Assertion :The extensor muscles of the human back remain in sustained contraction to maintain erect posture against gravity. Reason: The extensor muscles are rich in red muscle fibres with abundant mitochondria and myoglobin.

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Assertion is correct but Reason is incorrect

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Both Assertion and Reason are incorrect

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
The extensor muscles of the human back are bulky red in colour due to high amounts of myoglobin and mitochondria. They are called as red muscles. They can remain in sustained contraction to maintain erect posture against gravity due to high amounts of myoglobin. $O_{2}$ is present in abundant levels in myoglobin. So in case of $O_{2}$ deficiency these oxygen molecules are released into cytoplasm of the muscle and help the muscles to be sustained contraction by supplying energy.
So, the correct option is A.

Suggest Corrections

Similar questions

H_{2}

H e

(1 + \frac{P b}{R T})

H_{2}

H e

Assertion – The non-fusible impurities present in iron ore are removed by $C a C O_{3}$ .

Reason: $C a C O_{3}$ which decomposes into $C a O$ and $C O_{2}$ . The $C a O$ formed reacts with $S i O_{2}$ to remove silica

{SiO}_{2}

{CaCO}_{3}

CaO

{CaCO}_{3}

{SiO}_{2}

ASSERTION: n-Pentane and n-Hexane belong to a homologous series.

REASON: n-Pentane and n-Hexane belong to the same class of hydrocarbons and they differ by a - $C H_{2}$ - group.

Join BYJU'S Learning Program