Tag: biology

Quizzes (1160) Questions (12174)

Questions Related to biology

Multiple choice biology natural disasters: winds, storms and cyclones composition of air introduction to air natural resources - air

Most abundant constituent of dry air in terms of volume is:

  1. carbon dioxide

  2. helium

  3. nitrogen

  4. oxygen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The most abundant gas in the Earth's atmosphere is nitrogen, which accounts for about 78% of the mass of dry air. 

Oxygen is the next most abundant gas, present at levels of 20 to 21%. 
Although humid air seems like it contains a lot of water, the maximum amount of water vapour that air can hold is only about 4%.

Hence, the correct option is $\text{C}$

Multiple choice biology natural disasters: winds, storms and cyclones composition of air introduction to air natural resources - air

Which of the following constituent gas is not directly used by the living beings?

  1. Oxygen

  2. Nitogen

  3. Hydrogen

  4. Carbon dioxide
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nitrogen gas cannot be used by the human beings directly, breathing pure nitrogen means we're not breathing oxygen, which means that we'll die of oxygen deprivation in a matter of minutes
Hence option B is correct.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

If two solution have the same osmolarity, they are said to be

  1. Hypertonic

  2. Hypotonic

  3. Isotonic

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Isotonic means two solutions having the same osmolarity. It allows the free movement of water across the membrane without changing the solute concentration. Hypotonic surrounding solution means a solution with less osmolarity. This means that concentration of solutes is less in the surrounding medium, than the concentration of solutes in cell sap and hypertonic surrounding solution means the concentration of solutes is more than the concentration of solutes in the cell sap.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

The space between the plasma membrane and the cell wall of a plasmolyzed cell surrounded by a hypertonic solution is occupied by the

  1. Hypotonic solution.

  2. Isotonic solution.

  3. Hypertonic solution.

  4. Water.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A plant cell wall is fully permeable and it cannot regulate the entry or exit of a solution. When a plant cell is placed in a hypertonic solution it will lose water by exosmosis. This process is called plasmolysis. The protoplasm will shrink and will move inwards and away from the cell wall. As a result, the hypertonic solution will occupy the space between the plasma membrane and the cell wall. Thus the correct answer is option C.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

All the following involves osmosis except.

  1. Water from soil entering a root hair

  2. Water passing from root hair to adjacent cells

  3. Water passing up a xylem vessel element to xylem vessel element above it

  4. Water entering a mesophyll cell from xylem vessel element
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Osmosis is the movement of water across a semi-permeable membrane. Water moving up a xylem vessel is primarily driven by transpiration pull and cohesion-tension, not osmosis.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Two cells A and B are contiguous. Cell A has osmotic pressure $10$atm, turgor pressure $1$ atm and diffusion pressure deficit $3$ atm. Cell B has osmotic pressure $8$ atm, turgor pressure $3$ atm and diffusion pressure deficit $5$ atm. The result will be?

  1. Movement of water from cell B to A

  2. No movement of water

  3. Equilibrium between the two

  4. Movement of water from cell A to B
Reveal answer Fill a bubble to check yourself
A Correct answer