Q: The transverse section of a plant material shows the following anatomical features:
a) The vascular bundles are conjoint, scattered and surrounded by a sclerenchymatous
bundle sheaths.
b) Phloem parenchyma is absent. What will you identify it as?
A: Monocot stem.
Q: Why xylem and phloem are called complex tissues?
A: Xylem and phloem are made up of more than one type of cells and these cells work
together as a unit. Hence they are called complex tissues.
Q: How is the study of plant anatomy useful to us?
A: Study of plant anatomy is useful to us for better understanding of tissue organization in the roots, stems and leaves.
Q: Protoxylem is the first formed xylem. If the protoxylem lies radially next to phloem, what kind of arrangement of xylem would you call it? Where do you find it?
A: Exarch xylem. It is found in Dicot and Monocot roots.
Q: What is the function of phloem parenchyma?
A: The phloem parenchyma stores food material and other substances like resins, latex
and mucilage.
Q: a) What is present on the surface of the leaves which helps the plant to prevent
loss of water but is absent in roots?
b) What is the epidermal cell modification in plants which prevents water loss?
A: a) Cuticle
b) Multicellular trichomes. In monocot leaves Bulliform cells.
Q: What are the cells that make the leaves curl in plants during water stress? Give an
example.
A: Bulliform cells.
Ex: Grasses (Monocot leaf)
Q: What constitutes the vascular cambial ring?
A: Intra fascicular cambium and inter fascicular cambium.
Q: Give one basic functional difference between phellogen and phelloderm.
A: Phellogen cuts off cells on both sides and produces phellem (outside) and phelloderm
(inside).
The phelloderm or secondary cortex is parenchymatous and helps in storage.
Q: If one debarks a tree, what parts of the plant are removed?
A: Periderm (Phelloderm, phellogen and phellem) and secondary phloem.
Q: Climax stage is achieved quickly in secondary succession as compared to primary succession. Why?
A: Since some soil or sediment is already present, climax stage is achieved quickly in
secondary succession.
Q: Among bryophytes, lichens and ferns which one is a pioneer species in a xeric succession?
A: Lichens.
Q: Give any two examples of xerarch succession.
A: Lichens, Bryophytes.
Q: Name the type of land plants that can tolerate the salinities of the sea.
A: Halophytes. Ex: Rhizophora.
Q: Define heliophytes and sciophytes. Name a plant from your locality that is either heliophyte or sciophyte.
A: Heliophytes: Plants that grow in direct sunlight.
Sciophytes: Plants that grow in shady places.
Ex: Pothos (Money plant)
Q: Define population and community.
A: Population: A group of similar individuals belonging to the same species found in an
area.
Community: A group of different populations in an area.
Q: Which part of the plant would show the following?
a) Radial vascular bundle b) Polyarch xylem
c) Well developed pith d) Exarch xylem
A: a) Roots b) Monocot roots
c) Monocot roots and dicot stems d) Roots
Junior Inter Botany 8 Marks Question from Chapters 12-13
Q: Describe the T.S of dicot stem.
A: The transverse section of a dicot stem shows: Epidermis, Cortex and Stele.
Epidermis: The epidermis is outer most protective layer covered by a cuticle. It may bear multicellular trichomes and stomata. It helps in protection, transpiration and
gaseous exchange.
Cortex: The cortex is the region between epidermis and stele. It is differentiated into: 1) Hypodermis 2) General cortex 3) Endodermis
The hypodermis is present below the epidermis and made up of collenchyma. It gives mechanical strength to young stems.
General cortex is parenchymatous with intercellular spaces. It helps in assimilation and
storage. The inner most layer of cortex is endodermis also called starch sheath. It
stores starch.
Stele: The stele is the central conducting cylinder and occupies large area in the stem.
It is differentiated into: 1) Pericycle 2) Vascular bundles 3) Medulla 4) Medullary rays
Pericycle is in the form of a semi lunar patch of Sclerenchyma above the vascular bundle.
The vascular bundles are arranged in a ring (eustele). Each vascular bundle is collateral, conjoint, open (cambium present between xylem and phloem) with endarch xylem.
Xylem is present towards centre and phloem towards periphery separated by cambium. Pith is large and parenchymatous at the centre and radiates as medullary rays in between the vascular bundles.
A: The transverse section of a dicot stem shows: Epidermis, Cortex and Stele.
Epidermis: The epidermis is outer most protective layer covered by a cuticle. It may bear multicellular trichomes and stomata. It helps in protection, transpiration and
gaseous exchange.
Cortex: The cortex is the region between epidermis and stele. It is differentiated into: 1) Hypodermis 2) General cortex 3) Endodermis
The hypodermis is present below the epidermis and made up of collenchyma. It gives mechanical strength to young stems.
General cortex is parenchymatous with intercellular spaces. It helps in assimilation and
storage. The inner most layer of cortex is endodermis also called starch sheath. It
stores starch.
Stele: The stele is the central conducting cylinder and occupies large area in the stem.
It is differentiated into: 1) Pericycle 2) Vascular bundles 3) Medulla 4) Medullary rays
Pericycle is in the form of a semi lunar patch of Sclerenchyma above the vascular bundle.
The vascular bundles are arranged in a ring (eustele). Each vascular bundle is collateral, conjoint, open (cambium present between xylem and phloem) with endarch xylem.
Xylem is present towards centre and phloem towards periphery separated by cambium. Pith is large and parenchymatous at the centre and radiates as medullary rays in between the vascular bundles.
Junior Intermediate Imp Questions for 4 Marks - Botany Chapters 12-13
Q: Define plant succession. Differentiate primary and secondary successions.
A: The gradual change in the composition of species in a given area is called ecological succession.
Plant succession may occur through xerosere or hydrosere. When plant succession starts on a bare rock it is called xerosere. When it starts on an aquatic habitat it is called hydrosere.
The sequence of communities that successively change in a given area are called seres.
If the succession starts where no living organisms ever existed like bare rock it is
called primary succession.
Ex: Cooled lava, bare rock, newly created reservoir or pond. It takes long period to
reach a climax community in primary succession.
If the succession starts in an area where organisms were existing but somehow lost is
called secondary succession. Ex: Abandoned farm lands, burned forests, flooded lands. Climax community is reached in less time when compared to primary succession.
Q: Define ecosystem / ecological services. Explain in brief with regard to pollination.
A: Ecosystem services or ecological services are the services provided by nature that are life supporting and life enhancing.
Ecosystem service - pollination: Pollination is an essential part of healthy ecosystem.
It is the transfer of pollen grains from the anthers to the stigma of a flower to facilitate fertilization process.
In many plants pollination is carried out by different species of animals especially
insects. The pollination carried out through insects is called entamophily. The animals (insects) which carry out pollination are called pollinators.
They are very important to ensure fertilization and seed and fruit production in majority of our crop plants. Decline in pollinator activity results in loss of
crop yield. Nearly one lakh species of invertebrates and 1035 species of vertebrates act as pollinators. According to US Fish and Wildlife Service lists 50 pollinator species are threatened or endangered. Causes of decline in pollinators are deforestation and chemical pesticides.
A: The gradual change in the composition of species in a given area is called ecological succession.
Plant succession may occur through xerosere or hydrosere. When plant succession starts on a bare rock it is called xerosere. When it starts on an aquatic habitat it is called hydrosere.
The sequence of communities that successively change in a given area are called seres.
If the succession starts where no living organisms ever existed like bare rock it is
called primary succession.
Ex: Cooled lava, bare rock, newly created reservoir or pond. It takes long period to
reach a climax community in primary succession.
If the succession starts in an area where organisms were existing but somehow lost is
called secondary succession. Ex: Abandoned farm lands, burned forests, flooded lands. Climax community is reached in less time when compared to primary succession.
Q: Define ecosystem / ecological services. Explain in brief with regard to pollination.
A: Ecosystem services or ecological services are the services provided by nature that are life supporting and life enhancing.
Ecosystem service - pollination: Pollination is an essential part of healthy ecosystem.
It is the transfer of pollen grains from the anthers to the stigma of a flower to facilitate fertilization process.
In many plants pollination is carried out by different species of animals especially
insects. The pollination carried out through insects is called entamophily. The animals (insects) which carry out pollination are called pollinators.
They are very important to ensure fertilization and seed and fruit production in majority of our crop plants. Decline in pollinator activity results in loss of
crop yield. Nearly one lakh species of invertebrates and 1035 species of vertebrates act as pollinators. According to US Fish and Wildlife Service lists 50 pollinator species are threatened or endangered. Causes of decline in pollinators are deforestation and chemical pesticides.
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