Edexcel IAL Biology 7.10 Fast and slow twitch fibres

Identify the activity's force and endurance demands, select the matching fibre features and explain each structural difference through ATP supply or contraction speed.

Exam points

Compare fast and slow twitch fibres using athlete, distance or activity evidence.
Explain rapid contraction through fibre diameter, glycogen and phosphocreatine stores.
Link mitochondria, capillaries and myoglobin to sustained aerobic ATP supply.

[Maximum number: 5]

Movement in mammals results from interactions between muscles, tendons, ligaments and bones.

(a)

The photograph shows part of a skeletal muscle fibre as seen using an electron microscope.

Figure for Question (a) — Edexcel A-Level Biology A2

[ 5 ]

(i)

Which pair of letters represents the length of one sarcomere?

P to T

P to U

Q to T

R to S

[ 1 ]

(ii)

Describe how the structure of a fast twitch muscle fibre differs from a slow twitch muscle fibre.

[ 4 ]

All question bank results loaded

7.10—Skeletal muscle fibre and twitch types question 1

Question (a)

Question (i)

Question (ii)