In which method of transport, plasma membrane does not require carrier molecule?
Active transport
Facilitated diffusion
Simple diffusion
Na+ K+ pump
Correct Answer :
C. Simple diffusion
Simple diffusion is a process in which plasma membrane does not require any carrier molecule to pass small non- charged molecules or lipid soluble molecules between the phospholipids to enter or leave the cell. The particles move from areas of high concentration to areas of low concentration (they move down their concentration gradient). Oxygen and carbon dioxide and most lipids enter and leave cells by simple diffusion.
Related Questions
Consider the following statements and choose the correct statement.
- The endomembrane system includes mitochondria, chloroplast and peroxisomes.
- Smooth endoplasmic reticulum is the major site for synthesis of lipid.
- Rough endoplasmic reticulum is actively involved in protein synthesis.
- Mitochondrial matrix possesses single circular DNA, a few RNA and 80S ribosomes. Of the above statements.
(i) and (iii)
(ii) and (iv)
(iii) and (iv)
(ii) and (iii)
_______________ is the important site of formation of glycoproteins and golycolipids.
SER
Lysosome
Golgi apparatus
Mitochondria
Match column-I with column-II and select the correct option.
| Column - I | Column - II |
|---|---|
| A. RER | I. Intracellular and extracellular digestion |
| B. Cell wall | II. Provide structural support to the cell |
| C. Flagella | III. Protein synthesis and secretion |
| D. Lysosomes | IV Responsible for cell movement |
A III, B II, C IV, D I
A II, B III, C IV, D I
A I, B III, C II, D IV
A IV, B II, C III, D I
Plastids storing fat are called
Elaioplasts
Sphaerosomes
Aleuroplasts
Pyrenoids
Microtubules are absent in
mitochondria
centriole
flagella
spindle fibres
Which of the following pair are correctly matched.
A. Microtubules Structural components of cilia
B. Centrioles Store hydrolytic enzymes
C. Amyloplasts Store oil protein and starch in plants
A, B and C
A and B
A
A and C
Chromosomes having equal or almost equal arms are called
metacentric
acrocentric
polycentric
acentric.
Which of the following statements are correct ?
- In prokaryotic cells, a special membranous structure formed by the extension of the plasma membrane into the cell is known as polysome.
- The smooth endoplasmic reticulum is the major site for synthesis of glycoproteins.
- RuBisCO is the most abundant protein in the whole biosphere.
- Mitochondria, chloroplasts and peroxisomes are not considered as part of endomembrane system. Of the above statements
(iii) and (iv)
(i) and (ii)
(ii) and (iii)
(i) and (iv)
Golgi apparatus is absent in
higher plants
yeast
bacteria and blue-green algae
None of the above
Which of the following is absent in prokaryotes?
DNA
RNA
Plasma membrane
Mitochondria
Active transport across biomembrane involves
production of ATP
requirement of energy
production of toxin
release of energy
The figure below shows the structure of a mitochondrion with its four parts labelled (A), (B), (C) and (D).
Select the part correctly matched with its function.
Part (D): Outer membrane Gives rise to inner membrane by splitting.
Part (B): Inner membrane Forms infoldings called cristae.
Part (C): Cristae Possess single circular DNA molecule and ribosomes.
Part (A): Matrix Major site for respiratory chain enzymes.
Match column-I with column-II and select the correct option.
| Column - I | Column - II |
|---|---|
| A. Golgi apparatus | I. Storage |
| B. Mitochondria | II. Photosynthesis |
| C. Vacuoles | III. Transport |
| D. Grana | IV. Secretion |
| .. | V. Respiration |
A - IV, B - V, C - I, D - II
A - I, B - II, C - IV, D - III
A - IV, B - I, C - II, D - III
A - I, B - II, C - III, D - IV
According to widely accepted fluid mosaic model cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect?
Proteins in cell membranes can travel within the lipid bilayer.
Proteins can also undergo flip-flop movements in the lipid bilayer.
Proteins can remain confined within certain domains of the membrane.
Many proteins remain completely embedded within the lipid bilayer.
Which cellular structure helps in transferring genetic information from one generation to another?
W
X
Y
Z
Which of the following is not the function of cell wall?
- Provides shape to the cell.
- Protects the cell from mechanical damage and infection.
- Helps in cell to cell interaction.
- Provides barrier to undesirable macromolecules.
Only (i)
Only (iv)
Only (ii), (iii) and (iv)
None of the above
Golgi apparatus is concerned with
excretion
secretion
ATP synthesis
RNA synthesis
Select the incorrect statement about prokaryotic ribosomes.
50S and 30S subunits unite to form 70S ribosomes.
Polysome/polyribosome consists of many ribosomes only.
Ribosome is the site of protein synthesis.
Polysome indicate the synthesis of identical poolypeptide in multiple copies.
In the given figure of animal cell, one orginelle is marked as A. Select the correct identification and function of the organelle A from the given option.
Endoplasmic reticulum Synthesis of lipids.
Mitochondria Produce cellular energy in the form of ATP.
Golgi body Provides packaging material.
Lysosomes Secrete hydrolytic enzymes.
Match column I (cell type) with column II (size) and choose the correct option.
| Column-I | Column-II |
|---|---|
| (Cell type) | (Size) |
| A. Viruses | I. 1-2 ??m |
| B. PPLO | II. 10-20 ??m |
| C. Eukaryotic cell | III. About 0.1 ??m |
| D. Bacterium | IV. 0.02 - 0.2 ??m |
A I, B II, C III, D IV
A IV, B III, C II, D I
A I, B III, C II, D IV
A IV, B II, C III, D I
Which of the following statement is correct regarding vacuole?
It is membrane-bound and contains storage proteins and lipids.
It is membrane-bound and contains water and excretory substances.
It lacks membrane and contains air.
It lacks membrane and contains water and excretory substances.
Identify the cell organelle given below. Which is an important site of formation of glyeoproteins & glycolipids
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Golgi body
mitochondria
Prokaryotic and eukaryotic flagella differ in the
type of movement and placement.
location and mode of functioning.
microtubular structure and function.
microtubular organization and type of movement.
Cell sap is a
living content of cytoplasm.
nonliving content of cytoplasm.
nonliving content of vacuole.
living content of vacuole.
Which of the following statements are incorrect ?
- Plant cells have centrioles which are absent in almost all animal cells.
- Ribosomes are the site of protein synthesis.
- The middle lamella is a layer mainly of calcium carbonate which holds the different neighbouring cells together.
- In animal cell, steroidal hormones are synthesized by smooth endoplasmic reticulum. Of the above statements
(i) and (iii)
(iii) and (iv)
(ii) and (iv)
(i) and (iv)
Which of the following statement is false?
The ribosomes of a polysome translate the mRNA into protein.
Mitochondria divide by fragmentation.
All cell arise from pre-existing cells.
The lipid component of the membrane mainly consists of phosphoglycerides.
In which of the following the cells are held together by a Ca-pectate layer?
Primary cell wall
Secondary cell wall
Middle lamella
Tertiary cell wall
Which of the following statements are correct?
Na+/K+ pump is an example of active transport.
In plant cells lipid like steroidal hormones are synthesized in SER.
In plant cells, the vacuoles can occupy up to 10% of the volume of the cell.
Chlorophyll and leucoplast are responsible for trapping light energy essential for photosynthesis.
The given diagram shows the sectional view of a mitochondrion.
Identify the parts labelled as A, B, C, D & E
A - Outer membrane, B - Inner membrane, C - Matrix, D - Inter- membrane space, E - Crista
A - Outer membrane, B - Inner membrane, C - Intermembrane space, D - Matrix, E - Crista
A - Outer membrane, B - Inner membrane, C - Matrix, D - Crista, E - Inter - membrane space
A - Outer membrane, B - Inner membrane, C- Crista, D - Matrix, E - Inter-membrane space
Extension of plasma membrane in prokaryotic cell is
mesosome
haploid
ribosome
none of these