B1- Understanding organisms Flashcards
(143 cards)
1
Q
What is blood pressure measured in?
A
Millimetres of mercury
(mmHg)
2
Q
What is systolic pressure?
A
Maximum pressures the heart produces
3
Q
What is diastolic pressure?
A
Blood pressure between heart beats
4
Q
What can **increase **blood pressure?
A
- stress
- high alcohol intake
- smoking
- being overweight
5
Q
What can **decrease **blood pressure?
A
- regular exercise
- balanced diet
6
Q
What can high blood pressure cause?
A
- Blood vessels can burst
- Leading to damage to the brain (stroke)
- Or kidney damage
7
Q
What can low blood pressure cause?
A
- Dizziness and fainting as blood supply to the brain is reduced
- Poor **circulation **to other areas such as fingers and toes
8
Q
Define fitness.
A
The ability to do physical activity
9
Q
Define health.
A
Being free from diseases such as those caused by **bacteria **and viruses
10
Q
What can general fitness be measured by?
A
Cardiovascular efficiency
11
Q
What else can your fitness be measured by?
A
- strength
- flexibility
- stamina
- agility
- speed
12
Q
How can smoking increase blood pressure?
A
**Carbon monoxide **causes blood to carry less oxygen. So, the heart rate increases and tissues do not receive enough oxygen.
Also, nicotine directly increases heart rate.
13
Q
What does carbon monoxide do to haemoglobin in the blood?
A
It combines with it, preventing it from combining with oxygen, so less oxygen is carried around the body
14
Q
What is heart disease caused by?
A
Restricted blood flow to the heart muscle
15
Q
What can increase the risk of getting heart diease?
A
- High level of saturated fat in the diet, which leads to a build up of cholesterol (a **plaque) **in the arteries
- High levels of salt, which can increase blood pressure
16
Q
What can cause the coronary arteries narrow?
A
If there are plaques in the coronary arteries, it can reduce blood flow to the heart muscle.
17
Q
What is thrombosis?
A
A blood clot
18
Q
What are carbohydrates made of?
A
Simple sugars such as glucose
19
Q
What is the function of carbohydrates?
A
Provide energy
20
Q
Where are carbohydrates stored and in what form?
A
In the liver as glycogen or converted into fats
21
Q
What are proteins made of?
A
Amino acids
22
Q
What is the function of proteins?
A
Growth and repair of tissue
Provide energy in emergencies
23
Q
Are proteins stored in the body?
A
No
24
Q
What are fats made of?
A
Fatty acids and glycerol
25
What is the function of fats?
* Provide energy
* Energy store
* Provide insulation
26
Where are fats stored as and in what form?
Stored under the skin and around organs as **adipose tissue**
27
What is the function of vitamins and minerals?
Various functions
e.g. Vitamin C to prevent scruvy
28
What is the function of water?
To prevent dehydration
29
What is the difference between first and second class proteins?
**First class proteins**- (animal proteins) contain all the _essential_ amino acids the body cannot make
**Second class proteins**- (plant proteins) do not contain these essential amino acids
30
How does balanced diet vary between people?
* **Age**- younger people need more proteins for growth, older people need more calcium for protection of bones
* **Gender**- females need more iron to replace iron lost through menstruation
* **Physical activity**- active people need more energy from food
31
What condition is caused by protein deficiency?
Kwashiorkor
32
Why do people in developing countries have poor diets?
* Overpopulation
* Lack of money to improve agriculture
33
How can EAR (Estimated Average daily Requirement) be measured?
EAR (g) = 0.6 x body mass (kg)
34
How can EAR be affected by pregnancy?
* Pregnant women need more protein to help their baby
* Breast feeding (**lactating**) needs extra protein to produce milk
35
What does BMI (Body Mass Index) measure?
Whether someone is underweight, overweight or obese
36
How can you calculate BMI?
BMI = body mass in kg / (height)² in m
37
Why is BMI not always reliable?
Muscle weighs more than fat
38
What are the 4 types of pathogens?
1. fungi (e.g. athlete's foot)
2. bacteria (e.g. cholera)
3. viruses (e.g. flu)
4. protozoa (single-celled organisms e.g. dysentery)
39
What is **malaria **caused by?
A protozoan
40
What is the vector in malaria?
Mosquitoes are vectors, as they carry disease without getting it themselves
41
What is the parasite in malaria?
The protozoan is the parasite (Plasmodium), which feeds on the human red blood cells
42
What is a parasite?
An organism that feeds on/ lives off another living organism and often causes harm
43
What is the host in malaria?
Humans
44
How can you stop the spread of malaria?
* draining _stagnant_ water
* putting oil on the water surface
* spraying **insecticide**
45
How can you reduce the risk of some cancers?
Changes in lifestyle and diet
46
How can you reduce **lung cancer**?
Not smoking
47
How can you reduce the risk of **skin cancer**?
Using sunscreen and less exposure to UV rays
48
What are **benign **tumours?
Divide slowly and are harmless, such as warts
49
What are **malignant **tumours?
Cells display uncontrolled growth and may spread (more dangerous)
50
What are **pathogens**?
Disease-causing organisms
51
What do pathogens cause?
Infectious disease by damaging the body's cells
52
What do pathogens produce?
Poisonous waste producs called **toxins**
53
What do **antibodies **do?
Lock onto **antigens **on the surface of pathogens such as bacterium, killing the pathogen
54
What does the body produce to protect itself from pathogens?
**White blood cells**
55
How do **phagocytes** destroy pathogens?
* ingest and absorb the pathogens or toxins
* release an enzyme to destroy them
56
How do **lymphocytes** destroy pathogens?
* coat pathogens, clumping them together so that they are easily ingested by phagocytes
* release antibodies that stick to the antigen, stopping it from damaging the body
57
Do all pathogens have the same antigen?
No, each pathogen has its own antigens, so a specific antibody is needed for each pathogen
58
What is **active immunity**?
The white blood cells producing antibodies when a pathogen enters. When the body is infected again, the white blood cells can destroy the pathogen easily
59
What is **passive immunity**?
A vaccination for example, where the body is given antibodies from another human or animal
60
What is the process of **vaccination**?
1. Injecting a live (harmless)/ dead/ weakened pathogen carrying antigens
2. The antigens will trigger a response and the white blood cells produce correct antibodies
3. **Memory cells **(a type of T-lymphocyte cell) remain in the body, providing long-lasting immunity
61
What do **antibiotics **and **antiviral drugs** do?
Antibiotics destroys pathogens and antiviral drugs slow down the pathogen's development
62
What is the order in which drugs are tested?
1. computer models
2. human tissue
3. animal
4. human trials
63
What are the arguments for and against **animal testing**?
**For**
**Against**
Human benefits
An animal’s response could be different from human’s
Suffering can be minimised
Causes suffering to animals
64
What is a **placebo**?
A harmless pill
65
Why is a placebo used?
As a comparison in drug testing so the effect of a new drug can be assessed
66
Explain a **blind trial** during human testing
The *patient *does not know whether they are receiving a new drug or placebo
67
Explain a **double-blind trial **during human testing
Neither the *patient *nor the *doctor/nurse *know which treatment is being used
68
What does the double-blind trial prevent?
A biased opinion from the doctor/nurse or a 'feel-good factor' from the patient
69
What are the functions of the main parts of the eye?
* suspensory ligaments- alter the shape of the lens in focusing
* iris- controls amount of light entering eye
* pupil- allows light rays to enter the eye
* cornea- refracts light rays
* ciliary muscle- control suspensory ligaments
* lens- refracts and focuses light onto the retina
* retina- contains light receptors (**rods and cones**)
* optic nerve- carries nerve impulses to the brain
70
What is **binocular** and **monocular** vision?
* binocular- front of face, helps judge distance
* monocular- side of face, gives wider view
71
What is **accomodation**?
The ability of the lens to change its shape to focus near and distant objects
72
What happens when the eye focuses light from **distant** objects?
* ciliary muscles relax
* suspensory ligaments tighten
* lens is thin and less curved
73
What happens when the eye focuses light from **near** objects?
* ciliary muscles contract
* suspensory ligaments slacken
* lens is fat and more curved
74
What is the cause of colour blindness?
Lack of specialised cells in the retina
75
What does the eye look like when it is long-sighted?
* eyeball too short
* lens too thin
* image focused **behind** the retina
76
What does the eye look like when it is short-sighted?
* eyeball too long
* lens too rounded
* image focused **in front** of the retina
77
How can you correct long or short sightedness?
* corneal surgery
* glasses
* contact lenses
78
What lens can correct long-sightedness?
Convex
79
What lens can correct short-sightedness?
Concave
80
What are **neurones**?
Nerve cells
81
Where do nerve impuleses pass along?
The **axon**
82
List the **reflex arc** in order
1. stimulus
2. receptor
3. sensory neurone
4. central nervous system
5. (relay neurone)
6. motor neurone
7. effector
8. response
83
What is the pathway for a **spinal **reflex?
1. receptor
2. sensory neurone
3. relay neurone
4. motor neurone
5. effector
84
How are neurones adapted?
* long
* branched endings (**dendrites**) to pick up impulses
* insulator sheath
85
What is the gap between neurones called?
**synapse**
86
How do synapses work?
* arrival of an impulse in **pre-synaptic neurone**
* **vesicles** containing **neurotransmitters** fuse with the presynaptic membrane releasing neurotransmitters into the synapse
* neurotransmitter diffuses across the synapse and binds to the **receptor**
* this generates an impulse in the **post synaptic neurone**
87
What do the classes of drugs represent?
* Class A- most dangerous and heaviest penalties
* Class B- mid dangerous and medium penalties
* Class C- least dangerous and lightest penalties
88
What are the types of drugs (with examples)?
* **depressants** (alcohol, solvents, temazepam)
* **painkillers** (aspirin, paracetamol)
* **stimulants **(nicotine, MDMA/ecstasy, caffeine)
* **performance enhancers **(anabolic steroids)
* **hallucinogens** (LSD)
89
How do depressants affect synapses?
* block the tranmission of nerve impulses across synapses
* binding with the receptor molecules in the membrane of the receiving neurone
90
How do stimulants affect synapses?
more neurotransmitter substances cross synapses
91
What is cilia?
Tiny hairs
92
Where are cilia found?
The **epithelial lining** of the trachea, bronchi and bronchioles
93
What is 'smoker's cough' a result of?
* dust and particulates in cigarette smoke collecting and irritating the epithelial lining
* mucus not being moved by the cilia
94
What are the content of alcoholic drinks measured in?
Units of alcohol
95
What does drinking alcohol increase?
1. reaction time
2. risk of accidents
96
What is **cirrhosis** of the liver?
It is damaged when it breaks down **toxic** chemicals such as alcohol
97
What is **homeostasis**?
Keeping a constant internal environment involving balancing bodily inputs and outputs
98
What do automatic control systems do?
Keep the levels of temperature, water and carbon dioxide steady, making sure all cells can work at their optimum level.
99
What are negative feedback systems?
Cancel out a change such as decresing temperature level
100
Why is body temperature 37°C?
It is the **optimum temperature **for many enzymes
101
What can **high **temperatures cause?
* heat stroke
* dehydration
102
How does sweating cool the body?
* It increases heat transfer from body to environment
* **Evaporation **of sweat requires the body heat to change the liquid sweat in to water vapour
103
What is **vasodilation**?
The dilation of small blood vessels in the skin, causing more blood flow near the skin surface and resulting in more heat transfer
104
How does vasodilation work?
* body too hot
* small blood vessels in skin dilate
* blood flow increases
* more blood to surface
* lose heat
105
What can low temperatures cause?
* shivering
* hypothermia
106
What is **vasoconstriction**?
Constriction of small blood vessels in the skin, causes less blood flow and less heat transfer
107
How does vasoconstriction work?
* body too cold
* small blood vessels in skin constrict
* less blood flows through them
* reducing heat loss
108
Which area of the brain monitors blood temperature?
**hypothalamus** gland
109
Which area controls reaction to temperature extremes?
Nervous and hormonal systems, which trigger vasoconstriction or vasodilation
110
What hormone controls **blood sugar levels**?
Insulin
111
What is the difference between Type 1 and Type 2 diabetes?
1. Caused by the pancreas not producing any insulin, so must be treated by injecting insulin
2. Caused by either the body producing too little insulin or the body not reacting to it, can be controlled by changing diet and lifestyle
112
What does insulin do?
Convert excess glucose in the blood into glycogen
113
Where is glycogen stored?
The liver
114
What happens when blood glucose rises?
1. detected by pancreas and releases insul into blood
2. insulin travels in blood to liver
3. liver takes in glucose and converts it to glycogen
4. blood glucose falls to normal
115
What happens when blood glucose falls?
1. detected by pancreas and stops producing insulin, produces glucogon
2. glucogon travels in blood to liver
3. liver converts glucogon back to glucose and releases to blood
4. blood glucose increase to normal
116
What is **phototropism**?
The plant's growth response to light
117
What is **geotropism**?
The plant's growth response to gravity
118
How does a shoot's growth respond?
* positively phototropic (grow *towards* light)
* negatively geotropic (grow *away* from the pull of gravity)
119
How does a root's growth respond?
* negatively phototropic (grow *away* from light)
* positively geotropic (grow *with* the pull of gravity)
120
What are **auxins**?
A group of **plant hormones** which move trhough the plant in solution.
121
What are auxins involved in?
Phototropism and geotropism
122
Where are auxins made?
In the root and shoo tip
123
Where is more auxin usually found?
In the shady parts of the shoots
124
Why does this plant curve as it grows towards the light?
1. more auxin is produced on the shady side
2. this will increase the length of the cells
3. therefore the shady side causes curvature of the shoot towards the light
125
What experiment could you use to test how auxins work?
1. show auxins are produced in the tip of the plant (by covering certain areas of the shoot, bending is only prevented when the tip is covered)
2. show auxins cause bending by building up on the shaded side of the root (by cutting the tip, placing on block of agar, block placed on one side of the shoot and the shoot bending away from auxin)
126
What are some uses of **plant hormones**?
* selective weedkillers
* rooting powder (increase root growth of cuttings)
* delay or accelerate fruit ripening
* control dormancy in seeds
127
What is **dominant** and **recessive**?
Dominant- the characteristic which is stronger and more likely to inherit
Recessive- the characteristic which is less likely to inherit and would need two recessive alleles to produce that characteristic
128
What are **alleles**?
Different versions of the same **gene**
129
What is a **gene**?
A section of DNA that codes for a particular characteristic
130
What is an **allele**?
Inherited characteristics are carried as pairs of alleles on pairs of chromosomes. Different forms of a gene are different alleles
131
What is meant by *nature or nurture*?
The affect of genetics and environmental factors over certain things such as intelligence, sporting ability and health.
132
What are **chromosomes**?
Thread-like structures in the cell nucleus that carry genetic information
133
How many chromosomes does a human have?
46 (23 pairs)
134
What do **sex chromosomes** determine?
The gender/sex of a **mammal.**
e.g. females have XX and males have XY
135
What sex chromosome does and egg and sperm have?
Eggs always carry X chromosomes and sperm carry either an X or Y chromosome
136
What is **genetic variation** caused by?
* **mutations**
* rearrangement of genes during the formation of **gametes**
* fertilisation which results in a zygote with alleles from the father and mother
137
What is a mutation?
Where the DNA within cells have been altered (this happens in cancer)
138
What is a **monohybrid cross**?
Only one pair of characteristics controlled by a single gene, one allele being dominant and one recessive
139
What is the difference between **homozygous** and **heterozygous**?
Homozygous means having identical alleles
Heterozygous means having different alleles
140
What is the difference between **genotype** and **phenotype**?
Genotype is their genetic make-up (e.g. Bb) and phenotype is the observable, physical characteristics of that organism (e.g. brown eyes)
141
What are inherited disorders caused by?
Faulty genes/alleles, most of which are recessive
142
What are the personal and ethical issues with genetic disorders?
* in deciding to have a gentic test (positive could alter their life)
* knowing the risk of passing on an inherited disorder (could change their decision to marry/ have a family)
143
Why is it difficult to predict the probability of inheriting disorders using genetic diagrams?
Because there is always a chance that the child may get both recessive alleles, even if it is 25%
