This structure is called the epiglottis. This flexible leaf-shaped cartilage serves as a flap that covers the larynx to prevent food and liquids from entering the airway and the lungs. It is open when we breathe which allows air to enter into the larynx.
Answer:
B. They have a single small nucleus.
Explanation:
The presence of large nucleus is a characteristic feature of cells that frequently undergo cell division. Cancer cells are characterized by uncontrolled continuous cell division even when the new cells are not required by the body.
This leads to the formation of benign or metastatic tumors. To undergo continuous cell division, the cancer cells have a large nucleus. The nucleus of the cancer cells is mostly hyperchromatic and distinct due to higher nuclear to cytoplasmic ratio. It allows these cells to exhibit the uncontrolled cell division.
Answer:
False.
Explanation:
An Haemoglobin molecule is made up of 4-polypeptides, with each of the polypeptide chain containing an haem group. These haem group can bind with one oxygen atom each.
T<u>he binding of the first oxygen atom by the first haem group weakens the tertiary protein structure of Quaternary structure Hb, thus it makes it easier for the second Oxygen atom to bind faster, and the 3rd oxygen very fast and the 4th oxygen atom the fastest.These accelerated binding of the oxygen atoms, facilitated by the first binding O2, is called cooperative binding.It aids oxygen binding capacity and tranport functions of Hb,</u>
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<u>Myoglobin is an oxygen storage protein in muscles, and not oxygen carrying molecule, It releases stored O2 only in condition of low oxygen supply</u>.It has one haem group in its molecule.Therefore its structural features can not carry out cooperative binding.
