Q: Write any four physiological effects of cytokinins in plants. (4 Marks)
A: Some of the physiological effects of cytokinins in plants are: They
promote cell division in root apices, shoot buds and young fruits.
They help to produce new leaves and chloroplasts in leaves. They
promote adventitious shoot formation. Cytokinins help to overcome
apical dominance and promote lateral shoot growth. They promote
nutrient mobilisation and help in delay of leaf senescence.
Q: How are bacteria classified on the basis of number and distribution
of flagella? (4 Marks)
A: Based on the number and distribution of flagella the bacteria may
be classified as: Monotrichous having a single polar flagellum.
Amphitrichous having a single flagellum at each end of the cell.
Lophotrichous having two or more flagella at one pole of the cell.
Peritrichous having flagella distributed over the entire cell.
Q: Explain the lytic cycle with reference to certain viruses. (4 Marks)
A: Viruses like bacteriophages multiply by any of the two methods
lytic cycle and lysogenic cycle. Lytic cycle: Lytic cycle caused lysis
or death of host cell. T-even phages which cause lysis are called
virulent phages. Lytic cycle involves 5 steps:
Adsorption: It is the attachment of phage particle to the bacterial
host cell on complementary receptor sites.
Penetration: The tail sheath of the phage contracts and injects the
DNA into the bacterial cell. The capsid of the phage remains outside
the host cell as a ghost.
Bio synthesis: As the phage DNA enters the host cells it uses the cell
machinery and synthesizes phage DNA and capsid proteins. But the
complete virus particles do not appear hence called eclipse period.
Maturation: During this phase bacteriophage DNA and capsids assemble
into complete virions.
Release: At this stage the viral enzyme lysozyme produced in the host
cell dissolves the plasma membrane and breaks the cell wall to release
the newly synthesized
phage particles or virions. This phase is hence called lysis phase.
The number of newly synthesized phage particles released from a single
host cell is called 'burst size'. (50 to 200).
Q: Differentiate between the following: a) Dominant and recessive b)
Homozygous and heterozygous (4 Marks)
A: a) Dominant: It is the character that is expressed phenotypically
in both homozygous and heterozygous condition.
Recessive: It is the character which is not expressed phenotypically
in heterozygous condition.
b) Homozygous: An individual with two similar or identical alleles for
a single character. It produces only one kind of gametes with
reference to that character (gene).
Heterozygous: An individual with two different alleles for a single
character. It produces two different types of gametes with reference
to a gene.
IPE Exams - Senior Inter Botany Important Questions and Answers
As the questions in the academy textbook (2014 reprint) have been
revised, the students need to note that some of the questions have
been deleted while a few have been added. Some of the important
questions discussed here are according to the 2014 reprint textbook.
2 Marks Questions
Q: Define respiratory climacteric. Name the PGR associated with it.
A: A rise in the rate of respiration during fruit ripening is called
respiratory climacteric. Ethylene.
Q: Define the terms quiescence and dormancy.
A: When a seed is unable to germinate because of unfavourable external
conditions required for growth it is called quiescence. When a seed is
unable to germinate due to internal conditions like hard seed coats it
is called dormancy. (Though the external conditions are favourable).
Q: What is conjugation? Who discovered it and in which organism?
A: The direct transfer of DNA from donor cell to the recipient cell
through a conjugation tube between two live bacteria is called
conjugation. Lederberg and Tatum, Escherichia coli.
Q: What is transduction? Who discovered it and in which organism?
A: The transfer of genetic material from one bacterium to another
through bacteriophage is known as transduction. Lederberg and Zinder,
Salmonella typhimurium.
Q: What is the shape of T4 phage? What is its genetic material?
A: Tadpole shape. DNA (Deoxy Ribo Nucleic Acid)
Q: What is the shape of TMV? What is its genetic material?
A: Rod shape. RNA (Ribo Nucleic Acid)
Q: Explain the terms phenotype and genotype.
A: Phenotype: It is the physical or external appearance of a
character. Genotype: It is the genetic makeup of an individual.
revised, the students need to note that some of the questions have
been deleted while a few have been added. Some of the important
questions discussed here are according to the 2014 reprint textbook.
2 Marks Questions
Q: Define respiratory climacteric. Name the PGR associated with it.
A: A rise in the rate of respiration during fruit ripening is called
respiratory climacteric. Ethylene.
Q: Define the terms quiescence and dormancy.
A: When a seed is unable to germinate because of unfavourable external
conditions required for growth it is called quiescence. When a seed is
unable to germinate due to internal conditions like hard seed coats it
is called dormancy. (Though the external conditions are favourable).
Q: What is conjugation? Who discovered it and in which organism?
A: The direct transfer of DNA from donor cell to the recipient cell
through a conjugation tube between two live bacteria is called
conjugation. Lederberg and Tatum, Escherichia coli.
Q: What is transduction? Who discovered it and in which organism?
A: The transfer of genetic material from one bacterium to another
through bacteriophage is known as transduction. Lederberg and Zinder,
Salmonella typhimurium.
Q: What is the shape of T4 phage? What is its genetic material?
A: Tadpole shape. DNA (Deoxy Ribo Nucleic Acid)
Q: What is the shape of TMV? What is its genetic material?
A: Rod shape. RNA (Ribo Nucleic Acid)
Q: Explain the terms phenotype and genotype.
A: Phenotype: It is the physical or external appearance of a
character. Genotype: It is the genetic makeup of an individual.
10th Class Important Questions - Physical Sciences New Syllabus
Q: You are given a cylindrical vessel with a frictionless movable
piston. Water is taken in the vessel and it is heated by putting
weights on the piston.
a) How can you know when the boiling process of water started?
b) If the weights on the piston are increased what happens to the
boiling point of water?
A: a) The weights fall down when the boiling process starts.
b) There is no change in the boiling point of water, when the weights on the
piston are increased. This is because, as the piston is a frictionless
movable one, any increase in pressure in water pushes the piston
upwards.
Q: How much energy is released or absorbed when 1 gm. of water at 0°C
freezes to ice at 0°C?
A: Given: m = 1 gm.
Latent heat of fusion of ice L = 80 Cal/gm (We know)
Formula: Energy released Q = mL Cal.
Substituting the values: Q = 1 × 80 = 80 Cal.
Q: Why is slaked lime used for white washing walls?
A: A solution of slaked lime produced is used for white washing of walls.
Slaked lime (Calcium hydroxide Ca (OH)2) reacts slowly with the Carbon
dioxide in air to form a thin layer of Calcium Carbonate on the walls.
After two to three days of white washing, Calcium Carbonate formed
gives a shiny finish to the walls.
Q: Are the process of evaporation and boiling the same? (1 Mark)
A: Boiling of a liquid differs essentially from evaporation.
Evaporation takes place at any temperature while boiling occurs at a
definite temperature called the boiling point.
Q: Mention the uses of Propane, giving its formula. (1 Mark)
A: Propane is a colourless and odourless gas often used as a heating
and cooking fuel. ★ Its chemical formula is C3H8.
piston. Water is taken in the vessel and it is heated by putting
weights on the piston.
a) How can you know when the boiling process of water started?
b) If the weights on the piston are increased what happens to the
boiling point of water?
A: a) The weights fall down when the boiling process starts.
b) There is no change in the boiling point of water, when the weights on the
piston are increased. This is because, as the piston is a frictionless
movable one, any increase in pressure in water pushes the piston
upwards.
Q: How much energy is released or absorbed when 1 gm. of water at 0°C
freezes to ice at 0°C?
A: Given: m = 1 gm.
Latent heat of fusion of ice L = 80 Cal/gm (We know)
Formula: Energy released Q = mL Cal.
Substituting the values: Q = 1 × 80 = 80 Cal.
Q: Why is slaked lime used for white washing walls?
A: A solution of slaked lime produced is used for white washing of walls.
Slaked lime (Calcium hydroxide Ca (OH)2) reacts slowly with the Carbon
dioxide in air to form a thin layer of Calcium Carbonate on the walls.
After two to three days of white washing, Calcium Carbonate formed
gives a shiny finish to the walls.
Q: Are the process of evaporation and boiling the same? (1 Mark)
A: Boiling of a liquid differs essentially from evaporation.
Evaporation takes place at any temperature while boiling occurs at a
definite temperature called the boiling point.
Q: Mention the uses of Propane, giving its formula. (1 Mark)
A: Propane is a colourless and odourless gas often used as a heating
and cooking fuel. ★ Its chemical formula is C3H8.
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