Tag: biology

Questions Related to biology

Choose the correct answers from the alternatives given :
Why would an organism utilize fermentation if it was wasteful of the energy in food molecules and posed the threat f killing itself with high levels of toxic alcohol?

  1. Organism can survive short spells of anaerobic conditions and maintain growth and reproduction

  2. If glucose levels are not high, there may be time to disperse the alcohol waste

  3. Fermentation can provide a rapid burst of ATP since it does not have to go through the full breakdown cycle

  4. All of the above are advantages


Correct Option: B
Explanation:
  • Anaerobic respiration is done by the organisms which live in a condition with very little oxygen or no oxygen at all such as some of the bacteria and prokaryotic organisms. 
  • Also the cells in the body of a multicellular organism when they are used for extreme physical active where the body may not be able to provide oxygen to each and every cells. For example muscles of arms and legs while excriseing. 
  • In anaerobic condition the glucose molecule will undergo glycolysis where it is broken down to 2 molecules of pyruvate wilt the net gain of 2 ATP after which dur to unavailability of oxygen the pyruvate will under go lactic acid fermentation or alcoholic fermentation where the pyruvate molecule is converted to lactic acid or ethanol & carbon dioxide respectively with the regeneration of NAD for the continuation of glycolysis. 
  • Prokaryotic organisms perform this type of respiration as they do not have membrane bound organelles like mitochondria which is required for the competion of the aerobic cellular respiration. 
  • Also some of the aerobic respiring cells can survive in no oxygen condition for sometime by respiring this way. But they are usually under a stressful condition where they cells will not grow or divide as they whole energy will be focused on conserving energy and surviving. 
  • And prokaryotic organisms which mostly have cellular level of organisation or a single celled they are provided with immediate burst of ATP by breaking down glucose by glycolysis. 
  • Therefore the correct answer for this option B and C

Rajeev was absent in the class because of muscle pain which he claim to be due to excess physical exercise he had done yesterdays. This pain due to

  1. Formation of lactic acid

  2. Formation of acetic acid

  3. Formation of pyruvic acid

  4. Formation of hydrochloric acid


Correct Option: A
Explanation:
Glycolysis breaks a glucose molecule into two pyruvate molecules, producing a net gain of 2 ATP molecules. Lactic acid fermentation is the type of anaerobic respiration process carried out by yoghurt bacteria and by our own muscle cells when we work.
So the correct option is 'Formation of lactic acid'.

The respiration carried in the absence of oxygen is called

  1. Aerobic respiration

  2. Anaerobic respiration

  3. Mastication

  4. Haemoglobin respiration


Correct Option: B
Explanation:

  • In anaerobic respiration, glucose breaks down without oxygen.
  •  The chemical reaction transfers energy from glucose to the cell.
  •  Anaerobic respiration produces lactic acid, rather than carbon dioxide and water. Hence, The respiration carried in the absence of oxygen is called anaerobic respiration.
So, the correct answer is 'anaerobic respiration'.

In anaerobic respiration

  1. O$ _{ 2 }$ is taken in.

  2. CO$ _{ 2 }$ is taken in.

  3. O$ _{ 2 }$ is given out.

  4. CO$ _{ 2 }$ is given out.


Correct Option: D
Explanation:

Anaerobic respiration is a type of respiration that does not use oxygen. It is used when there is not enough oxygen for aerobic respiration. 
Anaerobic respiration in some microorganisms (such as yeast) produces ethanol and carbon dioxide, as opposed to lactic acid.

So, the correct answer is option D.

Which of the following will survive in a closed container and perform fermentation?

  1. Algae

  2. Yeast

  3. Virus

  4. Protozoa


Correct Option: B
Explanation:

  • Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom.
  •  Yeast is a microorganism that can undergo aerobic as well as anaerobic respiration. 
  • Yeast requires oxygen for growth. In addition to oxygen, they require a basic substrate such as sugar. 
When yeast cells are kept in an anaerobic environment (i.e., without oxygen)can ferment sugars to alcohol and carbon dioxide. They produce ethyl alcohol and carbon dioxide from simple sugars such as glucose and fructose. Hence, the yeast can survive in a closed container and perform fermentation.
So, the correct answer is 'yeast'.

The organisms that undergo anaerobic respiration to make alcohol are

  1. Bacteria

  2. Yeast

  3. Algae

  4. Protozoa


Correct Option: B
Explanation:
Yeast can undergo both aerobic and anaerobic respiration. Anaerobic respiration occurs in yeast in the absence of oxygen. It is also known as fermentation. The products of anaerobic respiration in yeast are carbon dioxide, alcohol and 2 molecules of ATP.
So the correct answer is 'Yeast'.

ATP is stored on the myosin cross bridges for immediate energy After 5 to 6 seconds, this supply is exhausted and the muscle must rely on to quickly produce more ATP.

  1. Phosphocreatine

  2. Lactic acid

  3. Acetyl choline

  4. Pyruvic acid


Correct Option: B
Explanation:

  • Myofibril activity is required for muscle contraction on the molecular level. 
  • When ATP binds to myosin, it separates from the actin of the myofibril, which causes a contraction.
  • The muscle contraction cycle is triggered by calcium ions binding to the protein complex troponin, exposing the active-binding sites on the actin.
  • ATP then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.
  • When ATP is exhausted lactic acid is produced 
So, the correct option is 'lactic acid'.

Which pressure is responsible for ascent of sap?

  1. Negative hydrostatic pressure

  2. Positive hydrostatic pressure

  3. Root pressure

  4. All of the above


Correct Option: C
Explanation:
  • In the Root Pressure, the root Xylem vessels absorb the minerals from the soil, as a result, the water potential outside the root increase and inside the root decreases so due to water potential difference water starts entering to the xylem of the root.

So, the correct answer is 'Root pressure'

Root pressure is caused by

  1. Osmosis

  2. Diffusion

  3. Passive transport

  4. Uphill transport


Correct Option: A
Explanation:

Root pressure is caused in the Xylem vessels due to osmosis. It is a positive pressure which is developed due to Osmotic pressure which is high in the root as compared to the water column above.

Diffusion is a very slow process and hence plant do not just depend on it for the ascent of sap.
Since it is not occurring through specialised proteins or usage of energy, it is neither passive transport nor uphill transport 
So the correct answer is 'Osmosis'.

Which condition will not favour guttation?

  1. High moisture

  2. High DPD in leaf

  3. Accumulation of ions in root side

  4. Low light intensity


Correct Option: B