Vaccines, Disease & Monoclonal Antibodies (AQA A Level Biology): Flashcards

Passive immunity is when a person receives ready-made antibodies without producing them, so no immune response or memory cells are formed.

Natural active immunity is acquired from infection by a pathogen, while artificial active immunity is acquired through vaccination.

False.

Passive immunity provides short-term protection because no memory cells are formed.

An example of natural passive immunity is antibodies passed from mother to baby via the placenta or breast milk (colostrum).

An example of natural passive immunity is antibodies passed from mother to baby via the placenta or breast milk (colostrum).

Passive immunity is useful when immediate protection is needed and there is no time to wait for an immune response.

Active immunity involves the production of memory cells and leads to a faster and stronger secondary response.

A retrovirus is a virus whose genetic material is RNA, and which uses reverse transcriptase to make a DNA copy in the host cell.

AIDS (acquired immune deficiency syndrome) is the disease caused by infection with HIV, where the immune system is weakened and cannot fight off infections.

Reverse transcriptase is an enzyme used by HIV to convert its RNA into DNA inside the host cell.

HIV is the virus that infects the body, while AIDS is the disease caused when HIV weakens the immune system until it can no longer fight infections.

HIV primarily infects and destroys helper T cells, which are crucial for the immune response.

After initial infection, HIV enters a latent period with no obvious symptoms.

When the immune system can’t respond to pathogens, AIDS develops and opportunistic infections can occur.

False.

Antibiotics are ineffective against viruses like HIV because viruses do not have the cellular structures targeted by antibiotics.

The genetic material in HIV is RNA, not DNA.

The enzyme that converts HIV RNA into DNA is reverse transcriptase.

HIV is transmitted by direct exchange of body fluids, such as during sexual intercourse or blood donation.

AIDS is characterised by a reduced number of helper T cells and a loss of the ability to fight infections.

With the use of antiviral drugs, HIV-positive individuals can have a normal life expectancy because these drugs slow down virus replication.

A monoclonal antibody is an identical antibody produced from a single clone of B cells.

Monoclonal antibodies are highly specific because they are produced by a single B cell clone and bind to only one particular antigen.

Monoclonal antibodies are produced from a single B cell clone and bind to a single antigen.

Monoclonal antibodies can be attached to a therapeutic drug and designed to bind only to cancer cells, delivering the drug directly to them and reducing damage to healthy cells.

In targeted drug delivery, a monoclonal antibody carries a therapeutic drug directly to the target cells, increasing effectiveness and reducing damage to healthy cells.

True.

Monoclonal antibodies are used in medical diagnosis to detect the presence and location of specific antigens.

Targeted drug delivery is the use of monoclonal antibodies to carry a therapeutic drug directly to specific cells, such as cancer cells, increasing effectiveness and reducing damage to healthy cells.

Diagnostic uses of monoclonal antibodies include pregnancy tests (detecting hCG in urine) and infection detection (such as HIV or Streptococcus).

Reproducibility refers to whether other scientists can obtain similar results using the same method and data.

Claims about vaccine or monoclonal antibody (mAb) safety and effectiveness must be backed by scientific evidence.

A large, unbiased sample reduces the risk of misleading results and increases the reliability and validity of a study's conclusions.

False.

Peer review and replication are essential for ensuring scientific claims are reliable and valid.

Herd immunity is when enough of the population is immune to a disease, reducing its spread and protecting individuals who are not immune.

Vaccines are often first tested on animals, which some consider unethical.

There is a concern about exploitation, as vulnerable people may take risks for payment.

True.

Producing monoclonal antibodies involves injecting mice and extracting cells, which can cause suffering and raises ethical concerns for animal welfare.

Informed consent is when a person fully understands the risks and benefits before agreeing to participate in a treatment or trial.

A concern with monoclonal antibody treatments is that they are often expensive, raising issues of fair access.

Transparency helps ensure that results are unbiased and trustworthy, reducing the risk of misleading conclusions due to hidden motives.

A study is considered valid if its data answer the research question and the variables are well controlled.

A major issue is fair distribution, as wealthier countries may obtain vaccines before poorer nations, raising concerns over equality.

An ELISA (Enzyme-Linked Immunosorbent Assay) is a test that uses antibodies to detect the presence and quantity of a specific antigen or antibody in a sample.

In an ELISA test, the enzyme attached to the antibody reacts with a substrate to produce a coloured product, which indicates the presence of the antigen or antibody of interest.

A direct ELISA test uses a single antibody that is complementary to the antigen being tested for.

An indirect ELISA uses two antibodies, a primary and a secondary, whereas a direct ELISA uses only a single antibody.

In an indirect ELISA, the antigen is attached to the bottom of the well, and the blood plasma from the patient is added.

A wash step removes unbound antibodies to prevent false-positive results in the ELISA test.

A primary antibody is the first antibody added in an ELISA that is specific to the antigen being tested for.

False.

A colour change indicates the presence of HIV-specific antibodies in the patient's blood, not HIV antigens.

In the final step of an indirect ELISA, a substrate is added. If the enzyme is present, a colour change occurs.