A-LEVEL BIOLOGY PAPER 1
COMPREHENSIVE EXAMINATION TEST
2026 FULL QUESTIONS AND CORRECT
ANSWERS
⩥ how to killer t-cells work? Answer: 1. virus attaches to and enters host
cell
2. viral DNA causes host cell to express viral antigens on its surface
3. killer t-cells attaches to viral antigens on infected cells
4. killer t-cells induces death of infected cell (apoptosis)
⩥ what is apoptosis? Answer: programmed cell death
⩥ how do killer t-cells destroy cancer? Answer: - cancerous = mutations
- mutations = abnormal antigens
- killer t-cell binds to abnormal antigens
- killer t-cells induces death of cancerous cell
⩥ What does perforin do? Answer: creates holes in the cell membranes
in order to destroy the infected cell
⩥ what do helper t-cells do? Answer: - produce cytokines
,- cytokines stimulate b-cells to divide into plasma and memory cells
- activate killer t-cells
⩥ define helper t-cells Answer: help humoral response by involvement
in the maturation of b-cells and by triggering the production of
antibodies by b-cells
⩥ what do suppressor t-cells do? Answer: - halt immune response
- prevent wastage of energy and resources
- prevent overactive immune response
- causes reduction of white blood cells after being ill
⩥ define memory t-cells Answer: work in the same way as memory b-
cells, ensuring rapid response on subsequent exposure to the same non-
self antigens
⩥ define suppressor t-cells Answer: regulate the immune response by
suppressing activity of killer t-cells and b-cells
⩥ define 'microorganism' Answer: organism that is too small to be seen
without a microscope
⩥ define 'pathogen' Answer: microorganism that causes disease
,⩥ outline phagocytosis Answer: 1. phagocyte follows conc gradient of
chemoattractants
2. phagocyte attaches to pathogen
3. pathogen engulfed and placed in a vesicle (phagosome)
4. lysosomes migrate to phagosome and bind with it to form a
phagolysosome
--> lytic enzymes released from lysosome
5. pathogen digested
6. useful parts absorbed
7. all waste products released by exocytosis
8. non-self antigens of the pathogen displayed on the phagocytes surface
(antigen-presenting)
⩥ where are t-cells made? Answer: thymus gland
⩥ where do b-cells mature? Answer: bone marrow
⩥ what do b-cells do? Answer: - humoral response
- release antibodies
- complementary to a specific antigen
⩥ what response are plasma cells? Answer: primary
, ⩥ what response are memory b-cells? Answer: secondary
⩥ outline the humoral response Answer: 1. antigen attaches to
complementary antibody on b-cell
2. antigen taken into cell (endocytosis)
3. presented on cell surface membrane
4. t-helper cells bind to antigen and stimulate b-cell to divide
⩥ what does mitosis do in humoral response? Answer: - forms clones of
b-cells (plasma and memory)
- clonal response
⩥ what do clones do? Answer: each clone can produce one type of
antibody (monoclonal) which can be used in medicine
⩥ outline plasma cells Answer: - primary response
- secrete antibodies
- only survive for a few day
- slow response = person gets ill before pathogen is killed
⩥ outline memory cells Answer: - secondary response
- circulated in blood and tissue fluid
- divide rapidly
COMPREHENSIVE EXAMINATION TEST
2026 FULL QUESTIONS AND CORRECT
ANSWERS
⩥ how to killer t-cells work? Answer: 1. virus attaches to and enters host
cell
2. viral DNA causes host cell to express viral antigens on its surface
3. killer t-cells attaches to viral antigens on infected cells
4. killer t-cells induces death of infected cell (apoptosis)
⩥ what is apoptosis? Answer: programmed cell death
⩥ how do killer t-cells destroy cancer? Answer: - cancerous = mutations
- mutations = abnormal antigens
- killer t-cell binds to abnormal antigens
- killer t-cells induces death of cancerous cell
⩥ What does perforin do? Answer: creates holes in the cell membranes
in order to destroy the infected cell
⩥ what do helper t-cells do? Answer: - produce cytokines
,- cytokines stimulate b-cells to divide into plasma and memory cells
- activate killer t-cells
⩥ define helper t-cells Answer: help humoral response by involvement
in the maturation of b-cells and by triggering the production of
antibodies by b-cells
⩥ what do suppressor t-cells do? Answer: - halt immune response
- prevent wastage of energy and resources
- prevent overactive immune response
- causes reduction of white blood cells after being ill
⩥ define memory t-cells Answer: work in the same way as memory b-
cells, ensuring rapid response on subsequent exposure to the same non-
self antigens
⩥ define suppressor t-cells Answer: regulate the immune response by
suppressing activity of killer t-cells and b-cells
⩥ define 'microorganism' Answer: organism that is too small to be seen
without a microscope
⩥ define 'pathogen' Answer: microorganism that causes disease
,⩥ outline phagocytosis Answer: 1. phagocyte follows conc gradient of
chemoattractants
2. phagocyte attaches to pathogen
3. pathogen engulfed and placed in a vesicle (phagosome)
4. lysosomes migrate to phagosome and bind with it to form a
phagolysosome
--> lytic enzymes released from lysosome
5. pathogen digested
6. useful parts absorbed
7. all waste products released by exocytosis
8. non-self antigens of the pathogen displayed on the phagocytes surface
(antigen-presenting)
⩥ where are t-cells made? Answer: thymus gland
⩥ where do b-cells mature? Answer: bone marrow
⩥ what do b-cells do? Answer: - humoral response
- release antibodies
- complementary to a specific antigen
⩥ what response are plasma cells? Answer: primary
, ⩥ what response are memory b-cells? Answer: secondary
⩥ outline the humoral response Answer: 1. antigen attaches to
complementary antibody on b-cell
2. antigen taken into cell (endocytosis)
3. presented on cell surface membrane
4. t-helper cells bind to antigen and stimulate b-cell to divide
⩥ what does mitosis do in humoral response? Answer: - forms clones of
b-cells (plasma and memory)
- clonal response
⩥ what do clones do? Answer: each clone can produce one type of
antibody (monoclonal) which can be used in medicine
⩥ outline plasma cells Answer: - primary response
- secrete antibodies
- only survive for a few day
- slow response = person gets ill before pathogen is killed
⩥ outline memory cells Answer: - secondary response
- circulated in blood and tissue fluid
- divide rapidly
