biology:5 Health and Disease

Explain why exercise can cause weight loss.(2)

Exercise reduces fat.

Explain how a gastric band helps a person to loose weight.(2)

reduces volume of starch

reducing food intake

The question in the image

A is overweight shown by the BMI but his waist to hip ratio is 0.85 showing he is not abdominally obese.

weight distribution not around abdomen

this question

wash hands before contact
sterilise equipment before use

Adults have usually developed immunity that bacteria produces during the infection.
Explain how an adult develops immunity to the toxin.(3)

exposure to bacteria

stimulates an immune response

production of memory lymphocytes

Explain how a gene is inserted into a plasmid.(2)

cut the DNA with the restriction enzyme

insert the gene into a plasmid using ligase

gene and plasmid have the same sticky ends

Discuss the possible benefits and risks of producing painkillers from genetically modified yeast cells rather than extracting the painkillers from poppies.(3)

increasing yield

yeast growth is not weather dependant

painkillers may not be identical

GM organisms entering the environment

The question in the pic

spread the bacteria plate on a different agar plate

add myxopyronin discs and incubate the plates

measure the zone of inhibition

Myxopyronin inhibits bacterial RNA polymerase. Explain why the antibiotic myxopyronin can be used to treat bacterial infections in humans.(4)

antibiotics destroy bacteria

does not affect host cells

prevents production of mRNA

during transcription

Why can viruses only replicate inside a host, and how do they first enter the cell?

Viruses cannot replicate outside a host cell.

The virus binds to the host cell and inserts its genetic material.

What does a vaccine contain to make a person immune to a pathogen?

antigens

What white blood cell type is created in the body as a result of a vaccination?

Memory lymphocytes

EXPLAIN how memory lymphocytes protect you if the real pathogen enters the body later

They lead to the rapid production of antibodies, causing a fast secondary immune response

DESCRIBE the lytic pathway steps inside the cell after genetic material is inserted.

Uses the host cell machinery to replicate viral components.

Components assemble into new viral particles.

Viruses exit by bursting the cell membrane

EXPLAIN how a lytic virus spreads from an infected host through a population.

Viral particles are released into body fluids.

They exit the host and spread through airborne contact.

They infect a new host in the population.

What medical action taken by a patient allows resistant bacteria to multiply and cause Colistin resistance in a population?

People do not finish their full course

What is the initial genetic cause of some bacteria being unaffected by Colistin?

Some bacteria have a random mutation causing genetic variation

What evolutionary process occurs when a patient stops taking Colistin early, and what do the surviving bacteria do?

Natural selection / evolution occurs.

The resistant bacteria survive and reproduce.

What enzyme is used to isolate the human insulin gene and open the plasmid, and why must it be the same enzyme?

Restriction enzymes are used to cut both the gene and the plasmid to leave complementary sticky ends

What structural feature is left on the cut DNA fragments that allows the insulin gene to bind to the plasmid?

Complementary sticky ends.

What enzyme is used to permanently join the insulin gene into the plasmid backbone?

Ligase

what happens to a patient's LDL cholesterol levels if they stop taking statins?

The level of LDL increases after the medication is stopped

EXPLAIN the long-term health risk of a patient's LDL cholesterol levels increasing after stopping statins.

It increases the risk of cardiovascular disease .