Questions Related to biology

Multiple choice biology human body respiration in humans mechanism of respiration in animals human lungs

Inspiration occurs when there is a negative pressure in the lungs with respect to atmospheric pressure. This negative pressure is achieved when

  1. intrapulmonary pressure is less than the atmospheric pressure

  2. intrapulmonary pressure is greater than the atmospheric pressure

  3. intrapulmonary pressure is equal to the atmospheric pressure

  4. intrapleural pressure becomes more than the intra-alveolar pressure.

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Because of the pressure gradient between the lungs and the atmosphere, the air moves into and out of the lungs. Inspiration occurs if the pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure i.e. there is a negative pressure in the lungs with respect to atmospheric pressure.

Multiple choice biology human body respiration in humans mechanism of respiration in animals human lungs

Choose the correct answer from the alternatives given.
The lung is enclosed in a double layered membrane called

  1. pericardium

  2. pleura

  3. periosteum

  4. perichondrium

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pleura refers to the double-layered membrane that covers the lungs. The space between the two membranes is called the pleural cavity. It is filled with a thin, lubricating liquid called pleural fluid, which acts as a lubricant and allows the pleurae to slide effortlessly against each other by reducing friction during respiratory movements. So, the correct option is 'pleura'.

Multiple choice biology option c: ecology and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity

The abbreviation M.P.N. stand for.

  1. Millions per night

  2. Millenium of probable number

  3. Most probable number

  4. None of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
In microbiology, M.P.N. stand for Most probable number. The M.P.N test is a method to estimate the concentration of viable microorganisms in a sample using replicate liquid broth growth in 10-fold dilutions. Thus the correct answer is option C.
Multiple choice biology option c: ecology and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity

What will be percentage of water absorbed?

  1. $\displaystyle\frac {U - V}{100} X 50$
  2. $\displaystyle\frac {V - U}{50} X 100$
  3. $\displaystyle\frac {U - V}{50} X100$
  4. $\displaystyle\frac {V - U}{100} X50$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

U - V ? 50 * 100 is the percentage of water absorbed where, 

U is the initial volume of water and V is the final volume of water. 
So, option C is the correct answer.