B6 Flashcards
What is genetic engineering?
Genetic engineering is the modification of an organism’s genetic material to achieve desirable traits.
Give an example of a genetically modified organism (GMO).
Bt corn is a GMO where a gene from bacteria is added to give resistance to pests.
What is sustainable development?
Sustainable development meets current needs without compromising the ability of future generations to meet theirs.
How do human activities contribute to climate change?
Activities like burning fossil fuels and deforestation release greenhouse gases, increasing global temperatures.
What is selective breeding, and give an example.
Selective breeding involves choosing parents with desirable traits to produce offspring with those traits, like breeding cattle for higher milk yield.
How can humans prevent the spread of disease?
Cover your mouth when sneezing or coughing.
Don’t have unprotected sex
How can farmers prevent the spread of disease?
Burn diseased plant material.
Slaughter infected animal herds.
Isolate infected livestock.
What is a pathogen?
A pathogen is any microorganism that causes disease in another organism.
‘patho’ = disease
‘gen’ = generating
Which pathogens cause the following diseases?
Athletes Foot
Food Poisoning
STIs
Athletes Foot- caused by fungi that spreads when a person steps on the same surface as an infected person
Food Poising- caused by bacteria that produce toxins
STIs- STIs such as chlamydia are caused by unprotected sex or genital contact that shares bacteria
These microorganisms are pathogens:
Bacteria
Fungi
Protists
Viruses
What are they/ what do they do?
Bacteria- Pathogenic bacteria are prokaryotic, reproduce rapidly and produce toxins.
Fungi- Fungal diseases are much more common in plants than animals. They can be single-celled or multicellular and they reproduce via spores.
Protists- Protists are a diverse group of eukaryotic (and usually single-celled) organisms. They are parasites.
Viruses- Viruses are not cells. They are pathogenic as they can only exist by living inside the living cells of other organisms (or by using these cells to create more viruses).
What is the difference between Communicable and Non-communicable diseases?
Communicable- Communicable diseases are caused by microorganisms called pathogens which can spread between individuals (they are contagious).
Non-communicable- Non-communicable diseases are not caused by pathogens and cannot be passed on between individuals. They are caused by lifestyle, genetics and the environment.
What is the incubation period?
The period of time between getting infected by a disease and showing it’s symptoms.
What is HPV, how is it transmitted and what can it cause?
HPV is an STI that is transmitted sexually from men (who carry the virus).
It can cause cervical cancer in women.
What does HIV do, how can this result in AIDS and what can be used to stop it?
HIV invades your white blood cells (lymphocytes), uses them to make copies of its self and then destroys them.
This can weaken the immune system to the point where every-day infections cannot be fought off. This is called AIDS.
However, there are drugs that stops HIV replicating and they are called antiretroviral drugs.
In what two ways can plants protect themselves from communicable disease?
Physical defences
Barriers that prevent pathogens/ organisms entering
Chemical defences
Substances secreted by the plant that kill microorganisms
What is Tobacco mosaic virus, what is it caused by and how does it affect plants?
TMV is a virus that makes leaves mottled and discoloured.
It is caused by a virus.
It reduces the amount of chlorophyll therefore less photosynthesis takes place and the plant respires less. This can lower the quality of the crops produced.
What is Crown Gall Disease, what is it caused by and how does it affect plants?
Crown Gall is a disease that produces large, tumour-like growths.
It is caused by bacteria (specifically agrobacterium tumfaciens).
The growths constrict the vascular bundles within the plant (phloem and xylem) reducing the flow of water and sugars. This results in poor growth and reduced fruit production.
What is Powdery Mildew, what is it caused by and how does it affect plants?
Powdery mildew is a disease that causes white powdery spots.
It is caused by a fungus.
The white spots are fungi that reduce growth, make leaves fall off and reduce crop yield.
Give examples of some physical and chemical defences in plants.
Physical
Waxy cuticles, bark, cellulose cell wall
Chemical
Cyanide, insecticides
What methods can you use to identify a plant disease?
- Observe a filed if plants for physical appearances or disease symptoms. (cheapest and easiest)
- Use microscopy to identify specific pathogens.
- DNA analysis to identify the DNA fingerprint of a pathogen. (more expensive yet more effective)
What happens during phagocytosis?
Phagocytes, a type of white blood cell, engulf and digest pathogens. This is a non-specific immune response as it works the same way for all pathogens.
What are antibodies, and how do they work?
Antibodies are Y-shaped proteins produced by B-lymphocytes. They bind to specific antigens on pathogens, causing agglutination (clumping) to make the pathogens easier for phagocytes to destroy.
What is the role of memory cells in immunity?
Memory cells are lymphocytes that remain after infection. They recognize specific pathogens and trigger a faster, stronger immune response if the pathogen invades again.
Name some non specific defences of the human immune system.
- Skin- acts as a physical barrier and secretes antimicrobials.
- Mucus and cilia in the respiratory tract. Goblet cells produce mucus that catch germs. Then the cilia waft the mucus up to the oesophagus where you swallow and the germs are sent into the stomach acid.
- HCL in stomach to kill pathogens you eat.
- Platelets clot blood to form a scab.
What were the key benefits of the Human Genome Project for medicine?
Prediction & prevention of diseases – Doctors can identify genes linked to diseases (e.g., cancer, heart disease) and give lifestyle advice to reduce risks.
Testing & treatment for inherited disorders – Faulty alleles (e.g., in cystic fibrosis) can be identified quickly, allowing earlier testing and treatment.
Development of better medicines – Drugs can be tailored to individuals’ genetic makeup, making treatments more effective with fewer side effects.
What are some drawbacks of using gene technology in medicine?
Increased anxiety & stress – Knowing you have a high risk of a disease can cause unnecessary worry, even if the disease never develops.
Ethical concerns – People with genetic diseases or faulty alleles may feel pressured not to have children.
Discrimination risks – Employers may avoid hiring people with a high disease risk, insurers could raise prices or deny coverage, and pharmaceutical companies might charge more based on a person’s condition.
