Sampling and Food Security Flashcards
Define sampling.
Taking observations or measurements from a small area, which is representative of a larger area.
Give 5 examples of sampling techniques/methods.
Posters, Pitfalls Traps, Sweep Nets, Kick Sampling, Tree Beating.
How does tree beating work?
A large white cloth is stretched out underneath a tree while said tree is shaken or beaten to dislodge invertebrates, which will fall onto the cloth.
Why do pitfall traps have to have rooves?
Without a roof, the trap could fill up with rainwater and drown any invertebrates inside.
Which sampling technique would you use to collect sample data for the number of diving beetles in an area?
Kick Sampling - diving beetles will be underwater.
Outline the process of kick sampling.
Kick a riverbank or bed to disturb mud and vegetation. Hold a net downstream to capture any organisms released into the flowing river.
What are the two main types of identification key?
Branched/Spider Key and Numbered/Dichotomous Key
What is the formula for estimating total population using the capture-recapture method?
Total population number = first sample size x second sample size/number of recaptured individuals
What are the advantages and disadvantages of random sampling?
A: It prevents bias.
D: The data collected may not be representative of the while population, as the area has not been chosen according to trends.
What is a quadrat and why is it useful?
A quadrat is a square frame divided into a grid used for marking out areas to take sample data from.
How do you work out the total population number from sample data taken from a quadrat?
Multiply the mean population per m2 by the total area.
What is used to study how the distribution of organisms changes over a gradient?
A transect.
Define biodiversity.
A measure of how many different species live in an ecosystem.
How does deforestation reduce biodiversity?
-Permanent removal of species’ habitat.
-Removes food sources and shelter.
-Affects predator species as their prey grows in scarcity.
What is the process of eutrophication and what causes it?
Eutrophication is caused by runoff from farmlands containing pollutants such as fertilisers flowing into rivers, causing an algal bloom. This algal bloom prevents sunlight from reaching the organisms beneath the river’s surface, meaning that the plants below shall die and microorganisms start to decompose them. Microorganisms respire as they decompose the plants, which requires oxygen; therefore the oxygen levels fall and kill other organisms (such as fish) living in the river, until nothing but algae lives.
What is growing only one crop in an area referred to as?
Monoculture.
How does monoculture affect biodiversity?
Very few species are supported by just one type of plant, so an abundance of that plant and little else cannot sustain a healthy, diverse ecosystem.
Give 4 ways in which biodiversity can be lost.
Deforestation, Hunting and Fishing, Agriculture, Pollution.
Give three ways in which agriculture reduces biodiversity.
- Herbicides used to kill plants growing in particular areas reduces the number of plant species present as well as the number of animal species present, as it can remove sources of food or shelter.
- Pesticides reduces the number of pest species and thus decreases the food source for predator species. It can also accumulate in a food chain, killing animals that were not targeted.
- The removal of hedgerows removes habitats and decreased the number of plant species.
What is the key word for: “Protecting a natural environment to ensure that habitats are not lost?”
Conservation.
Give a 6 examples of conservation methods.
-Protected habitats for species to live in
-Education to increase awareness of the problem
-Captive breeding in zoos to increase the population
-Seed banks to store the seeds of rare plants (E.G. Seed Bank in Kew Gardens)
-Artificial ecosystems made to replace destroyed ones
-Legal protection to stop hunting and trade.
What are coral reefs and rainforests both examples of?
Areas with high biodiversity.
Give three ethical reasons for maintaining biodiversity.
- No human has the right to cause extinction.
- Stewardship - humans have a moral duty to protect the environment.
- All organisms have a right to life.
Give four economic reasons for maintaining biodiversity.
- Technology often utilises the assets of living creatures - biomimicry.
- Plants give humans medicine.
- Tourists enjoy nature probably
- Resources. We require a variety of crops for food and fuel.
Give two examples of areas with low biodiversity.
Deserts and the Arctic.
Give 5 ecological reasons for maintaining biodiversity.
- Keystone species (e.g. coral) must be protected.
- Organisms are interdependent, including humans.
- Keeps soil fertile.
- Regulates the atmosphere.
- Maintains genetic resources.
What are the three strands that contribute to a strong biodiversity?
Exisystem, Genetics, Species.
How does a genetic diversity help an organism and strengthen biodiversity?
It allows them to adapt and cope with changes in the environment.
What does a large population of mayfly nymph in a river indicate?
Low levels of water pollution.
Which species of lichen indicate high levels of air pollution?
Crusty lichen.
Why do sludge worms indicate extremely high levels of water pollution?
They are the only organisms able to survive in water with such low levels of oxygen.
What is blackspot fungus, and what does it indicate?
It is a type of fungus that grows on rose leaves in areas with low levels of air pollution. It indicates clean airs.
Give four common types of air pollution.
Smoke, Carbon monoxide, Carbon dioxide, Sulfur dioxide.
How can sulfur dioxide cause water pollution?
Sulfur dioxide in the air can dissolve in water to form an acidic solution.
What is a living indicator?
An organism that can be used to measure environmental quality.
Give two advantages of Selective Breeding/Artificial Selection.
- Produces species with the most desirable characteristics; therefore is very profitable for farmers and breeders.
- Can help make farming a species more sustainable by making them more resistant to diseases or temperatures.
Give two disadvantages of Artificial Selection.
- Reduces the gene pool/genetic diversity. Potentially useful alleles for the future are lost, and the species’ immunity to genetic diseases decreases.
- Can cause health problems through exaggerated traits.
Give 3 similarities and 3 differences between Selective Breeding and Natural Selection.
SIMILARITIES:
1. Both involve useful characteristics being sorted and favoured over the non-useful ones.
2. Both take generations to breed out the non-useful characteristics entirely.
3. Both reduce the gene pool.
DIFFERENCES
1. Natural Selection takes generations longer than Selective Breeding.
2. NS is Natural, while SB is artificial.
3. NS has a purpose of survival, while SB is for profit.
What is ecotourism and how does it maintain biodiversity?
Ecotourism aims to ensure that tourism does not negatively impact the natural environment or local communities, whilst allowing people to view the wildlife.
Tourism generates money, which can be used to help preserve natural wildlife through extending or improving habitats and preventing poaching.
Why are local and international agreements needed to maintain biodiversity?
Many animals naturally migrate between countries so international cooperation is required as well as local agreements to improve habitats.
Who published the Red List? What is it for?
The IUCN published the Red List. It details the current conservation status of threatened animals so that countries can work together to conserve these species.
What is the name of the treaty that regulates which species of wild plants and animals can be traded internationally?
CITES treaty. It protects more than 35,000 species.
What is an example of a local agreement to maintain biodiversity?
Stewardship Schemes mean that farmers in England are offered government payment to conserve the landscape.
Give one disadvantage of ecotourism.
Hiking, biking and transportation trails damage vegetation and top soil, which leads to soil erosion.
Give four ways in which nature reserves are managed.
Controlled Grazing, Reintroduction of Species, Restricting human access, and Feeding animals.
What is controlled grazing?
Only allowing animals to graze on one piece of land for a certain period of time, before moving them elsewhere to allow the vegetation to recover.
What does reintroducing species mean?
Adding new individuals of a certain species back into the environment after their numbers decline significantly or where the species had not survived at all.
What is a seed bank an example of?
A gene bank. It provides a store of genetic material.
What are the potential advantages of captive breeding?
It enables animals to reproduce in a stable, safe and healthy environment and can create a stable and healthy species population.
It allows the species to be gradually reintroduced to its natural environment.
What is a hydroponic system?
Instead of being grown in soil, a plant is grown in water containing the dissolved minerals it needs.
What are some advantages of a hydroponic system?
-Space can be used more effectively, since plants can be stacked together closely.
-Since more plants can be grown in smaller spaces, crop yield increases.
-Plants grow quickly using this method.
Give three methods in which farmers can be more sustainable.
-Crop rotation: as different crops uptake different nutrients from the soil, crop rotation ensures that the soil has time to recover the depleted minerals. It also avoids a build-up of a particular crop pest.
-Spreading manure instead of using artificial fertilisers to replenish soil nutrients prevents chemical runoff.
-Biological control: farmers can exploit the predator-prey relationships between certain species to kill off pests from their crops without using pesticides. E.g. ladybirds will consume aphids, which are a pest.
Give 3 methods of sustainable food production.
-Organic farming
-Fishing Quotas
-Hydroponics
What sorts of things are prohibited according to international fishing quotas?
The mesh size in nets is regulated - only larger holes are allowed, meaning that smaller, younger fish are allowed to escape and maintain the fish population.
- Limits on the types and amounts of fish to be caught in an area.
State what is meant by sustainable food production.
Producing food in methods that can be continued indefinitely.
What is biotechnology?
The use of biological processes or living organisms to manufacture products.
What are some disadvantages of Selective breeding?
It is not very exact, and it is a slow process taking course over many generations.
What is genetic engineering?
Altering an organism’s genome to produce desired characteristics.
Suggest two advantages of genetic engineering over Selective Breeding.
SB takes a very long time, over the course of several generations. GE is quick - it can occur in one generation.
SB is not very exact; GE is able to target single genes and therefore is very precise.
Give 3 benefits of GE in agriculture.
-Increases crop yield.
-Can produce crops more resistant to pests.
-Produces medical drugs, such as insulin.
What is important about having crops that are resistant to pests?
It means less pesticides are used and therefore there is less of an environmental impact.
What are foreign genes and why are they called that?
Foreign genes are genes inserted into an organism to genetically engineer it. They code for the desired characteristic. They are taken from another organism, so
which makes them foreign genes.
What are the risks of GE?
-It could risk creating new allergens that may cause some people to be allergic to an organism they previously were not.
-Genetically modified crops may cross-pollinatw with wild plants, introducing a new gene into the wild plants. This could disrupt the balance of an ecosystem.
Give 3 examples of genetically modified organisms and their uses.
Flavr Savr Tomato - slowed down the rotting process by taking foreign genes from a fungus.
Venomous cabbage - made cabbage poisonous to pests by taking foreign genes from scorpion venom.
Golden Rice - contains lots of Vitamin A by taking foreign genes from carrots. This has helped save lives and prevent suffering in less developed areas - a vitamin A deficiency can cause blindness and death.
What are 3 simple steps for GE?
- identify the genes that code for a certain desired characteristic.
- remove the gene from the donor organism.
- insert the gene into the host organism.
What is often genetically engineered to produce vaccines, hormones and antibiotics?
Bacteria.
What is the role of enzymes in genetic engineering?
They move a gene between the genomes of the donor organism and the host organism.
Do restriction enzymes rejoin the DNA at the sticky ends?
No. That is the role of the ligase enzymes.
What are sticky ends?
When the restriction enzymes cut the DNA, they leave a few exposed unpaired bases on the ends of the DNA strands. These are called sticky ends.
What do restriction enzymes do?
They cut the donor DNA at specific base sequences. They make a staggered cut, leaving a few exposed unpaired bases on the ends of the DNA strands (sticky ends.) The same restriciton enzymes are used to cut open the bacterial plasmid, which means that it will have the same sticky ends and the foreign gene is able to join.
What is a loop of DNA separate from the chromosomal DNA that is ablr to replicate independently?
A bacterial plasmid.
How many steps are there to making insulin (that we are using for revision because this is very difficult and the test is tomorrow)?
8
What is step 1 for making insulin through GE?
- Take DNA from a human cell.
What is step 2 for making insulin using GE?
- Use a restriction enzyme to cut out the gene for insulin from the DNA.
What is step 3 for making insulin using GE?
- Use an enzyme called lysozyme to cut the plasmid out of a bacterial cell.
What is step 4 for making insulin using GE?
- Use the same restriction enzyme to cut DNA out of the plasmid.
What is step 5 for making insulin using GE?
- Insert the gene for insulin into the plasmid.
What is step 6 for making insulin using GE?
- Use an enzyme called ligase to join the ends of the DNA.
What is step 7 for making insulin using GE?
- Put the plasmid with the insulin gene back into a bacterial cell. The plasmid is called a vector as it contains the human gene.
What is step 8 from making insulin using GE?
- Leave the transgenic (containing DNA from another organism) to divide. Multiple copies of the bacteria which produce insulin for use by the medical industry.
