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.
Correct Answer :
B. Mitochondria divide by fragmentation.
Mitochondria divide by fission.
Related Questions
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
Which one of the following cellular parts is correctly matched with their characters ?
Centrioles Sites for active RNA synthesis.
Lysosomes Optimally active at a pH of about 8.5.
Thylakoids Flattened membranous sacs forming the grana of chloroplasts.
Ribosomes Those on chloroplasts are larger (80S) while those in the cytoplasm are smaller (70S).
The fluidity of membranes in a plant in cold weather may be maintained by
increasing the number of phospholipids with unsaturated hydrocarbon tails.
increasing the proportion of integral proteins.
increasing concentration of cholesterol in membrane.
increasing the number of phospholipids with saturated hydrocarbon tail.
Cell sap is a
living content of cytoplasm.
nonliving content of cytoplasm.
nonliving content of vacuole.
living content of vacuole.
The diagram given below represent a filuid mosaic model of plasma membrance. Match the components marked as A, B, C, D and E in the diagram below from the list (i) to (vii).
- Sugar
- Protein
- Lipid bilayer
- Integral protein
- Cytoplasm
- Cell wall
- External protein
A - (i), B - (ii), C - (iii), D - (iv), E - (v)
A - (ii), B - (i), C - (iii), D - (iv), E - (v)
A - (i), B - (ii), C - (iii), D - (iv), E - (vi)
A - (i), B - (ii), C - (iii), D - (vii), E - (v)
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.
Which of the following is absent in prokaryotes?
DNA
RNA
Plasma membrane
Mitochondria
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.
Both the membranes of mitochondrion are
structurally different but functionally similar.
structurally as well as functionally different.
structurally similar but functionally different.
structurally different but functionally similar.
Centrioles and centrosomes occur in the cells of
green plants
animals
bacteria and cyanobacteria
both (b) and (c)
The cell theory was given in year 1839 by Schleiden and Schwann. According to this theory all organisms are composed of cell and cells are the basic unit of life.
How did this theory help in the field of science?
It helped to study the working of cells.
It helped in curing diseases caused by cell.
It helped in restating the earlier theories on cell.
It helped in introducing the use of microscopes to study cell.
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
Chromosomes having equal or almost equal arms are called
metacentric
acrocentric
polycentric
acentric.
Given below are some characters of a cell organelle identify the correct organelle which shows all the characters described above.
- It is a membrane bound space found in the cytoplasm.
- It is bound by a single membrane called tonoplast.
- It contains water, sap, excretory products and other materials not useful to the cell.
- It has higher concentration of sap than the cytoplasm.
Golgi apparatus
Lysosomes
Endoplasmic reticulum
Vacuoles
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
Lysosomes contain
carbohydrates
hormones
nucleic acids
hydrolases.
Which of the following terms is not correctly matched with its feature?
Osmosis Movement of water by diffusion.
Nucleoplasm Site of active synthesis of ribosomal RNA.
Mesosome Infolding of cell membrane and characteristics of eukaryotes.
Pili Elongated tubular surface structures (made of special protein) of bacteria.
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.
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.
Grana are
protein storing plastids.
coloured plastids.
stacks of thylakoids.
individual thylakoids present in stroma.
In which method of transport, plasma membrane does not require carrier molecule?
Active transport
Facilitated diffusion
Simple diffusion
Na+ K+ pump
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 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.
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.
Which of the following will determines the shape of the cells and provides a strong structural support to prevent the bacterium from bursting or collapsing?
Plasmids
Cell wall
Mesosome
Cell membrane
_______________ is the important site of formation of glycoproteins and golycolipids.
SER
Lysosome
Golgi apparatus
Mitochondria
Identify the components labelled as A, B, C, D and E in the diagram given below from the list (i) to (viii).
- Cristae of mitochondria
- Inner membrane of mitochondria
- Cytoplasm
- Smooth endoplasmic reticulum
- Rough endoplasmic reticulum
- Mitochondrial matrix
- Ribosome
- Nucleus
A - (viii), B - (v), C - (vii), D - (iii), E - (iv)
A - (i), B - (iv), C - (vii), D - (vi), E - (iii)
A - (vi), B - (v), C - (iv), D - (vii), E - (i)
A - (v), B - (i), C - (iii), D - (ii), E - (iv)
Select the correct match of the types of neuron present in column I with its location given in column II.
| Column I | Column II |
|---|---|
| A. Centrioles | (i) Non-membrane bound organelle which helps in cell division |
| B. Fimbriae | (ii) Special structure of bacteria which help them to attach with rocks in stream and also to host tissue |
| C. Endomembrane | (iii) Includes those organelles system whose functions are coordinated |
| D. Mitochondria | (iv) Divide by fission and site of aerobic respiration |
A - (i), B - (ii), C - (iii), D - (iv)
A - (iii), B - (i), C - (ii), D - (iv)
A - (iii), B - (i), C - (iv), D - (ii)
A - (i), B - (iv), C - (iii), D - (ii)
Most of water, in mature plant cells occurs in
nucleus
cell wall
vacuoles
cytoplasm
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