Biology MCQs
Biology MCQs Test Preparation | Latest 2025 Quiz FPSC, NTS, KPPSC, PPSC, SPSC, BPSC, OTS, UTS, PTS, CTS, ATS, ETEA MCQs Test Questions.
In an annelids, the contraction of circular muscle results in___________?
A: Lengthening of the body.
B: Shortening of the body.
C: Widening of body
D: Thinning of body
Thinning of body
The most important function of troponin is___________?
A: To bind with actin
B: To bind with tropomyosin.
C: To bind with Ca2+ ions.
D: All of these
All of these
Which of the following statement is incorrect about Molluscans?
A: They are surrounded by single or double pieces of hard skeleton.
B: Their shell grows as the animal grows.
C: They have hydrostatic skeleton.
D: They move by tube feet
They move by tube feet
If a cross section of a sarcomere is seen, each myosin is surrounded by how many actin molecules:
A: 9
B: 5
C: 6
D: 7
6
Which one of the following forms the blk of exoskeleton of an arthropod?
A: Epicuticle
B: Procuticle
C: Ectocuticle
D: None of these
Procuticle
What happens during muscle contraction to the length of each myosin and action filament?
A: Z- lines get closer
B: A band becomes short
C: 1 band elongates
D: There is no change in sarcomere
Z- lines get closer
Which of the following step occurs immediately after binding of Ca2+ with troponin molecule during muscle contraction.
A: Binding sites of actin get attached to the myosin hea
B: Troponin uncovers the actin binding sites.
C: Tropomyosin gets removed from the binding sites of actin filaments.
D: Ca2+ goes back inside sarcoplasmic reticulum.
Tropomyosin gets removed from the binding sites of actin filaments.
Why skeletal muscles are called striated muscles?
A: They appear darker than smooth muscles by naked ey
B: Alternating dark and light bands appear on their surface when visualized by naked ey
C: Alternating dark and light bands appear on their surface when visualized via a microscop
D: All of these
Alternating dark and light bands appear on their surface when visualized via a microscop