Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

Multiple choice biology environmental factors soil-nature climate factors abiotic components

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

  1. Nostoc

  2. Algae

  3. Methanogens

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.
Multiple choice biology environmental factors soil-nature climate factors abiotic components

The three R's to save the environment are

  1. Reserve, Reduce, Recycle

  2. Reuse, Reserve, Reduce

  3. Reserve, Reuse, Reduce

  4. Reduce, Recycle, Reuse.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The three R's of waste management are a widely recognized framework for environmental sustainability: Reduce (use less), Reuse (use again), and Recycle (process into new materials).

Multiple choice biology environmental factors soil-nature climate factors abiotic components

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

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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'. 

Multiple choice biology environmental factors soil-nature climate factors abiotic components

The surface temperature of the sun is _____________

  1. $6000^o C$
  2. $1000^o C$
  3. $10,000^o C$
  4. $9000^o C$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The photosphere, which is the visible surface of the sun, has an effective temperature of approximately 5778 Kelvin, which is commonly rounded to 6000 degrees Celsius.

Multiple choice muscle contraction locomotion and movements biology

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.

  1. i and iv

  2. i and iii

  3. ii and iii

  4. i, ii and iii

  5. i and ii
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

Multiple choice muscle contraction locomotion and movements biology

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

  1. ATP

  2. Glycolysis

  3. Pyruvate and lactate

  4. Oxidative metabolism
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.
Multiple choice muscle contraction locomotion and movements biology

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

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

Multiple choice muscle contraction locomotion and movements biology

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

  1. Preformed ATP

  2. Oxidative metabolism

  3. Pyruvate and lactate

  4. Glycolysis
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.