Response to Stimuli Word Stimulants

Question 1

Response

Answer 1

To environmental changes

Increase survival chance

Question 2

Tropism

Answer 2

Plants
Positive/Negative
Directional stimuli

Question 3

Phototropism

Answer 3

Positive/Negative

Light intensity

Question 4

Geotropism

Answer 4

Positive/Negative

Gravity

Question 5

Hydrotropism

Answer 5

Positive/Negative

Water abundance in soil

Question 6

Directional Stimuli

Answer 6

One direction

Question 7

Behaviour

Answer 7

Animal
Response to Stimuli
Find correct environment

Question 8

Taxis

Answer 8

Directional movement
Positive - towards
Negative - away

Question 9

Phototaxis

Answer 9

Positive/Negative

Light

Question 10

Chemotaxis

Answer 10

Positive/Negative
Chemicals
Phagocytes/Pathogens (Phagocytosis)

Question 11

Kinesis

Answer 11

Random non directional movement
Moves faster, changes direction more
More intense/threatening stimuli = more movement = more likely to find less threatening

Question 12

Woodlice

Answer 12

Photokinetic
+ Humid, dark
Choice chamber

Question 13

Indoleacetic Acid (IAA)

Answer 13

Distributed in tissue
Regulates growth
Causes cell elongation
Root/shoot tips
Phloem translocation

Question 14

IAA Cause Elongation

Answer 14

Stimulates H+ secretion
\+acidity
Cell walls loosen
lower Water potential - water into cell (osmosis)
\+hydrostatic pressure = cell elongation

Question 15

Curve in shoot/roots

Answer 15

Cell elongation
IAA = stimulate/inhibit elongation
Phototropism - shaded side IAA
Geotropism - lower side IAA - inhibits elongation

Question 16

Experiments on growth factors

Answer 16

Cap on shoot = no change (IAA in tip)
Collar below tip = curve (IAA in tip)
Metal in half of shoot = what side IAA in

Question 17

Nervous System

Answer 17

Central

Peripheral

Question 18

Central Nervous System

Answer 18

Brain

Spinal Cord

Question 19

Peripheral Nervous System

Answer 19

Cranial nerves
Spinal Nerves
Join to CNS

Question 20

Voluntary response

Answer 20

Conscious

Question 21

Involuntary response

Answer 21

Automatic Response
Unconscious
Reflex Arc

Question 22

Nerves

Answer 22

Bundles of neurones

Into effectors

Question 23

Reflex Arc

Answer 23

Unconscious

Stimulus>receptor>neurones>effector>response

Question 24

Receptor

Answer 24

Sensory receptor cells

Turn into nerve impulses

Question 25

Neurones

Answer 25

Sensory (receptor>spinal cord) Relay (in spinal cord, sensory>neurone) Motor (Relay>effector)

Question 26

Effector

Answer 26

Muscle fibres contract | Muscles, glands`

Question 27

Sensory Receptos

Answer 27

Dendrites in Sensory neurones | Detect specific stimuli

Question 28

Mechanoreceptors

Answer 28

Physical change detectors | Pacinian Corpuscle

Question 29

Photoreceotors

Answer 29

``` Detect light (vision) Rod and Cone Cells in Retina ```

Question 30

Pacinian Corpuscle Structure

Answer 30

``` Neurone Nerve ending Layers of connective tissue and viscous gel (lamellae) Blood Capillary Capsule ```

Question 31

Pancinian Corpuscle Response

Answer 31

``` Pressure Deforms stretch mediated Na channels Na+ diffuse down conc gradient to inner membrane Depolarised Generator potential Threshold Action potential in neurone ```

Question 32

Retina

Answer 32

Rod and Cone Cells Light > Electrical Energy (Generator Potential) Connected to neurones of optical nerve > eye > visual cortex Action potentials = nerve impulses

Question 33

Rod Cells

Answer 33

``` 120 million Edges of retina (periphery) Low intensity light Black and white Poor visual acuity 3 to one sensory neurone (convergence) Rhodopsin pigment broken down > generator potential (pooled) ```

Question 34

Rhodopsin Pigment

Answer 34

Rod Cells | Broken Down > Generator potential (pooled)

Question 35

Cone Cells

Answer 35

``` 6 million Densely packed Middle of retina (fovea) High intensity light Colour High visual accuracy 1 to 1 bipolar cell/sensory neurone (low convergence) Three types - wave length ranges Iodopsin pigment broken down > generator potential ```

Question 36

Iodopsin Pigment

Answer 36

Cone Cells | broken down > generator potential

Question 37

Heart Rate Control

Answer 37

``` Sinoatricular node Cardiovascular centre Sympathetic and Vagus Nerve Pressure receptors Chemoreceptors ```

Question 38

Sinoatricular Node

Answer 38

Wall of right atrium (electrical impulse wave across atrias > contract > heart beat) Pace maker - determines heart rate

Question 39

Cardiovascular centre

Answer 39

Brain Medulla oblongata Increase/decrease heart rate

Question 40

Sympathetic Nerve

Answer 40

Cardiovascular centre > SAN Autonomic nervous system Antagonistic effects Via spinal cord

Question 41

Vagus nerve

Answer 41

``` Parasympathetic Cardiovascular centre > SAN Autonomic nervous system Antagonistic effects Not via spinal cord ```

Question 42

Pressure Receptors

Answer 42

``` Baroreceptors Carotid artery Walls of heart High - centre to decrease Low - centre to increase ```

Question 43

Chemoreceptors

Answer 43

Carotid artery body Aorta Heart walls Medulla Oblongata

Question 44

Increase heart rate

Answer 44

SAN > Sympathetic NS, Cardiovascular centre

Question 45

Decrease heart rate

Answer 45

SAN > Parasympathetic NS, Cardiovascular centre

Question 46

Increased activity/exercise

Answer 46

More CO2, pH lowered Chemoreceptors>increase impulses to C Centre> Sympathetic NS> + heart rate > SAN increase rate More CO2 exhaled> conc decreases

Question 47

Cardiac output

Answer 47

Heart rate x stroke volume