B3 Infection and Response

What is a pathogen?

A microorganism that causes disease.

What are the four main types of pathogens?

Viruses, bacteria, fungi, and protists.

Give animal examples for each: Virus, Bacteria, Fungi, Protists

HIV (potentially leading to AIDS), Salmonella, Athlete's foot, Malaria.

Give plant examples for each: Virus, Bacteria, Fungi and Protists

Tobacco mosaic virus, Agrobacterium, Rose black spot, Downy mildew.

What is the life cycle of pathogens?

They infect a host, reproduce/replicate, spread from their host, and infect other organisms. They also have structural adaptations enabling them to cause disease.

What are communicable diseases?

Diseases caused by pathogens that can be transferred from one person to another.

What are other types of diseases that are non-communicable?

Inherited genetic disorders, deficiency diseases, and diseases like cancer.

What are the ways Transmission can occur?

Direct contact, water, air, unhygienic food preparation, and vectors.

What are examples of direct contact transmission?

Sexual contact or shaking hands.

What are waterborne transmission examples?

Dirty water transmitting diseases like cholera.

What are airborne transmission examples?

Sneezing, which spreads virus particles of diseases such as the common cold.

What are examples of transmission caused by unhygienic food preparation?

Undercooked or reheated food causing bacterial diseases such as Escherichia coli in food poisoning.

What is a vector?

Any organism that can spread a disease (e.g., badgers

Are viruses alive?

Viruses are non-cellular entities because they do not complete all seven life processes.

What are viruses made of?

A relatively short length of genetic material (DNA) surrounded by a protein coat.

How do viruses reproduce?

They replicate their DNA and protein coats within a host cell, which then bursts to release new virus particles.

Can viral infections be treated by antibiotics?

Viral infections cannot be treated by antibiotics.

How does tobacco mosaic virus affect plants?

It infects chloroplasts, changing leaf color and reducing the plant's ability to photosynthesise.

How is HIV transmitted and how does it affect the body?

Transmitted by body fluids, it attacks the patient's immune system, potentially leading to AIDS.

How does tobacco mosaic virus affect plants?

It infects chloroplasts, changing leaf color and reducing the plant's ability to photosynthesise.

What does TMV affect?

The tobacco mosaic virus infects tobacco and closely related species like tomatoes and peppers. Transmitted by contact,

How is tobacco mosaic virus transmitted?

Contact between plants, either naturally or through the hands of farmers.

What are the symptoms of tobacco mosaic virus?

It infects the chloroplasts of plant leaves, changing their colour from green to yellow or white in a mosaic pattern. It can also make leaves crinkle or curl up.

How does tobacco mosaic virus affect plant growth?

It reduces the plant's ability to photosynthesise and grow properly, which reduces the crop yield for farmers.

What can farmers do to manage tobacco mosaic virus?

Farmers must try to reduce the infection to their crops or attempt to reduce the spread of the virus, as there is no cure.

What is rose black spot?

A fungal disease affecting roses.

What causes rose black spot?

It's caused by a fungus called Diplocarpon rosae.

What are the visual symptoms of rose black spot?

Black spots on the leaves, which may turn yellow and drop early.

How can rose black spot be treated and prevented?

Fungicides can be used to treat it. Removing and disposing of affected leaves can help prevent the spread.