UNIT II
Chapter:5 Morphology of flowering plants
Content at a glance.
1. Studying the external features of plants is called Plant Morphology.
A flowering plant has root (underground) and shoot (above ground)
systems.
2. Root is meant for anchorage and absorption of water and minerals.
Some roots are modified to perform special functions as storage,
Respiration and support .
3. Stem holds leaves,flowers and fruits. Stems are modified to perform
The function of storage, protection,climbing and photosynthesis.
4. Leaves are photosynthetic organs.They are modified in certain plants
to perform the job of climbing(tendril in Pea),trapping insects(Pitcher
plant),protection(spines in cactus) etc.
5. Leaves have either reticulate venation(Dicots) or parallel
venation(Monocots)
6. Leaves are arranges on stem in 3 ways. Alternate,opposite or
whorled.
7. Inflorescence is the arrangement of flowers on the floral axis.It is of 2
types.Racemose and cymose.
8. Based on the position of ovary flowers are 3 types. Hypo, Peri and
Epigynous.
9. 4 whorls in a complete flower. Calyx(sepals) Corolla(Petals)
Androecium(Stamens and Gynoecium(pistil)
10. Arrangement of ovules in the ovary is called placentation.
Marginal,axile,free central,parietal and basal are different types of
placentation.
11. Fruits are formed after fertilization.Parthenocarpic fruits are
formed without fertilization. Fruit wall has epi,meso and endocarp.
12. Seeds have seed coat and embryo.Embryio has cotyledons, plumule
and radicle.Monocot seeds generally have endosperm
(endospermouus seeds) ans dicots are mostly non-endospermous
seeds.
13.Description of flower can be simplified with the representation of
floral formula and floral diagram.
14. Fabaceae(Pea family/Lugume family)Solanaceae(Potato/Brinjal
family),(Both dicots) Liliaceae(Lily/Onion family-Monocots) include
many economically important plants
IMPORTANT QUESTIONS
1. Draw a labelled diagram of a monocot seed to show its embryo.
2. Differentiate between Racemose and Cymose inflorescence.
Ans.
Racemose / CymoseIndefinite growth of inflorescence axis / Definite growth
Acropetal arrangement of flowers / basipetal
3. Draw the floral diagram and write the floral formula of Fabaceae
flower.
Br, K(5) C 1+2+(2), A (9)+1, G 1
Definitions
Pulvinus: The swollen leaf base in legume plants
Venation: Arrangement of veins in lamina of leaf
Phyllotaxy: Arrangement of leaves on stem.
Inflorescence: Arrangement of flowers on inflorescence axis.
Parthenocarpy: Development of fruit without fertilization
Mind mapping
1. Explain various stem modifications.
Storage and Grass/strawberry,mint/jasmine tendrils & thorns
Perennation Pisia,Chrysanthemum/Banana/Pineapple
Ginger,Potato,Colacasia,
Onion etc
2. Explain various types of placentation.
Ans. Placentation is arrangement of ovules in the ovary.
Marginal Axile Parietal free central Basal
Ovules on ovules on on inner on central axis, from base,
ridge axial wall of ovary no septa single ovule
Eg. Pea Eg Hibiscus Eg.mustard Eg.Primrose Eg.sunflower
HOTS
1. While digging the soil, you find a tuberous, swollen plant part. How
would you identify whether it is a stem or root?
A.
Stem / RootNodes and internodes present / No nodes and internodes. .
Scale leaves and axillary buds present / No leaves and buds
2. What benefits are offered to a leaf by a long petiole ?
A. 1.hold the leaf lamina to light 2. Allows leaf blade to flutter in wind
and helps in cooling of leaf/allow fresh air to leaf surface.
3. What kind of root modifications are found in the following?
a. Banyan b. Maize c. Mangrove plants d. Carrot
Ans. Prop roots for support, stilt roots for support, Pnematophores for
breathing, Storage of food.(respectively)
VBQs
1. A student of class XI feels that the introduction of plant morphology in his syllabus is to load his mind with many technical terms and botanical names. His teacher tells him that studying morphology has several traditional values and is of economic importance. List any 3 advantages of studying it. What value is being shown by the teacher?
Ans. Help in identifying the plants, to use them as medicines, to predict the
flowering period and plan accordingly (to help the farmer)
Concern for nature and promoting the enthusiasm to learn.
2. Students of class XI along with their biology teacher went on excursion to a Botanical garden.They saw a few pitcher plants.Rajesh plucked 2 such pitchers and wanted to preserve them in the lab museum while Rakesh took its photograph in various angles. Teacher appreciated Rakesh.
i. What values(any 2) did Rakesh show?
ii. What is the speciality of pitcher plant?
iii.What kind of soils support such plants?
Ans. Respect for nature/Scientific attitude/Vision for future/Protecting the
vulnerable sps/biodiversity
ii. Its an insectivorous plant.
Chapter 6 ANATOMY OF FLOWERING PLANTS
Content at a glance
1. Studying the internal structure of plants is Plant Anatomy.
2. Cells form tissues to perform a specific function.
3. Plant tissues are basically of 3 types .Protective
tissue(Epidermis),Temporary tissue(Meristematic) and Permanent
tissue.(Simple tissues such as Parenchyma, Collenchyma and Sclerenchyma) Complex tissues such as Xylem and Phloem(These are also
called Vascular tissue)
4. In transverse section(TS), stem shows collateral,conjoint vascular
bundles,endarch condition. Dicot stem vascular bundles are OPEN
while in monocots they are closed.Monocot stem has scattered vascular
bundles.
5. In TS of root,vascular bundles appear radial,separate, exarch.The
number of xylem elements are less and no pith in dicot root while the
xylem elements are more with pth in monocot root.
6. Leaves have upper and lower epidermis with mesophyll in
between. Dicots have palisade and spongy parenchyma in mesophyll
while such differentiation is not seen in monocot leaves.
7. Dicots undergo secondary thickening of stems and roots in a specific
manner. Seasons influence the activity of cambium and regulate
secondary growth of plants.
8. Plants grow girth-wise due to secondary growth in their stelar and
cortical regions.
9. Secondayr Xylem secondary Phloem and medullary rays are formed
during secondary thickening.Epidermis is replaced by bark. Stomata are
replaced by lenticels.
Most important questions
1. Draw a labeled diagram to show the location of 3 different types of
meristems.
2. What are the differences between dicot and monocot stem anatomy?
Dicot stem / Monocot stemRing like arrangement of vascular bundles / Scattered bundles
Open with cambium / No cambium hence closed
3. What are the differences between dicot and monocot root anatomy?
Dicot root / Monocot rootLess number of xylem elements(3-5) / More number( > 5)
No pith / Pith present
5. Differentiate between the anatomy of stem and root.
STEM / ROOTMulti cellular epidermal hairs / Unicellular hairs
Collateral conjoint bundles / Radial,separate
endarch / exarch
Important Definitions
Exarch: Protoxylem towards periphery and metaxylem towards
centre.
Endarch: Protoxylem towards centre and metaxylem towards
periphery.
Mind mapping
HOTs
1. Mango and coconut are categorized as Drupe fruits.What are the edible
parts in these fruits in terms of Morphology? What does the water in
tender coconut represent?
A. Mango—Mesocarp, Coconut- endosperm, Coconut water represents
free nuclear endosperm.
2. While eating guava or custard apple, we find gritty substance in their
pulp.What are these structures called?Do these cells have the ability to
divide. Give reason.
Sclereids, no..they are dead and hence can not divide.
3. Cattle graze on grass. Still grass continues to grow. Which tissue makes
it possible?Why don’t grasses grow girth-wise like that of mango or
tamarind plants?
Ans. Due to intercalary meristem in grass stems.
No cambium between vascular bundles,Closed vascular bundles. No
secondary thickening.
4. The TS of an old stem shows concentric rings/growth rings.How are
these rings formed? How are they significant to us?
Ans. These rings are called Annual rings which are formed due to the
formation of secondary xylem.Helps us calculate the age of the
tree.
5. Cell organ organ system organism. What is the link missing
in this chain?What adavantage do organisms with different levels of
organization have?
A. Tissue is the missing link. Division of labour, loss of few cells do not
have major impact on the organism, efficiency in metabolism.
6. A student is given 3 microscopic slides of plant anatomy and observed
the following. What can he identify them as?
i. Open vascular bundles with collateral and conjoint arrangement.
ii. Scattered vascular bundles,collateral conjoint arrangement.
iii. Radial,separate and a few vascular xylem elements with no pith.
Ans. i. Dicot stem ii. Monocot stem iii. Dicot root.
7. Why are maize and rice considered grains but not seeds.
Ans. In many monocots ,the fruit wall is attached to the seed.
Hence they are fruits or grains.
8. Differentiate between a lenticel and a stomata.
Ans.
Lenticel / StomataPore on the surface of older stems not bound by guard cells. / present in younger parts and leaves. Bound by guard cells.
They have complementary cells / No cpmplementary cells
9. Justify the statement that blood is a connective tissue.
Blood connects various body parts through its flow.It has loosely
arranged cells such as RBCs and WBCs and fluid matrix called Plasma.
10. How do gap junctions facilitate communication between cells?
Ans. By connecting the cytoplasm of adjoining cells and transferring
ions,molecules very rapidly.
VBQs
1. Ajit’s sister finds the leaves of grass rolled in winter.She thinks
that their long lamina is responsible for the rolling.Ajit
explains her the mechanism.
i. What is the reason for such rolling?
ii.What advantage does it offer to the plant?
iii. Mention any 2 values shown by Ajit.
Ans. Bulliform cells, it minimizes water loss,
sharing knowledge and dispelling myths.
2. Ranbir went to a village fair but refused to go for a ride on merry go round.He feels that the fast movement of the chair will displace his internal organs.His friends convinced him saying that it will not happen by mere fast circular motion.
1.What supports the internal organs of our body and prevents
their displacement??
2. Give 2 examples of such supporting structures in our body.
3. What value is shown by his friends?
Ans. Connective tissue, tendon/ligament/areolar/adipose.
Concern for friend/sharing knowledge/dispelling myth/awareness
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Chapter 7 Structural Organisation in Animals
Content at a glance
- Animal tissues are classified in to Epithelial tissue,Connective tissue,Muscle tissue and Nerve tissue.
- Epithelial tissue is meant for protection, absorption and secretion.
It covers or lines the organs.Glands are modified epithelial tissue.
- Connective tissue links and supports other tissues. Areolar,adipose,Bone,Cartilage,tendon, Ligament and Blood
are some connective tissues.
- Muscle tissue has ability to contract and relax. Striated
muscles,smooth muscles and cardiac muscles are 3 different types of muscle tissues.
- Nerve tissue has neurons and non-neural neuroglia.
- Insect body has 3 parts, Head,Thorax and abdomen.
- Male cockroach differs from female cockroach in having anal styles and position of genital pouch.
- Trachea are the respiratory organs, Malpighian tubules are the excretory organs in cockroach.
Important Definitions:
Monoecious: One organism bearing male and female sex organs.
Eg. Earthworm
Dioecious: male and female sex organs in different organisms of
the species Eg. Cockroach,Humanbeings
Most important questions
1. Explain various types of muscle tissue with the help of diagrams.
Striated / Unstriated/smooth / cardiaccylindrical,unbranched / spindle shaped / cylindrical branched
multi nucleated / single nucleus / single nucleus
dark and light bands / No bands / Faint bands
voluntary / involuntary / involuntary
2. Differentiate between a tendon and a ligament
Tendon / LigamentConnects muscle to bone / Connects bone to bone
More strength and less flexibility / More flexibility
3. Differentiate between bone and cartilage.
Bone / cartilageCells in concentric rings / Cells occur single or in pair
Matrix rich in Ca and P / Matrix with sugar and protein
4. Explain the functions of the following in cockroach
i. hepatica caeca(in digestive system) ii. Gizzard(in digestive system)
iii. malpighian tubules iv. Trachea v. ootheca
structure / functionhepatica caeca / Secretion of digestive enzymes
gizzard / grinding of food
Malpighian tubules / excretion
trachea / respiration
ootheca / Protects eggs (in cockroach)
HOTs
1. Justify the statement that blood is a connective tissue.
Ans. Blood connects various body parts through its flow.It has loosely
arranged cells such as RBCs and WBCs and fluid matrix called
Plasma.
2. How do gap junctions facilitate communication between cells?
Ans. By connecting the cytoplasm of adjoining cells and transferring
ions,molecules very rapidly.
3. What is the advantage of having ciliated epithelium in the inner
linings of bronchioles?
Ans. To move mucus in a specific direction and to clean up.
VBQs
1. Ranbir went to a village fair but refused to go for a ride on merry go round.He feels that the fast movement of the chair will displace his internal organs.His friends convinced him saying that it will not happen by mere fast circular motion.
1.What supports the internal organs of our body and prevents
their displacement??
2. Give 2 examples of such supporting structures in our body.
3. What value is shown by his friends?
Ans. Connective tissue, tendon/ligament/areolar/adipose.
Concern for friend/sharing knowledge/dispelling myth/awareness
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Unit III Chapter 8, Cell-The unit of life
Content at a glance
- Cell theory states that all living beings are made of cells and their products.
- Prokaryotes have no membrane bound nucleus and no membrane bound organelles.Their genetic material is concentrated at NUCLEOID region.Bacteria are of 2 types based on stainability (gram +ve and Gram –ve)
- Depending on the shape of bacteria are classified as bacilli(rod) cocci(spherical),spirilli(spiral) and vibrio(comma shape).
- Plant cell,animal cell and fungal cell have proper membrane bound nucleus and are called Eukaryotic.
- Plant cell has cell wall ,large vacuole and plastids.
- Mitochondria,ER,golgi,lysosomes,ribosomes etc are various common cell organelles of eukaryotes.
- Animal cell has no cell wall. It has centriole and centrosome.
- Chromosomes are classified as metacentric, Sub-metacentric, Acro-centric and telocentric based on the position of centromere.
Important Definitions:
Osmosis: Movement of water from the area of low solute conc to
the area of high soplute conc through a semi-permeable
membrane.
Active transport: Movement of ions against concentration
gradient(Up-hill tranasport). ATP used.
Eg. Na-K pumps
Passive transport: Movement of ions down the concentration
gradient(down-hill tranasport). No ATP used
Eg. Osmosis, Diffusion
Most important questions
1. Differentiate between a prokaryotic cell and a eukaryotic cell.
Prokaryote / EukaryoteNo membrane bound nucleus / Proper nucleus
No membrane bound organelles / Membrane bound organelles such as mitochondria,vacuole are present.
2. Explain fluid mosaic membrane concept.
i. Protein icebergs in sea of lipids
ii. Protein-bi-lipid membrane
iii. Peripheral and integral proteins are present.
3. Draw labelled diagrams of 4 types of chromosomes based on the
position of their centromere.
4. Wrie the functions of the following .
i. Chloroplast ii Mitochondria iii ER iv. Golgi v. Vacuole
Photosynthesis respiration lipid and Packing storage
and ATP protein synthesis &
release transport
Mind mapping
3. Various types of cells, organelles and functions.
Prokaryotic Eukaryotic
Eg. Bacteria
Plant cell Animal cell
i. Cell envelope cell wall Nucleus
ii.mesosome Nucleus Mitochondria
iii.pili Plastid Golgi and ER
iv. flagellum Mitochondrion Centrosome
v. NUCLEOID Golgi and ER Centriole
vi. ribosome Vacuole
Lysosome
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NUCLEUS contains genetic material
Mitochondrion respiration-energy storing
Plastids photosynthesis/colours/storage
Cell wall rigidity and shape
Cell membrane osmosis/transport
Vacuole storage
ER lipid(SER) and Protein synthesis(RER)
Golgi packing and transport
Lysosomes suicide bags
Ribosomes protein synthesis
HOTs
1. Reason why
i. nucleoli are larger in cells which carry active protein synthesis.
ii. Water soluble compounds are transported across the membrane.
iii. Golgi apparatus remains closely associated with ER.
Ans. Nucleoli are the sites for RNA synthesis.
Polar substances cannot pass through lipid part of membrane and
hence they are transported through membrane receptor proteins
across the membrane.
Materials synthesized by ER are packed and transported by Golgi.
2. What advantage does a cell get by having membranous extensions?
A. increased surface area for activities.
3. Ribosomes are invariably found in the cytoplasm all types of cells. What
other sites within the cell lodge them?
A. Plastids and Mitochondria
4. If the cell membrane of the cell is damaged, which cell organelle is
associated with its formation? Why?
Ans. ER. Smooth endoplasmic reticulum forms lipids and RER forms
proteins.Cell membrane is made of proteins and lipids.
5. In the sequential order of formation, arrange the following layers of a
plant cell.