PHGY 215 Final Exam 2026 Questions
and Answers
The muscle tissue represents the greatest - Correct answer-The greatest tissue mass
in the body at around half of the bodys total weight.
The majority of muscles tissue is - Correct answer-The majority is skeletal muscle
(represents 40% of bw in men and 32% in women)
skeletal muscle - Correct answer-striated and voluntary
straited - Correct answer-striped
Level of skeletal muscle organization - Correct answer-The muscle > muscle fibre
> myofibrils > sacromere
muscle - Correct answer-tissue composed of fibers that can contract, causing
movement of an organ or part of the body
Muscle fibre - Correct answer-a single muscle cell. They are much longer than
normal cells and are multinucleate.
Myofibrils - Correct answer-protein structures that make up muscle fibers
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,A band - Correct answer-dark area; extends length of the thick filaments
I band of sarcomere - Correct answer-the light band between the ends of thick
filaments
H zone - Correct answer-The region at the center of an A band of a sarcomere that
is made up of myosin only. The H zone gets shorter (and may disappear) during
muscle contraction.
Slightly lighter portion of A band
M line of sarcomere - Correct answer-mid-line of sarcomere
Made of proteins that hold thick filaments together
Z line - Correct answer-A dark thin protein band to which actin filaments are
attached in a striated muscle fiber, marking the boundaries between adjacent
sarcomeres.
Sacromere - Correct answer-Basic contracting unit of muscle cell consits of actin
and myosin filaments between z-lines in a muscle cell
Muscle cross bridge - Correct answer-Connection formed when mobile myosin
heads bind to actin molecules in muscles
Thick filaments (myosin) - Correct answer-Myosin myofilament with heads that
bind to actin by reaching up and ratcheting forward
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, About 300/filament
Myosin - Correct answer-The contractile protein that makes up the thick filaments
of muscle fibers
Dimer of two subunits that looks like a golf club in that it has a long shaft with a
globular head
Thin filaments (actin) - Correct answer-Made up of proteins actin, tropomyosin,
troponin. The main structural component is two actin filaments
Actin - Correct answer-A globular protein that links into chains, two of which twist
helically about each other, forming microfilaments in muscle and other contractile
elements in cells.
Tropomyosin - Correct answer-Thin double helix protein that lies end to end along
the actin helix structure. Regulatory protein that covers the actin binding sites
preventing interaction of actin and myosin
Troponin - Correct answer-Regulatory protein complex made up of 3 polypeptides.
1 binds tropomyosin, 1 binds actin, 1 binds Ca 2+
muscle contraction - Correct answer-The activation of tension generating sites
within muscle fibres when a muscle contracts it shortens
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and Answers
The muscle tissue represents the greatest - Correct answer-The greatest tissue mass
in the body at around half of the bodys total weight.
The majority of muscles tissue is - Correct answer-The majority is skeletal muscle
(represents 40% of bw in men and 32% in women)
skeletal muscle - Correct answer-striated and voluntary
straited - Correct answer-striped
Level of skeletal muscle organization - Correct answer-The muscle > muscle fibre
> myofibrils > sacromere
muscle - Correct answer-tissue composed of fibers that can contract, causing
movement of an organ or part of the body
Muscle fibre - Correct answer-a single muscle cell. They are much longer than
normal cells and are multinucleate.
Myofibrils - Correct answer-protein structures that make up muscle fibers
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,A band - Correct answer-dark area; extends length of the thick filaments
I band of sarcomere - Correct answer-the light band between the ends of thick
filaments
H zone - Correct answer-The region at the center of an A band of a sarcomere that
is made up of myosin only. The H zone gets shorter (and may disappear) during
muscle contraction.
Slightly lighter portion of A band
M line of sarcomere - Correct answer-mid-line of sarcomere
Made of proteins that hold thick filaments together
Z line - Correct answer-A dark thin protein band to which actin filaments are
attached in a striated muscle fiber, marking the boundaries between adjacent
sarcomeres.
Sacromere - Correct answer-Basic contracting unit of muscle cell consits of actin
and myosin filaments between z-lines in a muscle cell
Muscle cross bridge - Correct answer-Connection formed when mobile myosin
heads bind to actin molecules in muscles
Thick filaments (myosin) - Correct answer-Myosin myofilament with heads that
bind to actin by reaching up and ratcheting forward
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, About 300/filament
Myosin - Correct answer-The contractile protein that makes up the thick filaments
of muscle fibers
Dimer of two subunits that looks like a golf club in that it has a long shaft with a
globular head
Thin filaments (actin) - Correct answer-Made up of proteins actin, tropomyosin,
troponin. The main structural component is two actin filaments
Actin - Correct answer-A globular protein that links into chains, two of which twist
helically about each other, forming microfilaments in muscle and other contractile
elements in cells.
Tropomyosin - Correct answer-Thin double helix protein that lies end to end along
the actin helix structure. Regulatory protein that covers the actin binding sites
preventing interaction of actin and myosin
Troponin - Correct answer-Regulatory protein complex made up of 3 polypeptides.
1 binds tropomyosin, 1 binds actin, 1 binds Ca 2+
muscle contraction - Correct answer-The activation of tension generating sites
within muscle fibres when a muscle contracts it shortens
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
