homeostasis and response

Question 1

What is homeostasis?

Answer 1

all of the processes that happen in a cell or organism to maintain (keep) optimal conditions

Question 2

If internal conditions are not optimal, what happens to enzymes?

Answer 2

they denature (change shape) and do not catalyse metabolic reactions properly

Question 3

If our internal conditions are not regulated, which substances could denature?

Answer 3

enzymes

Question 4

Why must humans regulate their body’s internal conditions?

Answer 4

to make sure that enzymes and cells function well

Question 5

What conditions need to be regulated in the body?

Answer 5

Internal body temperature

Urea concentration

Water levels

Blood sugar levels

Carbon dioxide levels

Question 6

Which of these is NOT an example of homeostasis?

a. controlling the body’s blood sugar levels
b. blood vessels dilating because its too hot
c. leaving a room because its too hot
d. reducing water levels in the body if it is too hot

Answer 6

c. leaving a room because its too hot

Question 7

Name the control systems and what they do

Answer 7

Coordination centres - they receive process the information from the receptors
Effectors (muscles or glands) - carry out response to stimuli that help restore to optimum levels
Receptors - detect changes in the environment

Question 8

What is the negative feedback loop?

Answer 8

When an internal condition changes and is no longer optimal the body works to counteract (reverse) the change and return conditions to the optimum

Question 9

What is positive feedback?

Answer 9

It makes a small change even bigger.

Example: the body is the release of oxytocin (hormone), which increases the number of contractions during childbirth.

Question 10

What is the optimum human body temperature?

Answer 10

37°C

Question 11

Which of the options below receives and processes information in the control system?

a. homeostasis
b. effector
c. coordination centre
d. receptor

Answer 11

c. coordination centre

Question 12

Which of the following are examples of how our bodies respond to increased oxygen supply to the muscles?

a. increased heart rate
b. decrease heart rate
c. do more exercise
d. increase breath volume

Answer 12

a. increased heart rate

d. increase breath volume

Question 13

What are the components of the CNS?

Answer 13

Brain

Spinal cord

Question 14

What are synapses?

Answer 14

Gaps between neurones

Question 15

Where are synapses found?

Answer 15

At each junction of a reflex arc

Question 16

What does the CNS stand for?

Answer 16

Central Nervous System

Question 17

What are neurotransmitters?

Answer 17

Chemicals that diffuse across synapses and bind to receptors on the next neurone

Question 18

What are the gaps between neurones called?

Answer 18

Synapses

Question 19

Define a reflex action.

Answer 19

An unconscious reaction that allows a person to respond to a dangerous situation automatically and rapidly via a reflex arc

Question 20

What are the components of a reflex arc?

Answer 20

Stimulus
Receptor
Neurones
Effector
Response

Question 21

What type of signal are neurotransmitters?

Answer 21

Chemical

Question 22

Which part of a reflex arc carries the signal to the CNS?

Answer 22

Sensory neurone