IB DP Biology Mock Exam SL Paper 1B Set 5 - 2025 Syllabus
IB DP Biology Mock Exam SL Paper 1B Set 5
Prepare for the IB DP Biology Exam with our comprehensive IB DP Biology Exam Mock Exam SL Paper 1B Set 5. Test your knowledge and understanding of key concepts with challenging questions covering all essential topics. Identify areas for improvement and boost your confidence for the real exam
Question
(a) The diagram shows the human heart.
On the diagram, label
the aorta.
the right atrium.
b. Explain how valves control the flow of blood through the heart.
c. Outline the causes and consequences of blood clot formation in coronary arteries.
d. Outline the role of lymphocytes in defence against disease.
Answer/Explanation
Ans:
a (i) & (ii) both labelled clearly as in diagram
b)
a. valves open and close in response to changes in blood pressure/heart contraction/pumping
b. valve prevents backflow/maintains direction of blood flow
c. valves allow heart chambers to fill/to empty
c)
a. coronary heart disease/CHD/coronary artery disease/CAD occurs when there is reduction of oxygen to the heart muscle
b. high ratio of LDL to HDL/fatty diet leads to plaque formation in arteries
c. plaque breaks off causing damage that activates blood clot formation
d. clots «in the bloodstream» may block a coronary artery/coronary thrombosis reducing blood flow/oxygen
OR
clots can cause heart attack/muscle death
e. sickle cell anemia «crisis» produces blood clots «that can cause coronary/arterial blockage»
d)
a. produce antibodies
b. memory cells confer immunity
c. specific immunity results from production of antibodies specific to a particular antigen
d. recognize pathogens