Biological Classification — BIOLOGY STD 11 Science — Question

1. They have dark colour and high rate of reproduction and excrete solid urine.
2. They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs.
3. They feed on dry seeds and do not require drinking water.
4. They excrete very concentrated urine and do not use water to regulate body temperature.

$(I)$ In human body, it is made of number of muscle bundles.

$(II)$ Muscle bundles contains a number of muscle fibers and fiber is lined by the sarcollemma.

$(III)$ In Muscle fiber, sarcoplasm contains only one nucleus.

$(IV)$ In muscle fiber, sarcoplasmic reticulum is the store house of calcium ions.

$R$ : This is due to non-availability of $ATP$ molecules.