Biology Paper 2 Flashcards
1
Q
Define homeostasis.
A
Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes.
2
Q
Name 3 things that homeostasis controls.
A
1) Blood glucose concentration
2) Body temperature
3) Water levels
3
Q
Are homeostatic control systems automatic or manual?
A
Automatic.
4
Q
Name the three things that all control systems include.
A
1) Receptor cells
2) Coordination centres
3) Effectors
5
Q
What do receptor cells do?
A
They detect stimuli.
6
Q
What are stimuli?
A
Changes in the environment.
7
Q
What do coordination centres do?
A
They receive and process information from receptors.
8
Q
What do effectors do?
A
They bring about a response.
9
Q
Give 3 examples of coordination centres in the body.
A
1) Brain
2) Pancreas
3) Spinal cord
10
Q
Give 2 examples of effectors in the body.
A
1) Muscles
2) Glands
11
Q
What does the nervous system enables human to do?
A
It allows them to react to their surroundings and coordinate their behaviour.
12
Q
What does CNS stand for?
A
Central nervous system.
13
Q
Name the three parts of the nervous system.
A
1) The brain
2) The spinal cord
3) nerves
14
Q
Name the two parts of the CNS.
A
1) The brain
2) The spinal cord
15
Q
What type of impulses pass ACROSS neurones, chemical or electrical?
A
Electrical.
16
Q
What type of impulses pass BETWEEN neurones?
A
Chemical.
17
Q
The CNS coordinates the response of effectors which may cause muscles to…
A
Contract.
18
Q
The CNS coordinates the response of effectors which may cause glands to…
A
Secrete hormones.
19
Q
Put the following in the following order starting with stimulus: coordinator, stimulus, effector, receptor, response
A
Stimulus -> receptor -> coordinator -> effector -> response
20
Q
What is a reflex action?
A
It is an automatic and rapid action that does not involve the conscious parts of the brain.
21
Q
Why are reflex actions important?
A
They reduce the chances of being injured.
22
Q
What is a synapse?
A
The connection (gap) between two neurones.
23
Q
The human endocrine consists of glands that secrete what?
A
Hormones.
24
Q
What are hormones?
A
Chemical messengers.
25
Where are hormones released into?
The bloodstream
26
What do hormones act upon?
Target organs.
27
Describe the differences in the effects caused by nerves and hormones.
1) Nerves have a faster action / Hormones have a slower action
2) Nerves act for a short time / Hormones act for a longer time
3) Nerves act on a precise area / Hormones act in a more general way
28
Name the 'master gland' in the body
The pituitary gland.
29
Where is the pituitary gland located?
In the brain.
30
Name the gland which produces many digestive enzymes.
Pancreas
31
Name the gland which produces testosterone.
Testes
32
Name the gland which produces thyroxine.
Thyroid
33
Name the gland which produced adrenaline.
Adrenal gland
34
Name the gland which produces hormones such as oestrogen and progesterone.
Ovary
35
Which gland is located in the neck?
Thyroid.
36
What is monitored for changes in glucose concentration?
The blood.
37
Which gland controls the response to changes in blood glucose concentration?
The pancreas.
38
What does the pancreas produce if the blood glucose concentration is too high?
The hormone insulin.
39
What does insulin do?
Causes glucose to move from the blood into cells, lowering the blood glucose concentration.
40
What is excess glucose in the liver and muscle cells stored as?
Glycogen.
41
What happens in type 1 diabetes?
The pancreas fails to produce sufficient insulin.
42
Describe the blood glucose concentration of a person suffering from type 1 diabetes.
Expect them to have a high blood glucose concentration.
43
How is someone with type 1 diabetes treated?
They are normally treated with insulin injections.
44
What happens in type 2 diabetes?
The body cells no longer respond to insulin produced by the pancreas.
45
Name a risk factor for type 2 diabetes.
Obesity.
46
What treatment is recommended to a person suffering from type 2 diabetes?
1) A carbohydrate controlled diet.
| 2) An exercise regime
47
What does the pancreas produce if the blood glucose concentration is too low?
Glucagon.
48
What does glucagon do?
It causes glycogen to be converted into glucose and released into the blood.
49
Describe the effect increased levels of glucagon will have on blood glucose concentration.
Cause blood glucose concentration to rise.
50
Briefly describe how insulin interacts with glucagon in a negative feedback mechanism to control blood glucose levels.
1) If blood glucose levels are too high insulin is released by the pancreas causing glucose to move into cells and so lower blood glucose levels.
2) If blood glucose levels are too low, glucagon is released by the pancreas causing glycogen to be converted into glucose and released into he blood, increasing blood glucose levels.
51
Name the main female hormone involved in development and reproduction.
Oestrogen.
52
Name the main male hormone involved in development and reproduction.
Testosterone.
53
During puberty reproductive hormones cause secondary characteristics to develop. Give examples of those that happen in men.
Develop facial hair, voice deepens, underarm and pubic hair growth
54
During puberty reproductive hormones cause secondary characteristics to develop. Give examples of those that happen in women.
Breasts develop, eggs mature, underarm and pubic hair growth, hips widen
55
Approximately how often is an egg released in a woman?
Every 28 days.
56
What is ovulation?
When an egg is released from an ovary.
57
Where is testosterone produced and released form?
The testes.
58
Testosterone stimulates the production of what?
Sperm.
59
Describe the role of FSH in the menstrual cycle.
Causes an egg to develop in one of the ovaries.
60
Describe the role of LH in the menstrual cycle.
Stimulates the release of an egg - ovulation
61
Which hormones are involved in the maintenance of the uterus lining?
Oestrogen and progesterone.
62
What stimulates the production of oestrogen in the ovaries?
FSH.
63
What stimulates the release of LH and inhibits the release of FSH?
Oestrogen.
64
What inhibits the release of FSH and LH?
Progesterone.
65
How do oral contraceptives containing hormones prevent pregnancy?
Inhibits FSH production so no eggs mature
66
How does an injection, implant or skin patch containing slow-release progesterone prevent pregnancy?
Inhibits the maturation of eggs
67
How do barrier methods, such as condoms and diaphragms, prevent pregnancy?
Prevents the sperm reaching the egg
68
How do intrauterine devices prevent pregnancy?
Prevents the implantation of an embryo AND/OR release hormones
69
How do spermicidal agents prevent pregnancy?
Kills or disable sperm
70
How does abstaining from sexual intercourse prevent pregnancy?
Reduces the chance of sperm meeting an egg in the oviduct
71
How does surgical sterilisation prevent pregnancy?
Prevents sperm or eggs being release by the male or female
72
Name the two hormones given to women to increase fertility.
FSH and LH.
73
State three drawbacks to IVF treatment.
1) It is very emotionally and physically stressful
2) The success rates are not high
3) It can lead to multiple births which are a risk to both the babies and the mother
74
State one positive of IVF treatment.
It allows pregnancy when previously not possible.
75
Detail the four steps in IVF treatment.
1. The mother is given FSH and LH to stimulate the maturation of several eggs
2. The eggs are collected from the mother and fertilised by sperm from the father in the laboratory
3. The fertilised eggs develop into embryos.
4. At the stage when they are tiny balls of cells, one or two embryos are inserted into the mother's uterus (womb).
76
Why are some people against IVF?
IVF results in the unused embryos being destroyed.
| They say this is unethical because each embryo is a potential human life.
77
Name the hormone which controls the “fight or flight” reaction in humans.
Adrenaline
78
Describe the effect adrenaline has in the body.
It increases heart rate and boosts the delivery of oxygen and glucose to the brain and muscles.
79
Name the glands that produces adrenaline.
Adrenal glands.
80
Which gland produces the hormone thyroxine?
The thyroid.
81
What does thyroxine regulate?
Basal metabolic rate.
82
What two things does thyroxine play an important role in?
Growth and development.
83
What is TSH and what does it do?
Thyroid stimulating hormone. It stimulates the thyroid to release thyroxine.
84
Where is TSH produced and released from?
The pituitary gland.
85
What are gametes?
Sex cells.
86
Name the gametes in animals.
Sperm and egg.
87
Name the gametes in plants.
Pollen and egg.
88
Complete the sentence: “Sexual reproduction leads to …… in the offspring.”
Variation.
89
Does mitosis or meiosis lead to identical cells?
Mitosis
90
What process leads to the formation of gametes?
Meiosis.
91
What is meant by cells being clones?
They are identical and have exactly the same genes.
92
Describe the 4 main differences between sexual and asexual reproduction.
1) Sexual involves the fusion of gametes asexual does not
2) Sexual involves two parents asexual involves one
3) Sexual involves the mixing of genetic material, asexual does not
5) Sexual leads to variation, asexual does not (asexual produces clones)
93
What process leads to the formation of gametes?
Meiosis.
94
What effect does meiosis have on the number of chromosomes in a cell?
Halves it.
95
In animals, where are the gametes formed?
Ovaries and testes.
96
When a new cell is formed through fertilisation, how does it divide?
Mitosis.
97
If 80 chromosomes are present in an animal cell. How many chromosomes will be present in a gamete?
40 chromosomes.
98
What must first happen before the cell starts to divide in meiosis?
The genetic information must be copied.
99
How may divisions occur during meiosis?
Two
100
How many gametes are formed from one parent cell?
Four
101
When an embryo is formed, by what process to the cells become specialised?
Differentiation.
102
How can you genetically describe the gametes that are formed in meiosis?
They are genetically different. There is variation.
103
The genetic material in the nucleus of a cell is made up of which molecule?
DNA
104
DNA is found in structures called?
Chromosomes
105
What is DNA?
A polymer made up of two strands forming a double helix.
106
What is a gene?
A small section of DNA on a chromosome.
107
What does each gene code for?
A particular sequence of amino acids, to make a specific protein.
108
What is the genome of an organism?
It is the entire genetic material of that organism.
109
State 3 ways in which understanding of the human genome will be important.
1. To search for genes linked to different types of disease
2. To understand and treat inherited disorders
3. To trace early human migration patterns
110
Do chromosomes normally come in pairs or triplets?
Pairs
111
Describe the structure of DNA.
Double helix.
112
What is a gamete?
A sex cell (egg or sperm; egg or pollen).
113
What is a gene?
A small section of DNA on a chromosome that codes for a specific protein.
114
What is an allele?
A different version/form of a gene.
115
What does the term “dominant” mean?
The individual only needs one copy of this allele for its phenotype to be seen.
116
What does the term “recessive” mean?
The individual needs two copies of this allele for its phenotype to be seen.
117
What does the term “homozygous” mean?
The individual has two identical alleles for this gene.
118
What does the term “heterozygous” mean?
The individual has two different alleles for this gene.
119
What is meant by genotype?
The combination of alleles for a specific gene.
120
What is meant by phenotype?
The displayed characteristics of the genotype.
121
All characteristics are controlled by a single gene. True or False?
False.
122
How many copies of each gene do we inherit from each parent?
One from each parent.
123
Some diseases disorders are inherited? True or False?
True.
124
What are inherited disorders caused by?
By inheriting faulty alleles.
125
What is polydactyly?
A condition that causes a person to have extra fingers or toes.
126
What is cystic fibrosis.
A disorder of cell membranes that leads to excess mucus production in the lungs and digestive system.
127
Is cystic fibrosis caused by a dominant or recessive allele?
Recessive.
128
Is polydactyly caused by a dominant or recessive allele?
Dominant.
129
State one argument for aborting embryos with faulty alleles discovered by embryonic screening.
1) Stop people suffering
| 2) Save government money through not needed to treat people
130
State one argument against aborting embryos with faulty alleles discovered by embryonic screening.
It implies people with genetic problems are undesirable, this could lead to prejudice.
131
How many pairs of chromosomes does an ordinary human body cell have?
23
132
How many pairs of chromosomes determine the sex of the individual?
1
133
What is the genotype of a female?
XX
134
What is the genotype of a male?
XY
135
Which chromosome X or Y causes male characteristics?
Y
136
Would an egg cell ever possess a Y chromosome?
No.
137
Define variation.
Differences in the characteristics of individuals in a population.
138
Only genes determine the phenotype of an organism – true or false?
False – the environment also plays a role.
139
State three causes of variation in a population.
1. Genes
2. The environment
3. A combination of both
140
Within a population, there is normally very little genetic variation – true or false?
False.
141
What causes variation within a population?
Mutations.
142
How often does a mutation result in a new phenotype?
Very rarely.
143
What is a mutation?
A rare and random change in an organism's DNA.
144
Do mutations occur continuously?
Yes.
145
Mutations are always bad. True or False?
False.
146
Why can mutations cause changes in phenotype?
Changes in the DNA can produce a different form of a gene. Genes code for the sequence of amino acids that make up a protein. Could lead to changes in the protein being made.
147
True or false – does the theory of evolution by natural selection state that all living things evolved from simple life forms more than three billion years ago?
True.
148
Would the best organism within a species to survive and reproduce be:
a) the strongest?
b) the one which reproduces the fastest?
c) the best adapted to the environment?
c)
149
What is the definition of a species?
Organisms that can interbreed to produce fertile offspring.
150
What is evolution?
A change in the inherited characteristics of a population over time through a process of natural selection which may result in the formation of a new species.
151
How do we know when two populations of a species have formed two new species?
When they can no longer interbreed to produce fertile offspring.
152
Animals that are not adapted to their environment are more likely to survive. True or False?
False.
153
Are animals that are suited to their environment more likely to pass on their characteristics, why?
Yes, because they are more likely to survive and reproduce.
154
What is selective breeding?
The process by which humans breed plants and animals for particular genetic characteristics.
155
Name two historic examples of selective breeding.
1. Breeding food crops from wild plants
| 2. Domesticating animals
156
State four modern examples of selective breeding.
1. Disease resistance in food crops
2. Animals which produce more meat or milk
3. Domestic dogs with a gentle nature
4. Large or unusual flowers
157
State a drawback to selective breeding.
Inbreeding – some breeds are prone to disease or inherited defects because of a reduction in the gene pool.
158
Describe the four steps involved in selective breeding.
1) Select parents with the desired characteristics from a mixed population.
2) The parents are bred together.
3) From the offspring those with the desired characteristics are bred together.
4) This continues over many generations until all the offspring show the desired characteristic.
159
What is genetic engineering?
The process which involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic.
160
State two ways plants might be genetically engineered.
1. Resistant to insect attack
2. Resistant to herbicides
3. Increased yields
161
Give one example of how bacterial cells have been genetically engineered.
To produce useful substances such as human insulin to treat diabetes.
162
How is a gene “cut out” from the genome of one species and inserted the genome of another?
Using enzymes.
163
Into what is the gene inserted before it is introduced to an organism?
A vector
164
Give two examples of vectors used in genetic engineering
A bacterial plasmid, a virus
165
Why should a gene be transferred between organisms at an early stage of development?
So that they develop with desired characteristics.
166
What is the name given to crops that have had their genes modified?
Genetically modified crops (GM crops)
167
State two concerns about GM crops.
1) They can have a negative impact on the number of wildflowers and insects
2) Some people feel the effects of eating GM crops on human health have not been fully explored.
168
State three discoveries that supported the theory of evolution by natural selection.
1) The discovery of genetics. Characteristic are passed on as genes.
2) Fossils and how changes in organisms developed slowly over time.
3) Bacteria developing antibiotic resistance.
169
How did the discovery of genetics support the theory of evolution by natural selection?
It showed that characteristics are passed on to offspring in genes.
170
How did the discovery of fossils support the theory of evolution by natural selection?
By looking at fossils of different ages it allows you to see how changes in organisms developed slowly over time.
171
How has observing bacteria supported the theory of evolution by natural selection?
By observing how resistance to antibiotics evolves in bacteria.
172
Who came up with the theory of evolution by natural selection?
Charles Darwin.
173
What are fossils?
The remains of organisms from millions of years ago, which are found in rocks.
174
What are the three ways fossils may be formed?
1. From parts of organisms that have not decayed as one (or more) of the conditions needed for decay is absent.
2. Parts of the organisms have been replaced with minerals as they decay.
3. Preserved traces of organisms such as footprints, burrows and rootlet traces.
175
Why are few fossils of early life found?
Most early life were soft-bodied and so left little trace behind.
176
What does the lack of fossils of early life on Earth mean about the theories scientists have on the beginning of life on Earth?
We can’t be certain about them as there is little evidence.
177
Why are fossils useful?
Can be used to determine how much or how little organisms have changed as life developed on Earth.
178
In evolutionary diagrams, what do junctions between the lines represent?
A common ancestor of two species
179
When is a species said to be extinct?
When there are no remaining individuals of that species alive.
180
State two of the 5 ways a species can become extinct.
1) The environment changes to quickly
2) A new predator kills them off
3) A new diseases kills them off
4) They can't compete with another species for food
5) A catastrophic event kills them off
181
Why do bacteria evolve so rapidly?
They have a very fast reproduction rate.
182
New strains of bacteria are caused by…..
Mutation of their DNA.
183
State the 4 steps leading to the development of antibiotic resistance in a population of bacteria.
1. The population is exposed to an antibiotic, some of the population are resistant to the antibiotic.
2. The resistant bacteria are not killed, so survive the treatment.
3. These resistant bacteria reproduce and pass on the resistance genes to the next generation.
4. The new resistant strain spreads quickly as hosts are not immune to it and there is no effective treatment.
184
State three ways we can reduce the rate of antibiotic resistance development.
1. Stop prescribing antibiotics inappropriately, such as for viral infections.
2. Patients should complete their course of antibiotics so all bacteria are killed.
3. Use of antibiotics in agriculture should be restricted or banned.
185
Why aren’t many new antibiotics being developed?
The development of new antibiotics is very costly and very slow.
186
Which is quicker, the development of new antibiotics or the development of antibiotic resistance in bacteria?
The development of antibiotic resistance in bacteria (currently).
187
Traditionally, how have we classified living things into groups?
Based on their structure and characteristics.
188
Who developed the first true classification system of living organisms?
Carl Linnaeus.
189
What are the titles of each classification level?
Kingdom, Phylum, Class, Order, Family, Genus, Species
190
Escherichia coli and homo sapiens are examples of the naming of organisms by the binomial system. Which two classification groups are used in these names?
Genus (Escherichia and homo) and species (coli and sapiens)
191
Name two developments which led to new classification systems being invented.
Developments in microscopes and development in the understanding of biochemical processes in cells.
192
Carl Woese proposed the “three-domain system” for living organisms. What are these three domains?
Archaea, Bacteria and Eukaryota
193
What are "Archaea"?
Primitive (old) bacteria often living in extreme environments.
194
Give an example of a type of cell in the Bacteria domain.
True bacteria.
195
Give an example of a type of cell in the Eukaryota domain.
Protists, fungi, plants and/or animals
196
What is an ecosystem?
An ecosystem is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment.
197
What do organisms require from their surroundings in order to survive and reproduce?
A supply of materials from their surroundings
198
State four factors plants compete with each other for.
Space, light, mineral ions, water
199
State three factors animals compete with each other for.
Food, mates, territory
200
What is interdependence?
Each species within a community depend on others for food, shelter, pollination, seed dispersal, etc. If one species is removed, this will affect the whole community.
201
In a stable community, what should be a common trend in the populations of all the different species?
All of the species and environmental factors will be in balance so that population sizes remain fairly constant.
202
Name the 7 abiotic factors
Light intensity, temperature, moisture levels, soil pH and mineral content, wind intensity (and direction), carbon dioxide concentration (for plants), oxygen concentration (for aquatic animals)
203
What is an abiotic factor?
A non-living factor which can affect a community.
204
How could a decrease in light intensity affect plant numbers?
Decrease in light intensity could decrease the rate of photosynthesis. This could affect plant growth and cause a decrease in the population size.
205
What is a biotic factor?
A living factor which may affect a community.
206
State all 4 possible biotic factors which may affect a community.
Availability of food, new predators, new pathogens, one species outcompeting another
207
How could a new predator cause population numbers to change?
A new predator could hunt and kill a species as prey. The prey population would decrease.
208
Organisms have adaptations to enable them to survive in their usual conditions. What 3 categories do these adaptations fall under?
Structural, behavioural, functional (cellular reactions)
209
What is an extremophile?
An organism that lives in an extreme environment, such as at high temperature, pressure or salt concentration.
210
Give an example of an extremophile.
Bacteria living in deep sea vents/Organisms living in water with a high salt concentration.
211
Arctic fox have white fur to help them camouflage, what type of adaptation is this?
Structural.
212
Animals that live in hot places have a large surface area to volume ratio, what type of adaptation is this?
Structural.
213
Many species migrate to warmer climates during the winter, what type of adaptation is this?
Behavioural.
214
Desert animals conserve water by producing very little sweat and small amounts of concentrated urine. What type of adaptation is this?
Functional.
215
Brown bears hibernate over winter. What type of adaptation is this?
Functional.
216
What type of organisms are the producers of biomass for life on Earth?
Photosynthetic organisms.
217
How can we represent feeding relationships within a community?
Food chains and food webs.
218
What do all food chains begin with?
A producer?
219
What is a producer?
An organism that makes its own food.
220
Give an example of a producer.
Green plants or algae
221
What are producers eaten by?
Primary consumers.
222
What are primary consumers eaten by?
Secondary consumers.
223
What are secondary consumers eaten by?
Tertiary consumers.
224
What name is given to consumers that kill and eat their prey?
Predators.
225
How would you describe the change in predator and prey numbers in a stable community?
The numbers of predators and prey rise and fall in cycles.
226
Calculate the mean of the following numbers: 12, 25, 64, 34, 97.
46.4
227
Calculate the median of the following numbers: 12, 25, 64, 34, 97.
34
228
Calculate the mode of the following numbers: 12, 25, 64, 34, 97, 12, 25, 54, 12, 84, 76.
12
229
What is a quadrat?
A square frame enclosing a known area, e.g. 1m2
230
Why are all materials in the living world recycled?
To provide the building blocks for future organisms.
231
Name the process by which carbon dioxide is removed from the atmosphere.
Photosynthesis.
232
State three processes which return carbon from organisms to atmospheric carbon dioxide.
1. Respiration – releases carbon dioxide.
2. Release (carbon containing) waste – microorganisms decompose this and respire – releases carbon dioxide.
3. Death – microorganisms decompose the body and respire – release carbon dioxide.
233
Whys is the water cycle important for life?
It provides fresh water for plants and animals.
234
What does water fall from clouds as?
Precipitation.
235
Water evaporates from the land and sea. How else is water vapour formed?
Evaporates from plants - Transpiration
| Animals release water vapour into the air when they breathe
236
When precipitation falls, what happens to the water that doesn't get absorbed by the soil?
It will run off into streams and rivers.
237
How does carbon move from plants to animals?
Animals eat plants.
238
How is carbon release from plants back into the atmosphere, other than plant respiration.
The burning of products made from plants produces carbon dioxide.
239
Define biodiversity
Biodiversity is the variety of all the different species of organisms on Earth, or within an ecosystem.
240
Why does a high level of biodiversity ensure the stability of ecosystems?
It reduces the dependence of one species on another for food, shelter, and the maintenance of the physical environment.
241
What is human activity reducing, which may be an issue for the future of the human species on Earth?
Biodiversity.
242
How is water polluted?
Sewage, fertilisers or toxic chemicals.
243
How is air polluted?
Smoke and acidic gases.
244
How is land polluted?
Landfill and toxic chemicals.
245
Why does pollution reduce biodiversity?
It kills plant and animals.
246
What two things are causing more resources to be used and more waste to be produced?
The rapid growth in the human population and an increase in the standard of living.
247
What is the increased release of waste and chemical materials causing?
(More) pollution.
248
How do humans reduce the amount of land available for other animals and plants?
By building, quarrying, farming and dumping waste
249
Why are peat bogs being destroyed?
To produce garden compost.
250
What effect does destruction of peat bogs have on an area?
Reduces biodiversity.
251
What happens as a result of decay or burning of peat?
Release of carbon dioxide into the atmosphere.
252
State the two main reasons for large-scale deforestation in tropical areas.
1) Provide land for cattle and rice fields
| 2) Grow crops for biofuels
253
What affect does large scale deforestation have on biodiversity?
Reduces biodiversity.
254
Why does cutting more trees down mean less carbon dioxide being removed from the atmosphere.
Trees take-in carbon dioxide for photosynthesis. Less trees mean less photosynthesis, so less carbon dioxide needed.
255
Which 2 gases are increasing in the atmosphere and contributing to global warming?
1. Carbon dioxide
| 2. Methane
256
What are the four main biological consequences of global warming?
1. Affecting migration patterns of animals
2. Melting of polar ice caps, causing flooding
3. Reduced habitats in polar regions
4. Reduced biodiversity
257
State three positive human interactions to reduce the negative effects of humans on ecosystems and biodiversity.
1. Breeding programmes for endangered species
2. Protection and regeneration of rare habitats
3. Reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
4. Reduction of deforestation and carbon dioxide emissions by some governments
5. Recycling resources rather than dumping waste in landfill
258
State two negative human interactions in an ecosystem.
1. Clearing of land for agriculture, buildings and/or transport
2. Hunting of rare species
3. Mining from the land
