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Worksheets6.3 Defence Against Infectious diseases (IB Biology)
Total questions: 12
Worksheet time: 6mins
What is thought of as the primary defenses against pathogens in the human body?
Lymphocytes and phagocytes
Antibodies and lymphocytes
The skin and mucous membranes
The circulatory system
If the skin is broken then a blood clot forms to seal this cut.
What is the first step in the process of blood clotting?
Fibrinogen turns into fibrin
Platelets release clotting factors
Fibrinogen is converted into thrombin
Thrombin is converted into prothrombin
What is the effect which thrombin has on the process of blood clotting?
Fibrinogen is converted to fibrin
Prothrombin is converted to thrombin
Platelets are caused to release clotting factors.
Clotting factors are taken up by red blood cells.
Which type of blood cells are capable of ingesting pathogens?
Erythrocytes
Antibodies
Lymphocyte cells
Phagocyte cells
Anitigens on pathogens which have got into the human body can lead to the development of specific immunity.
That is an immunity which responds only to this antigen.
Which of the following cells causes the specific immunity?
Erythrocytes
Macrophages
Lymphocytes
Phagocytes
Why do antibiotics have little or no effect on human cells, yet they can cause the death of bacteria?
Antibiotics block prokaryote cell processes, but not the processes in eukaryote cells.
Antibiotics can only affect cells below a certain size.
Human cells have a protective plasma membrane which prokaryote cells don't have.
Antibiotics are made of proteins which cannot pass through the plasma membrane.
There are limits to the effectiveness of antibiotics.
Why is this?
Viruses are not affected because they have no metabolism, and some bacteria have evolved resistance.
Bacteria are not affected by antibiotics, only viruses.
Only one species of bacteria is affected by a single antibiotic.
Only some types of virus and bacteria are affected by antibiotics, because of the evolution of resistance.
Which of the following best describes the effect of HIV on the immune system.
HIV infection causes a reduction in the number of active blood cells resulting in a high fever.
HIV reduces the number of active lymphocytes limiting the body's ability to produce antibodies.
HIV reduces the number of active erythrocytes limiting the production of antibodies.
HIV reduces the number of phagocytes which in turn limits the production of antibodies.
When activated by the presence of a pathogen some lymphocytes produce antibodies and other lymphocytes act as memory cells.
Which of the following best describes the role of memory cells in the immune system?
They store antigens from the pathogen for lymphocytes to use as a template for antibodies in the future.
They remember the antigen on the pathogen and tell the lymphocytes how to respond if it is re-encountered.
They quickly clone to form a group of phagocytes if the pathogen is re-encountered.
They quickly clone to form a group of plasma cells if the pathogen is re-encountered.
Which of the following is the best explanation of the likely consequences of a blood clot forming in a coronary artery?
Part of the heart receives a slower supply of blood, and contractions of the heart become irregular.
The blood is prevented from getting to the cardiac muscle and it stops contraction, the heart stops beating.
The blood stops flowing into the heart and this prevents the flow of blood around the body.
The blood clot moves from the coronary artery to the brain causing a stroke.
Florey and Chain shared a Nobel Prize with Alexander Fleming for their work on penicilin.
Which of the following statements best describes their experiment which tested penecillin on mice?
Four mice injected with a bacterial disease and four injected with penicillin to test toxicity and effectiveness.
Two mice injected with penicillin and a bacterial disease to test both toxicity and effectiveness against bacteria.
Toxicity test on two mice, then eight mice injected with a lethal dose of disease bacteria, four of which were also given penicillin to test its effectiveness against bacteria.
Hundreds of mice injected with penicillin and their lives monitored to measure how many of the mice developed infections during their lives.
Which of the following lists methods of transmission of HIV?
Sex without a condom, from breast milk, contaminated blood transfusions.
From saliva, sharing food and mosquito bites.
From bodily fluids such as sweat, semen and saliva.
Sex without a condom, mosquito bites and contaminated blood transfusions.
