What is the sequence of components of a reflex?

Stimulus->receptor->coordinator->effector->response

What is the role of ABA in seed germination?

Antagonistic to gibberellin and maintains dormancy.

What is the order of events for stomatal closure ? CSMR = cell surface membrane receptor

ABA binds to CSMR>cations enter>anions leave>loss of turgor

Whats the difference between a nerve and a neurone?

A nerve is a group of neurones and a neurone is a cell.

What is the value of the folds in the surfaces of the cerebral hemispheres? SA = surface area

Increase SA to allow a greater number of cell bodies.

Which one is the most correct?

IAA is made in the meristem and stimulates expansins.

The process by which herbivores eat plants.

What is the role of creatine phosphate?

A source / reserve of phosphate ions to produce ATP.

Which is a commercial use for auxin?

At high concentrations, it can be used as a weed killer., Preventing apples from falling of the branch when ripe.

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OCR A Level Biology Plant and Animal responses

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#OCR A-level 20 questions, see what you know.

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Questions 20

Answers

1
Which hormone is involved in apical dominace?
ethene
Auxin
Gibberellin
ABA
2
What is positive aquatropism?
None of the above.
The growth of plant shoots towards a source of water.
The growth of plant roots towards a source of water.
The growth of plat roots away from a source of water.
3
What is the response of a coleoptile when a mica barrier is inserted into the shaded side?
No response.
The coleoptile dies.
None of the above.
Growth towards the light source
4
What is the sequence of components of a reflex?
Stimulus->receptor->coordinator->effector->response
Stimulus->response->effector->receptor
receptor->response->effector
Stimulus->receptor->effector->response
5
Which number is the hypothalamus?
9
5
3
8
6
What is the role of ABA in seed germination?
Antagonistic to gibberellin and maintains dormancy.
Antagonistic to gibberellin and stimulates seed germination.
None of the above.
synergistic to gibberellin and stimulates seed germination.
7
Which of the following muscle types is not striated?
Skeletal muscle.
Cardiac muscle.
Smooth muscle.
8
What is the order of events for stomatal closure ? CSMR = cell surface membrane receptor
anions leave>loss of turgor>ABA binds to CSMR>cations enter
ABA binds to CSMR>loss of turgor>cations enter>anions leave
cations enter>anions leave>loss of turgor>ABA binds to CSMR
ABA binds to CSMR>cations enter>anions leave>loss of turgor
9
What do you call a plant response?
A tropism
A turntism
A torpism
A tropsm
10
What happens immediate after an action potential reaches a neuromuscular junction?
Calcium ion channels open.
The muscle relaxes.
Acetalcholine is released.
Depolarisation.
11
Whats the difference between a nerve and a neurone?
A nerve is a cell and a neurone is a group of nerves.
A nerve is a nerve which is a nerve of a neurone.
A nerve is a group of neurones and a neurone is a cell.
Semantics! They both mean the same thing...
12
What is the value of the folds in the surfaces of the cerebral hemispheres? SA = surface area
Bigger SA.
More of everything.
Decrease volume to bring cell bodies closer together.
Increase SA to allow a greater number of cell bodies.
13
Which one is the most correct?
IAA affects proteins in the cell wall called expansins.
Auxin is made in the meristem and stimulates expansins.
Auxin is made in plant stem cells and affects proteins.
IAA is made in the meristem and stimulates expansins.
14
Which of the following is a reflex?
speaking
Gagging
pupil dialation
Jumping
15
Response(s) to herbivory include:
Alkaloids
Tannins
Expansins
All of the above
16
What is herbivory?
The process by which herbivores eat plants.
When a plant cannabilises another plant.
All of the above.
How plants defend themselves against animals.
17
What is the effector of the knee-jerk reflex?
The contraction of the quadriceps muscle.
Strech receptors in the quadtriceps muscle.
The qudriceps muscle.
The cerebellum.
18
What is the role of creatine phosphate?
To create a electrochemical gradient in the sarcomere.
Binds to myosin head to enable the filamets to retract.
A source / reserve of phosphate ions to produce ATP.
19
Which is a commercial use for auxin?
At high concentrations, it can be used as a weed killer.
Preventing apples from falling of the branch when ripe.
Fortifying bread with nutrients.
Stimulating the ripening of fruit.
20
(look at the lower diagram) Which letter represents the thick filament of myosin?
A
C
J
F

OCR A Level Biology Plant and Animal responses Flashcards | StudBud