compounds
that buid to digestive enzymes produced wi
Saliva viactivate them . t .
g . tea
.
pheromones chemicals released
-
that
affect behaviour of other members of
Whe same species
.
↳ E .
.
g If a maple tree is attacked by
insects ,
it releases pheromones which are
absorbed by the leaves on other .
branches
This causes the leaves to make callose
to protect them S
Mimosa Pudica is a plant that folds
&
un response to touch It contals an .
alkaloid The stem has sharp prickles
.
If the leaves are touched , they collapse,
frightening large herbivores dislodging
Small visects which have landed on the
leaves The leaf recovers .
after 10 muintes
because of potassium ion is water
movement -
This is a nastic response (non-
directional) .
TROPISMS = directional response to stimuli
·
phototropism = growth in response to light
·
geotropism : growth in response to gravity
·
chemotropism = growth hi response to chemicals
·
Thigmotropism = growth in response to
touch
, Darwin's investigations
into phototropism
② If thetip
~is
of
cut
the shoot
off the
①shoots light -
is still
,
sunung ou
normally it , but i
grow doesn't bend .
towards ↳ So, the tip
right of the Shoot
must detect
Light or
Y
Produce
aux wi
⑤
If the Shoot
Boysen-Jensen's -
his is covered
,
the Shoot
investigations into
doesn't bend
.
phototropism So it must be
unowed
-
un the
detection of
-O when we
Light
put the mica
on the suaded
side the shoot ,
didn't bend &
because anxu
-
C
2
Couldn't pass
down the
shaded side +
⑪ cause
elongation
A thin layer
of mica (material
that blocks movement ③ Gelatin allows
of chemical messengers)
chemical messengers
was put on the to pass through .
tip
S
the shoot
uminated side of The of
wasout off
the shootI it bend towards &
gelatin was placed
the light on top of the cut
Shoot , and tip
replaced (put&
on top
of genatur) ,
when
right was shone on
Mis the shoot bent
towards light
↳ this is because
The auxai could pass -
through the gelati
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lizziebowles. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.28. You're not tied to anything after your purchase.
