B6 Flashcards
What is biodiversity
The variety of living organisms in an area
What is species richness
Number of different species in a habitat
What is species eveness
Abundance of each different species in an area
What is genetic diversity
Number of different alleles in a gene pool of one species
What is a quadrat
A large square split into an even number of sections
What is a transect
A fixed path (often a measuring tape) that can have information recorded along
How are transects and quadrats used to collect samples
An example of data these can collect is the area of grass cover.
Lay down the transect and put your quadrat down along it at equal intervals
Count the squares with grass in and record where this was along the transect
The quadrat here is used to measure % of cover but can also be used to count number of species
What is the minimum sample size that should be used when investigating biodiversity
10
How do you estimate the number of species in an area
Take a sample of organisms and tag them
Wait a few days then take another sample at the same time from the same place. See how many have the tags and then:
Use petersons capture recapture
Sample 1 × sample 2 ÷ marked organisms in sample 2
What is a pitfall trap / used for
A small hole with a slight cover that insects fall into
The hole must be deep enough so the animals cannot escape
This allows you to collect samples
What is a pooter / used for
Used to collect samples of insects
Two tubes collected to a container
Place one end of the tube to the insect and the other end in your mouth
Suck on the tube to take the animal into the jar
A filter stops the organism from entering your mouth
What is a fly net
A large net that can be used to pick up flying insects and aquatic organisms
What is a branched key
A key that helps to determine what species an organism is from by answering yes or no questions
(E.g is it a plant
Does it have broad leaves. Narrow leaves)
What is a dichotomous key (numbered)
A key where the correct answer to a question tells you which question to ask next.
Correctly answering these questions will lead you to your organism
Does a large or small population have more genetic diversity
Large - more organisms so bigger gene pool
Small - less organisms → more in breeding → smaller gene pool → less genetic diversity
How does deforestation cause a loss of biodiversity
Cutting down trees destroys the habitat
There is less food and shelter available so animals die + plants
Animals and plants can be killed during deforestation
Rainforests hold 89% of the worlds species
How does agriculture cause loss of biodiversity
Cutting down areas to make room for crops destroys natural habitats
Pesticides used to kill insects reduces food availability for the insects predators
Fertilisers lead to Eutrophication
What is Eutrophication
Surface run off (due to rain) causes fertilisers to be washed into bodies of water
As more useful minerals enter the water an algal bloom happens
(Rapid expanse of algae)
This causes organisms in the bodies of water to die
Why do algal blooms kill organisms
As they cover the surface they prevent any aquatic plants from being able to photosynthesis
This reduces the oxygen concentration in the water, killing fish
Oxygen is also used up by bacterial decomposers breaking down the now dead plants
How does hunting and fishing cause loss of biodiversity
Overfishing leads to fish populations decreasing, and these populations will struggle to recover
Hunting animals also reduces the number of natural predators or prey
Hunting / fishing also causes changes in species richness and evenness
How does global warming affect biodiversity
By heating the earth many enzymes may stop functioning correctly (denature)
What is conservation
Protecting a natural environment to ensure habitats and organisms are not lost
What is ex-situ
(Conservation)
Outside the habitat
What is in-situ
(Conservation)
Within the habitat
What is captive breeding / where and how is it done
Pros and cons
Breeding animals together in places like zoos, in an attempt at increasing the population
Pros
Helps to increases population
Cons
Low population numbers → low gene pool →↑risk of inbreeding
Inbreeding means risk of harmful mutations
Ethical issues (animals have limited spaces)
How do different groups try to prevent inbreeding (captive breeding)
Programmes work together and exchange animals of the same species to reduce the risk of inbreeding
What is wildlife management
A conservation method of limiting human access to certain areas
Trapping invasive species
Controlled grazing + coppicing
What is controlled grazing
Limiting the amount of grazing in certain areas so that plant species have time to recover and grow
What is coppicing
Cutting down trees to their stumps, promoting the growth of tree roots
This gives plants more access to light and promotes shoots growth (↑light ↑ photosynthesis)
So more trees grow
What is an extinct species
Species with no surviving organisms left in the world
How do seed banks help prevent extinction
By safely storing seeds there will always be a seed from that plant species, so they can never go extinct
How are seeds prepared / stored in seed banks
The seeds need to be processed cleaned and x-rayed
They are disinfected to kill bacteria and microorganisms on the seed (reduces rate of decomposition)
They are x-rayed to see if the seed is able to germinate
The seeds are frozen to slow the rate of germination + decomposition
What are indicator species
An organism whose presence or absence is used as a measure of pollution
How are lichens used to monitor air pollution
They are made of fungi and algae (symbiotic mutualism)
Sulfur dioxide in the air causes acid rain which effects lichens
Bushy lichens tolerate low levels of pollution.
Leafy lichens tolerate moderate amounts of pollution.
Crusty lichens tolerate high amounts of pollution.
Where each lichen is found tells you the pollution levels in that area
How is water pollution measured (indicator species)
Stonefly nymph → dragonfly nymph →
Low →→
freshwater shrimp → hoglouse →
Slight Medium
Sludge worm → red tailed maggot
High High
How are canaries used to detect carbon monoxide
As they are more sensitive to it than humans, the canaries would be sent into caves and if they died we would know carbon monoxide is present
What are conservation agreements
Agreements maid between different organisations to protect species and bio diversity at a local and international scale
What do the ICUN do
The international union for the conservation of nature
Publishes a ‘red list’ which details the current conservation status of threatened animals
Countries can then work together to help these species
What do the CITES do
Convention on International Trade in Endangered Species of Wild Fauna and Flora
A treaty that regulates trade of wild plants and animals, as well as there products.
Protects more than 35000 species
What is ecotourism
A method of conservation that reduces the environmental impact of tourism
Money made from ecotourism is often used in protecting animals + species
What is food security
The ability to access food of sufficient quality and quantity
What factors affect food security
Population
Changing diets - wealthier people have a more varied diet
Climate change - affects what crops can be grown
Pests and Diseases
Condlicts
Food missuse
How does the climate affect food security
Increasing temperature causes plant enzymes to denature, reducing the rate of photosynthesis
How can food production be increased
Maximising photosynthesis - controlling moisture and light levels (+co2)
Using fertilizers - helps to produce more nutritious crops + land remains fertile
Removing competition and pests
Planting varieties of crops that are pest resistant or have a higher yeild
What is intensive farming
Farming using artificial chemicals to make farming easier (e.g using pesticides, fertilizers or machinery)
What is organic farming
Farming using natural methods for producing crops and rearing animals
Avoids the use of artificial chemicals
What are npk fertilisers (and why they are used)
Nitrogen phosphate potassium fertilisers
Nitrogen - needed to make chlorophyll + protein synthesis + nitrogenous DNA bases
Potassium - Needed to open the stomata
Phosphate - needed for chlorophyll
What is battery farming
A form of farming where animals are kept in small cages to limit movement
As they have protection from predators
More ATP is available for protein synthesis, mitosis and DNA replication
They are unable to wate enrgy on movement
They use less atp for thermoregulation as they are packed together
(More growth)
For chickens more energy will be used to lay eggs, more frequently
What is sustainable food production
Producing food in ways that can be continued indefinitely
What is fish farming
A sustainable method of food production
Fish are bred and reared large cages in seas or rivers
This protects the fish from predators and makes them easier to catch
Fish farming also means less overfishing so natural populations can recover
Different species are sperperated to reduce interspecific competition
Adults and young are also seperated to reduce intraspecific conpetitiom
Antibiotics can be used to prevent disease
Growth hormones and selective breeding can be used for bigger / better fish (higher yield)
How do pesticides affect biodiversity
They are used to kill insects, preventing them from eating plants
This causes a loss in biodiversity (killing pest species may affect ‘non pest’ species)
Insecticides may harm bees and other polinators
What is biological control
Introducing natural predators to kill plant pests
For example introducing wasps to kill aphids
Biological control is a sustainable way of killing pests
What are hydroponics
Plants grown in water instead of soil and adding oxygen and minerals ions
What factors can be controlled when using hydroponics
Temperature can be easily controlled in the building for photosynthesis
C02 can be regulated to 1000 parts per million (optimal amount)
Using bulbs that emit red and blue light saves energy and allows for 24h photosynthesis
Why are hydroponics more sustainable than traditional farming
No need for pesticides
Uses over half the water
Less co2 produced as food doesnt need to be transported far (usually grown in the city)
What is selective breeding
Choosing organisms with desirable characteristics (alleles) and breeding them together over many generations
E.g
Plant size
Milk yield
Musscle mass
How is selective breeding done
A farmer will choose several animals with the desired characteristics and breed them together
The offspring with the desirable characteristics are then selected and bred
(Repeated over many generations)
What are the disadvantages of selective breeding
Reduces the number of alleles over many generations (lower gene pool)
A new disease could kill the whole population if no organisms have an allele that defends them from it
Increases the chance of inheriting a genetic disease
What is genetic modification
Taking a gene from one organism and inserting it into the DNA of another organism
What is a vector
A method of transferring a gene of interest
Give an example of a common vector
A plasmid
What is the difference between bacterial DNA and human
Plasmid DNA is circular while human DNAA is linear
What are the benefits of genetic engineering in agriculture
Crop yield from the same area of land
Produce toxins to kill insects
What are restriction enzymes
Enzymes that recognise and cut at specific DNA base sequences
How are recombinant plasmids formed
A restriction enzyme is used to extract a gene of interest by cutting a specific base sequence
The same restriction enzyme is used to cut out a space in the plasmid
The gene of interest can then join the plasmid (through cbp of sticky ends)
Finally DNA ligase is used to join the gene of interest to the plasmid
Why is the same restriction enzyme used on the gene of interest and plasmid
So the same DNA base sequences are cut, producing complimentary sticky ends
What are sticky ends
Unpaired DNA bases, due to being cht by a restriction enzyme
How are recombinant plasmids inserted into a bacteria cell
Using an electrical shock
(Electroporation)
The electric shock makes the bacteria permeable for a short time, so the plasmid can enter
What is a recombinant plasmid
A plasmid that has been combined with a gene of interest
How can we test if the insertion of a recombinant plasmid is successful
When initially inserting the gene of interest, also add an antibiotic gene
When the recombinant plasmid is inserted into the bacteria it should now have both if these genes
The Bacteria can then be grown on an agar plate containing the antibiotic
If the bacteria survives and reproduces it has the gene of interest and will pass it down to its offspring
How can genetic engineering be used to produce insulin
Insulin is a hormone (protein)
The gene for insulin can be inserted into a bacteria cell (in a recombinant plasmid)
The bacteria will then transcribe the gene producing insulin
The bacteria can be grown to increase the insulin production
The insulin can then be extracted and purified
How are recombiant plasmids inserted plants
The recombinant plasmid is inserted into specific bacteria such as AGROBACTETIUM TUMEFACIENS
This bacteria inserts its DNA into the plants genome
The harmful gene would be replaced by the recombinant plasmid (beneficial gene)
The bacteria can be inserted into the plant by squirting it onto the underside of a leaf
What is biotechnology
The use of biological processes or organisms to produce products
What is golden rice
Rice that has been genetically modified
A gene called beta-carotene is taken and introduced into the rice
This gene is used to make vitamin A
This is important as Vitamin A is very important and prevents night blindness
What are the benefits of using genetic modification on plants
Makes frost resistant crops - can grow all year (uses antifreeze genes from fish)
Herbicide resistance - used to kill anything except a specific crop
Diesease resistance
What are the main risks of using biotechnology
Health risks
Possible allergens
Ethical concerns
Pollination of wild plant species causes a loss of biodiversity as the modified genes are introduced into the wild
Expensive
What is health
A complete state of physical, emotional and social wellbeing and not just the abscence of disease
What is disease
The deviation from the normal structure and function of an organism
What are communicable diseases
Diseases caused by pathogens that can be spread between organisms
What are non communicable diseases
Diseases that cannot be spread between organisms
(E.g cancer)
What are pathogens
Microorganisms that can cause disease
What are the most common pathogens
Fungi
Bacteria
Viruses
Protozoa
What is HIV - (spread / treatment / complications)
Human immunodeficiency virus
Communicable disease
It causes AIDS - acquired immune deficiency syndrome - which weakens the immune system
It cannot be cured but can be treated
People dont die of HIV but can catch other diseases like Tuberculosis
It is passed on through bodily fluids
Treated using antivirals that stop if from replicating
Spread can be reduced by wearing protection, and not sharing needles
Prep can also be taken prior to exposure to reduce the risk of infection
Pep can be taken within 72 hours to reduce the risk of infection
What is Staf infection ( spread / symptoms / prevention)
An infection caused by staph BACTERIA which often live harmlessly on peoples skin (becomes damaging when entering the skin)
Most common type of staph infection is a skin infection
Causes red lumps on the skin, hot red and swollen skin, sores crusts or blisters
The bacteria can be transferred by touch
Antibiotics are used to treat it
To prevent it from spreading, keep personal items personal and clean surfaces
If it enters the bloodstream it can cause sepsis
What is ringworm ( spread / symptoms / prevention)
Ringworm is a fungal infection
It causes a red / silver rash that is often ring shaped
Scaly dry swollen rash
Treated using antifungal creams that can be rubbed onto the skin
To prevent the spread dont share personal items and change tour clothes every day
What is influenza (spread / symptoms / prevention)
Influenza is also known as the flu
It is a common virus that causes, high temperatures, head ahes and an aching body
It can be transferred by droplets when sneezing
It is treated through an annual flu vaccine
Antibiotics don’t help since it’s a virus, but painkillers can be used to reduce the effects
Spread can be stopped by covering your mouth when sneezing
Influenza can lead to diseases such as pneumonia or ear infections as it weakens the immune system
How are pathogens transferred in animals
Airborn - droplets / spores
Direct contact - skin to skin / bodily fluids
Indirect contact - surfaces / food / bedding / towels
What are vectors (disease)
An organism that transmits disease but does not cause disease
