Tag: cell membrane

Quizzes (6) Questions (56)

Questions Related to cell membrane

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Types of chemoreceptors involved in respiration regulation is

  1. Central chemoreceptors

  2. Peripheral chemoreceptors

  3. Spinal chemoreceptors

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Central and peripheral chemoreceptors involve in the regulation of respiration. They detect reduction and elevation in the concentration level of oxygen, carbon dioxide and pH in the body.
So the correct answer is 'Both A and B'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

In response to a decrease in blood pH, the respiratory center sends nervous impulses to

  1. Increase breathing rate

  2. Decrease breathing rate

  3. Increase heart beat

  4. None of th above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Respiratory centre is located in the medulla oblongata and pons. They control the rate and depth of respiratory movements of the diaphragm. The increase in CO$ _2$ level in the blood lowers the pH of the blood which in response cause respiratory center to send impulses to breath fast and increase breathing rate.
So the correct answer is 'Increase breathing rate'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Central chemoreceptors are found in

  1. Pons

  2. Medulla

  3. Spinal cord

  4. Cerebrum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Central chemoreceptors are located on the ventrolateral medullary surface in the central nervous system. There receptors act to detect the changes in pH of their environment by detecting alteration in the concentration of O$ _2$ and CO$ _2$ of nearby cerebrospinal fluid. The decrease in CO$ _2$ causes the blood to become more acidic while it's increase makes the blood alkaline
So, the correct answer is 'Medulla'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Central chemoreceptors are sensitive to the

  1. pH of their environment

  2. Level of oxygen

  3. High blood pressure

  4. Level of sugar in blood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Central chemoreceptors are located on the ventrolateral medullary surface in the central nervous system. There receptors act to detect the changes in pH of their environment by detecting alteration in the concentration of O$ _2$ and CO$ _2$ of nearby cerebrospinal fluid. The decrease in CO$ _2$ causes the blood to become more acidic while it's increase makes the blood alkaline.
So, the correct answer is 'pH of their environment'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

In a $PCR$, which of the following components is not required?

  1. Nucleotide precursors
  2. A primer containing $3'-OH'$

  3. DNA helicase to separate the strands

  4. DNA polymerase to catalyse the reaction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A common laboratory technique used to make many copies (millions or billions) of a particular region of DNA is called Polymerase Chain Reaction(PCR). It requires a primer, DNA helicases, DNA polymerases, etc.,

So, the correct option is ‘ Nucleotide precursors’.

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Receptors associated with aortic arch and carotid artery can recognise changes in (i) and (ii) concentration and send necessary signals to (iii) for remedial actions.

  1. (i) $O _{2}$ (ii) $CO _{2}$ (iii)pneumotaxic centre
  2. (i) $CO _{2}$ (ii) $H^+$ (iii) rhythm centre
  3. (i) $CO _{2}$ (ii) $H^+$ (iii) apneustic centre
  4. (i) $O _{2}$ (ii) $H^+$ (iii)pneumotaxic centre
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Receptors associated with aortic arch and carotid artery can recognise a change in $CO _{2}$ and $H^+$ concentration and send necessary signals to the rhythm centre (medulla oblongata) that controls the rate of breathing.

So, the correct answer is (B).

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Sterols are not fats but solid alcohols. These are put as lipids because they form

  1. Fats and fatty acids

  2. Triglycerides

  3. Cholesterol

  4. Ester and fatty acids
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sterols are classified as lipids because they are hydrophobic and soluble in organic solvents. Cholesterol is the most well-known sterol and serves as a fundamental component of cell membranes.

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

At physiological temperature, sterols in biological membranes

  1. Increase their fluidity

  2. Decrease their fluidity

  3. Increase their permeability to water

  4. Decrease their permeability to water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Biological membranes are made up of lipid bilayer. These sterols affects the fluidity and rigidity of the membrane. At physiological temperature, sterols in biological membranes increase their fluidity but makes them more stronger and rigid. Environmental conditions like higher temperatures or unsaturated fatty disrupts close packing of lipids. This results in increase in the fluidity of the membrane. The membranes become more permeable to water. However, at lower temperatures, membranes become rigid. 

So the correct option is 'Increase their fluidity'.