Biology paper 2 (INCOMPLETE) Flashcards
1
Q
B7 - What is the definition of an ecosystem?
A
The interaction of a community of living organisms with the non-living parts of their environment.
2
Q
B7 - What do plants compete with other plants for?
A
Light
Space
Water and mineral ions from the soil
3
Q
B7 - What do animal compete with each other for?
A
Food
Mates
Territory
4
Q
B7 - List two ways a plant may depend on another species for its survival.
A
Pollination
seed dispersal
5
Q
B7 - What is interdependence?
A
If one species is removed it can affect the whole community.
6
Q
B7 - What is meant by a stable community?
A
One where all the species and environmental factors are in balance so that population sizes remain fairly constant.
7
Q
B7 - What is the definition of an abiotic factor?
A
A non living factor
8
Q
B7 - List three abiotic factors which may affect an aquatic organism.
A
Oxygen levels
Temperature
Carbon dioxide levels
Light intensity
9
Q
B7 - List three abiotic factors which can affect a plant.
A
Light intensity
Temperature
Carbon dioxide levels
Oxygen levels
10
Q
B7 - What is the definition of a biotic factor?
A
A living factor which may affect a community
11
Q
B7 - List four biotic factors which can affect a community.
A
Food availability
A new predator
A new pathogen
One species outcompeting another so that numbers are no longer sufficient to breed
12
Q
B7 - There are three types of adaptation that an organism may show to aid its survival.
what are the three types?
A
Behavioural
Structural
Functional
13
Q
B7 - What is an extremophile?
A
An organism which lives in an extreme environment
14
Q
B7 - Give three examples of what might make an environment be described as extreme.
A
High temperature
Pressure
Salt concentration
15
Q
B7 - What is biomass?
A
Amount of living material in an organism
16
Q
B7 - What does a food chain show?
A
Feeding relationships within a community
17
Q
B7 - What do all food chains begin with?
A
A producer
18
Q
B7 - Name two different types of organism which would be found at the start of a food chain.
A
Green plant
algae
19
Q
B7 - What might eat a secondary consumer?
A
A tertiary consumer
20
Q
B7 - Define the term predator.
A
An animal which kills and eats another animal.
21
Q
B7 - Define the term prey.
A
An animal which is hunted and killed for food by a predator
22
Q
B7 - What piece of equipment is usually used to sample abundance of an organism in an area?
A
Quadrat
23
Q
B7 - Why is it essential that materials are recycled in the living world?
A
To provide the building blocks for future organisms.
24
Q
B7 - What is precipitation in the water cycle?
A
Rain
25
B7 - List three main processes in the carbon cycle.
Photosynthesis
Respiration
Combustion
Decay
26
B7 - Name three factors which must be present for rapid decay of waste biological material to occur.
Warmth
Oxygen
Water
Microorganisms (Decomposers)
27
B7 - What do gardeners call the end product after waste biological material has decayed?
compost
28
B7 - What is this end product then used for? (compost)
As a natural fertiliser for garden plants or crops
29
B7 - What causes anaerobic decay to occur?
Insufficient oxygen
30
B7 - Name a useful end product of anaerobic decay.
Methane
31
B7 - What is the name of the equipment used to process and collect this end product?
A biogas generator
32
B7 - List three environmental changes which may alter the distribution of a species in an ecosystem.
Temperature
Availability of water
Composition of atmospheric gases
33
B7 - Name three reasons why these environmental changes may occur.
Seasonal
Geographic
Human interaction
34
B7 - Define the term biodiversity?
The variety of all the different species or organisms on Earth or within an ecosystem.
35
B7 - What two factors have increased the use of resources by humans?
Rapid growth in population and rise in standards of living
36
B7 - List three categories of pollution caused by human activity.
Air
Water
Land
37
B7 - What can cause pollution in each of these three categories?
Air: smoke and acidic gases
Water: sewage, fertiliser or toxic chemicals
Land: from landfill and from toxic chemicals
38
B7 - Name four processes which humans carry out that reduces the land available to other animals , plants and microorganisms.
Building
Quarrying
Dumping waste
Farming
39
B7 -Give three reasons why humans should not destroy peat bogs to make compost.
- Decay of peat releases carbon dioxide into the atmosphere.
- Reduces the area of the natural habitat for organisms that live there.
- Reduces the diversity of the area as it reduces the number of animals, plants and microorganisms living there.
40
B7 - What is a biofuel?
A fuel made by living organisms.
41
B7 - Why do humans undertake large scale deforestation in tropical areas?
To provide land for cattle farming
To provide land for rice fields
To grow crops for biofuels
42
B7 - Name two gases which are increasing in the atmosphere and are contributing to global warming.
Carbon dioxide and methane
43
B7 - List three biological consequences of global warming.
Ice caps melting and causing rise in sea levels
Change in climate – droughts and flooding
Loss of habitat and species needing to migrate
44
B7 - Negative effects of human interaction on an ecosystem
Global warming and deforestation
Animals and plants becoming in danger of extinction due to reduction in habitat
Large 40 acre fields growing one crop
Dumping waste in landfill sites
45
B7 - Positive effects of human interaction on an ecosystem
- Agreement by governments to reduce carbon dioxide emissions and deforestation
- Introducing breeding programmes and protection of habitats by conservation trusts
- Reintroduce smaller fields and replant hedgerows and leave edges of field to grow wild.
- Recycle resources more effectively
46
B7 - Define the term trophic level.
Feeding level within an ecosystem
47
B7 - What is a carnivore?
| What is a herbivore?
Meat eating animal
| Plant eating animal
48
B7 - What type of consumer is a carnivore which eats another carnivore?
Tertiary consumer
49
B7 - What do we call a carnivore that has no predators?
Apex predator
50
B7 - What is a decomposer?
Microorganisms that break down dead plant and/or animal matter
51
B7 - How do decomposers gain their food from dead plant or animal matter?
By secreting enzymes into the environment. Small soluble food molecules diffuse into the microorganism.
52
B7 - What does the pyramid of biomass represent?
The relative amounts of biomass at each level of a food chain.
53
B7 - How much energy as a percentage is transferred by producers from incident light for photosynthesis ?
Approximately 1%
54
B7 - How much biomass as a percentage is transferred approximately from a trophic level to the one above it?
10%
55
B7 - List 2 ways in which biomass can be lost at each stage of a food chain.
- Not all ingested food is absorbed- some is lost as faeces.
| - Not all absorbed food is converted into biomass – some used for keeping constant body temperature or movement.
56
B7 - What is meant by the term food security?
Having enough food to feed a population.
57
B7 - List four biological factors which threaten food security.
Increasing birth rate
Changing diets in developed countries leading to food being shipped around the world
New pests and pathogens affecting farming
Environmental changes
Costs of agricultural inputs
Conflicts which have reduced access to food and water
58
B7 - Give two ways in which energy transfer to the environment can be restricted in food animals.
Restrict movement
Control the temperature of the surroundings
59
B7 - Some farmers feed their animals high protein food. Why?
| Increase growth
Increase growth
60
B7 -List two things which can be done to conserve fish stocks in the ocean at a sustainable level.
Control size of holes in net
| Introduce fishing quotas
61
B7 - What type of food does the fungus Fusarium produce?
Mycoprotein
62
B7 - How is Fusarium grown?
On glucose syrup in aerobic conditions
63
B7 - What is golden rice?
Genetically modified rice which has high levels of beta carotene present.
64
B7 - What type of organism produces genetically engineered human insulin?
Bacteria
65
B6 - What is a gamete?
A cell with half the number of chromosomes of the parent cell.
66
B6 - Name the male and female gametes in a) a human b) a daisy plant
A) male = sperm female = egg
| b) male = pollen female = egg
67
B6 - Meiosis
Genetic mixing happens
Gamete production occurs
New cells show variation
Two divisions occur
68
B6 - Mitosis
New cells have same no. of chromosomes as parent
Happens in skin cells
Two new cells are formed as a result
Identical cells are formed
69
B6 - How many chromosomes are found in the nucleus of a human:
a) ovary cell ?
b) egg cell ?
c) embryo cell ?
d) a cell just after fertilisation has occurred?
e) a testes cell ?
```
46
23
46
46
46
```
70
B6 - Name the shape which best describes the DNA polymer.
Double helix
71
B6 - How is DNA organised inside the cell nucleus?
Arranged in chromosomes
72
B6 - Which is larger, a chromosome or a gene?
Chromosome
73
B6 - What does a gene code for?
A particular sequence of amino acids
74
B6 - Write down the definition of the genome of a horse.
All the genetic material of the horse.
75
B6 - List two reasons why it is important to understand more about the human
genome.
To be able to identify the genes which are linked to different diseases
To understand and be able to treat inherited disorders
To use in tracing human migration patterns from the past.
76
B6 - What are three advantages of sexual reproduction?
Produce variation in the offspring
If environment changes can give a survival advantage meaning some organisms
are likely to survive
Humans can speed up natural selection by selective breeding to increase food
production
77
B6 - What are three advantages of asexual reproduction?
Only one parent needed
More time and energy efficient as do not need to find a mate
Faster than sexual reproduction
Many identical offspring can be produced when conditions are favourable
78
B6 - List three organisms which reproduce using both sexual and asexual reproduction.
Malarial parasites
Fungi
Strawberry plants
Daffodils
79
B6 - Where would you find a nucleotide?
DNA
80
B6 - What does a nucleotide consist of?
Common sugar, phosphate group, base
81
B6 - What are the symbols of the 4 bases found in DNA?
A T C G
82
B6 - What does the code for an amino acid consist of?
A sequence of three bases
83
B6 - The long strands of DNA are made of alternating __ and ______
sections.
Attached to each _ is one of the four bases.
The DNA polymer is made up of repeating ___ units.
The long strands of DNA are made of alternating __sugar___ and __phosphate____
sections.
Attached to each __sugar____ is one of the four bases.
The DNA polymer is made up of repeating _____nucleotide_______ units.
84
B6 - In the complementary strands of DNA – which base is T always linked to?
A`
85
B6 - Which organelle in the cytoplasm carries out protein synthesis?
Ribosome
86
B6 - What do carrier molecules bring to the organelle from the cytoplasm?
Amino acids
87
B6 - What happens in protein synthesis once the protein chain is complete?
The protein folds
| up into a unique shape.
88
B6 - What happens if a mutation codes for a slightly altered enzyme protein with a different
shape?
The enzyme may no longer fit the substrate binding site
89
B6 - What can non-coding parts of DNA do?
Switch genes on or off and affect how genes are
| expressed.
90
B6 - Homozygous
The same alleles for a particular characteristic are described as homozygous
91
B6 - Phenotype
Mice fur can be described by its colour. This is known as the phenotype
92
B6 - Genotype
The alleles for a particular characteristic determine its genotype
93
B6 - What are the different forms of a gene called ?
Alleles
94
B6 - Why is it easy to describe an organisms phenotype for a particular characteristic but very
difficult to state the genotype?
Most characteristics are a result of multiple genes interacting .
95
B6 - List the alternative ways of describing the following outcome of a genetic cross:
3 in every 4 crosses will have black fur.
3 in every 4 crosses will have black fur.
75% 0.75 3/4
96
B6 - If two heterozygous tall plants were crossed 75 times, what proportion of the offspring
would you expect to be short?
25% or 19
97
B6 - What is polydactyly and is it caused by inheriting a recessive or dominant allele?
A genetic disorder which results in having extra fingers or toes - dominant allele
98
B6 - How many chromosomes does this person have in a normal body cell?
23 pairs or 46
99
B6 - Is someone who is heterozygous for cystic fibrosis healthy?
Yes, they are a carrier but do not suffer from CF themselves
100
B6 - Many people feel opposed to the screening of embryos to identify the CF allele.
Suggest two reasons why they may feel this way.
Screening procedure may cause miscarriage or damage embryo/fetus
The embryo has a right to life
Screening is expensive and could be used for other purposes
Have to make moral/ethical or religious decisions as a result such as whether to
terminate.
101
B6 - What does variation mean?
Variation means the differences in the characteristics of individuals in a population.
102
B6 - Write a definition for evolution.
A change in the inherited characteristics of a population over time, through a process
of natural selection.
103
B6 - What does the theory of evolution by natural selection state?
All species of living things have evolved from simple life forms that first developed
more than 3 billion years ago.
104
B6 - What is the definition of the term species?
A group of similar looking individuals who can breed together and produce fertile
offspring.
105
B6 - Humans choose animals or plants to breed from based on usefulness or appearance.
List four characteristics which would be selected (two in plants and two in animals).
Disease resistance in crop plants
Animals which produce more meat or milk
Domestic dogs with a gentle nature
Large or unusual flowers
106
B6 - What is a major disadvantage caused by selective breeding?
can lead to inbreeding where some breeds are particularly prone to disease or
inherited defects
107
B6 - How often do mutations occur?
| How likely is it that a mutation will lead to a new phenotype?
Continuously and very rare
108
B6 - What is genetic engineering?
A process which involves modifying the genome of an
organism by introducing a gene from another organism to give a desired
characteristic.
109
B6 - What human product is made by genetically engineered bacteria to treat diabetes?
insulin
110
B6 - What are plants more commonly called when they have had their genome modified?
GM crops
111
B6 - How are the required genes isolated from the host?
Using an enzyme
112
B6 - What is the role of a vector in genetic engineering?
Used to insert the gene into the
| required cells
113
B6 - Name a common vector used in genetic engineering.
Bacterial plasmid / virus
114
B6 - When in the life cycle must genes be transferred to the cells of animals, plants or
microorganisms?
Early on in development so the new cells develop with the desired
characteristic
115
B6 - List three reasons which people are concerned about in relation to genetic engineering
Do not know the effect of using GM crops on populations of wild flowers and insects.
may kill insects which are needed to pollinate other plants.
Some people feel that the effects of eating GM crops on human health have not been
fully explored.
For ethical reasons - should humans be inserting genes from one organism into a
totally different organism?
116
B6 - What is tissue culture?
Using small groups of cells from a part of a plant to grow
| identical new plants.
117
B6 - Why is tissue culture important?
To preserve rare plant species
| Commercially in nurseries to grow lots of new identical plants
118
B6 - Why is an electric shock used in adult cell cloning?
To stimulate the egg cell to divide
| and form an embryo
119
B6 - Name two pieces of evidence for Darwin's theory of evolution through natural
selection which mean it is now largely accepted.
Fossil record
knowledge of how resistance to antibiotics evolves in bacteria
passing on of characteristics to offspring in genes.
120
B6 - What are fossils?
The remains of organisms from millions of years ago
121
B6 - How many fossils be formed?
from parts of organisms that have not decayed
when parts of organism are replaced by minerals
as preserved traces like footprints, burrows or rootlets.
122
B6 - List two reasons why there are not many traces of early life on Earth.
Organisms were mainly soft bodied so little trace left
| Any traces destroyed by geological activity
123
B6 - What can be learned from studying fossils?
how much or how little organisms have changed as life developed on Earth
124
B6 - What does an evolutionary tree show?
how organisms are related using current classification data or fossil data is a species
is extinct
125
B6 - What does it mean when we say an organism is extinct?
There are no remaining individuals of a species still alive
126
B6 - List four factors which may contribute to the extinction of a species.
A change in food availability and the inability to find an alternative source.
Climate change
Creation of a new species by speciation that is better adapted to the environment
Human activity: Road/house building, mining, pollution, poaching, deforestation
A new predator or disease that a species cannot defend itself from.
Failure to breed successfully
127
B6 - Why do bacteria evolve rapidly?
Because they reproduce at a rapid rate
128
B6 - Name a bacterial pathogen which is resistant to several strains of antibiotics.
MRSA
129
B6 - Why are pharmaceutical companies not developing many new antibiotics ?
Very costly
| and takes a long time to develop.
130
B6 - Name three things that can be done to reduce the rate of development of antibiotic
resistance.
Doctors should not prescribe antibiotics for non serious or viral infections.
Patients must complete the course of antibiotics to ensure all bacteria are killed and
none survive to mutate and become resistant.
Restrict the use of antibiotics in agriculture
131
B6 - Name the seven groups that Linnaeus used to classify living organisms from largest to
smallest.
Kingdom, phylum, class, order, family, genus, species.
132
B6 - What is the binomial naming system?
A method of scientifically naming animals using
| the genus and species.
133
B6 -Carl Woese used information from chemical analysis to suggest a new method of
classification. What is it called?
The three domain system
134
B6 - List the groups that organisms are divided into using Carl Woese’s method.
Archaea
Bacteria
Eukaryota
135
B6 - What theory did Charles Darwin propose?
The theory of evolution by natural selection.
136
B6 - List three observations Darwin made which led him to propose his theory.
• Individual organisms within a particular species show a wide range of
variation for a characteristic
• Individuals with characteristics most suited to the environment are more
likely to survive to breed successfully
• The characteristics that have enabled these individuals to survive are then
passed on to the next generation
137
B6 - List three reasons why Charles Darwin’s theory was only partially accepted at the
time.
i. The theory challenged the idea that God made all the animals and plants that
lived on Earth
ii. There was insufficient evidence at the time the theory was published to convince
many scientists.
iii. The mechanism of inheritance and variation was not known until 50 years after
the theory was published.
138
B6 - Jean Baptiste Lamarck put forward his theory of evolution. What was his idea?
that changes occur in an organisms life time and these can be inherited.
139
B6 - Alfred Wallace also put forward his theory of evolution by natural selection
independently to Darwin but what work is he best known for?
His work on warning colouration in animals and his theory of speciation
140
B6 - List the steps needed for a new species to be formed.
* Populations of the same species become isolated
* Environmental conditions differ for each population
* Individuals in each population most suited to the environment breed
successfully
• Over time each population will have greater differences in their genotype.
• If two populations of one species become so different in phenotype that they
can no longer interbreed and produce fertile offspring – 2 new species have
been formed.
141
B6 - What did Gregor Mendel observe when he carried out breeding experiments on pea
plants?
Inheritance of each characteristic is determined by units that are passed onto
the next generation unchanged.
142
B6 - What was discovered in the late 19th century which helped to develop our
understanding of genetics further?
The behaviour of chromosomes in cell division
143
B5 - Define homeostasis.
The regulation of the internal conditions of a cell or organism to
maintain optimum conditions.
144
B5 - Why does homeostasis need to maintain optimal conditions?
For enzyme action and all cell functions.
145
B5 - List three conditions that the body needs to maintain.
Blood glucose concentration, body temperature and water levels.
146
B5 -What do the two automatic response systems involve?
Nervous responses or chemical responses.
147
B5 - Define stimuli.
Changes in the environment.
148
B5 - List the receptor cells and state what stimulus they detect.
```
Eye (retina) - light,
Ear – sound,
Nose – Chemicals in the air, Mouth
(tongue) – chemicals in food,
Skin - touch, pressure, pain and
temperature
```
149
B5 - Name the 3 coordination centres in the body and describe what
each of them coordinates.
Brain - coordinates information from the receptor cells and send
signals to the muscles and glands.
Spinal cord - Coordinates messages from the brain and receptor cells
and coordinates reflexes.
Pancreas - coordinates the glucose levels in the blood.
150
B5 - What is an effector?
A muscle or gland
151
B5 - Name the two parts of the central nervous system.
Brain and spinal
| cord
152
B5 - What does the CNS coordinate?
The response of effectors
153
B5 - Put these in the correct order: receptor, stimulus, response,
coordinator, effector.
stimulus receptor coordinator
| effector response
154
B5 - What is the role of the sensory neurone?
Carry impulses from the
| receptors to the central nervous system (CNS)
155
B5 - What is the role of the relay neurone?
Connect the sensory
| neurones to the motor neurones in the CNS.
156
B5 - What is the role of the motor neurone?
Connect the sensory
| neurones to the motor neurones in the CNS.
157
B5 -What is a synapse?
A gap between two neurones
158
B5 - Describe what happens at the synapse.
An impulse reaches the end
of a neurone; neurotransmitter is released across the gap. It then
diffuses across the synapse and when it reaches the next neurone this
starts another impulse.
159
B5 - Why are reflex actions important?
They protect the body from
| injury
160
B5 - Recall the pathway of the reflex arc.
receptor sensory neurone
| spinal cord motor neurone effector
161
B5 - Name the three main parts of the brain and state the role of each.
cerebral
cortex – is the outer ‘wrinkled’ layer of the brain it is responsible for
intelligence, language, memory and consciousness;
cerebellum – is
located at the lower part of the back of the brain and is responsible for
voluntary coordination of the muscles;
medulla – is located in the lower
part of the brain stem. It is responsible for involuntary coordination such
as breathing, swallowing and heart rate
162
B5 - How do neuroscientists study the brain?
Studying patients with brain
damage, electrically stimulating the brain and using magnetic resonance
imaging (MRI) scanning.
163
B5 - What is an EEG?
Electroencephalogram (EEG) is a test used to find
| problems related to electrical activity of the brain.
164
B5 - What is an MRI and what does it do?
What is an MRI? A device that uses strong magnetic fields and radio
waves to produce detailed images of the brain and spinal cord.
5. What does an MRI do? MRI can distinguish between different types of
tissues, including detecting cancerous cells.
165
B5 - What is accommodation?
The process of changing the shape of the lens focus on
| near or distant objects
166
B5 - How does the eye focus on distant objects?
The ciliary muscles relax, the
suspensory ligaments are pulled tight, the lens is then pulled thin and only slightly
refracts light rays
167
B5 - How does the eye focus on near objects?
The ciliary muscles contract, the
| suspensory ligaments loosen, the lens is then thicker and refracts light rays strongly
168
B5 - What is myopia? How can it be corrected?
Short-sightedness, it can be corrected
| with concave lenses
169
B5 - What is hyperopia? How can it be corrected?
Long-sightedness, it can be
| corrected with convex lenseS
170
B5 - Name three ways that vision can be corrected?
Contact lenses, laser surgery and
| lens replacement
171
B5 - What part of the brain monitors and controls temperature?
Thermoregulatory
| centre
172
B5 - Describe what happens in vasoconstriction and vasodilation.
• If the body temperature is too low, blood vessels constrict (vasoconstriction),
sweating stops and skeletal muscles contract (shiver).
• If the body temperature is too high, blood vessels dilate (vasodilation) and
sweat is produced from the sweat glands. Both these mechanisms cause a
transfer of energy from the skin to the environment.
173
SLIDE 58 QUESTION 1
174
SLIDE 58 QUESTION 1
