Coordination and Response Flashcards
(104 cards)
1
Q
what does responding to their environment help organisms do?
A
survive
2
Q
animals increase their chances of survival by responding to changes in their external environment..give an example
A
avoiding places that are too hot or cold
3
Q
why do organisms respond to their internal environment?
A
to make conditions right for their metabolism
4
Q
what is a change in the external or internal environment called?
A
a stimulus
5
Q
what is the connection between the receptor and the effector?
A
the receptors detect a stimuli and the effectors produce a response
6
Q
give an example of a receptor cell in the eye
A
-cone and rod cells which detect changes in light
7
Q
give examples of effector cells
A
-cells in muscles which contract
-cells in glands e.g. pancreas which secrete
8
Q
how do receptors communicate with effectors
A
through the hormonal and nervous system
9
Q
what does the CNS do?
A
coordinated information
10
Q
what does the CNS consist of?
A
-brain
-spinal cord
11
Q
what 3 neurones is the CNS made up of?
A
sensory, relay and motor
12
Q
what happens when a receptor in a sense organ detects a stimuli?
A
they sent electrical impulses along sensory neurones to the CNS
13
Q
after the CNS receive the impulse from the sensory neurone what happens next?
A
the CNS then sends electrical impulses to an effector along a motor neutron then the effector responds
14
Q
how can the CNS able to brung about very rapid responses
A
neurones transmit information using high speed electrical impulses
15
Q
what is the connection between two neurones called?
A
a synapse
16
Q
how does the impulse travel across the synapse?
A
by chemicals called neurotransmitters which diffuse across the gap
17
Q
what do reflexes help prevent?
A
injury
18
Q
what type of response is a reflex?
A
automatic
19
Q
how does your eye have a reflex response to bright light?
A
-if bright light is shone in someones eye their pupils ill automatically get smaller
-so that less light can get into the eye
-this helps prevent damage
20
Q
what automatic response does your body do when you get shocked?
A
release of adrenaline
21
Q
what is the reflex arc?
A
the route taken by information in a reflection (from receptor to effector)
22
Q
what is the order of the reflex arc? (7)
A
1.stimulus
2.receptor
3.sensory neurone
4. unconscious CNS and relay neurone
5.motor neurone
6.effectors
7.response
23
Q
what does the conjunctiva do?
A
lubricates and protects the surface of the eye
24
Q
what does the sclera do?
A
is the tough outer later that protects the eye
25
what does the cornea do?
-refracts light into the eye
26
how does 02 get to the cornea?
-cornea is transparent and has no blood vessels so O2 diffuses in from the outer surface
27
what does the iris do?
controls the diameter of the pupil(the hole in the middle) and therefore how much light enters the eye
28
what does the lens do?
focuses the light onto the retina(the light-sensitive part which is covered in rods and cones)
29
what to rod cells detect/ sensitive to?
-more sensitive in dim light, can't detect colour
30
what to cone cells detect/ sensitive to?
-more sensitive to colours, aren't so good in dim light
31
where are cones found?
all over the retina but most are at the fovea
32
what does the optic nerve do?
carries impulses from the receptors to the brain
33
what does very bright light do to the eye?
damage the retina
34
what happens to the eye in dim light?
the brain tells the radial muscles to contract which makes the pupil bigger
35
what happens to the ciliary muscles and suspensory ligaments when an object is far away?
the ciliary muscles contract which allows suspensory ligaments to pull tight
36
what happens to the lens after the ciliary muscles contract which allows suspensory ligaments to pull tight?
the lens goes thin and less curved so it refracts light by a smaller amount
37
what happens to the ciliary muscles and suspensory ligaments when an object is close up?
the ciliary muscles contract which slackens the suspensory ligaments
38
what happens to the lens after the ciliary muscles contract which slackens the suspensory ligaments?
the lens becomes fat and more curved which increases the amount by which it refracts light
39
what are short-sighted people unable to do and why?
-unable to focus on distant objects
-because the cones or lens vend the light too much or the eyeball is too long
-the image of distant objects are brought into focus in front off the retina
40
what are long-sighted people unable to do and why?
-unable to focus on near objects
-because the cornea or lens doesn't bend the light enough or the eyeball is too short
-the images of hear objects are brought into focus behind the retina
41
what are hormones?
chemical messengers
42
where are hormones released into an what are they carried in?
-released directly into the blood stream
-carried in the blood plasma to t[other part of the body
43
what are the particular cells which hormones effect?
target cells
44
where are hormones produced?
in glands
45
how fast to hormones travel and last?
travel slow and are long lasting
46
where is adrenaline produced?
adrenal glands
47
where is insulin produced?
pancreas
48
where is testosterone produced?
testes
49
where is progesterone produced?
ovaries
50
where is oestrogen produced?
ovaries
51
where is ADH produced?
pituitary gland
52
where is FSH produced?
pituitary gland
53
where is LH produced?
pituitary gland
54
what is the role and effects of adrenaline?
-readies the body for a 'fight or flight' response
-increases HR, blood flow to muscles and blood sugar level
55
what is the role and effects of insulin?
-helps control the blood sugar level
-stimulates the liver to turn glucose into glycogen of storage
56
what is the role and effects of testosterone?
-main male sex hormone
-promotes male secondary sexual characteristics such as facial hair
57
what is the role and effects of progesterone?
-supports pregnancy
-maintains the lining of the uterus
58
what is the role and effects of oestrogen?
-main female sex hormone
-controls the menstrual cycle and promotes female secondary sexual characterises e.g. widening of the hips
59
what is the role and effects of ADH?
-controls water content
-increases permeability of the kidney tubules to water
60
what is the role and effects of FSH?
-female sex hormone
-causes an egg to mature in the ovary
-stimulates the ovaries to produce oestrogen
61
what is the role and effects of LH?
-female sex hormone
-stimulates the release of an egg from an ovary
62
state 3 differences between hormones and nerves
-nerves act very fast but hormones act slow
-nerves act for a very short amount of time but a hormone acts for a long time
-hormones act fairly generally but nerves act on a very precise area
63
what is homeostasis?
the maintenance of a constant internal environment
64
how is body temperature maintained in homeostasis?
you must get rid of excess body heat when you hot and retain heat when the environment is cold
65
state 3 ways water is lost from the body
-through the skin as sweat
-via the lungs as breath
-via the kidney as urine
66
how does a cold weather effect water balance? (2)
-on a cold day (or when you're not exercising) you don't sweat much
-you'll produce more urine which will be pale (as its more diluted)
67
how does a hot weather effect water balance?(3)
-on a hot day (or when you're exercising) you sweat a lot
-so you produce less urine, but it will be more concentrated
-you will also lose water through your breath when you exercise because you breath faster
68
what temperature is body temp kept at?
-why?
-37'c
-it is the optimum temperature for the enzymes to work best at
69
how does the brain detect when temp is too high or low?
-its sensitive to the blood temp in the brain
-and it receives messages from temperature receptors in the skin that provide information about skin temperature
70
how does the CNS regulate temperature?
based on the signals from the skin receptors your CNS can actuate the necessary effectors to make your body temperature stay just right
71
state the 3 things your body does when your too hot?
-sweating
-vasodilation
-hairs lie flat
72
how does sweating decrease temperature?
when sweat evaporates from the surface of the skin it transfers heat energy from your skin to the environment
73
how does vasodilation cool you down? (3)
blood vessels close to the surface of the skin widen
-which allows more blood to flow near the surface
-so it can transfer more energy to the surroundings
74
state the 4 things your body does when your too cold?
-little/no sweat
-vasoconstriction
-shiver
-hairs stand on end
75
how does vasoconstriction warm you up? (3)
-blood vessels near the surface of the skin constrict
-this measles blood flows near the surface
-so less energy is transferred to the surroundings
76
how does shivering heat up the body? (2)
-increases the rate of respiration
-transfers more energy to warm the body
-(exercise does the same)
77
smaller organs can cool down ......
quicker
78
why do small organs cool down quicker? (2)
-they have a bigger surface area to volume ratio
-so they can gain or lose heat faster because there is more area for the heat to transfer across
79
why do small organisms do well in hot climates but very vulnerable in cold climates? (2)
-they can lose body heat more easily (surface area to vol ration) in hot climates and reduce the change of overheating
-but this also means they can freeze in cold climates
80
why do organisms with a smaller surface area to volume ratio lose heat slowly?
because there is less area for the heat to transfer across
81
what shape do animals living in cold conditions have and why?
-a compact (rounded) shape to keep surface area minimum
-which reduces heat loss
82
what do plants do when they sense the direction of light and why?
-grow towards it
-to maximise light absorption for photo
83
why do plants need to sense gravity?
-so their roots and shoots grow in the right direction
84
why sense do climbing pants have and why is it useful?
-touch
-so they can fins things and claim to reach the sunlight
85
how does white clover protect itself from cattle?
-when the fields are overgrazed white clover starts to be eaten
-the white clover responds by producing toxins to avoid being eaten
86
what is the name for anything harmful that's natural but non-living e.g. drought?
abiotic stress
87
how do carrots respond to abiotic stress?
-carrots produce antifreeze proteins at low temperatures
-the proteins bind to ice crystals and lower the temperature that the water freezes at
-which stops more ice crystals from growing
88
what are auxins?
-plant hormones which control growth at the tips of shoots and roots
89
how do auxins move through the plant?
in solution (dissolved water)
90
where is auxin produced?
the tips
91
what does auxin do just behind the tip?
-diffuses behind and starts cell elongation
92
how does auxin act differently in the shoots and root?
-promotes growth in the shoot
-inhibits growth in the root
93
what 2 responses are auxins involved in?
-light (phototropism)
-gravity (geotropism)
94
shoots are ........ phototrophic
positively
-(crowns towards light)
95
what happens when a shoot tip is exposed to light
it accumulates more auxin on the side that's in the shade than the side that's in the light
96
what happens when more auxin accumulates on the shaded side of the shoot? (2)
-this makes the cells elongate and grow faster on the shaded side
-so the shoot bends towards the light
97
shoots are ......... geotropic
negatively
(grow away from gravity)
98
describe how a shoot is negatively geotropic
-when a shoot is growing sideways, gravity produces an unequal distribution of auxin in the tip
-so there is more auxin on the lower side
-this causes the lower side to grow faster, bending the shoot upwards
99
roots are ......... geotropic
positively
-(grow towards gravity)
100
which side will a root growing sideways have more auxin on?
the lower side
101
how does auxin inhibit growth in the roots? (2)
-the extra auxin will inhibit growth
-this means the cells on the top will elongate faster, and the root bends downwards
102
roots are .......... phototropic
negatively
-(grows away from light)
103
what happens if a root starts being exposed to some light? (2)
-more auxin accumulates on the shaded side
-the auxin inhibits cell elongation on the shaded side, so the root bends downwards, back into the ground
104
why do roots underground (not exposed to light) still grown down?
due to a positive gravitropism
