Cell Membrane

Q.

What is the unit membrane model of the plasma membrane?

Q.

What is the structure and function of cell membrane?

Q.

Which of the following best describes the structure of the plasma membrane?

1. Proteins sandwiched between two layers of phospholipid.

2. A layer of protein coating a layer of phospholipid.

3. Phospholipids embedded in two layers of protein.

4. Proteins embedded in two layers of phospholipid.

Q. The cell membrane is in nature.

1. impermeable
2. semi-permeable
3. rigid

Q.

Cell recognition and adhesion are facilitated by certain components of cell membrane. These components are generally

1. Proteins and lipids

2. Glycoproteins and glycolipids

3. Lipids only

4. Proteins only

Q.

The cell membrane is a non-living membrane.

False

True

Q. The plasma membrane is made up of a bilayer with molecules embedded in it.

1. phospholipid
2. lignin
3. cellulose
4. protein
5. phosphate

Q. Keeping in view the "fluid mosaic model" for the structure of cell membrane, which one of the following statements is correct with respect to the movement of lipids and proteins from one lipid monolayer to the other (described as flip-flop movement)?

1. While proteins can flip-flop, lipids cannot
2. neither lipids nor proteins can flip-flop
   
3. Both lipids and proteins can flip -flop
4. While lipids can rarely flip - flop proteins cannot

Q.

Plasmodesmata connection helps in

1. Cytoplasmic streaming

2. Synchronous mitotic division

3. Locomotion of unicellular organism

4. Movement of substances between cells

Q.

The most appropriate characteristic of a semi-permeable membrane is that

(a) it has minute pores.
(b) it has no pores.

(c) it allows the solute to pass through but not the solvent.

(d) it allows a solvent to pass through freely but prevents the passage of the solute.

Q.

Which is the correct statement regarding a cell membrane?

1. It only allows polar solvents like water to pass through it.

2. It allows no molecule to pass through it.

3. It is permeable only during a certain stage of the cell cycle.

4. It only allows certain molecules to pass through it.

Q.

What is semipermeable membrane?

Q. (a) Mention whether the following statements are true (T) or false (F).
(b) Correct the false statements by altering the last word only.
The cell wall of the root cell is a differentially permeable membrane.

Q.

Plasma membrane is

1. Impermeable

2. Selectively permeable

3. permeable

4. None of these

Q. Which of the following is the basic component of a cell membrane?

1. Carbohydrate
2. Lipids
3. Proteins
4. Both A and C

Q.

What controls the flow of substances in and out of a cell?

Q.

What do we know about the permeability of the cell membrane?

1. Impermeable membrane

2. Freely permeable membrane

3. Selectively permeable membrane

4. The permeability differs in different cells

Q. An example of a selective permeable membrane is
(a) cell wall
(b) mitochondrial membrane
(c) chloroplast membrane
(d) plasmalemma

Q. In Symplast Pathway, water molecules move to the adjacent cells, through

Q.

The fluid-mosaic model was advocated by:

1. Robertson

2. Singer and Nicolson

3. Danielli

4. Davson

Q.

Name the membrane that allows solvent molecules to pass through it.

1. Semi-permeable membrane

2. Selectively permeable membrane

3. Impermeable membrane

4. Both A and B

Q.

Label the image

1. a - Chromosome, b - Centrosome

2. a - Chromatin, b - Chromosome

3. a - Centrosome, b - Chromatin

4. a - Centrosome, b - Chromosome

Q. A cell will swell up if________________

1. The concentration of water molecules is same in the cell and in the surrounding medium.
2. The concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium.
3. The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell.
4. Concentration of water molecules does not matter.

Q. what are the differences between Chromatin and Chromatid ?

Q.

All cells possess a plasma membrane that functions to ___________.

1. enclose the cell

2. isolate the cell from random disturbances in the environment

3. allow metabolic events to occur in an orderly fashion

4. all of the above

Q. Explain the following terms:
Exosomosis:

[1 Mark]

1. Inward movement of solvent molecules through a selectively permeable membrane from a region of lower concentration to a region of higher concentration
2. Loss of water in the form of water droplets by plants from the margins of their leaves through special pores known as hydathodes
3. Outward movement of water through a semipermeable membrane when the surrounding solution is more concentrated
4. Movement of molecules of a substance from a region of higher concentration to a region of lower concentration

Q.

Differentiate between the following:

1. Turgor pressure and Wall pressure

Q. Which of the following cell organelles lacks DNA and bounding membrane?

1. Ribosome
2. Plastid
3. Plasmid
4. Nucleolus

Q.

The barrier which separates the protoplasm from the external environment is known as

1. Plasma membrane

2. Chlorophyll

3. Nucleus

4. Ribosomes

Q.

Name the membrane that allows solvent molecules to pass through it.

1. Impermeable membrane

2. Semi-permeable membrane

3. Selectively permeable membrane

4. Both A and B