BADHANEDUCATION D96 MUNIRKA VILLAGE NEW DELHI 110067 & VIKAS PURI NEW DELHI
CONTACT FOR COACHING MATHEMATICS FOR 11TH 12TH NDA DIPLOMA SSC CAT SAT CPT
CONTACT FOR ADMISSION GUIDANCE B.TECH BBA BCA, MCA MBA DIPLOMA AND OTHER COURSES 09810144315
1. What is a mesosome in a prokaryotic cell? Mention the functions that it performs.
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Solution:
Mesosomes are special membranous structure formed by the extension of plasma membrane. These
extensions are in the form of vesicles, tubules, and lamella
Functions
(1) They help in the formation of cell wall
(2) They take part in the replication of and distribution DNA to the daughter cells.
(3) Mesosomes help in respiration, and secretion processes.
(4) They increase the surface area of the plasma membrane and enzymatic content.
2. How do neutral solutes move across the plasma membrane? Can the polarmolecules
also move across it in the same way? If not, then how are thesetransported across the
membrane?
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Solution:
Neutral solutes move across the membrane by the process of simple diffusion along the
concentration gradient which is from higher concentration to lower concentration.
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Polar molecules cannot move across the membrane in the same way. They require a carrier protein
of the membrane to facilitate their transport.
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3. Name two cell-organelles that are double membrane bound. What are the
characteristics of these two organelles? State their functions and draw labeled diagrams of
both.
Solution:
The double membrane bound cell-organelles are
(2) Chloroplast.
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(1) Mitochondria
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Characteristics of Mitochondria and Chloroplast
The outer membrane forms the limiting membrane. The inner membrane encloses a lumen. It is
known as matrix in mitochondria and stroma in chloroplast.
Functions of Mitochondria
(1) It is the site of aerobic respiration.
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CONTACT FOR MATHEMATICS GROUP/HOME COACHING FOR CLASS 11TH 12TH BBA,BCA,
DIPLOMA CPT CAT SSC AND OTHER EXAMS Also home tutors for other subjects in DELHI AND OTHER MAJOR CITIES
EMAIL:1 [email protected] web site www.badhaneducation.in
BADHANEDUCATION D96 MUNIRKA VILLAGE NEW DELHI 110067 & VIKAS PURI NEW DELHI
CONTACT FOR COACHING MATHEMATICS FOR 11TH 12TH NDA DIPLOMA SSC CAT SAT CPT
CONTACT FOR ADMISSION GUIDANCE B.TECH BBA BCA, MCA MBA DIPLOMA AND OTHER COURSES 09810144315
(2) They produce cellular energy in the form of ATP; hence they are called as the "power house of
the cell".
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Functions of Chloroplast
(1) They are the site of photosynthesis.
(2) They store the enzymes required for the synthesis of carbohydrates.
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CONTACT FOR MATHEMATICS GROUP/HOME COACHING FOR CLASS 11TH 12TH BBA,BCA,
DIPLOMA CPT CAT SSC AND OTHER EXAMS Also home tutors for other subjects in DELHI AND OTHER MAJOR CITIES
EMAIL:2 [email protected] web site www.badhaneducation.in
BADHANEDUCATION D96 MUNIRKA VILLAGE NEW DELHI 110067 & VIKAS PURI NEW DELHI
CONTACT FOR COACHING MATHEMATICS FOR 11TH 12TH NDA DIPLOMA SSC CAT SAT CPT
CONTACT FOR ADMISSION GUIDANCE B.TECH BBA BCA, MCA MBA DIPLOMA AND OTHER COURSES 09810144315
4. What are the characteristics of prokaryotic cells.
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Solution:
(1) Prokaryotes have cell wall surrounding the cell membrane.
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(2) They do not have a well defined nucleus.
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(3) The genetic material is not covered by a nuclear membrane.
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(4) Extra chromosomal DNA called plasmids is present in the cytoplasm.
(5) Prokaryotes do not have membrane bound organelles.
5. Multi cellular organisms have division of labour. Explain.
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Solution:
Multi cellular organisms have different types of cells and each of these cells have different functions
to perform. For e.g. red blood cells helps in the transport of oxygen, white blood cells help in
protection of the body against pathogens, nerve cells for bodily co-ordination etc. A group of cells,
which are of the same type, perform the same function like the cells of the kidney helping in
excretion, the cells of the respiratory system helping in respiration, the cells in the digestive system
helping in nutrition etc. Thus we can see that in multi cellular organisms each function is performed
by each system, which exhibits division of labour.
6. Cell is the basic unit of life. Discuss in brief.
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Solution:
All living organisms are composed of small, tiny structures or compartments called cells. These cells
are called the ‘building blocks’ of life.
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The cells in a true sense are considered as the basic unit of life because all the life processes, i.e.,
metabolism, responsiveness and reproduction are carried out by the cells. Cells are the seat of all
metabolic processes. Respiration, nutrition and release of energy are carried out within the cells.
Even the animals and plants reproduce because the cells reproduce individually. Growth occurs
because cells grow and multiply.
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Let us take the example of amoeba, a unicellular organism. In amoeba, all the life processes are
performed within the boundaries of the single cell. On the other hand, the body of a multi cellular
organism is made up of many cells. In these organisms, the cells do not behave independently, but
get organized into tissues. Each tissue is specialized to perform specific functions. Different tissues
then get organized into organs, which perform certain specific functions. Different organs are finally
organized to form organ systems. These tissues, organs and organ systems of the organisms work
because the cells work.
On account of the above discussion, it can be said that cells are the structural and functional unit of
living beings. Hence it is the basic unit of life.
7. What are nuclear pores? State their function.
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CONTACT FOR MATHEMATICS GROUP/HOME COACHING FOR CLASS 11TH 12TH BBA,BCA,
DIPLOMA CPT CAT SSC AND OTHER EXAMS Also home tutors for other subjects in DELHI AND OTHER MAJOR CITIES
EMAIL:3 [email protected] web site www.badhaneducation.in
BADHANEDUCATION D96 MUNIRKA VILLAGE NEW DELHI 110067 & VIKAS PURI NEW DELHI
CONTACT FOR COACHING MATHEMATICS FOR 11TH 12TH NDA DIPLOMA SSC CAT SAT CPT
CONTACT FOR ADMISSION GUIDANCE B.TECH BBA BCA, MCA MBA DIPLOMA AND OTHER COURSES 09810144315
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Solution:
The minute pores formed by the fusion of the two nuclear membranes which envelopes the nucleus
is called as the nuclear pores.
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Function
It forms the passage for the movement of RNA and proteins in both the directions between the
nucleus and the cytoplasm.
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8. Both lysosomes and vacuoles are endo membrane structures, yet they differ in terms
of their functions. Comment.
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Solution:
Lysosomes are membrane bound vesicular structure, which contains all types of hydrolytic enzymes.
The main function of these enzymes is the digestion of carbohydrates, proteins, lipids, and nucleic
acids.
Vacuoles are membrane bound space found in the cytoplasm, which contain water, sap, excretory
products, and other materials not necessary for the cell. Its helps in the excretion of unwanted waste
products.
In some organisms like amoeba it forms food vacuole for digestion of food and also contractile
vacuole for excretion of waste.
9. Describe the structure of the following with the help of labeled diagrams.
(i) Nucleus
(ii) Centrosome.
Solution:
(i) Structure of Nucleus
In 1831 Robert Brown first described the nucleus. During the inter phase stage in the nucleus we can
see the nucleoprotein fibers called chromatin, nuclear matrix, and one or more spherical bodies
called nucleoli. It is covered by a nuclear envelope, which consists of two membranes with a space in
between called peri nuclear space. The outer membrane is usually continuous with the endoplasmic
reticulum and it bears ribosome's on it.
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The nuclear envelope is interrupted at a number of places by number of pores, formed by the fusion
of its two membranes.
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The nucleoplasm contains nucleolus and chromatin. The content of the nucleolus that is spherical
structures is continuous with the rest of the nucleoplasm. The nucleolus is not a membrane bound
structure. The chromatin during cell division gets condensed and is called chromosomes.
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CONTACT FOR MATHEMATICS GROUP/HOME COACHING FOR CLASS 11TH 12TH BBA,BCA,
DIPLOMA CPT CAT SSC AND OTHER EXAMS Also home tutors for other subjects in DELHI AND OTHER MAJOR CITIES
EMAIL:4 [email protected] web site www.badhaneducation.in
BADHANEDUCATION D96 MUNIRKA VILLAGE NEW DELHI 110067 & VIKAS PURI NEW DELHI
CONTACT FOR COACHING MATHEMATICS FOR 11TH 12TH NDA DIPLOMA SSC CAT SAT CPT
CONTACT FOR ADMISSION GUIDANCE B.TECH BBA BCA, MCA MBA DIPLOMA AND OTHER COURSES 09810144315
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(ii) Structure of Centro some
Centrosome consists of two cylindrical structures called centrioles which are surrounded by
amorphous pericentriolar materials. In a Centrosome both the centrioles lie perpendicular to each
other. The centrioles are made up of nine evenly peripheral fibrils of tubulin. Each fibril is a triplet
and the adjacent triplets are linked. The central portion of the centriole is proteinaceous.
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10. What is a Centromere?
(i) How does the position of Centromere form the basis of classification of chromosomes?
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(ii) Support your answer with a diagram showing the position of Centromere on different
types of chromosomes.
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Solution:
(i) The primary constriction present in the chromosome is called Centromere. On either sides of the
Centromere there are disc shaped structures called kinetochores.
There are four types of chromosomes based on the position of the Centromere they are
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CONTACT FOR MATHEMATICS GROUP/HOME COACHING FOR CLASS 11TH 12TH BBA,BCA,
DIPLOMA CPT CAT SSC AND OTHER EXAMS Also home tutors for other subjects in DELHI AND OTHER MAJOR CITIES
EMAIL:5 [email protected] web site www.badhaneducation.in
BADHANEDUCATION D96 MUNIRKA VILLAGE NEW DELHI 110067 & VIKAS PURI NEW DELHI
CONTACT FOR COACHING MATHEMATICS FOR 11TH 12TH NDA DIPLOMA SSC CAT SAT CPT
CONTACT FOR ADMISSION GUIDANCE B.TECH BBA BCA, MCA MBA DIPLOMA AND OTHER COURSES 09810144315
• Met centric
The chromosome has the Centro mere in the middle forming two equal arms of the
chromosome.
• Sub-met centric
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The chromosome has the Centro mere nearer to one end of the chromosome resulting in the
formation of one long arm and another short arm.
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• Areocentric
The Centromere lies extremely close to one end of the chromosome resulting in the
formation of one long arm and the other very short arm.
• Telocentric
In this type the Centro mere lies in the terminal end of the chromosome.
(ii)
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CONTACT FOR MATHEMATICS GROUP/HOME COACHING FOR CLASS 11TH 12TH BBA,BCA,
DIPLOMA CPT CAT SSC AND OTHER EXAMS Also home tutors for other subjects in DELHI AND OTHER MAJOR CITIES
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