You're viewing 3 free preview questions for Biology HL — subscribe to unlock 93 more, plus the Full Question Bank, Mock Papers & Worksheets.Upgrade

Transport · Paper 1 — Free Biology HL Practice Questions

What this topic covers

This theme is built on one repeated argument: structure exists because it does a job, and you can predict the job from the structure. Examiners test this exact logic at every scale — a motor protein's shape tells you which way it walks a microtubule, a red blood cell's missing nucleus tells you why it can pack more haemoglobin, a gill's countercurrent geometry tells you why it out-performs a lung-style parallel flow. Several chunks here — muscle and motility, enzyme kinetics, endosymbiotic theory, detailed phloem loading — exist only on the HL paper, and they're flagged below. Get the mechanism words right (troponin, not tropomyosin; ATP-binding, not hydrolysis) because that's where the marks actually sit.

Read the full Form and Function lesson notes →

1FoundationMCQCirculatory systems: Open vs closed1 markPaper 1~2 min

An earthworm has a closed circulatory system with five pairs of aortic arches connecting a dorsal and a ventral longitudinal vessel. A cockroach has an open circulatory system with a single dorsal tubular heart. The maximum distance blood must travel from the heart to the most distant tissue is 2 cm in the earthworm and 0.5 cm in the cockroach. What is the most likely advantage of the earthworm's closed circulatory system over the cockroach's open system?

Solutions

2FoundationMCQCirculatory systems: Open vs closed1 markPaper 1~2 min

A biologist injects a blue dye into the heart of a live crab and into the heart of a live fish. The dye appears in the crab's leg joints within 30 seconds, but takes 2 minutes to appear in the fish's tail fin. Which conclusion is best supported by this observation?

Solutions

3MasteryMCQCirculatory systems: Open vs closed1 markPaper 1~2 min

A researcher injects an equal volume of blue dye into the dorsal vessel of a cockroach (open circulatory system) and into the left ventricle of a rat (closed circulatory system). Both animals are similar in mass. After 10 seconds, the dye in the cockroach is found spread throughout a large haemocoel sinus surrounding the leg muscles, while in the rat the dye remains confined within narrow capillaries inside the leg muscles. Which conclusion about fluid pressure is best supported by these observations?

Solutions

Questions 4-96

Unlock these questions with Premium

That's every free question here — 3 of 96.

+93 more questions, plus Mock Papers & Worksheets, are waiting in Premium.

Upgrade