Tag: biology

Questions Related to biology

If the $CO 2$ content of the atmosphere is as 300 parts per million ______________.

biology environmental factors soil-nature climate factors abiotic components

  1. All plants would be killed

  2. The plants would not grow properly

  3. Plants would grow for some time and

  4. The plants would thrive well

Show answer
Correct Option: A

$71$% of the carbon is found in ____________.

biology environmental factors soil-nature climate factors abiotic components

  1. Organisms

  2. Oceans

  3. Fossil fuels

  4. Soil

Show answer
Correct Option: B
Explanation:

Oceans have highest carbon content close to ~80%. So the answer is B. Oceans are called CO2 Sinks.

Which of the following fixes atmospheric ${ N } _{ 2 }$?

biology environmental factors soil-nature climate factors abiotic components

  1. Nostoc

  2. Algae

  3. Methanogens

  4. None of these

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Correct Option: A
Explanation:
Nostoc is a genus of cyanobacteria that are involved in nitrogen fixation. They are commonly found in the form of a gelatinous sheath that is composed of microfilaments.
So, the correct answer is 'Nostoc'.

The three R's to save the environment are

biology environmental factors soil-nature climate factors abiotic components

  1. Reserve, Reduce, Recycle

  2. Reuse, Reserve, Reduce

  3. Reserve, Reuse, Reduce

  4. Reduce, Recycle, Reuse.

Show answer
Correct Option: D

The two sides of a given mountain have the same latitude and altitude Are they likely to have the same climate

biology environmental factors soil-nature climate factors abiotic components

  1. No, because there is likely to be less water on the side of the mountain that faces away from the prevailing winds

  2. No. because there is always on desert on one side of a mountain

  3. Yes, because latitude and altitude are the two most important climate-controlling factors

  4. Yes, because locations at the same latitude all have the same climate

Show answer
Correct Option: A
Explanation:

Although latitude does play a major role in determining what kind of climate a certain place will have, there are many other factors that will play a part s well. Here are a couple of major factors that can make cities at similar latitudes have very different weather.

So, the correct option is 'No, because there is likely to be less water on the side of the mountain that faces away from the prevailing winds'. 

The surface temperature of the sun is _____________

biology environmental factors soil-nature climate factors abiotic components

  1. $6000^o C$

  2. $1000^o C$

  3. $10,000^o C$

  4. $9000^o C$

Show answer
Correct Option: A

Which statements about muscle contractions are true?
(i) Acetylcholine is released when neural signal reaches motor end plate
(ii) Muscle contraction is initiated by a signal sent by CNS via a sensory neuron
(iii) During muscle contraction, isotropic band gets elongated
(iv) Repeated activation of the muscle can lead to lactic acid accumulation.

muscle contraction locomotion and movements biology

  1. i and iv

  2. i and iii

  3. ii and iii

  4. i, ii and iii

  5. i and ii

Show answer
Correct Option: A
Explanation:

  • Acetylcholine is the neurotransmitter used at the neuromuscular junction, it is the chemical that motor neurons of the nervous system release in order to activate muscles when acetylcholine is released when the neural signal reaches motor end plate. 
  • Repeated activation of muscle induces processes resulting in decreased performance (fatigue) as well as enhanced performance (potentiation).  Lactic acid is formed and accumulated in the muscle under conditions of high energy demand, rapid fluctuations of the energy requirement and insufficient supply of O2. Hence,  Repeated activation of the muscle can lead to lactic acid accumulation.
So, the correct answer is ' i and iv'.

In hurdle race, what is the major energy source of the leg muscle?

muscle contraction locomotion and movements biology

  1. ATP

  2. Glycolysis

  3. Pyruvate and lactate

  4. Oxidative metabolism

Show answer
Correct Option: A
Explanation:
  • The source of energy that is used to power the movement of contraction in working muscles is adenosine triphosphate (ATP).
  • ATP is considered as the energy currency of the cell.
  • Hence In a hurdle race, what is the major energy source of the leg muscle ATP. It helps in muscle contraction that facilitates running in the race.
  • So, the correct answer is 'ATP'.

Electron microscopic studies of the sarcomeres have revealed that during muscle contraction

muscle contraction locomotion and movements biology

  1. The width of A-band remains constant

  2. The width of the H-zone becomes smaller

  3. The width of I-band increases

  4. The diameter of the fibre increases

Show answer
Correct Option: A
Explanation:

During muscle contraction, the A - band with a length of 1.85 micrometers does not undergo any contraction. However, the I-bands and the H-zone shorten. This causes the Z lines to come closer together. So, the correct answer is 'The width of A-band remains constant'.

In hurdle race, what is major source of energy to leg muscle?

muscle contraction locomotion and movements biology

  1. Preformed ATP

  2. Oxidative metabolism

  3. Pyruvate and lactate

  4. Glycolysis

Show answer
Correct Option: B
Explanation:

  • In the hurdle race, a person requires energy production faster than our bodies can adequately deliver oxygen. 
  • In those cases, the working muscles generate energy anaerobically. This energy comes from glucose through a process called glycolysis, in which glucose is broken down or metabolized into a substance called pyruvate through a series of steps.
  •  When oxygen is limited, the body temporarily converts pyruvate into a substance called lactate, which allows glucose breakdown and thus energy production to continue.
  •  The working muscle cells can continue this type of anaerobic energy production at high rates for one to three minutes, during which lactate can accumulate to high levels.
Hence, In the hurdle race,  Oxidative metabolism is a major source of energy to the leg muscle.
   So, the correct answer is 'Oxidative metabolism'.