Adaptations and Regulation

Question 1

Stimulus

Answer 1

change

Question 2

Receptor

Answer 2

receives change

detects change

Question 3

Control Centre

Answer 3

interprets the change and triggers a response

Question 4

Effector

Answer 4

produces body’s response to the stimulus

- always a muscle or gland

Question 5

Feedback: Negative

Answer 5

returns the body to normal

Question 6

Evaporation

Answer 6

heat loss through water (sweat)

Question 7

Convention

Answer 7

heat loss through air (vasodilation)

Question 8

Homeostasis

Answer 8

the ability of organisms to the constant internal environment despite variations in external conditions
- stays the same

Question 9

Thermoregulation

Answer 9

control of internal temperature

Question 10

Hypothalamus

Answer 10

control centre for homeostasis

linked to the endocrine system via pituitary gland

Question 11

Two pathways for homeostatic responses

Answer 11

nervous and hormonal

Question 12

External receptors of the human body

Answer 12

• skin (mechano, thermo)
• eyes (photo)
• ears (mechano)
• tongue (chemo)
• nose

Question 13

What do enzymes do for chemical reactions within the body?

Answer 13

speed up reactions

Question 14

What can changes in internal conditions do to enzymes?

Answer 14

slow them down

Question 15

What is the collective name for the parts of an organism that detect external and internal stimuli?

Answer 15

receptors

Question 16

What is the collective name for the parts of an organism that carry out homeostatic responses?

Answer 16

effectors

Question 17

What is the constant level of an organism’s internal environment known as?

Answer 17

set point

Question 18

What are some of the body systems maintained by homeostasis?

Answer 18

• pH
• temperature
• blood pressure
• concentration of waste products
• water/salt balance

Question 19

Vasoconstriction

Answer 19

narrowing of blood vessels so heat does not get released through the skin

Question 20

Vasodilation

Answer 20

releases heat through blood vessels dilating

Question 21

Piloerection

Answer 21

hair standing on end

Question 22

Adaptation

Answer 22

enhances survival and reproductive potential of an organism in a particular environment conditions

Question 23

Structural adaptations

Answer 23

physical features

- shape, size, body parts, colour

Question 24

Behavioural adaptations

Answer 24

the way the organism acts

- nocturnal, migration, hibernation

Question 25

Physiological adaptations

Answer 25

inner workings of the organism’s body

- the ability to make venom, regulate temperature, digest nutrients, produce concentrated urine