B1 Understanding organisms Flashcards
1
Q
Explain why the blood in the arteries is under pressure
A
- due to contraction of heart muscles
- so that it reaches all parts of the body
2
Q
What factors increase the risk of developing heart disease?(4)
A
- high blood pressure
- smoking
- eating too much saturated fat
- eating too much salt
3
Q
Describe how cholesterol can restrict blood flow in the arteries
A
- Your liver makes cholesterol from saturated fats
- Cholesterol is carried in the blood and may be deposited in artery walls
- These deposits narrow the arteries and restrict blood flow. The blood pressure increases to flow blood through the small gap
4
Q
Describe the factors that increase blood pressure
A
- Being overweight
- Stress
- Smoking
- High alcohol intake
5
Q
Describe the factors that decrease blood pressure
A
- Regular exercise
- Balanced diet
6
Q
Explain the possible consequences of having high blood pressure
A
- Stroke
- Heart attack
- Kidney damage
7
Q
Explain the consequences of having low blood pressure
A
- Fainting
- dizziness
- Poor circulation and organ failure
8
Q
Explain the difference between health and fitness
A
Health is being free from any disease and fitness is the ability to do physical activity
9
Q
What are the different ways of measuring fitness? (6)
A
- Agility
- Cardiovascular efficiency
- Strength
- Speed
- Stamina
- Flexibility
10
Q
Explain how smoking increases blood pressure
A
Tobacco contains carbon monoxide and nicotine:
- Carbon monoxide binds with the haemoglobin in red blood cells, hence reducing the oxygen carried. The heart has to beat faster to compensate, putting a strain on the heart.
- Nicotine increases heart rate
11
Q
Explain how diet can increase the risk of heart disease
A
- Saturated fats can lead to build up of cholesterol in the arteries which may cause a plaque to form
- High levels of salt can cause high blood pressure
12
Q
Explain how narrowed coronary arteries, together with thrombosis increase the risk of heart disease
A
Narrow coronary arteries can cause the blood pressure to increase as the heart requires greater pressure to force the blood through the narrower arteries.
A thrombosis is a blood clot in a blood vessel, heart attack may occur if the artery leading to the heart muscle is clotted
13
Q
Explain what and why a balanced diet should include?
A
- Protein : for growth and repair
- Carbohydrates and fat : to give you energy
- Iron : to make haemoglobin
- Vitamin C : to prevent scurvy
- Fibre : to prevent constipation
- Water : to prevent dehydration
14
Q
Explain why:
- A high protein diet is required by teenagers
- In many parts of the world, diets are deficient
A
A. Proteins are required by teenagers because at this age their body is constantly growing
B. Religion, age, medical reasons, gender, personal choices and how active you are.
3rd world countries —-> overpopulation and not enough money invested in agricultural techniques
15
Q
Proteins can be used as a source of energy when fats or carbohydrates are unavailable
A
True
16
Q
What are the problems associated with being obese? (4)
A
- Arthritis
- Breast cancer
- Heart disease
- Diabetes
17
Q
What are carbohydrates made of?
A
Simple sugars such as glucose
18
Q
What are fats made up of?
A
Fatty acids and glycerol
19
Q
What are proteins made up of?
A
Amino acids
20
Q
What factors cause variation in balanced diets?
A
- personal choice
- medial reasons
- how active you are
- gender
- religion
- age
21
Q
Where and how are carbohydrates stored?
A
In the liver as glycogen or converted to fats
22
Q
Where and how are fats stored?
A
Under the skin and around organs as adipose tissues
23
Q
Where are proteins stored?
A
Not stored
24
Q
What is the name for protein deficiency?
A
Kwashiorkor
25
Explain why protein deficiency is common in developing countries
- Overpopulation
| - Limited investment in agricultural techniques
26
Formula for Estimated average daily requirement (EAR)
EAR= 0.6 * body mass in kg
27
Formula for BMI
Mass in kg / (height in m)^2
28
Why may people in developed countries choose to eat little
Poor self image
Low self esteem
They think they will look better if they eat little and look skinny
29
What are infectious diseases caused by?
Microorganisms
30
Give one example of a disease caused by each type of pathogen
Fungi : athlete's foot
Virus : flu
Bacteria : Cholera
Protozoa : Malaria
31
Give example of non-infectious diseases
Vitamin deficiency: scurvy (vitamin C)
Mineral deficiency : anaemia (lack of iron)
Body disorder : diabetes, cancer
Genetic inheritance: red-green colour blindness
32
Describe how the human body is defended against pathogens
- skin provides a barrier
- blood clotting prevents entry of pathogens
- pathogens are trapped by mucus in the airways
- hydrochloric acid in the stomach kill pathogens
33
Describe the difference between infectious and non-infectious disease
Infectious diseases are caused by parasites, whereas non-infectious diseases are caused by body disorders, deficiencies and genetic inheritance
34
Immunisation gives protection against certain pathogens
True
35
Describe how pathogen that enter your body are destroyed by the immune system
- engulfed by white blood cells
| - destroyed by antibodies
36
Explain why new drugs have to be tested before use
To ensure that the drug conforms to the specification and doesn't cause any unknown side effects to the subject it is administered to
37
Describe how vectors spread disease
Malaria is caused by a parasite which is spread by female mosquitoes. When the mosquitoes bite people they spread the disease. Humans and mosquitoes are host for the disease
38
How can one control malaria?
- sleeping under a mosquito net and using insect repellent
- draining areas of stagnant water
- using insecticides to kill mosquitoes
39
Describe some changes in lifestyle and diet which may reduce the risk of cancers
- sunbathe a little, make sure they don't burn
- avoid eating too much fat and being overweight
- avoid eating too much red meat and processed food
- eat plenty of fruit and vegetables
- take regular exercise
- avoid drinking too much alcohol
40
Describe the difference between benign and malignant tumours
Benign cancer involves the tumour not spreading across other parts of the body whereas malignant cancer involves the tumour spreading across other parts of the body
41
Explain how pathogens cause the symptoms of an infectious disease
- By cell damage
| - Production of toxins
42
Antibodies lock on to the antigens leading to the death of the pathogens
True
43
Explain the difference between passive immunity and active immunity
Passive immunity involves antibodies being received and active immunity involves antibodies being self-produced
44
What is the difference between antiviral drugs and antibiotics
Antibiotics kill bacteria and fungi, however can't deal with viruses as they have no antigens on the protein surface. Antiviral drugs inhibit the the replication of the virus within the host
45
Benefits of passive immunity
- can be used to avoid pandemics and epidemics
46
Explain how antibiotics can be used carefully to prevent increase of restraint strains such as MRSA
- Complete the antibiotics course
| - Should only be prescribed if necessary
47
Example of a good antiseptic
Iodine solution
48
Antiseptics can be used to kill microbes on the surface of your skin and can kill many resistant strains
True
49
Describe how animals detect changes in their stimuli
- using receptors which generate nerve impulses
50
Advantages and disadvantages of monocular vision
- wider field of view
| - poorer judgement of distance
51
Advantages and disadvantages of binocular vision
- narrower field of view
| - better judgement of distance
52
Problems with being long-sighted
- Can't see nearby object clearly
| - light rays don't meet on the retina
53
Problems with being short-sighted
- Can't see objects in the distant clearly
| - Light rays meet in front of the retina
54
Problems with red-green colour blindness
- Can't differentiate between colours of red and green
| - Lack the specialised cells in the retina
55
Name and locate the main parts of the nervous system
- Central nervous system: brain and spinal cord
| - Peripheral nervous system: nerves taking information from sense organs into CNS
56
Describe the nerve impulse
An electrical signal that is carried by nerve cells called neurones
57
Describe reflex actions
Fast, automatic and protective responses
58
Describe voluntary responses
Actions under the conscious control of the brain
59
Describe the functions of the main parts of the eye
Cornea - refract light
Iris - controls how much light enters the pupil
Lens - focuses light on to retina
Retina - contains light receptors, some sensitive to light of different colours
Optic nerve - carries impulses to the brain
60
Explain how the eye focuses light from near and distant objects
Close viewing
- ring of ciliary muscle: contracted
- suspensory muscle : slacken
- lens : rounded, fat shape
Distant viewing
- ring of ciliary muscle : relaxed
- suspensory muscle : become taut
- lens : flatter, thinner shape
61
Describe the pathway of light in the eyeball
- being refracted by the cornea
| - brought to focus on the retina
62
Explain how binocular vision helps to judge distance well
Helps to judge distance by comparing images from each eye, the more the similar images, the further away the object is
63
Explain how long sightedness and short sightedness
- Corrected by corneal surgery
- Different lens in glasses
- Different contact lens
64
The nerve impulse passes along the axon of a neurone
True
65
Describe a reflex arc
```
Receptor
Sensory neurone
Central nervous system
Motor neurone
Effector
Response
```
66
Describe the path taken by a spinal reflex
```
Receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
Response
```
67
The gap between neurones is called
Synapse
68
How are neurones adapted to their function?
Length - long
Insulating sheath - to ensure the impulses don't leak away
Branched endings - so they can communicate with other neurones
69
Describe how an impulse is passed from one neurone to the other
The release of a neurotransmitter substance and it diffuses across the synapse to bind with receptor molecules in the membrane of the next neurone causing the impulse to continue
70
Drugs can be harmful and useful
True
71
Why are some drugs available only on prescription?
- they may have side effects
- may interfere with other medications
- be harmful for a patient if they have another condition
- be harmful if too much is taken
72
What does addiction mean?
Addicted to a drug is when the body is unable to function without the drug and are dependent on the drug
73
What do withdrawal symptoms mean? (5)
If you stop taking drugs, you get withdrawal symptoms such as:
- nausea
- diarrhoea
- vomiting
- hallucinations
- craving for the drug
74
What does tolerance mean?
When the drug alters your body chemistry
75
What does rehabilitation mean?
It is when the individual wants to stop the use of drugs and is given help from other people and restoring the individual's life before they used drugs
76
Describe the general effects of each drug category
Depressants : slow down the brain's activities
Pain killers : block nerve impulses
Stimulants : increase brain's activities
Performance enhancers : muscle development
Hallucinogens : distort what is seen and heard
77
Tobacco smoking can cause emphysema, bronchitis, cancer and heart disease
True
78
Describe the effects of tobacco smoking due to different substances (4)
Carbon monoxide : lack of oxygen and heart disease
Nicotine : addictive
Tars : irritant and carcinogenic
Particulates : accumulation in lung tissue
79
What are the short term effects of alcohol? (10)
- blurred vision
- impaired speech
- impaired judgement
- increased reaction times
- loss of self control
- violent behaviour
- drowsiness
- unconscious or coma
- increased blood flow to the skin means you feel warm but are losing core body heat
80
What are the long term effects of alcohol? (7)
- cirrhosis of liver
- brain damage
- can damage the foetus if pregnant woman drinks regularly
- weight gain
- fatty liver
- increased risk of liver and heart disease
- cancer of liver, mouth, throat and oesophagus
81
Explain why there is a legal limit for the level of alcohol in the blood/breath for drivers and pilots?
Because alcohol impairs judgement and slows reactions, drivers and pilots cannot perform properly if they have drunk too much alcohol. Their risk of having an accident is greatly increased. So there is a legal limit for the amount of alcohol allowed in their blood and breath.
82
Which class of drugs is the most dangerous with the heaviest penalties
Class A
83
Which class of drugs is the least dangerous with the lightest penalties?
Class C
84
Examples of depressants
Alcohol and temazepam
85
Examples of pain killers
Aspirin and paracetamol
86
Examples of stimulants
Nicotine, Ecstasy and caffeine
87
Examples of performance enhancers
Anabolic steroids
88
Examples of hallucinogens
LSD
89
Explain the action of depressants and stimulants on the synapses of the nervous system
- Depressants bind with receptor molecules in the membrane of the next neurone blocking the transmission of the impulses
- Stimulants cause more neurotransmitter to cross the synapse
90
Describe how the liver can become damaged as it remove alcohol (cirrhosis)
- Enzymes in liver breakdown alcohol
| - Toxic products of alcohol breakdown cause liver damage
91
The body works to maintain steady levels of temperature, water, and carbon dioxide and it is essential for survival
True
92
The core temperature of the human body is approximately 37 'C
True
93
Describe appropriate procedures to measure body temperature
- Ear,finger,mouth
| - Use clinical thermometer, sensitive strips, digital recording probes or thermal imaging
94
Describe how heat can be gained
- respiration
- shivering
- less sweating
- exercise
- less blood flow near the skin (vasoconstriction)
95
Describe how heat can be lost
- More sweating
- Less clothes being worn
- More blood flowing near the skin (vasodilation)
96
Pancreas produces a hormone called insulin
True
97
Type 1 diabetes is caused because
The pancreas fails to produce enough insulin
98
Describe how insulin travels around the body
As insulin is a hormone, it is secreted from the pancreas in to the bloodstream, they travel in the blood to target organs.
99
Define homeostasis
Maintenance of a constant internal environment balancing bodily inputs and outputs
100
Explain why temperature has to be maintained
Temperature:
- below 35'C can cause hypothermia and if not treated it can cause death
- above 40'C can cause dehydration and if not treated it can cause death
- 37'C is Optimum temperature for enzymes to work at
101
What other factors have to be maintained?
Carbon dioxide
Temperature
Water levels
102
Temperature is monitored by the brain which will bring about temperature control mechanisms via the nervous and hormonal systems
True
103
Insulin controls blood sugar levels
True
104
Type 2 can often be controlled by diet but type 1 diabetes also needs to be treated by insulin dosage
True
105
Explain why responses controlled by hormones are usually slower than responses controlled by the nervous system
Hormones have to be synthesised and released from the cells in the body where they are made, and then travel all over the body, in blood, to reach their target organs. Nerve impulses are generated very quickly and travel via neurones directly to the effector.
106
Explain how insulin helps to regulate blood sugar levels
- the pancreas secretes insulin
- which travels in the blood to the liver
- and makes the liver absorb extra glucose and change it to another carbohydrate called glycogen. This is a method of storing energy
107
Explain how the dosage of insulin taken by a person with type 1 diabetes can be reduced with regular exercise.
Some excess glucose in the body is converted into energy during exercise, thus less insulin is required as there is less glucose is available
108
Plant growth (growth of shoots and roots, flowering and fruit ripening) is controlled by_________
Auxin
109
Why do plant's roots grow downwards?
Positive geotropism, roots grow down in response to gravity
110
Plant hormones can be used in agriculture speed up or slow down plant growth
True
111
Shoots can be described as positively phototropic, but negatively geotropic
True
112
Roots can be described as negatively phototropic, but positively geotropic
True
