LESSON PLAN ON BIOLOGY FOR WEEK 4 ENDING 4th OF OCTOBER, 2024

SUBJEC TOPIC CONTENT NUMBER OF PERIODS DURATION

T
Cell as a living
unit of
Biology The Cell organism. 3 45 minutes each
Forms in which
living organism
exits. Cell
structure
CLASS: S.S.1
SUBJECT: Biology
DATE: 2nd Monday – 4th Friday October, 2024
AGE: 13-16 years
REFERENCE MATERIAL: Modern Biology for Senior Secondary Schools by S.T. Ramalingam
Essential Biology by M.C Michael, New School Biology by H. Stone and Cozen, New System Biology by
Lam and Kwan, College Biology by Idodo Umeh
INSTRUCTIONAL MATERIAL: Marker, Lesson note, Textbook, Whiteboard, Internet.
INSTRUCTIONAL OBJECTIVE: By the end of the lesson, students should be able to define the cell.
INSTRUCTIONAL PROCEDURE
STEP 1: Teacher revises the previous lesson with students.
STEP 2: Teacher introduces new topic to students.
STEP 3: Teacher gives detailed explanation of topic to students.
STEP 4: Teacher gives room for the students to ask questions.
STEP 5: Teacher writes note on the board.

CONTENT OF LESSON
PERIOD: 1
SUB-TOPIC: The Cell
SPECIFIC OBJECTIVES: By the end of the lesson, students should be able to define the cell.

BOARD SUMMARY

DEFINITION AND FORMS OF CELLULAR EXISTENCE

The cell is the simplest, smallest, basic, structural and functional unit of life. The cell can carry out all life
activities such as growth, respiration e. t. c. Cells can exist in various forms which include as a single cell,
colonies, filamentous and as apart of multicellular organisms.

1. SINGLE CELLS (UNICELLULAR)

CHLAMYDOMONAS (Chlamydomonas rivalries)

Chlamydomonas is a unicellular plant like protist, motile using its flagellum and has a cup shaped
chloroplast. It is sensitive to light using its eye spot. In the presence of light, starch grains appear in the
cytoplasm. These disappear in a dark environment.
Chlamydomonas cells through its flagella (whip like) respond to changes in the surrounding such as moving
from a dark region to a region of light. This organism disposes off its excess water using its contractile
vacuoles. It reproduces asexually and sexually when it reaches its maximum size.

AMOEBA (Amoeba proteus)

Amoeba is a unicellular animal like protest and the simplest organism with heterotrophic mode of feeding. It
is shapeless. It digests its complex food with its food vacuole. The undigested food materials are got rid of
with excess water through its contractile vacuole. Amoeba moves about and captures its food with the aid of
its pseudopodia (‘’false feet’’). At maximum growth, amoeba reproduces asexually by dividing into two
daughter cells (binary fission)

PARAMECIUM
Paramecium is a more complex unicellular organism compared to Amoeba. It is slipper- shaped and moves
with the aid of its cilia, which also directs food into its gullet. The undigested food material is removed
through the anal pore. Excess water is got rid of through the anterior and posterior contractile vacuoles.
Two types of nucleus are visible in this organism, the micronucleus and mega nucleus

EUGLENA (Euglena viridis)

Euglena viridis is a protist that has both plant and animal features.
As a plant, it has chloroplasts (star shaped) for photosynthesis, pyrenoid for starch storage and paramylum
granules (form in which starch is stored).
As an animal, it has no cellulose cell wall, but a plasma membrane called pellicle, a gullet, eye spot,
contractile vacuole and flagellum for movement.

2. COLONY AND FILAMENTOUS CELLS

VOLVOX
Volvox is made up of several Chlamydomonas-like cells which are arranged in angular layer to form a
hollow ball-like structure. The cells are connected by cytoplasm strands.
The cell of Volvox moves about through the beating of the flagella. Most cells of Volvox lose their ability to
reproduce. Only a few of them can reproduce to form two daughter cells

SPIROGYRA
Spirogyra is a filament of identical cells which are joined end to end without branching. Each cell of
spirogyra carries out its function independent of another cell. Spirogyra has spirally arranged chloroplast for
photosynthesis.
The filament grows indefinitely. The break-off cells from the filament have the ability to reproduce
asexually to form a new filament. Spirogyra also has ability to reproduce sexually.

3. MULTICELLULAR ORGANISMS
A multicellular organism is made up of interdependent cells carrying out several special functions. The cells
of the multicellular organisms are arranged to perform similar functions and then form tissues. A group of
specialized tissues performing similar function forms an organ. Organs are further organized to carry out
special functions in form of system or organ system. Ultimately, the interdependent biological system results
in the complex multicellular organisms.

PERIOD: 2
SPECIFIC OBJECTIVE: by the end of the lesson students should be able to explain:
 Cell components and their functions
 Cell structure

BOARD SUMMARY

CELL COMPONENTS AND THEIR FUNCTIONS

CELL DESCRIPTION OF STRUCTURE FUNCTIONS

COMPONENT/ORGANELLE
S
i. Mitochondria These are oval or rod-shaped. They Site of cellular
are bounded by a double membrane. respiration for energy
The inner membrane is folded and the production. It consists
interior is filled with matrix. The of enzymes and
matrix contains ribosome. DNA. The enzymes
 convert ADP to ATP.
ii. Vacuole It occupies a large central portion of Surrounded by a
plant cell. It is lined with a membrane membrane called
and filled with cell sap. The cell sap tonoplast. It contains
acts as a “store house” for many cell sap mineral salt
substances. and sugar. It act as an
osmoregulator
(removing excess
water).
iii. Endoplasmic reticulum (ER) They are membrane like structures Aids transport of
that form channels between the materials within the
cytoplasm. cytoplasm. Rough
endoplasmic
reticulum (RER)
(having ribosome
attached) is for
protein synthesis and
transportation.
Smooth endoplasmic
reticulum (SER) is for
lipids and steroids
synthesis and
transportation.
iv. Golgi bodies/apparatus They are series of disc shaped sac. For synthesis,
packaging and
distribution of
materials.
v. Chloroplasts These are large green organelles in Contains chlorophyll
plant cells. They contain chlorophyll for photosynthesis in
green plants
vi. Lysosomes These are thin-wall bodies and they Site for production of
contain enzymes. enzymes for
respiration and
destruction of worn-
out cells.
vii. Ribosome They are small round bodies attached They are responsible
to endoplasmic reticulum. for protein synthesis
viii. Centrioles These are two small granules near Active in cell division
nucleus of animal’s cells from which by producing spindle
flagella or cilia arise. fibres to which
chromosomes are
attached. (Present
only in animal cell).
ix. Cell membrane This is flexible membrane made up of This is flexible and
mainly proteins and lipids. It is selectively
selectively permeable. permeable. It controls
the materials entering
(absorption) the cell.
x. Chromosome These are located in the nucleus and It contains the DNA
contain deoxyribonucleic acid or which stores genetic
DNA traits.
xi. Cell wall It is a tough, fairly rigid structure that It protects the cell,
is freely permeable in plant cells. thus providing
mechanical support in
plants.
xii. Nucleolus They are dense structures within the They produce the
nucleus. ribosome for protein
synthesis
xiii. Nucleus They have spherical body which is It controls all life
covered by a double membrane which activities of cell. It
contains heredity materials, also stores heredity
chromosomes and genes often information as it
centrally located in the cell embedded contains DNA inside
in cytoplasm. chromosomes which
takes part in cell
division.

CELL STRUCTURE
The study of a cell is called cytology. A cell consists of a living material called protoplasm, which is
surrounded by a membrane called plasma membrane. In plants, a cell wall (non-living part) is also present
surrounding the plasma membrane. The protoplasm is made up of two major parts:
a. cytoplasm
b. Nucleus

CYTOPLASM: It contains cell organelles or inclusions, which are cellular structures with specific
functions. The cells which contain a nucleus and organelles are called eukaryotic cells. These show a high
level of cellular organization. However, some cells lack definite nucleus and organelles. In such cells
(prokaryotic cells e.g., bacteria), materials containing instructions for growth and development are found in
a particular part of the cell and so are not enclosed in any membrane.

NUCLEUS: It is the largest cellular organelle enclosed by a double-layered nuclear membrane with many
pores. It contains chromosomes and nucleolus which are rich in proteins and nucleic acids. The nucleus
performs the following functions:
a. Exchange of materials between the nucleus and the cytoplasm through the nuclear pores.
b. Storage of hereditary information by the chromosomes
c. Control center of cellular activities
 Fig. Structure of a typical animal cell

Fig. Structure of a typical plant cell

LESSON EVALUATION
1. List five cell organelles and their functions
2. What is a cell, list four forms of cellular existence with examples?
3. Discuss feeding, movement and reproduction in a named unicellular organism

PERIOD: 3
SPECIFIC OBJECTIVE: By the end of the lesson students should be able to:
 Similarities of plant and animal cell
 Differences between plant and animal cells.
 Cell theory

BOARD SUMMARY
SIMILARITIES BETWEEN PLANT AND ANIMAL CELLS
Both plant and animal cells have the following in common:
(a)Nucleus (b) Golgi bodies (c) Mitochondria (d) Cytoplasm (e) Chromosomes (f) Endoplasmic reticulum
(g) Nucleolus (h) Ribosomes (i) Lysosomes (j) Cell membrane

DIFFERENCES BETWEEN PLANT AND ANIMAL CELL

PLANT CELL ANIMAL CELL
1 Has chloroplast No chloroplast
2 Rectangular and definite in shape Usually spherical or shapeless
3 Has rigid cellulose cell wall No cell wall
4 Centrioles/centrosome are absent Centrioles/centrosome are present for cell
division
5 Cytoplasm is less dense Cytoplasm is denser
6 Starch granules present in the cytoplasm Glycogen granules present in the
cytoplasm
7 Presence of large central permanent Vacuoles are absent or small and
 vacuole temporary when present
8 Stores lipids as oil Stores lipids as fat

CELL THEORY
This is the summary of research efforts of many scientists like Robert Hooke, Matthias Schleiden and
Theodore Schwann in 1838 and 1839 likewise, Rudolf Virchow (1855) etc.
The cell theory states that:
a. All living organisms are composed of one or more cells.
b. The cell is the structural and functional unit of all living organisms i.e., the basic organizational unit
of life.
c. All existing cells come from pre-existing ones.
d. A cell contains information for its structural and functional development in its nucleic acids. This
information is passed down from the parents to the off spring

LESSON EVALUATION
1. State three similarities and five differences between plants and animal’s cell
2. Write short note on the history of the cell
3. Describe briefly the history of the cell
4. State the four forms of cell existence.
5. Discuss, with a diagram, a named plant- like unicellular protest.
6. Discuss, with a diagram, a named animal-like protist.
7. Draw the diagram of a named filamentous organism.
8. Differentiate between: (a) cells forming tissues and those forming colonies
(a) Colonial and filamentous organisms
(b) Differentiate between prokaryotic and eukaryotic cells
(c) Describe and state three functions each of (i) rough endoplasmic reticulum (ii) vacuoles