Biology unit 2 Flashcards
1
Q
How quickly can the body carry electrical impulses?
A
Up 120m/sec
2
Q
What are receptors?
A
A group of specialised cells which detect stimuli
3
Q
What’s a stimuli?
A
Change in environment
4
Q
What are the stimuli detections converted into?
A
Electrical impulses
5
Q
Where are receptors often located?
A
In the sense organs
6
Q
What are the sense organs?
A
Skin, tongue, nose, eyes and ears
7
Q
What are each of the sense organs receptive to?
A
Skin: Touch, pain, pressure and temperature
Tongue: Chemicals in food (taste)
Nose: Chemicals in air (smell)
Eyes: Light
Ears: Sound (and head position, balance)
8
Q
What does the CNS (Central Nervous System) consist of?
A
Brain and spinal cord
9
Q
What happens when a receptor is stimulated?
A
It sends a signal along the nerve cells (neurones) to the brain
10
Q
What is a neurone
A
A nerve cell
11
Q
What is an effector?
A
Any part of the body that produces a response
12
Q
Give an example of an effector in a human body
A
Muscle contracting to move the arm/muscle squeezing saliva from the salivary gland/a gland releasing a hormone into the blood
13
Q
What is the pattern for a conscious response?
A
Stimulus-> Receptor-> Sensory Neurone->Relay Neurone-> Coordinator-> Motor neurone ->
Effector->Response
14
Q
Give an example of a CONSCIOUS response
A
- ) Sensor cell detects stimulus (I.e treading on a pin) which is STIMULUS AND RECEPTOR
- )Nerves transmit the impulse from the sensor cell to the spinal cord (which is SENSORY NEURONE in the pattern)
- ) Nerves in the spinal cord transmit impulses to and from the brain (RELAY NEURONE)
- )Brain coordinates a response to stimulus (COORDINATOR)
- )Neurones transmit the impulse from the spinal cord to the effector cell (MOTOR NEURONE)
- ) Effector cell causes muscle to contract, lifting foot away from the pin (EFFECTOR AND RESPONSE)
15
Q
What is the pattern for a REFLEX response?
A
Stimulus->Receptor->Sensory Neurone->Relay Neurone->Motor Neurone->Effector->Response
16
Q
Give an example of a REFLEX RESPONSE
A
The way the eye reacts to light, I.e
In bright light, the radial muscles of the iris contract which results in less light entering through the eye via the contracted pupil
In dim light, radial muscles of the iris contract and circular muscles of the iris relax, resulting in more light entering through the eyes via the dialysed pupil.
17
Q
What is a co-ordinator?
A
Part of the body that coordinates a response
18
Q
What is a response?
A
A change in the body
19
Q
What do neurones carry?
A
Information as tiny electrical signals
20
Q
Name the three types of neurones and their functions
A
Motor neurone: Carry signals from CNS (central nervous system) to effectors
Sensory neurones: Carry signals from the receptors to brain and spinal cord
Relay neurones: Carry messages from one pet of the CNS to another
21
Q
Describe the parts of a neurone
A
The neurone has: a cell body (containing cell membrane, cyptoplasm and dendrites (convey nerve impulses to body)
Nerve endings: Where synapses are located (connection between 2 neurones)
Axon: Long extension from neurone to carry the impulse
Nucleus
22
Q
What happens when 2 neurones meet?
A
When 2 neurones meet, there is a gap called a ‘synapse’. Signals cross this gap using chemicals; one neurone releases the chemical into the gap and the chemical diffuses across, resulting in the next neurone transmitting an electrical signal.
23
Q
What is a REFLEX response?
A
A quick response that happens without thinking
24
Q
What does the REFLEX response miss our?
A
Brain signals
25
What temperature does the body need to stay at?
37 degrees
26
Define homeostasis
Regulation of the internal conditions of a cell or organism to maintain optimum conditions for a function in a response to internal and external changes
27
What does homeostasis maintain?
Conditions for enzyme action and cell functions
28
What does homeostasis control in the body?
Blood glucose concentration, body temperature and water levels
29
What is a negative feedback system?
When something's too high, it will get brought back down and vice versa
30
What is body temp controlled by?
Thermoregulatory centre in brain.
31
What does the thermoregulatory centre contain?
Receptors sensitive to temperature of blood.
32
What does the skin contain
Temperature receptors and sends nervous impulses to the thermoregulatory centre
33
What happens if the body temp is too high
Blood vessels dilate (vasodilation) and sweat is produced from the sweat glands
34
What happens if body temp is too low?
Blood vessels constrict (vasoconstriction) and sweating stops and skeletal muscles contract (shiver)
35
How does water leave the body?
Via lungs through exhalation
36
How does water, ions and urea leave the body?
Sweat
37
Is there any control over water, ion or urea loss by lungs or skin?
No
38
How is excess water, ions and urea removed?
Via kidneys in urine
39
What does the digestion of proteins from diet result in?
Amino acids, which need to be excited as in the liver it turns into ammonia, which is toxic, so it is immediately converted to urea for safe excretion
40
What happens if body cells lose or gain too much water by osmosis?
Don't function efficiently
41
How does the function of the kidneys maintain water balance in the body?
A negative feed back system maintains water levels
42
What are nephrons
Filtration units in the kidneys which are under high pressure. Water, urea, ions and sugar are squeezed out of the blood into bowmans capsule
43
What is a renal artery?
Carries blood w/waste products
44
What is a renal vein?
Carries clean blood in kidney
45
What does a ureter carry?
Waste products (urine) to bladder
46
How do kidneys produce urine?
By filtering the blood and selective reabsorption of useful substances such as glucose, some ions and water
47
What is water level controlled by
ADH hormone, which is released by the pituitary gland when the blood is too concentrated, and causes more water to be reabsorbed back into the blood from kidney tubules. Controlled by neg. feedback
48
How do substances get reabsorbed?
Absorbed by active transport against a concentration gradient
49
What does a dialysis machine do?
Filter blood if a patients kidney does not work (blood flows along a selectively permeable barrier). This must be repeated three times a week at 4 hours per session until a donor is found
50
How does a dialysis work in the body?
The machine is connected to the patient which removes most of the urea and restores or maintains water and ion balance. 'Dirty' urea filled blood is mixed with blood thinners to prevent clotting and is pumped into the machine. Then it is separated by a partially permeable membrane and the blood flows in the opportune direction to the dialysis fluid, an allowing an exchange when there's a concentration gradient
51
Give advantages and disadvantages of a kidney dialysis and transplant
Dialysis advantages: useful if an immediate donor can't be found and does job of kidneys for you
Disadvantages: need to plan life around it as it can take 4 hours, and diet and fluid intake has to be restricted
Donors advantages: patients can lead more of a normal life as they don't have to worry about eat to eat and drink and it's cheaper for NHS
Disadvantages: Must take immune-suppressants drugs which increase infection rush and kidneys last 8/9 years on avg. there's a shortage of donors and all operations obv carry a risk
52
How does a kidney transplant work?
When a kidney is taken from a matched donor to the patients body to replace the damaged kidney
53
What is blood glucose monitored and controlled by?
Pancreas
54
What is glucagon
A hormone produced by the pancreas
55
What does the adrenal gland produce?
Adrenaline, which targets the liver, heart etc and prepares body for rapid activity by increasing heart rate and level of sugar in blood and muscles
56
What do the ovaries produce
Oestrogen and progesterone, which target the ovaries, uterus and pituitary gland and cause puberty and menstrual cycle
57
What TWO hormones does the pancreas produce?
Insulin and Glucagon, which target the liver and cause blood sugar and water level to be controlled
58
What does the pituitary gland produce?
FSH (follicle stimulating hormone) and LH (lutenising hormone) and ADH (Anti-diuretic hormone) target the ovaries and kidneys to cause egg maturation, egg release and water resorption
59
What are hormone?
Chemical molecules releases directly into the blood to regulate bodily processes (carried in blood plasma) affecting particular target organs
60
What do hormones make up?
The endocrine system
61
What do the testes produce?
Testosterone, which target the male reproductive organs and cause puberty
62
What does the thyroid gland produce?
Thyroxine, which targets cells and causes metabolic rate and protein synthesis
63
What are levels of thyroxine controlled by
negative feedback
64
Where are the hormones secreted for the menstrual cycle?
Ovaries and pituitary gland
65
What is FSH?
Follicle stimulating hormone that causes an egg to mature in the ovary and stimulates ovaries to release the hormone oestrogen. Secreted by pituitary gland and has affect between 6-13 days
66
What does oestrogen do?
Stops FSH being produced so one egg matures in a cycle and stimulates the pituitary gland to release the LH hormone
67
What is luteinising hormone? (LH)
Causes a mature egg to be released from the ovary around day 14
68
What is progesterone?
It's secreted by ovaries and maintains the uterus lining so levels stay HIGH during pregnancy. If no egg is fertilised progesterone stops getting released and menstruation stops
69
Name 5 ways to stop pregnancy
```
'The pill'
Contraceptive patch
Contraceptive injection
Condom
Abstaining
```
70
Name the benefits and problems with the pill
Benefits: 99% effective and reduces some types of cancer risk
Problems: not 100% effective, can cause side effects like headaches, nausea, irregular menstrual bleeding and fluid retention and doesn't protect against STDs
71
Name a type of fertility treatment and what it does
IVF- when an egg is fertilised outside the body and the egg is out back into uterus (IVF- in vitro fertilisation)
72
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What is the:
Cerebral cortex
Medulla
Cerebellum
And what do they do?
```
Cerebral cortex- outer wrinkly layer of brain that's responsible for consciousness, intelligence, memory and language
Medulla- base of brain (top of spinal cord) and controls unconscious activities like breathing and heartbeats
Cerebellum- found at the back of the brain and is responsible for muscle co-ordination
73
What are scientists that study the brain called?
Neuro-scientists
74
Give an example of a way to study the brain.
A Magnetic resonance imaging (MRI) scan which shows what part of the brain is active when people are awake and doing something specific (I.e listening to music)
Electrically stimulating the brain using tiny electrodes and observing what stimulating the different parts of the brain does
75
What is an anomaly?
A measurement that's different than expected
76
What is an: Independent, dependent and control variable?
I.V- thing you change
D.V- thing you measure
C.V- things you keep the same
77
What is a range?
The biggest and smallest numbers Of independent or dependent variables
78
What is a categoric variable?
Variable with category names as labels
79
What is a continuous variable?
Variables that can be any number called a quantity (I.e 1,2,3,4)
80
What is a measurement error?
Difference between measured and true value
81
What is a random error
Readings that vary from the expected result with unknown reason
82
What is a systematic error?
Readings that differ from the true value by a consistent amount each time a measurement is made
83
What does repeatable mean?
A measurement that means the original experimenter could do the investigation again with the same equipment and method and get the same results
84
What does reproducible mean?
An experiment is taken place with a different person using the same method and the same results are obtained
85
What do plants grow towards
Water light gravity
86
What is growth in plants affected by
Their environmental conditions (stimulus)
87
What is a growth in response to a stimulus in plants called
Tropism
88
What is a pos and neg tropism
Pos- towards stimulus
| Neg-away from stimulus
89
What is photo/hydro/geo tropism?
Phototropism- towards light
Hydrotropism-towards water
Geotropism-towards gravity
90
What are gibberellins important in?
Initiating seed germination
91
What does Ethene control
Cell division and fruit ripening
92
What are auxins used for
Weed killers, rooting powders and for promoting growth in tissue culture
93
What can gibberellins be used for
Ending seed dormancy, promoting flowering and increasing fruit size
94
Where are auxins made
In the tip of a growing shoot and move down the stem.
95
What do auxins do in a growing shoot
Speeds up the growth
96
What amount of auxins are there in a plant above light
An equal amount
97
Where are the auxins in a plant not getting enough light
There are more auxins on the shaded part of the shoot so the shaded side grows faster making the bright side bens towards the light
98
What do auxins do in roots
Slow growth
99
What do auxins do to a plant on its side
Collect in lower side of the root and stem. The auxins slow down growth on the lower side of the root so it curves down. Auxins speed up growth on the lower side of the stem so it curves up
100
Where will roots always grow towards
Water
101
What can plant hormones be used synthetically for
Growing cuttings, ripening fruits and killing weeds
102
How does Ethene ripen fruits
it's sprayed on fruits to control growth through storage so it's ripe in time for the shops
103
What do selective weed killers contain
Hormones at concentrations that will only affect plants with broad leaves
104
What's Ethene
A gas
105
What does the iris do
Contains muscles which allow it to control the diameter of pupil and how much light enters the eye
106
What does the cornea do
Focused and controls the entrance of light into the eye and helps shield eye from dust and germs. Refracts light into the eye
107
What does the pupil do
Controls amount of light that enters the eye
108
What does the lens do
Focuses light into the retina
109
What does the ciliary muscle do
Controls lens shape
110
What is the sclera
The supporting tough wall of the eye
111
What does the optic nerve do
Carries impulses from receptors on retina to brain
112
What does the retina do
Contains receptor class that are sensitive to light intensity and colour
113
What do the suspensory ligaments do
Controls lens shape
114
What does the eye do to focus on a close object
The ciliary muscles contract, the suspensory ligaments loosen and the lens is thicker and refracts light rays strongly
115
What does the eye do to focus on a distant object
The ciliary muscles relax, the suspensory ligaments are pulled tight and the lens is pulled thin and only slightly refracts light rays
116
What is myopia and how can it be corrected
Short sightedness that occurs when lens is wrong shape and refracts light too much/eyeball is too long. Can be corrected with glasses or a concave lens that curves inwards (lets light rays focus on retina)
117
What is hyperopia and how can it be corrected
Long sightedness where images are brought into focus behind retina. Happens when lens is the wrong shape or doesn't refract (bend) the light enough/eyeball is too short. Can be corrected with a convex lens (curved outwards) which refracts light rays so they focus on retina
118
What are pathogens
Micro organisms that enter the body and cause communicable (infectious) disease that can be spread
119
What are the four pathogens
Bacteria fungi viruses and protests
120
What happens when a virus enters the body
We are deemed infected
121
What do bacteria and viruses have the ability to produce
Toxins
122
What is the spread of disease known as
Transmission
123
Give examples of how pathogens spread
Air, (breathed in) water (drinking or bathing in dirty water)and direct contact (touching contaminated surfaces)
124
How is salmonella spread
By bacteria on ingested food or food prepared in unhygienic conditions
125
What is gonorrhoea caused by and spread by
Caused by a bacterium and spread by sexual contact
126
What type of disease is measles
A viral disease that shows symptoms of fever and a red skin
| Rash
127
What happens if HIV isn't successfully controlled with antiretroviral drugs
The virus attacks the body's immune cells. AIDS (late HIV infection) is when the body's immune system is so badly damaged it can't deal with infections
128
How is HIV spread
Sexual contact
129
What is the Tobacco Mosaic Virus
A plant pathogen affecting many species of plants such as tomatoes which causes a mosaic pattern of discolouration and affects plant growth due to a lack of photosynthesis
130
What is rose black spot
A fungal siestas that causes purple of black spots to develop on leaves that turn yellow and drop early . Treated by fungicides
131
What are the pathogens that cause malaria
Protists
132
What does malaria cause
Recurrent episodes of fever
133
What do viruses contain
Genetic material insides a protective protein coat
134
What do viruses do to cells
Get inside them and replicate themselves
135
What are the stages of virus reproduction
Approach-> gets breathed into body/gets into by kissing etc
Attachment-> virus secures itself to host cell surface
Insertion-> virus injects its genetic material through injection tube and into host cell
Replication-> genetic material makes multiple copies of itself
Assembly->Viruses are assembled using chemicals from host cell (original virus dies and breaks down)
Cell lysis-> The host cell splits open and dies and viruses escapes and release toxins
Each virus starts a new round of replication
136
What are protists
Eukaryotes and most are single celled. Some are parasites and are often transferred by organism to organism via vector which doesn't get the disease (i.e. Malaria and mosquito)
137
What are fungi
Either single celled or have bodies made up of hyphae (thread like structures). The hyphae can grow and penetrate human skin and surface of plants that causes disease. Hyphae can also produce spores which can spread to other plants and animals(i.e. Black spot fungus)
138
Who was DR ignaz Semmelweis and what did he do?
In 1840s he was responsible for more hygiene in maternity wards and ordered doctors to wash hands with a chlorinated solution before examining women in labour. Mortality went from 12% to 1%
139
What can plant diseases be detected by
Stunted growth, spots on leaves, areas of decay (rot) growths malformed stems or leaves discolouration and presence of pests
140
What can identification be made by
A ref to a gardening manual or site
| Taking infected plants to a lab to identify the pathogen or by using testing kits that contain monoclonal antibodies
141
What can plants be infected by
Viral, bacterial fungal pathogens and insects
142
What can ion deficiency do to planes
Stunted growth caused by nitrate deficiency and chlorosis caused by magnesium deficiency
143
What is knowledge of ions limited to
Nitrate ions needed for protein synthesis and growth and magnesium Ions needed to make chlorophyll
144
Where do plants get mineral
| Ions
From the soil
145
What is crown gall
A bacterial disease that causes growths on plants
146
Give some examples of plants physical defences against pests
Tough waxy cuticle on leaves
Cellulose cell walls
Layers of dead cells around stems (bark on trees i.e)
147
Give some examples of chemical plant defence responses
Antibacterial chemicals and poisons to deter herbivores
148
Give some examples of mechanical adaptions of plants
Thorns and hairs deter animals
Leaves which droop or curl when touched
Mimicry to trick animals
149
Define biohazard
A biological substance which poses a threat to the health of living organisms primarily humans
150
What is microbiology
The study of micro organisms too small to be seen with the naked eye
151
How is the inhibition zone calculated
Are=Pi r squared
152
What is MRSA resistant to
Antibiotics
153
How can doctors reduce the rate of development of antibiotic resistance strains
Shouldn't prescribe antibiotics inappropriately
Patients should complete their antibiotic course
The agricultural use of antibiotics should be restricted
154
What is the steps of a bacteria and virii resistance
1. ) variation- some strains are resistant
2. )Competition- the non resistant bacteria are killed by penicillin
3. )survival of the fittest-the resistant bacteria survive
4. )reproduction- the resistant bacteria reproduce and pass on their adaptions to their offspring
155
How are monoclonal antibodies produced
From a single clone of cells. They are specific to one binding site on one protein antigen and are able to target a specific chemical or specific cells in the body
156
How do mouse lymphocytes help to produce monoclonal antibodies
They are stimulated to make a particular antibody. The lymphocytes are combined with a particular kind of tumour cell to make a cell called a hybridoma cell
157
What can hybridoma cells do
Divide and make the antibody. Single cells are cloned to produce many identical cells.
158
What can a large amount of the antibodies made by the hybridoma cell do
Be collected and purified
159
Give some examples of how monoclonal antibodies can be used
For diagnosis in pregnancy tests
To measure hormone levels and other chemicals in the blood
To locate or identify specific molecules in a cell or tissue by binding them with fluorescent dye
To treat some disease i.e. For cancer the monoclonal antibody can be bound to a radioactive substance
160
Give some side effects of monoclonal antibodies
Fever
Vomiting
Low blood pressure
161
Define natural immunity
Antibodies are produced by a person when needed or they are passed on by the mother during pregnancy
162
Define artificial immunity
A vaccine with dead microbes is injected tricking the body into producing antibodies ready for the real thing
163
Define vaccination
Taking a vaccine as a precaution against disease
164
Define immunisation
Making an animal resistant (immune) to a disease by taking a vaccine
165
Give the pros and cons of vaccines
```
Pros:protects against disease
Protects against more serious damage
Reduced epidemic chances
Cons:discomfort for young children
Side effects like bruising
Health concerns (MMR and autism link although this was disproven)
```
166
What are painkillers used for
To treat disease symptoms BUT they don't kill pathogens
167
Give examples of drugs extracted from plants
Digitalis from foxgloves
Aspirin originates from willow
Penicillin was discovered by Alexander Fleming from penicillium mound
168
What are new drugs tested for
Toxicity, efficacy and dose
169
Give examples of legal and illegal recreational drugs
Legal: alcohol and tobacco
Illegal: heroin and cocaine
170
What are the steps in drug synthesis
1. ) researchers target a disease to develop treatment
2. )pc models and chemicals are screened for use as drugs
3. )possible drugs made in lab
4. )drugs are tested on cell cultures to make sure they're non toxic
5. )animal testing takes place
6. )human trials begin
7. )a licence is given for a drug so doctors can prescribe them
8. )drugs are monitored
171
Define placebo
When a drug is given like the one being tested but doesn't acc do anything
172
Define placebo effect
When a patient expects the treatment to work so feels better even though the treatment didn't do anything
173
What is a blind trial
When the patient doesn't know if they're getting a drug or placebo
174
What's a double blind trial
When the patient and the doctor don't know who was the actual drug and who has the placebo until the results have been gathered
175
What happens to drug tested before they're published
They're peer reviewed
