Plant and animal responses

Question 1

Types of stimuli (plants)

Answer 1

Higher temps- thicker waxy cuticle
Wind- more lignified vascualr tissue
Herbivores:
* Tannins -toxic to mammals + stops pathogens coming to roots
* Alkaloids- (aa) Bitter taste to animals
* Pheromones- Affects behaviour and physiology of another

Question 2

Tropisms

Answer 2

Directional growth responses of plants
Can be positive (towards) or negative (away)

Question 3

Phototropism

Answer 3

(+) Growth towards the light

Question 4

Geotropism

Answer 4

(+) Roots growing towards the pull of gravity

Question 5

Chemotropism

Answer 5

(+) (when pollen lands on a flower) the pollen tubules growing towards chemicals produced by the ovary so it can be fertilised.

Question 6

Thigmotropism

Answer 6

(+) shoots of climbing plant/ growth towards touch

Question 7

Nastic responses

Answer 7

Non-directional responses to external stimuli

Example: thigmonasty- folding of leaves

Question 8

What controls plant responses?

Answer 8

Hormones
Not produced in endocrine glands but a variety of tissues in the plant.

Question 9

How are hormones transported around the plant?

Answer 9

• Active transport
• Diffusion
• Mass flow in phloem sap

Question 10

Auxin

Answer 10

Plant hormone (IAA)
* Promotes cell elongation
* inhibit growth of side shoots
* inhibit leaf abscission (leaf fall)

Question 11

Apical dominance

Question 12

Abscisic acid

Plant hormone

Answer 12

• Inhibits seed germination and growth
• causes stomatal closure when water availability is low

Question 13

Cytokinins

PLANT HORMONE

Answer 13

• Promote cell division
• Delay leaf senescence (aging in plants)
• Overcome apical dominance
• Promote cell expansion

Question 14

Gibberellins

Answer 14

Promote seed germination and growth of stems

Question 15

Ethene

PLANT HORMONE

Answer 15

Promotes fruit ripening

Question 16

FUNCTIONS

Cerebrum

brain

Answer 16

• Conscious thought
• Ability to override some reflexes
• Emotional responses
• Intelligence (reasoning and judgement)

Question 17

FUNCTIONS

Cerebral cortex- Sensory areas

brain

Answer 17

Recieve impulses indirectly from receptor

Question 18

FUNCTIONS

Cerebral cortex- Motor areas

brain

Answer 18

Motor areas on left side of brain control muscle movement on the right side of the body and vice versa

Question 19

FUNCTIONS

Cerebral cortex- Association areas

brain

Answer 19

Compares input w/ prev. experience in order to interpret meaning and appropriate response.

Question 20

Hypothalamus

Answer 20

Controls body’s homeostatic mechanisms via its own sensory receptors
* osmoregulation
* thermoregulation

Question 21

Pituitary gland-Posterior

Answer 21

Releases hormones made in the hypothalamus
* ADH
* Oxytocin (childbirth)

Question 22

Pituitary gland- Anterior

Answer 22

** Releases pituitary gland’s own hormones** (made in response to hypothalamus releasing factors).
Regulates:
* stress
* lactation
* growth
* reproduction

Question 23

Medulla Oblongata

Answer 23

Location of regulatory centres for vital processes
* Cardiac centre
* Vasomotor centre (blood pressure)
* Respiratory centre

Question 24

FUNCTIONS

Medulla Oblongata

Answer 24

Controls non-skeletal (involuntary) muscle to regulate:
* heart rate
* blood pressure
* breathing rate & depth

Question 25

Cerebellum | SENSORY INFO

Answer 25

**Processes sensory info:** * joints * muscle splindle fibre * inner ear * retina

Question 26

Cerebellum | MOTOR RESPONSES

Answer 26

**Coordinates motor responses (unconsciously)**: * staying balanced & upright * Operation of antagonistic muscles * muscle tension for instrument use

Question 27

Corpus Callosum

Answer 27

**Connects both sides of the brain** -ensures both sides can communicate w/ each other

Question 28

What is a reflex action?

Answer 28

Responses to changes in the environment that don't involve the brain to coordinate the movement * Short and rapid * Only 3 neurones most of the time: sensory >>> relay>>> motor

Question 29

Why do we need reflexes?

Answer 29

* To get out of danger * avoid damage to part of the body * maintain balance

Question 30

What is the blinking reflex?

Answer 30

**Temporary closure of eyelids to protect the eyes.** A cranial reflex (passes through part of the brain) but doesn't require thought. Reflex arc (effector and receptor in the same place)

Question 31

What stimulates blinking?

Answer 31

* Lound sounds * Sudden movements close to the eye * sudden bright light (optical reflex) * foreign object touching eye (corneal reflex)