Polysome is a chain of
oxysomes
sphaerosomes
ribosomes
dictyosomes
Correct Answer :
C. ribosomes
Several ribosomes may attach to a single mRNA and forms a chain called polysomes. The ribosomes of a polysome translate the mRNA into proteins.
Related Questions
Centrioles and centrosomes occur in the cells of
green plants
animals
bacteria and cyanobacteria
both (b) and (c)
Which of the following statements is/are correct ?
- The endomembrane system includes plasma membrane, ER, Golgi complex, lysosomes and vacuoles.
- ER helps in the transport of substances, synthesis of proteins, lipoproteins and glycogen.
- Ribosomes are involved in protein synthesis.
- Mitochondria help in oxidative phosphorylation and generation of ATP.
(ii), (iii) & (iv)
(i) only
(ii) only
(iii) only
Axoneme with 9 + 2 microtubular arrangement occurs in
cilia
flagella
both (a) and (b)
centriole
Grana are
protein storing plastids.
coloured plastids.
stacks of thylakoids.
individual thylakoids present in stroma.
Golgi apparatus is concerned with
excretion
secretion
ATP synthesis
RNA synthesis
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
Read the statements given below with regard to the functions performed by Golgi apparatus ?
- Transport and chemically modify the materials contained within it.
- Performs the function of packaging materials.
- Important site of formation of glycoproteins and glycolipids.
Which of the following is the correct answer ?
(i) is wrong but (ii) and (iii) are correct
(ii) is wrong but (i) and (iii) are correct
(ii) and (iii) are wrong but (i) is correct
All are correct.
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.
9.A student was given cell samples (A and B) to identify parts which are highlighted. He observed the samples under the microscope and list down the function of the part of cell sample. The information collected by the student is listed in the table below, on the basis of which the student infers that the samples contain the organelles.
| Sample A | Sample B |
|---|---|
| Make energy available for cellular metabolism | Generates ATP and synthes izes s ugar |
| Absent in cell that carry oxygen throughout the body | Present in plant cell |
| Called the energy currency of cell | Source o f all the food energy |
Explain why the samples were belonged to eukaryotic cell and not prokaryotic cell? Because,
eukaryotic cell have membrane bound organelles.
eukaryotic cell have non - membrane bound organelles.
eukaryotic cell are smaller and multiply more rapidly than prokaryotic cells.
eukaryotic cell are larger and multiply more rapidly than prokaryotic cells.
The given figures show two types of cell. Which structures are common to both the cells?
Nucleus and cell wall
Nucleus and cytoplasm
Ribosomes and flagella
Ribosomes and cell wall
Match column-I and column-II and select the correct answer
| Column-I | Column-II |
|---|---|
| A. Bacteria without walls | I. Lysosome |
| B. Small circular DNA | II. Mycoplasma cells |
| C. Flattened sacs in | III. Thylakoid a chloroplast |
| D. A vesicle in which | IV. Plasmid hydrolytic enzymes are stored |
A III; B IV; C II; D I
A II; B IV; C III; D I
A I; B II; C III; D IV
A IV; B III; C I ; D II
Microtubules are absent in
mitochondria
centriole
flagella
spindle fibres
The given diagram shows the types of chromosomes (labelled as A, B, C & D) based on the position of centromere.
Which one is the correct option for the labelled chromosomes. A, B, C and D ?
A Telocentric chromosome, B Acrocentric chromosome, C Submetacentric chromosome, D Metacentric chromosome
A Acrocentric chromosome, B Telocentric chromosome, C Metacentric chromosome, D Submetacentric chromosome
A Submetacentric chromosome, B Metacentric chromosome, C Telocentric chromosome, D Acrocentric chromosome
A Metacentric chromosome, B Submetacentric chromosome, C Acrocentric chromosome, D Telocentric chromosome.
Cell sap is a
living content of cytoplasm.
nonliving content of cytoplasm.
nonliving content of vacuole.
living content of vacuole.
Microtubules, motor proteins, and actin filaments are all part of the
mechanism of photosynthesis that occurs in chloroplasts.
rough ER in prokaryotic cells.
cytoskeleton of eukaryotic cells.
process that moves small molecules across cell membranes.
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
You are asked to examine a cell using a powerful light microscope. The image you see has a clearly defined nucleus and mitochondria. It also has a large central vacuole and chloroplasts. From what group of organisms did this cell most likely come?
Bacteria
Protists
Fungi
Plants
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.
Active transport differs from passive transport in that active transport
requires energy.
always requires input of ATP.
moves molecules against a concentration gradient.
both (a) and (c)
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.
Which of the following lacks cell wall?
Gametes
Amoeba
Mycoplasma
All of these
Which of the following statements is/are correct ?
- The shape of the cells may vary with the function they perform.
- Human RBC is about 7.0 ??m in diameter.
- Cytoplasm is the main area of cellular activities.
- Various chemical reactions occur in cytoplasm to keep the cell in the living state.
(i), (ii), (iii) and (iv)
Only (i) and (ii)
Only (iv)
None of the above
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
Plastids storing fat are called
Elaioplasts
Sphaerosomes
Aleuroplasts
Pyrenoids
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
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)
The main organelle involved in modification and routing of newly synthesized proteins to their destinations is
chloroplast
mitochondria
lysosome
endoplasmic reticulum
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.
The lipid component of the membrane mainly consists of __________.
polysaccharides
phosphoglyceride
monosaccharaides
both (a) and (c)
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