Muscle Contraction Quiz

What initiates a muscle contraction?

• A signal from the nervous system

• A signal from the digestive system

• A signal from the respiratory system

• A signal from the circulatory system

What happens to muscle fibers during contraction?

• They get longer

• They get shorter

• They stay the same

• They disappear

What are the organelles called that are found in muscle fibers?

• Mitochondria

• Myofibrils

• Ribosomes

• Lysosomes

Tags

NGSS.HS-LS2-5

What are the two types of protein filaments in myofibrils?

• Actin and myosin

• Collagen and elastin

• Keratin and fibrin

• Tubulin and dynein

Which protein filament is thicker?

• Actin

• Myosin

• Collagen

• Elastin

What are actin filaments anchored to?

• Z lines

• M lines

• A bands

• I bands

What is the region between two Z lines called?

• Sarcomere

• Myofibril

• Sarcolemma

• Sarcoplasm

What overlaps the actin filaments within a sarcomere?

• Myosin filaments

• Collagen fibers

• Elastin fibers

• Keratin filaments

What are the tiny structures on myosin filaments that attach to actin filaments?

• Cross bridges

• Cross links

• Cross fibers

• Cross bands

What must happen for a muscle cell to contract?

• The sarcomere must lengthen.

• The sarcomere must shorten.

• The filaments must shorten.

• The filaments must lengthen.