Nucleolus is
rounded structure found in cytoplasm near nucleus.
rounded structure inside nucleus and having rRNA.
rod-shaped structure in cytoplasm near the nucleus.
none of the above.
Correct Answer :
B. rounded structure inside nucleus and having rRNA.
Nucleolus is a small rounded body within a resting nucleus that contains RNA and proteins. It is usually associated with a specific chromosomal site and involved in ribosomal RNA synthesis and the formation of ribosomes.
Related Questions
Match column-I with column-II and choose the correct option.
| Column-I | Column-II |
|---|---|
| A. Tonoplast | I. Contain digestive enzyme |
| B. Contractile vacuole | II. Store metabolic gases |
| C. Food vacuole | III. Excretion |
| D. Air vacuole | IV. Transport of ions in plants |
A IV; B III; C I; D II
A II; B III; C IV; D I
A IV; B II; C III; D I
A I; B III; C II; D IV
Chromosomes having equal or almost equal arms are called
metacentric
acrocentric
polycentric
acentric.
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
Function of contractile vacuole in Amoeba is
excretion and osmoregulation.
digestion and respiration.
osmoregulation and transportation.
none of the above.
Which of the following pair are correctly matched ?
(I) Amyloplasts Store proteins
(II) Mitochondrion Power house of the cell
(III) Stroma Chlorophyll pigment
(IV) Axoneme 9 + 2 array
(I) and (III) only
(II), (III) and (IV) only
(III) and (IV) only
(II) and (IV) only
Extension of plasma membrane in prokaryotic cell is
mesosome
haploid
ribosome
none of these
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
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.
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)
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
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 option correctly match A, B, C, and D indicated in the given sectional view of chloroplasts.
A - Thylakoid, B-Stromal lamella, C - Stroma, D - Granum
A - Granum, B - Thylakoid, C - Stromal lamella, D - Stroma
A - Thylakoid, B - Granum, C - Stromal lamella, D - Stroma
A - Granum, B - Thylakoid, C - Stroma, D - Stromal lamella
Which function is carried out by the cell organelle 'X'?
helps control the movement of substance in and out of the cell
passes information from the parent cell to newly formed cell
maintains the proper shape of the cell and serves as a protective barrier
helps the cell to make food with the help of chlorophyll and sunlight
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
Match column-I with column-II and choose the correct option.
| Column-I | Column-II |
|---|---|
| (Chromosome) | (Position of Centromere) |
| A. Metacentric | I. At the tip |
| B. Submetacentric | II. Almost near the tip |
| C. Acrocentric | III. At the middle |
| D. Telocentric | IV. Slightly away from the middle |
A III; B IV; C II; D I
A IV; B III; C II; D I
A I; B II; C III; D IV
A IV; B III; C I ; D II
Identify the components labelled A, B, C and D in the given section of cilia/flagella showing different parts. Choose the option which shows the correct labelling of parts.
A Plasma membrane, B Interdoublet bridge, C Central microtubule, D Radial spoke
A Plasma membrane, B Arm, C Central microtubule, D Radial spoke
A Plasma membrane, B Interdoublet bridge, C Hub, D Radial spoke
A Plasma membrane, B Interdoublet bridge, C Hub, D Arm
Which of the following organelles is directly connected to the outer membrane of the nucleus in a eukaryotic cell?
Mitochondrion
Lysosome
Golgi apparatus
Endoplasmic reticulum
Membranous extensions in blue green algae are known as
phytochrome
chromatophore
mesosome
pneumatophore
Which of the following cell organelles were discovered after the introduction of electron microscope?
Mitochondria
Endoplasmic reticulum
Ribosomes
Both (b) and (c)
Match column-I (scientists) with column-II (discovery) and select the correct option.
| Column-I | Column-II |
|---|---|
| A. Leeuwenhoek | I. First saw and described a living cell |
| B. Robert Brown | II. Presence of cell wall is unique to plant cells |
| C. Schleiden | III. Discovered the nucleus |
| D. Schwann | IV. All plants are composed of different kind of cells |
A I, B III, C IV, D II
A I, B III, C II, D IV
A III, B I, C IV, D II
A I, B IV, C II, D III
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
Active transport across biomembrane involves
production of ATP
requirement of energy
production of toxin
release of energy
Golgi apparatus is concerned with
excretion
secretion
ATP synthesis
RNA synthesis
The following diagram represents a structure chromosome.
Identify the structures marked as A, B and C.
A - Satellite, B - Primary constriction, C - Acrocentric
A - Satellite, B - Secondary constriction, C - Metacentric
A - Satellite, B - Centromere, C - Telocentric
A - Satellite, B - Centromere, C - Submetacentric
Study the following statements on cilium or flagellum and answer the question.
- Cilium / Flagellum contains an outer ring of nine doublet microtubules surrounding two singlet microtubules.
- Cilia are smaller which work like oars, causing the movement of either the cells or surrounding fluid.
- Flagella are comparatively longer and responsible for cell movement.
- Cilium and flagellum are covered with plasma membrane.
Which of the above statements are correct?
(i) and (ii)
(i), (ii), (iii) and (iv)
(i) and (iv)
(ii) and (iii)
The membrane of the erythrocytes has approximately ___% of proteins and ___% lipids.
42, 50
52, 40
50, 50
60, 40
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 prokaryotes, chromatophores are
specialized granules responsible for colouration of cells
structures responsible for organizing the shape of the organism.
inclusion bodies lying free inside the cells for carrying out various metabolic activities.
internal membrane system which becomes extensive and complex in photosynthetic bacteria.
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 is incorrect ?
Mycoplasma is the smallest cell (0.3 �).
Bacteria are 3 to 5 �m in size.
The largest cell is the egg of an ostrich.
Nerve cells are some of the smallest cells.