Chapter 12

Question 1

What does stimuli mean?

Answer 1

changes in the enviroment that can be detected by organisms

Question 2

What is receptors?

Answer 2

cells or groups of cells that detect stimuli

Question 3

What is effetors?

Answer 3

parts of the body that respond to a stimulus

Question 4

Give 2 examples to effectors?

Answer 4

muscles
glands

Question 5

How do muscles respond to stimulus?

Answer 5

by contracting

Question 6

What does coordination mean?

Answer 6

ensuring that the actions of different parts of the body work together

Question 7

name the 2 ways animals send info from receptors to effectors?

Answer 7

1.fastest: nerves
2.slower: hormones

Question 8

What are nerves?

Answer 8

a group of neurone axons lying together

Question 9

What are the human nervous system made of?

Answer 9

special cells called,neurones

Question 10

What is the largest fibre in a neurone called?

Answer 10

axon

Question 11

What are the shorter fibers in a neurone called?

Answer 11

dendrites

Question 12

What are nerve impulses?

Answer 12

an electrical signal that passes rapidly along an axon

Question 13

What is a neurone?

Answer 13

a cell that is specialized for conducting electrical impulses

Question 14

What does all mammals have?

Answer 14

central nervous system (CNS)
peripheral nervous system (PNS)

Question 15

What is a central nervous system?

Answer 15

the brain & the spinal cord

Question 16

What is a peripheral nervous system?

Answer 16

the nerves outside the brain & spinal cord

Question 17

What is a sensory neurone?

Answer 17

a neurone that transmits electrical impulses from the receptor to the central nervous system

Question 18

What is a relay neurone?

Answer 18

a neurone that transmits electrical impulses within the central nervous system

Question 19

what is a reflex arc?

Answer 19

a series of neurones that transmits electrical impulses from a receptor>effector

Question 20

name the 3 neurones involved in a reflex arc?

Answer 20

sensory neurone
motor neurone
relay neurone

Question 21

What is a reflex action?

Answer 21

the reaction that happens after the impulse has sped around the reflex arc

Question 22

What kind of action is a reflex action?

Answer 22

automatic actions

Question 23

What is a synaptic gap?

Answer 23

tiny gap between 2 neurones

Question 24

What is a synapse?

Answer 24

a junction between 2 neurones

Question 25

What is a sense organ?

Answer 25

group of receptor cells that are able to respond to specific stimulus

Question 26

what is a retina?

Answer 26

a tissue at the back of the eye,which contains receptor cells that respond to light

Question 27

how is the surface of the eye always kept moist?

Answer 27

by a liquid made in the tear glands

Question 28

What helps to stop dirt from landing on the surface of your eyes?

Answer 28

eyelids eyebrows lashes

Question 29

where does your retina sit?

Answer 29

at the back of the eye

Question 30

What is a optic nerve?

Answer 30

a nerve that carries electrical impulses from the retina to the brain

Question 31

how does the brain build an image?

Answer 31

impulses from the receptor cells

Question 32

what is a blind spot?

Answer 32

part of the retina where the optic nerve leaves

Question 33

what is a iris?

Answer 33

the coloured part of the eye

Question 34

What is the gap in the middle of the iris called ?

Answer 34

pupil

Question 35

what happens if the pupil is wider?

Answer 35

the more light can get to the retina

Question 36

What happens when theres high light intensity?

Answer 36

the iris closes in,making the pupils smaller

Question 37

What happens when theres low light intensity?

Answer 37

iris pulls back from the pupil(pupil becomes larger) allowing more light to reach the retina

Question 38

What does refraction mean?

Answer 38

bending light rays

Question 39

Why does light rays have to be bend?

Answer 39

so that they can focus exactly onto the retina

Question 40

What is a cornea?

Answer 40

refraction of light entering the eye

Question 41

What is a lens?

Answer 41

structure in the eye,which changes shape to focus light rays onto the retina

Question 42

what is hormones?

Answer 42

chemicals that are produced by a gland & carried in the blood

Question 43

What are endocrine glands?

Answer 43

glands that secrete hormones

Question 44

What are target organs ?

Answer 44

organs those activity is altered by a hormone

Question 45

What hormone does the adrenal gland secrete?

Answer 45

adreneline(prepares body for action)

Question 46

What hormone does the pancrea galnd secrete?

Answer 46

insulin(- the concentraction of glucose in blood)

Question 47

what hormone does the testis gland secrete?

Answer 47

testosterone(development of male secondary sexual characteristics)

Question 48

where does the 2 adrenetine glands sit?

Answer 48

1 above each kidney

Question 49

name the 4 most important endocrine glands?

Answer 49

1.adrenal 2.pancreas 3.testis 4.ovary

Question 50

What hormone does the ovary gland secrete?

Answer 50

oestrogen(development in female secondary sexual chararcteristics) (helps control menstrul cycle)

Question 51

how do plants respond to stimuli?

Answer 51

by changing their rate or direction of growth

Question 52

if plants growth towards stimuli,what is it called?

Answer 52

postive responce

Question 53

if plants grow away from stimuli,what is it called?

Answer 53

negative responce

Question 54

what does tropism mean?

Answer 54

growth responce by a plant

Question 55

What are growth responces to light called?

Answer 55

phototropism

Question 56

What are growth responces to gravity called?

Answer 56

gravitropism

Question 57

What are roots?

Answer 57

positively gravitropic