Tag: transport across membrane

Questions Related to transport across membrane

Which of the following statements is not correct?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. In plant cells, vacuoles are absent.

  2. Vacuole is bounded by a single membrane.

  3. In Amoeba, contractile vacuole is important for excretion.

  4. Flagellum is important for transport of bacteria.

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Correct Option: A

Passage of cell contents out of the cell. Water potential can be calculated as : 

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. $\pi + WP$

  2. $\Psi + WP $

  3. Osmotic potential + TP

  4. $\pi + TP$

Show answer
Correct Option: A
Explanation:

  • Water potential is the energy potential of water compared to pure water in a system when both temperature and pressure are same .
  •  When the contents of the the cell moves out then then the wall pressure or turgour pressure will decrease .
So the correct answer is ' B ' . 

$2\%$ NaCl as compared to $18\%$ glucose solution is

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Isoomotic

  2. Hypersmotic

  3. Hypoosmotic

  4. None of the above

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Correct Option: A

When the cell is placed in water, it takes water this is due to?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Osmotic pressure

  2. Suction pressure

  3. Diffusion

  4. Water potential and TP

Show answer
Correct Option: A

Red blood cells when placed in a hypotonic solution will ______.This process is known as ______.

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Shrink, crenation

  2. Swell up, plasmolysis

  3. Turgid, deplasmolysis

  4. Burst, haemolysis

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Correct Option: A
Explanation:

Crenation is defined as the process by which a blood cell shrinks when it is exposed to a hypotonic solution.

The value of $2, 4$-D is $25$ ppm. How many amount of $2, 4$-D should require for making its $5$ litres, $15$ litres and $25$ litres solutions respectively.

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. $25$gm, $50$gm, $75$gm

  2. $50$gm, $175$gm, $525$gm

  3. $250$gm, $750$gm, $1250$gm

  4. $125$gm, $375$gm, $625$gm

Show answer
Correct Option: D
Explanation:

1 ppm is equal to 1 gm per litre.

25 ppm is equal to 25 gm per litre.
Therefore, 
for 5 litres, amount needed is 5 times 25= 125 gm
for 15 litres, amount needed is 15 times 25= 375 gm
for 25 litres, amount needed is 25 times 25= 625 gm.
So the correct option is D.

Plant cells do not burst in distilled water, because

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Cells wall is rigid and do not get overstretched

  2. Cell wall is living

  3. Cell wall is the outer most layer of plant cell

  4. Cell wall is permeable

Show answer
Correct Option: A
Explanation:

Cell wall is the outermost, rigid, protective, non living and supportive layer found in all the plant cells. Due to its rigid nature it prevent the cell from bursting. It is not found in animal cells. An animal cell placed in pure water will swell up and burst, because of endosmosis.

When a grape is placed in concentrated sugar solution, then it will show

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Endosmosis

  2. Exosmosis

  3. Imbibition

  4. None of the above

Show answer
Correct Option: B
Explanation:

When a grape is placed in a solution of concentrated sugar solution, it will show the process of exosmosis and lose water. When a cell is kept in hypertonic solution, it readily crosses the cell wall and fills the space between the cell wall and cell membrane. This hypertonic solution in direct contact with the cell membrane causes plasmolysis and extracts water from the cytoplasm of the cell.

So, the correct answer is option B.

A cell is plasmolysed after being kept in a hypertonic solution. What will be present between the cell wall and plasmalemma?

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Isotonic solution

  2. Hypertonic solution

  3. Air

  4. Hypotonic solution

Show answer
Correct Option: B
Explanation:

The cell wall is nonliving and cannot regulate the entry and exit of solute or solvent molecules. When a cell is kept in hypertonic solution, it readily crosses the cell wall and fills the space between the cell wall and cell membrane. This hypertonic solution in direct contact with the cell membrane causes plasmolysis and extracts water from the cytoplasm of the cell.

So, the correct answer is option B.

Which bacterium causes cotton destruction

bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

  1. Clostridzum botulinum

  2. Spirochaeta cytophaga

  3. Mycobacterium

  4. Vibrio

Show answer
Correct Option: B
Explanation:

Some bacteria damage cellulose of textiles. e.g., Spirochaete cytophage, cellulomonas etc.