Multiple Choice QuestionsAssertion: In a pivot joint, rounded or pointed bone fits into a shallow depression in another bone.
Reason: Pivot joints are present between the metacarpals and phalanges of the fingers.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
During muscular contraction, which of the following events occur
(i) H-zone disappears
(ii) A band widens
(iii) I band reduces in width
(iv) Width of A band is unaffected
(v) M line and Z line come closer
(i), (iii), (iv) and (v)
(i), (i) and (v)
(ii), (iv) and (v)
(i), (ii) and (iii)
Which of the following is true for the labelled parts in the figure below?
A - Z- line - located at centre of I - band
B - Thin filament - occurs in A- band only
C - Thick filament - confined to I- band
D - H- zone - located at centre of M - Line
Which of the following is correct about the given figure?
The length ofthe thick and thin myofilaments has changed.
Length of both anisotropic and isotropic band has changed.
The myosin cross-bridges move on the surface of actin and the thin and thick myofilaments slide past each other.
Length of the sarcomere remains same.
C.
The myosin cross-bridges move on the surface of actin and the thin and thick myofilaments slide past each other.
Myofibrils are composed of smaller structures called myofilaments. These are of two types: Thick filaments and Thin filaments.
1. Thick filaments- composed of myosin proteins, tails of which bind together leaving the heads exposed to the interlaced thin filaments.
2. Thin filaments- composed of actin, tropomyosin band troponin.
The molecular model of contraction which describes the interaction between actin and myosin myofilaments is called the cross- bridge cycle.
What is diapedesis?
A kind of amoeboid movement.
The process of filtration of urea in kidney.
A type of locomotion found in Hydra
Migration of WBCs into the tissue spaces from blood capillaries
Skeletal muscles appear striated due to presence of two characteristic proteins in alternating dark and light bands. Which of the following is a correct match of the protein with its light refractive property and colour
| Protien | Colour | Property |
| Myosin | Light | Anisotropic |
| Actin | Dark | Anisotropic |
| Myosin | Dark | Isotropic |
| Actin | Light | Isotropic |
A cricket player is fast chasing a ball in the field. Which one of the following groups of bones are directly contributing in this movement
Femur, malleus, tibia, metatarsals
Pelvis, ulna, patella, tarsals
Sternum, femur, tibia, fibula
Tarsals, femur, metatarsals, tibia
Given diagram shows bone of the left human hindlimb as seen from front. It has certain mistakes in labeling. Two of the wrongly labelled bones are
tibia and tarsals
femur and fibula
fibula and phalanges
tarsals and femur
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