Myofibril Structure Quiz

What are the dark discs that separate the segments of the myofibril called?

• M-lines

• H-bands

• A-bands

• Z-discs

What is the length of a sarcomere?

• 1-2 um

• 2-3 um

• 4-5 um

• 3-4 um

What type of filament is formed of myosin?

• Intermediate filaments

• Thick filaments

• Thin filaments

• Elastic filaments

What is the thickness of thick filaments?

• 4 nm

• 7 nm

• 10 nm

• 15 nm

What area in the center of the A-band is not reached by thin filaments?

• I-band

• H-band

• Z-line

• M-line

What connects the thick filaments together in a transverse direction?

• Z-line

• M-line

• I-band

• H-band

What is the composition of the Z-line?

• Titin

• Actinin and filament

• Actin

• Myosin

What is the thickness of titin?

• 15 nm

• 7 nm

• 4 nm

• 10 nm

What prevents too much stretch of the sarcomere?

• Z-line

• Titin

• Myosin

• Actin

What is the length of thin filaments?

• 4 um

• 3 um

• 2 um

• 1 um