Diffusion

Q.

why is diffusion insufficient to meet the oxygen requirement of multicellular organisms like humans.

Q.

Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans ?

Q.

Describe how exchange of gases take place in our lungs?

Q. How did the unicellular organism takes food , do exchange of gases and remove waste from the body?

Q. What are molecular movement and why are the molecular movement is important for life? Give examples also

Q.

Give reasons why multicellular organisms require special organ for exchange of gases b/w their body and their environment

Q.

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

Q.

Name the following:

(a) The condition of a cell placed in a hypotonic solution.

(b) The process by which intact plants lose water in the form of droplets from leaf margins.

(c) The process by which water enters root hairs.

(d) The tissue concerned with upwards conduction of water in plants.

(e) The term for the inward movement of solvent molecules through the plasma membrane of a cell.

(f) The process by which molecules distribute themselves evenly within the space they occupy.

(g) The pressure which is responsible for the movement of water molecules across the cortical cells of the root.

Q. When a drop of ink is added to water, it gets evenly distributed in sometime. This happens due to the process of ___.

1. diffusion

2. osmosis

3. active transport

4. respiration

Q.

Where does diffusion occur in the body?

Q.

The transport of oxygen and carbon dioxide in the cell takes place by which process?

1. Diffusion

2. Imbibition

3. Osmosis

4. Plasmolysis

Q.

Why are molecular movements needed for life? Is this invisible molecular movement necessary for life?

Q.

(a) Why is diffusion insufficient to meet the oxygen requirements of large multicellular organisms like humans ?
(b) What type of arrangement exists in the bodies of large animals to meet their oxygen requirements adequately ?
(c) What advantage a terrestrial animal has over an aquatic animal with regard to obtaining oxygen for respiration ?

Q.

Movement of molecules of a substance from the region of their higher concentration to the region of their lower concentration without the involvement of a separating membrane is called

(a) Osmosis (b) Diffusion

(c) Active transport (d) Capillarity

Q.

How do plants remove excess water?

Q.

Question 70
Why and how does water enter continuously into the root xylem?

Q.

Which of the following statements is correct regarding diffusion?

1. Diffusion takes place only in gases.

2. Movement of substances takes place from high concentration to low concentration.

3. Diffusion takes place only in liquids

4. Movement of substances takes place from low concentration to high concentration.

Q.

How does the process of diffusion take place across the cell membrane?

Q.

Substances like carbon dioxide and oxygen move across the cell membrane by the process of:

Photosynthesis

Diffusion

Transpiration

Respiration

Q.

The movement of substances from a region of higher concentration to a region of lower concentration is called __.

Q. How will the following conditions affect transpiration?​ ​
(i) Still air

Q. Materials like oxygen and carbon dioxide enter and leave cells by diffusion.

1. Passive transport
2. Osmosis
3. Diffusion
4. Active transport

Q. Diffusion occurs in
(a) Solids
(b) Liquids
(c) Gases

1. a, b
2. b, c
3. a, c
4. All

Q.

The phenomenon by which the living or dead plant cells absorb water by surface attraction is ___ .

1. Diffusion

2. osmosis

3. Imbibition

4. Plasmolysis

Q.

The diffusion of ${CO}_2$ across the alveolar membrane is 20 times faster than that of $O_2$ because

1. CO₂ is actively transferred.

2. The alveolar area available for CO₂ diffusion is larger.

3. CO₂ is more soluble in H₂O than O₂, which enables it to pass the membrance more readily.

4. The CO₂ pressure gradient in larger.

Q.

Why is molecular movements necessary for life

Q.

Multicellular organisms cannot meet oxygen requirement only by diffusion . give reason.

Q.

Exchange of gases in the body takes place by which of the following mechanisms?

1. External respiration

2. Internal respiration

3. Cellular respiration

4. Counter-current exchange

Q.

Which of the following always involves the process of diffusion in?
A. The movement of minerals from the soil into root hair cells.
B. The movement of water into the cells of living things.
C. The movement of dissolved oxygen from the surrounding water into an amoeba.
D. The movement of carbon dioxide from the air into leaf cells.

1. Only C and D

2. Only A and B

3. Only A and C

4. Only B and C

Q. What is diffusion? Explain about diffusion in solid , liquid and gas with the help of suitable diagram.