B1 Flashcards
1
Q
What’s the definition of being fit?
A
A measure of how well you can perform physical tasks (strength, speed, agility, flexibility and stamina)
2
Q
What is systolic pressure?
A
Where the blood pressure is at its highest when the heart contracts
3
Q
What’s diastolic pressure?
A
Where the blood pressure is at its lowest when the heart relaxes
4
Q
What is blood pressure measured in?
A
Mm of mercury (mmHg)
5
Q
Name four factors that can increase your blood pressure
A
Smoking
Being overweight
Drinking too much alcohol
Being under stress
6
Q
What problems can high blood pressure cause?
A
Blood vessels can burst leading to strokes, brain damage and kidney damage
7
Q
What problems can low blood pressure cause?
A
Poor circulation so tissues don’t get enough food or oxygen can lead to fainting
8
Q
What two chemicals in cigarette smoke increase blood pressure?
A
Carbon monoxide
Nicotine
9
Q
How does carbon monoxide increase blood pressure?
A
Combines with haemoglobin in red blood cells reducing the amount of oxygen they can carry - heart rate increases to make up for this increasing blood pressure
10
Q
How does nicotine increase blood pressure?
A
Increase heart rate
11
Q
What two things in a diet can put you more at risk of developing heart disease?
A
High in saturated fat
High in salt
12
Q
What’s the definition of being healthy?
A
Being free from any infections or diseases
13
Q
What can eating too much saturated fat cause?
A
A build up of cholesterol in your arteries forming a plaque that restricts the flow of blood - can lead to a heart attack
14
Q
What can having high salt levels in your diet cause?
A
High blood pressure - increases risk of damage to arteries which can encourage a build up of plaque which leads to a heart attack
15
Q
What’s a thrombosis and what problems can it cause?
A
A blood clots
Restricts blood flow
If happens in already narrow arteries can block of blood flow completely causing a heart attack
16
Q
What problems do having narrow arteries cause?
A
Restrict blood flow so heart receives less oxygen
17
Q
Name three facts about carbohydrates
A
Made up of simple sugars (glucose)
Provide energy
Stored in the liver as glycogen or converted into fats
18
Q
Name six facts about fat
A
Made up of fatty acid and glycerol Stored under skin and around organs as adipose tissue Provide energy Act as an energy store Provide insulation
19
Q
Name three facts about proteins
A
Needed for growth and repair
Provide energy in emergencies
Contain essential amino acids
20
Q
Why is vitamin c needed?
A
Prevents scurvy
21
Q
Why is iron needed?
A
Makes haemoglobin in the blood
22
Q
What problem can eating too little protein cause and what is a common symptom?
A
Kwashiokor
Swollen stomach
23
Q
What are the four different types of pathogens?
A
Fungi
Bacteria
Viruses
Protozoa
24
Q
What’s a vector?
A
Something that carries a disease without getting infected itself e.g a mosquito (malaria)
25
How can we target the spread of malaria?
Areas of water drained or sprayed with insecticides
Fish introduced to eat mosquito larvae
Use of insecticides and mosquito nets
26
What are the three lines of attack of a white blood cell?
Consuming them
Producing antitoxins (counteract toxins)
Producing antibodies
27
Describe the process the White blood cell does to produce antibodies
Produces antibodies rapidly to lock on to the foreign antigen on surface of the pathogen
Keeps antibodies as memory cells making the person naturally immune
28
What's immunisation?
Dead or inactive pathogens injected to trigger production of antibodies so if live pathogens appear antibodies are produced rapidly and pathogen killed immediately instead of waiting for antibodies to be made
29
What's active immunity?
Where the immune system makes its own antibodies - usually permanent
30
What's passive immunity?
Where you use antibodies made by a different organism e.g. Mother to baby through breast milk - only temporary
31
What are the benefits and risks of immunisation?
Stops you from getting ill
Disease won't spread as easily
Short term side effects: feeling under the weather after vaccination, redness and swelling at injection site
Can't have vaccinations if already ill (weak immune system)
32
What are the benefits and problems of antibiotics?
Kill bacteria but don't kill viruses
Some bacteria are naturally resistant to certain antibiotics
Misuse has increased development of these resistant strains
Only get antibiotics for something serious to prevent this
33
What do antivirals do?
Stop viruses from reproducing
34
What is a benign tumour?
Isn't dangerous
Only grows until there's no more room
Cells stay where they are
35
What's a malignant tumour?
Dangerous
Grows and can spread to other sites in the body
Can be fatal
36
What can you do to reduce your risk of cancer?
Don't smoke
Eating less processed meat
More fibre
37
What is the placebo effect in a double blind study?
The doctor gives some people normal some people placebo
| The doctor and the patient doesn't know which one is which
38
What are the five kinds of drugs and what do they do?
Depressants - decrease brain activity
Stimulants - increase brain activity
Pain killers - reduce the number of "painful" stimuli at the nerve endings
Performance enhancers - build muscle and allow athletes to train harder
Hallucinogens - distort what's seen and heard by altering brain pathways
39
Name 3 class A drugs
Heroin
LSD
Cocaine
40
Name 2 class B drugs
Cannabis
| Speed/amphetamines
41
Name 2 class C drugs
Anabolic steroids
| Tranquillisers
42
What kind of drug is alcohol?
A depressant
43
What is cirrhosis of the liver?
Drinking too much alcohol over a long period of time
Toxic products made when alcohol broken down by enzymes kills liver cells forming scar tissue that stops blood reaching the liver this is cirrhosis
44
What happens if the liver isn't working properly?
Blood isn't cleaned properly so dangerous substances build up and cause damage to the rest of the body
45
Name 4 illnesses caused by smoking
Heart disease
Lung, throat, mouth and oesophageal cancer
Smokers cough and severe loss of lung function - emphysema and bronchitis
Low birth weight in babies
46
What is smokers cough?
Damages the cilia on the epithelial tissue lining the trachea bronchi and bronchioles - encourages production of mucus - but it can't be cleared so sticks to air passages causing smokers cough
47
Why does smoking cause cancer?
The carcinogens in the cigarette tar cause the cells to divide rapidly
48
What does the cornea do?
Refracts the light into the eye
49
What does the iris do?
Confirms how much light enters the pupil
50
What does the lens do?
Refracts light and focuses it onto the retina
51
What does the retina do?
Light sensitive part covered in receptors called rods and cones which detect light
52
What do rods do?
More sensitive in dim light but can't sense colour
53
What do cones do?
Sensitive to different colours but not good in dim light
54
What causes red green colour blindness?
A lack of certain specialised cone cells
55
What does the optic nerve do?
Carries impulses from the receptors to the brain
56
What is accommodation?
When the lens focuses light by changing its shape
57
What happens to the eye when you look at distant objects!
Ciliary muscles relax
Suspensory ligaments pull tight
Lens becomes a less rounded shape so light is refracted less
58
What happens to the eye when you look at close objects?
Ciliary muscles contract
Slackens the suspensory ligaments
Lens becomes more rounded shapes I light is refracted more
59
What is long sighted ness and what fixes it?
Unable to focus on near objects
Images of near objects are brought into focus behind the retina
Need convex lens to fix it
60
What is short sightedness and what corrects it?
Unable To focus on distant objects
Distant objects are brought into focus on front of the retina
Need concave lens to fix it or can be corrected with corneal laser surgery
61
What is binocular vision?
Your brain combines the images from each eye
The more similarities between the images the further away the objects
Allows judgement of distance
But gives narrow field of vision
62
Name two ways glucose is removed from the blood
Normal respiration
| Vigorous exercise
63
What organ monitors and controls the level of glucose in the blood?
Pancreas
64
What happens if the glucose level in the blood is too high?
The pancreas releases insulin which tells the liver to remove glucose from the blood and store it as glycogen in the liver
65
What happens if the glucose level in the blood is too low?
The pancreas doesn't release any insulin - if there's no insulin present in the blood the liver turns its glycogen store into glucose and releases it into the blood
66
What is insulin?
A hormone
67
What's a hormone and what are its disadvantages?
Travel in the blood and tell a certain organ to do something (messenger)
It takes the body longer to respond to a hormone than to an electrical impulse sent along a nerve
68
What is type 1 diabetes and how is it controlled?
The persons pancreas produces little or no insulin - their blood glucose level can rise to a level that can kill them
Carefully controlling their diet and having insulin therapy (injecting insulin several times a day often at mealtimes)
69
What's type 2 diabetes and how is it controlled?
The person becomes resistant to insulin (their body cells don't respond properly)
Controlled by limiting the intake of foods rich in simple carbohydrates (sugars)
70
What are auxins?
Plant hormones which control growth at the tips of shoots and roots
71
How do auxins move through a plant?
In solution
72
Where is auxin produced and how does it cause growth?
Produced in the tips
| Diffuses backwards to stimulate the cell elongation process
73
What are the growth responses of shoots to light and gravity?
Positively phototrophic and negatively geotropic
74
What does it mean when a shoot is positively phototrophic?
The side in the shade accumulated more auxin making the cells elongate faster on the shaded side making the tip bend towards the light
75
What does it mean when a shoot is negatively geotropic?
When a shoot grows sideways gravity produces an unequal distribution of auxin causing there to be more auxin on the lower side making the lower side grow faster bending the shoot upwards
76
What are the growth responses of roots to light and gravity?
Negatively phototrophic and positively geotropic?
77
Why do roots react to light and gravity in the opposite way to shoots?
In a root extra auxin as what gravity causes when the auxin collects on the lower side of the root actually inhibits growth so the cells grow slower than the ones on top causing the opposite reaction
78
What are selective weed killers and why do they work?
They've been developed from plant growth hormones and only affect broad leaves plants - disrupt their normal growth pattern killing the weeds
Most weeds growing in fields or lawns are broad leaved where's the crop and grass are narrow leaved
79
What are the benefits of rooting powder?
It contains a growth hormone which allows a cutting to grow as new plants (they wouldn't in soil without rooting powder)
Growers can produce lots of clones of a good plant quickly
80
Name four ways that plant hormones are used commercially
Selective weed killers
Rooting powder
Controlling the ripening of fruit
Controlling dormancy
81
What's an advantage of being able to control the ripening of fruit?
It can be picked whilst it's unripe so is less likely to be damaged in transit
82
What hormone controls dormancy?
Gibberellin
83
What's the advantages of controlling dormancy?
Commercial growers can make seeds germinate at times of the year they wouldn't normally
Helps make sure all the seeds in a batch germinate
84
What is dormancy?
Where seeds won't germinate until they've been through certain conditions
85
What does the central nervous system consist of?
The brain and spinal cord
86
What are the three types of neurones that the nervous system is made up of?
Sensory neurones
Relay neurones
Motor neurones
87
What does a sensory neurone do?
Carries the information (you detect a change in the environment) from receptors to the CNS
88
What does a motor neurone do?
Receives the information from the CNS and takes it to an effector
89
What is the central nervous systems job?
To coordinate the information
90
What happens in a reflex action and why is it faster than a normal action?
The sensory neurone connects to a relay neurone in the spinal cord which links it directly to the motor neurone
The conscious brain isn't involved so no time is wasted thinking about it
91
In what format is the information sent around the body in the CNS?
It's sent as electrical impulses
92
What are the 6 cell structures in a neurone?
```
Nucleus
Cell body
Dendrites
Axon
Insulating sheath
Synapse
```
93
What is the job of the axon?
Electrical impulse passed along it
94
What do dendrites do?
Connect with lots of other neurones
95
What does the insulating sheath do?
Acts as an electrical insulator speeding up the electrical impulse
96
Why are neurones really long?
Speeds up the impulse as one long one is much faster than lots of short ones joined together (connecting slows it down)
97
What is the connection between two neurones called and what is it basically?
A synapse
| It's basically a very tiny gap
98
How is the electrical impulse transmitted across the synapse?
The impulse triggers the release of transmitter chemicals which diffuse across the synapse (gap) they bind to receptor molecules on the membrane of the next neurone setting off a new electrical impulse
99
How do stimulant drugs affect the synapse?
Increase the amount of transmitter chemicals making more frequent impulses in the next neurone
100
How do depressant drugs affect the synapse?
They bind with receptor molecules blocking the electrical impulse decreasing brain activity
101
What are three examples of conditions that your body controls as part of homeostasis?
Levels of CO2
Water content (levels)
Body temperature
102
What is homeostasis?
Maintaining a constant internal environment
103
How does your body achieve homeostasis?
By using negative feedback
104
Whats negative feedback and what's a disadvantage of it?
Where changes in the environment trigger a response which counteract the change - the internal environment stays around the norm
Only works within limits - if the environment changes too much it might not be possible to counteract it
105
What is the optimum temperature for the human body?
37 degrees C
106
What controls your body temperature?
The thermoregulatory centre in your brain
Has receptors sensitive to blood temp
Receives impulses from skin about skin temp
Uses nervous and hormonal systems to initiate temperature control mechanisms
107
What happens when you're too hot?
Your hairs on your skin lie flat
Lots of sweat produced - when it evaporates it transfers hear from your skin to the environment
Blood vessels closest to the surface widen - more blood flows near surface increasing heat loss (vasodilation)
108
What happens when you're too cold?
Hairs stand on end to trap an insulating layer of air
Blood vessels near surface constrict (vasoconstriction) so less blood flows near surface
You shiver generating hear in your muscles
109
What is vasodilation?
Where blood vessels close to the surface widen
110
What is vasoconstriction?
Where blood vessels close to the surface constrict
111
How many pairs of chromosomes are in a human body cell?
23 pairs
112
What is a gene?
A short length of a chromosome
113
What are different versions of the same gene called? (E.g. Blue or brown eyes)
Alleles
114
What are the three sources of genetic variation?
Gamete formation
Fertilisation
Mutations
115
What are gametes?
Sperm or egg cells
116
What's special about gametes?
They only have half of the chromosomes they should have (only 23)
117
What are your features determined by?
Genes and environment
118
How is your health determined by genes and environment?
More likely to get certain diseases because of genes
| Lifestyle affects the risk as well
119
How is intelligence determined by genes and environment?
Your maximum possible IQ is determined by genes
| Whether you reach it depends on upbringing and school life
120
How is your sporting ability determined by genes and environment?
Genes determine potential
| Training determines whether you reach it
121
What are the two types of alleles?
Dominant and recessive
| Dominant overrules recessive
122
What does it mean if you're homozygous?
You have two alleles the same (two recessive or two dominant)
123
What does it mean if you're heterozygous?
You have two different alleles (one recessive one dominant)
124
What is your genotype?
Your genetic makeup
125
Why is your phenotype?
The characteristics the alleles produce
126
What's the name of the diagram that shows the chance of someone's child having the recessive gene or not?
Punnett the squares
127
What are people with only one copy of a recessive allele called?
Carriers
128
What is cystic fibrosis?
A genetic disorder causing the body to produce lots of thick sticky mucus in the air passages and pancreas
