CourseCourseConceptConceptDocumentDocument

IB Biology HL B3.2 Transport Questions

Practise IB Biology HL B3.2 by linking transport structures to pressure, cardiac cycles, xylem, phloem and mass-flow evidence.

Syllabus
First assessment 2025
Course
Biology HL
Level
HL

Exam points

  • Explain how thin, fenestrated capillary walls permit tissue-fluid formation and exchange.
  • Compare artery, vein and capillary structure to explain pressure, flow direction and exchange.
  • Measure pulse rate reproducibly by timing beats at the radial or carotid artery.
  • Compare single and double circulation, tracing blood flow and linking heart structures to pressure.
  • Interpret ECG, pressure or heart-sound data to identify cardiac-cycle stages and valve states.
  • Explain root-to-leaf water movement through xylem using transpiration pull and root pressure.
  • Identify vascular bundles and xylem/phloem positions in stem and root diagrams.
  • Explain phloem pressure-flow translocation using sieve tubes, companion cells and source-sink loading.

Covered syllabus points

B3.2.1—Capillary adaptationsB3.2.2—Artery and vein structureB3.2.3—Artery adaptationsB3.2.4—Pulse rate measurementB3.2.5—Vein adaptationsB3.2.6—Coronary artery occlusionB3.2.7—Water transport in plantsB3.2.8—Xylem vessel adaptationsB3.2.9—Stem tissue distributionB3.2.10—Root tissue distributionB3.2.11 (HL)—Tissue fluid in capillariesB3.2.12 (HL)—Exchange between tissue fluid and cellsB3.2.13 (HL)—Lymph ductsB3.2.14 (HL)—Single vs. double circulationB3.2.15 (HL)—Mammalian heart adaptationsB3.2.16 (HL)—Cardiac cycle stagesB3.2.17 (HL)—Root pressure generationB3.2.18 (HL)—Phloem adaptations

Question 1

[Maximum number: 3]

Explain how the structure of capillaries relates to their functions.

Question 2

[Maximum number: 1]

Which characteristic of the subclavian vein distinguishes it from the subclavian artery?

A

Larger lumen

B

Absence of valves

C

Presence of pores

D

Two layers of muscle

Question 3

[Maximum number: 2]

Hypertension (blood pressure exceeding 140 mmHg ) affects millions of people worldwide. Many modern societies consume more sodium in the form of salt (NaCl) than is required for normal physiology. The effect of changing the levels of dietary sodium has been studied in various organisms.

Scientists recorded the blood pressure changes in chimpanzees (Pan troglodytes) fed a diet without added sodium (control) or a sodium supplemented diet (experimental) as follows
- 5 grams of salt per day from December 1991 until May 1992
- 10 grams of salt per day until June 1992
- 15 grams of salt per day until August 1993
after which no more salt was added to the diet until the experiment ended.

Figure for Question 3 — IB Biology HL

Blood pressure is measured in the arteries. Explain how arteries are adapted to withstand increases in blood pressure.

All question bank results loaded