Biology Flashcards
1
Q
What are carbohydrates, fats and proteins used by the body to do
A
Release energy and to build cells
2
Q
What is needed for healthy functioning of the body
A
Mineral ions and vitamins in a small amount
3
Q
When is a person malnourished
A
If they don’t have a balanced diet
4
Q
What can malnourishment lead to
A
Being underweight or overweight
5
Q
What can an unbalanced diet lead to
A
Deficiency diseases or conditions such as Type II diabetes
6
Q
When does a person lose mass
A
When the energy content of the food taken in is less than the amount of energy expended by the body
7
Q
What is metabolic rate
A
The rate at which all the chemical reactions in the cells of your body are carried out
8
Q
How can you increase the amount of energy expended by the body
A
Through exercise
9
Q
What does the metabolic rate vary with
A
The amount of activity you do and the proportion of muscle to fat in your body
10
Q
What can metabolic rate be affected by
A
Inherited factors
11
Q
What can inherited factors affect
A
Our health e.g. cholesterol levels
12
Q
Who are healthier than people who take little exercise
A
People who exercise regularly
13
Q
What are pathogens
A
Microorganisms that cause infectious disease
14
Q
How do bacteria and viruses make us feel ill
A
By reproducing rapidly inside the body and producing toxins
15
Q
What do viruses damage
A
The cells in which they reproduce
16
Q
How do white blood cells help to defend against pathogens
A
Ingesting pathogens
Producing antibodies, which destroy particular bacteria or viruses
Producing antitoxins, which counteracts the toxins released by the pathogen
17
Q
How does the immune system kill a particular pathogen
A
By producing specific antibodies which can then lead to immunity
18
Q
How is antibody production stimulated
A
Dead or inactive pathogens in vaccines
19
Q
How is the spread of a pathogen reduced
A
If a large proportion of the population is immune to the pathogen
20
Q
What did Semmelweiss recognise
A
The importance of hand washing in the prevention of spreading some infectious diseases
21
Q
What did Semmelweiss insist
A
That doctors wash their hands before examining patients, and greatly reduced the number of deaths from infectious diseases in his hospital
22
Q
What do painkillers do
A
Relieve symptoms of infectious diseases but do not kill the pathogen
23
Q
What are antibiotics
A
Medicines that help cure bacterial disease by killing infectious bacteria inside the body
24
Q
What can antibiotics not be used for
A
To kill viral pathogens, which live and reproduce inside cells
25
What should specific bacteria be treated by
Specific antibodies
26
What has the use of antibiotics greatly reduced
Deaths from infectious bacterial diseases
27
What has the over use and inappropriate use of antibiotics increased
The rate of development of antibiotic resistant strains of bacteria
28
Why have many strains of bacteria, including MRSA, developed resistance to antibiotics
A result of natural selection
29
How can further resistance of bacteria be prevented
Avoiding overuse of antibiotics
30
What does the development of antibiotic – restraint strains of bacteria necessitate
The development of new antibiotics
31
What do mutations of pathogens produce
New strains
32
What would happen if there is a new resistant strain of a pathogen
Antibiotics and vaccinations may no longer be effective
33
Why would a new resistant strain of a pathogen spread rapidly
People are not immune to it and there is no effective treatment
34
How can people be immunised
Introducing small quantities of dead or inactive forms of the pathogens into the body
35
What do vaccines stimulate
The white blood cells to produce antibodies that destroy the pathogen. Which then makes the person immune to future infections by the microorganism
36
What happens after you get a disease you have been vaccinated against
Your body can respond by rapidly making the correct antibody, in the same way as if you had previously had the disease
37
What is the MMR vaccine used for
To protect children against measles, mumps and rubella
38
What are uncontaminated cultures of microorganisms required for
Investigating the action of disinfectants and antibiotics
39
How are uncontaminated cultures of microorganisms used to investigate the action of disinfectants and antibiotics
Petri dish and agar sterilised before use to kill unwanted bacteria
Inoculating loop passed through flame to sterilise it
Inoculating loop used to spread bacterium onto agar
Lid of petri dish open little as possible to prevent microbes entering
The lid should be secured with adhesive tape to stop microbes from the air contaminating the culture
It also allows the culture to be incubated and the bacteria to grow
40
What should cultures be incubated at a maximum temperature of in school and college labs
25°C, Which greatly reduces the likelihood of growth of pathogens that might be harmful to humans
41
What can higher temperatures of cultures incubated in industrial conditions produce
More rapid growth
42
What does a healthy diet contain
The right balance of the different foods you need and the right amount of energy
43
Why is it now difficult to develop drugs that kill viruses
They also damage the body's tissue
44
What kind of pathogens do antibiotics kill
The individual ones of the non - resistant strain
45
Why are antibiotics no longer used to treat non-serious infections
So that the rate of development of resistant strains is slowed down
46
What does the nervous system enable us to do
React to our surroundings and coordinate our behaviour
47
What are receptors
Cells that detect stimuli (changes in the environment)
48
What are the 2 types of effectors and how do they respond
Muscles - contracting
| Glands - secreting chemical substances
49
What conditions does the human body control
The water content of the body
The ion content of the body
Temperature
Blood sugar levels
50
What is Homeostasis
The maintenance of a constant internal environment
51
How does water leave the body
Via the lungs when we breathe out
Via sweat to cool us down
Excess water is lost via the kidneys in the urine
52
How are ions lost
Via the skin when we sweat
| Via the kidneys in the urine
53
Why does our temperature need to be maintained
Our enzymes are biological catalysts and function best at 37 degrees
54
Why does our blood sugar levels need to be maintained
So our cells can be provided with a constant supply of energy
55
What are hormones
Chemical substances that coordinate many processes in the body. They also regulate the functions of many organs and cells.
56
How are hormones secreted
Through glands and are usually transported to their target organs by the blood stream
57
What is FSH
Follicle Stimulating Hormone. It is secreted by the pituitary gland and causes eggs to mature in the ovaries. It also stimulates the ovaries to produce oestrogen
58
What are the 3 things plants are sensitive to
Light (Phototropism)
Moisture (Hydrotropism)
Gravity (Gravitropism/Geotropism
59
What are tissues and models used to do
Predict how drugs may behave in humans
60
What are new drugs extensively tested for
Toxicity
Efficacy
Dosage
61
How are drugs tested
In the lab, using cells, tissues and live animals
| In clinical trials, involving healthy patients
62
What happens in double blind trials
Some patients are given a placebo, which doesn't contain the drug. Neither the doctors or patients know who has received a placebo and who has received the drug until the trial is complete
63
What are statins
Drugs that lower cholesterol levels and the risk of heart and circulatory diseases
64
What drug caused drug testing to become much more rigorous
Thalidomide
65
What are ecstasy, cannabis and heroin
Illegal recreational drugs which may have adverse effects on the heart
66
What can cannabis cause
Mental illness in some people
67
Why is the overall impact of legal drugs on health greater than the impact of illegal drugs
Far more people use them
| Availability
68
Why do people become dependent upon drugs
Drugs change the chemical processes in people's bodies
69
When do people suffer from withdrawal symptoms
When they are addicted to a drug and try to go without it
70
What are anabolic steroids
Drugs that stimulate muscle growth
71
Can athletes use performance enhancing drugs
No they are all banned by law and some are available on prescription, but all are prohibited by sporting regulations
72
What kind of performance enhancing drugs do athletes use
Stimulants that boost bodily functions such as heart rate
73
To survive and reproduce, what do organisms require
A supply of materials from their surroundings and from the other living organisms
74
What do plants compete for
Light and space
| Water and nutrients from soil
75
What do animals compete for
Food
Mates
Territory
76
What are adaptations
Features that organisms have to enable them to survive in the conditions in which they normally live
77
What are extremophiles
Organisms that live in environments that are very extreme. Extremophiles may be tolerant to high levels of salt, high temperatures or high pressures e.g. Bacteria
78
How are animals adapted to live in dry and arctic environments
Changes to surface area
Thickness of insulating coat
Amount of body fat
Camouflage
79
How are plants adapted to survive in dry environments
Small surface area compared to volume
Water storage tissues
Extensive root systems
80
What are adaptations to deter predators and protect prey
Armour - roses (thorns), cacti (sharp spines) & tortoises (shells)
Poisons - have an unpleasant taste so prey will not be attacked again
Warning colours - confuse prey with poisonous organism
Long limbs - can escape faster
Large eyes - predator detected earlier so prey can escape sooner
Camouflage - less likely to see prey
81
How do changes in the environment affect populations
Population distribution of living organisms changes
Population size decreases
Population size increases
82
What are some examples of changes in environment caused by living factors
```
Change in:
Infectious diseases
Predators
Prey
Availability of food sources
Competitors
```
83
What are some examples of changes in environment caused by non living factors
Change in :
Average temperature
Average rainfall
Level of air or water pollution
84
What are changes in environment caused by
Living and non living factors
85
How do you measure environmental change
Using living and non living indicators
86
What are indicator species
Organisms that are very sensitive to changes in their environment and so can be studied to see the effect of human activities
87
What can lichen be used as
Air pollution indicators, particularly of the concentration of SO2 in the atmosphere
The more lichen, the cleaner the air
88
What can invertebrate animals be used as
Water pollution indicators and are also used as indicators of the concentration of dissolved O2 in water
The more of them, the cleaner the water
89
What non living indicators can be used to measure environmental changes
O2 levels - using meters
Temperature - using satellites
Rainfall - using rain gauges
Atmospheric temperature- using automatic weather stations
90
What is biomass
Mass of living material
91
What is a trophic level
A feeding level
92
How are pyramids of biomass constructed
Producer - primary consumer - secondary consumer - tertiary consumer - etc.
93
Why is the biomass at each successive stage reduced
Material and energy are always lost in the organisms' waste
Respiration supplies the energy needed for living processes, including movement. Most of this energy is eventually transferred to the surroundings as heat
Some material that makes up plants and animals are inedible e.g. bones
94
Why do living things remove materials from the environment
For growth and other processes. These materials are returned to the environment either in waste materials or when living things die and decay.
95
Why do materials decay
They are broken down (digested) by microorganisms.
96
When are microorganisms more active and digest materials faster
In moist, warm and aerobic conditions
97
What does the decay process release
Substances that plants need to grow
98
What happens in a stable community
The processes that remove materials are balanced by processes that return materials
99
What does the carbon cycle show
How carbon is constantly cycled
100
What is the 1st stage in the carbon cycle
CO2 is removed by photosynthesis
| Carbon is used to make carbohydrates, fats & proteins in the plants and algae
101
What is the 2nd stage in the carbon cycle
Carbon is returned as CO2 through respiration of the plants.
Some carbon becomes part of the fats and proteins in animals when the plants are eaten.
The carbon then moves through the food chain.
102
What is the 3rd stage in the carbon cycle
Carbon is returned as CO2 when those animals respire
103
What is the 4th stage in the carbon cycle
CO2 is returned to the atmosphere when detritus feeders and microorganisms who eat the remains of dead plants, algae and animals respire
104
What is the 5th stage in the carbon cycle
Detritus feeders and microorganisms also break down animal waste. Compounds in the waste are taken up from the soil by plants as nutrients - they're put back into the food chain
105
What is the 6th stage in the carbon cycle
Some useful plant and animal products e.g. wood & fossil fuels are burnt (combustion). This also releases CO2 into the air
106
What do genes carry
The information that results in plants and animals having similar characteristics to their parents, which are passed on in gametes from which the offspring develop
107
What are gametes
Sex cells
108
Why do genes operate at a molecular level
To develop characteristics that can be seen
109
What do different genes control
The development of different characteristics of an organism
110
Differences in the characteristics of different individuals of the same kind may be due to differences in
The genes they have inherited (genetic causes)
The conditions in which they have developed (environmental causes)
A combination of both
111
What are the two forms of reproduction
Sexual and asexual
112
What is sexual reproduction
The fusion of male and female gametes. The mixture of genetic information from two parents leads to variety in the offspring
113
What is asexual reproduction
No fusion of gametes and only one individual is needed as the parent. There is no mixing of genetic information and so no genetic variation in the offspring. These genetically identical individuals are known as clones
114
What is achieved by taking cuttings from older plants
New plants can be produced quickly and cheaply.
| These new plants are genetically identical to the parent plant
115
What do modern cloning techniques include
Tissue culture
Embryo transplants
Adult cell cloning
116
What is tissue culture
Using small groups of cells from part of a plant (explant) for cloning
They are grown in nutrient agar
Treated with auxin
Then develop in tiny plants
117
What are embryo transplants
Splitting apart cells from a developing animal embryo before they become specialised, then transplanting the identical embryos into host mothers
118
What is adult cell cloning
The nucleus is removed from an unfertilised egg cell. The nucleus from an adult body cell e.g. a skin cell, is then inserted into the egg cell. An electric shock then causes the egg to divide into embryo cells. These embryo cells contain the same genetic information as the adult skin cell. When the embryo has developed, it is inserted into the womb of an adult female to continue its development.
119
What happens in genetic engineering
Genes from the chromosomes of humans and other organisms can be 'cut out' using enzymes and transferred to cells of other organisms.
120
How do animals, plants or microorganisms develop with desired characteristics
Genes are transferred to the cells at an early stage in their development
121
What are some concerns about GM crops
Effects on populations of wild flowers or insects
| Uncertainty about the effects of eating GM crops on human health
122
Why do plants produce hormones
To coordinate and control growth
123
What is auxin
A plant hormone that controls growth near the tips of shoots and roots
124
Why do shoots grow towards light
When a shoot tip is exposed to light, more auxin accumulates on the shaded side than the side that's in the light. This makes the cells grow faster on the shaded side, so the shoot bends towards the light.
125
Why do shoots grow away from gravity
When a shoot is growing horizontally, gravity produces an unequal distribution of auxin on the lower side. This causes the lower side to grow faster, bending the shoot upwards
126
Why do roots grow towards gravity
A root growing horizontally will also have more auxin on its lower side. But in a root the extra auxin inhibits growth. This means the cells on top elongate faster, and the root bends downwards.
127
What do roots grow towards
Gravity and Moisture
128
What do shoots grow towards
Light
129
How are plants growth hormones used in agriculture and horticulture
As weed killers and rooting hormones
130
What is LH
Luteinising hormone. It stimulates the release of eggs from the ovary and is produced by the pituitary gland
131
What is oestrogen
A hormone produced in the ovaries which inhibits the production of FSH
132
How is IVF carried out
A mother is given FSH and LH to stimulate the collection of several eggs. The eggs are collected and fertilised by the father's sperm. The fertilised eggs develop into embryos and one or two embryos are inserted into the mother's uterus
133
How do oral contraceptives work
They contain hormones that inhibit FSH production e.g. oestrogen & progesterone. Large amounts of oestrogen lead women to suffer from significant side effects so now very little is used or none at all
134
What does Darwin's theory of evolution by natural selection state
That all species of living things have evolved from simple life forms that first developed more than three billion years ago
135
Why was Darwin's theory only gradually selected
The theory challenged the idea that God made all the animals & plants that live on earth
There was insufficient evidence at the time to convince many scientists
The mechanism of inheritance and variation was not known until 50 yrs after the theory was published
136
What idea is Lamarck's theory based mainly on
The idea that changes that occur in an organism during its lifetime can be inherited. We now know that in the vast majority of cases this type of inheritance cannot occur
137
What helps us to understand evolutionary and ecological relationships
Studying the similarities and differences between organisms allows us to classify living organisms into animals, plants and microorganisms
138
What do evolutionary relationships show
How all living things are related
139
What do ecological relationships show
How all living things interact with each other
140
What do evolutionary trees (models) allow us to do
Suggest relationships between organisms
141
How does evolution occur
Natural selection
142
What is natural selection
Individuals within a species show variation because of the differences in their genes
Individuals with characteristics that make them better adapted to the environment have a better chance of survival and so are more likely to breed successfully
The genes that have enabled these individuals to survive are then passed on to the next generation
143
How can evolution occur due to mutations
A mutation is a change in an organism's DNA. Occasionally, mutations are beneficial by producing a useful characteristic. This characteristic may give a better chance of surviving and reproducing. If so, the beneficial mutation is more likely to be passed on to future generations by natural selection. Over time, the beneficial mutation will accumulate in a population e.g. resistant strands of bacteria
144
What is bad cholesterol
Low Density Lipoproteins (LDL) - they carry cholesterol to cells and high levels cause fat to build up in the artery
145
What is good cholesterol
High Density Lipoproteins (HDL) - they carry cholesterol back to the liver and help prevent cholesterol building up
146
Why is cholesterol needed
For healthy cell membranes
147
What is the defence mechanism against droplet infection
Mucus
148
What is the defence mechanism against direct contact
Skin barrier
149
What is the defence mechanism against contaminated food and drink
Stomach acid
150
What is the defence mechanism against breaks in the skin
Scabs
151
What are antigens
Unique proteins on a cell surface
152
How do individual pathogens develop resistance
During antibiotic treatment the less resistant bacteria is killed first
The more resistant bacteria remain and will re-infect if full course of antibiotics not taken
