LESSON PLAN ON BIOLOGY FOR WEEK 1, ENDING ON 15TH OF SEPTEMBER, 2023

CLASS TOPIC CONTENT NO. OF PERIOD DURATION

Botanical classification of plants
S.S.2 Classification of Agricultural classification of plants 2 45 Minutes
Plants Classification of plants based on
life cycle

CLASS: S.S.2
SUBJECT: Biology
DATE: 11th Monday – 15th Friday September, 2023
AGE: 13-16 years
REFERENCE MATERIAL: Modern Biology Textbook for Senior Secondary Schools by S.T Ramalingam,
Internet
INSTRUCTIONAL MATERIAL: Marker, Lesson note, Textbook, Whiteboard, Internet.
INSTRUCTIONAL OBJECTIVE: By the end of the lesson, students should be able to classify plants by the
botanical, agricultural and life cycle method.
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: Classification of Plants
SPECIFIC OBJECTIVES: By the end of the lesson, students should be able to classify plants by the
botanical method.

BOARD SUMMARY
BOTANICAL CLASSIFICATION OF PLANTS

1. PHYLUM THALLOPHYTA: Thallophytes are a group of non-vascular plants that lack the specialized
structures we often associate with higher plants, such as roots, stems, and leaves. Instead, thallophytes have
a simple, threadlike or flat body called a thallus. Examples of thallophytes include algae, spirogyra, volvox,
Ulva, sargassum (brown algae).

SPIROGYRA:

Fig. Structure of Spirogyra

Spirogyra is a type of filamentous (threadlike) green algae. It reproduces asexually through a process called
fragmentation. This involves the filament breaking into smaller pieces, each of which can grow into a new
individual. It also reproduces sexually through a process called conjugation. During conjugation, two
neighbouring Spirogyra filaments come into close contact. They form conjugation tubes, which connect the
cells of each filament. Through these conjugation tubes, genetic material (nuclei) from one filament is
transferred to the other. The exchanged genetic material results in the formation of haploid cells called
zygospores. These zygospores are thick-walled and can withstand adverse conditions. They eventually
develop into new Spirogyra filaments when conditions become favourable again.

2. PHYLUM BRYOPHYTA: Bryophytes are non-vascular plants and include mosses, liverworts,
and hornworts. They are small and simple plants that lack true roots, stems, and leaves. Bryophytes rely on
diffusion for water and nutrients absorption. They grow in damp places on land.

MOSS PLANT: The moss plant are non-vascular plants found in damp and shaded environments. They have
simple structures called rhizoids that anchor them to the soil. They reproduce both asexually through
fragmentation of the main plant body and sexually through the production of spores and development of
sporophytes. Moss displays a life cycle that alternates between a gametophyte and sporophyte phase.
Because of this reliance on water for fertilization, mosses are commonly found in moist environments. The
need for water is a key feature of their reproductive strategy, distinguishing them from higher plants that use
pollen and do not require water for sperm to reach the egg.

Fig. Sexual reproduction in Moss with alternating generations.

3. PHYLUM PTERIDOPHYTA: Pteridophytes are multicellular and vascular green plants. They have true
roots, stems and leaves. They are non-flowering plants. They have mainly terrestrial plants while few
aquatics. They are non-seed producing plants. The most common example of pteridophytes is the ferns.

FERNS. Fern displays a life cycle of alternating generation but unlike the moss plant, its dominant phase is
the sporophyte stage. They have large, divided leaves called fronds that arise from an underground stem
called rhizome. The fronds bear spore-producing structures called sporangia on their lower surface.
4. PHYLUM SPERMATOPHYTA
Spermatophytes are multicellular, seed producing flowering plants. They are vascular plants and have well
developed vascular tissues. They have true roots, stems and leaves. They reproduce sexually and do not need
water for reproduction. They are mainly terrestrial green plants. Spermatophytes can be divided into two
major classes: Gymnosperms and Angiosperms.

GYMNOSPERMS
Gymnosperms are plants with naked seeds. The seeds are borne on special structures called cones. They
have needle-like or scale-like leaves that reduce water loss. They have woody stems that provide support.
Examples of gymnosperms are pine, cycads, ginkgo and conifers.

ANGIOSPERMS
Angiosperms are plants with seeds enclosed in the ovary wall. They bear flowers that attract pollinators. The
flowers have four whorls: sepals, petals, stamens and carpels. The carpels contain the ovules that develop
into seeds after fertilization. The ovary develops into a fruit that protects and disperses the seeds.
Angiosperms can be divided into two subclasses: Dicotyledons and Monocotyledons.

DICOTYLEDONS
Dicotyledons are angiosperms that have an embryo with two cotyledons or seed leaves. They usually have
net-veined leaves, tap roots, pentamerous or tetramerous flowers and secondary growth. Examples of
dicotyledons are hibiscus, cotton and okra, pea, bean and groundnut.

MONOCOTYLEDONS
Monocotyledons are angiosperms that have an embryo with one cotyledon or seed leaf. They usually have
parallel-veined leaves, fibrous roots, trimerous flowers and no secondary growth. Examples are onion, garlic
lily, wheat, rice and maize.

LESSON EVALUATION
1. Give a brief explanation of phylum thallophyta.
2. Name and describe one example of a plant under phylum thallophyta.
3. Give a detailed explanation on the sexual reproduction of the moss plant.
4. Give a detailed explanation on the sexual reproduction of fern plant.

PERIOD: 2
SUB-TOPIC: Classification of Plants
SPECIFIC OBJECTIVES: By the end of the lesson, students should be able to classify plants by the
agricultural and life cycle method.
 BOARD SUMMARY
AGRICULTURAL CLASSIFICATION OF PLANTS
1. CEREALS: Cereals are grass-like plants cultivated for their edible grains or seeds. Examples include
wheat, rice, maize (corn), barley, oats, and rye. They are a staple food source and provide carbohydrates in
the form of grains.

2. LEGUMES: Legumes are plants that produce pods containing seeds or beans. Examples include beans,
lentils, peas, and chickpeas. They are rich in protein and are often used as a source of plant-based protein.

3. ROOT CROPS: Root crops are plants where the edible part is the underground root. Examples include
carrots, potatoes, sweet potatoes, and beets. They are a source of carbohydrates and various nutrients.

4. FRUITS: Fruits are typically the mature ovaries of flowering plants and contain seeds. Examples include
apples, oranges, bananas, and berries. They are rich in vitamins, minerals, and natural sugars.

5. VEGETABLES: Vegetables encompass a wide range of edible plant parts, including leaves, stems, and
roots. Examples include spinach, broccoli, tomatoes, and carrots. They are a source of various vitamins,
minerals, and dietary fibre.

6. BEVERAGES: Beverage plants are cultivated primarily for producing drinks. Examples include tea (from
the tea plant), coffee (from coffee beans), and cocoa (for chocolate). These plants are processed to create
various beverages.

7. FIBER: Fiber plants are grown for their fibrous parts, often used in textiles and paper production.
Examples include cotton (for textiles), flax (for linen), and hemp. They provide natural fibers for a variety of
uses.

8. OIL: Oil plants are cultivated for their seeds or fruits, which are rich in oil content. Examples include
soybeans (for soybean oil), olives (for olive oil), and sunflowers (for sunflower oil). The extracted oils are
used for cooking and various industrial purposes.

9. SPICE: Spice plants are grown for their aromatic parts, such as seeds, leaves, or roots. Examples include
cinnamon (from tree bark), pepper (from berries), and ginger (from rhizomes). They are used to season and
flavor food.

10. LATEX: Latex-producing plants secrete a milky sap known as latex. Examples include rubber trees (for
natural rubber) and opium poppies (for opium latex). Latex has various industrial and medicinal
applications.

LIFE CYCLE CLASSIFICATION

The life cycle of a plant refers to the duration of time it takes for a plant to grow from a seed to producing
seeds of its own. Based on their life cycle, plants can be classified into three groups:

ANNUALS: These are plants that complete their life cycle in one year or less. They germinate, grow,
flower, produce seeds, and die within a single growing season. Examples of annuals are maize, beans, rice,
sunflower, etc.
BIENNIALS: These are plants that complete their life cycle in two years. They germinate and grow
vegetatively in the first year, and then flower, produce seeds, and die in the second year. Examples of
biennials are carrot, cabbage, onion, etc.
PERENNIALS: These are plants that live for more than two years. They can flower and produce seeds
repeatedly over many years. Some perennials may lose their leaves and become dormant during
unfavourable seasons, while others may remain green throughout the year. Examples of perennials are
mango, banana, coconut, etc.

LESSON EVALUATION
1. List and explain 6 agricultural classifications of plants.
2. Cocoa belongs to which agricultural classification.
3. Opium Latex is gotten from which tree.
4. What are annual crops? Give 3 examples of annual crops
5. What are perennial crops? Give 3 examples of perennial crops.

LESSON PLAN ON BIOLOGY FOR WEEK 2, ENDING ON 22nd OF SEPTEMBER, 2023

CLASS TOPIC CONTENT NO. OF PERIOD DURATION

Types of Alimentary Tracts,
S.S.2 Digestive System Modification of parts, feeding 2 45 Minutes
Habits, Transport system 1.

CLASS: S.S.2
SUBJECT: Biology
DATE: 18th Monday – 22nd Friday September, 2023
AGE: 13-16 years
REFERENCE MATERIAL: Modern Biology Textbook for Senior Secondary Schools by S.T Ramalingam,
Internet.
INSTRUCTIONAL MATERIAL: Marker, Lesson note, Textbook, Whiteboard, Internet.
INSTRUCTIONAL OBJECTIVE: By the end of the lesson, students should be able to explain the digestive
system of various higher organisms.
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: Digestive System.
SPECIFIC OBJECTIVES: By the end of the lesson, students should be able to explain the digestive system
of various higher organisms.

BOARD SUMMARY
ALIMENTARY CANAL
An alimentary canal is adapted for breaking up food into smaller piece, producing digestive secretions, and
absorbing food nutrients and water. A digestive system is made up of the alimentary canal and the associated
glands and organs that secrete enzymes that bring about digestion.

PLANARIA: The planaria are free living flat worms which feed on small microorganisms. The alimentary
canal of planaria consists of a mouth, pharynx, gastrovascular cavity, branching gut, and gastrodermal cells.
This simple digestive system allows planaria to feed on various small organisms and efficiently process
nutrients for survival and growth.

Fig. Alimentary canal of Planaria.

EARTHWORM
An earthworm's digestive system consists of a mouth for ingesting soil and decaying plant material,
followed by a pharynx to pump in food. It has a crop for temporary storage, a muscular gizzard to grind
food, and a stomach for chemical digestion. The intestine, including a specialized typhlosole, absorbs
nutrients. Finally, undigested waste exits through the anus at the rear of the worm. Earthworms play a
crucial role in soil health by breaking down organic matter and enriching it with their waste.

Fig. Alimentary Canal of Earthworm.

GRASSHOPPER
The alimentary canal of a grasshopper includes mouthparts for biting and chewing, a pharynx for food
passage, a crop for temporary storage, a gizzard for mechanical grinding, a midgut for enzyme-driven
digestion, a hindgut for water and nutrient absorption, Malpighian tubules for waste removal, and a
rectum/anus for waste elimination. This specialized system allows grasshoppers to efficiently process plant
material and extract nutrients to fuel their activities.

BIRD
Fig. Alimentary canal of a Bird.

Beaks are used to capture and manipulate food. The mouth of a bird typically lacks teeth. Instead, birds have
a muscular organ called the gizzard to help grind food. Saliva in the mouth contains enzymes that initiate the
digestion of carbohydrates. After being captured and partially processed in the mouth, food travels down the
oesophagus to the crop. The crop is a specialized pouch in the bird's throat where food is temporarily stored
and digested at a more convenient time. From the crop, food enters the proventriculus, which is the
glandular stomach. Acidic secretions and enzymes break down food further, particularly proteins. After the
proventriculus, food passes into the gizzard a muscular organ with thick walls that contain small, hard
particles such as pebbles or grit. These helps grind down tough food items like seeds and insects. The
partially digested food moves into the small intestine, where most of the nutrient absorption takes place.
Enzymes from the pancreas and liver further break down carbohydrates, proteins, and fats, allowing the bird
to absorb nutrients into its bloodstream. The small intestine leads to the large intestine, where water and
electrolytes are absorbed. Birds also have a cloaca were undigested waste and urine are combined and
expelled together through the vent. Some birds have ceca which play a role in fermentation and further
digestion of cellulose and other complex substances. The final part of the alimentary canal is the anus,
through which the remaining waste products are expelled from the bird's body.

RABBIT
Fig. Alimentary Canal of a Rabbit.

Rabbits have a relatively simple mouth with sharp, continuously growing incisor teeth. The saliva in the
mouth contains enzymes that begin the digestion of carbohydrates. After chewing, the food travels down the
oesophagus to the stomach. Unlike some other animals, rabbits don't have a crop or a muscular gizzard. In
the stomach, food is mixed with gastric juices, including hydrochloric acid and digestive enzymes. The
partially digested food moves into the small intestine, where the majority of nutrient absorption takes place.
Pancreatic enzymes further break down carbohydrates, proteins, and fats. The cecum is a significant feature
of the rabbit's digestive system. Specialized bacteria in the cecum break down complex plant fibers
(cellulose) into simpler substances, allowing rabbits to extract more nutrients from their fibrous diet. From
the cecum, the food moves into the large intestine, where water and electrolytes are absorbed. The remaining
waste products from the large intestine are expelled through the rectum and anus.

HUMANS
The human digestive system is a complex and highly efficient system responsible for processing the food we
consume. It plays a vital role in breaking down nutrients and converting them into energy for our bodies to
use.

Fig. Human Alimentary Canal

DIGESTION IN THE MOUTH AND STOMACH

When the teeth cut and grind food it into smaller pieces, chemical digestion begins in the mouth as saliva
contains an enzyme called ptyalin that acts on cooked starch, converting it into complex sugars. Saliva, a
watery and slightly alkaline substance secreted by the salivary glands, mixes with the food, forming a ball or
bolus that is then swallowed. From the mouth, the bolus food passes the pharynx which connects to the
oesophagus which leads to the stomach. During swallowing, the epiglottis covers the trachea to prevent
choking, allowing food to enter the oesophagus.

The oesophagus has muscular walls that contract and relax alternately, pushing each bolus of food
downwards slowly through a process called peristalsis. Peristalsis occurs throughout the entire alimentary
canal, and occasionally, food moves backward, known as anti-peristalsis. Food enters the stomach which has
muscular walls that contract and relax forcefully, churning the food. This process breaks down small food
pieces further and mixes them with gastric juice. Gastric juice contains two important enzymes, pepsin and
rennin, as well as dilute hydrochloric acid, produced by specialized cells lining the stomach.

Pepsin digests proteins into polypeptides, working best in an acidic medium. The acid also helps to eliminate
bacteria present in food. Rennin causes milk coagulation into thick curds. Food remains in the stomach for
about three to four hours, forming a thick, creamy fluid called chyme, which moves into the duodenum.

DIGESTION IN THE SMALL INTESTINE

The duodenum is the initial part of the small intestine, followed by the jejunum and ileum. Various
substances are secreted into the duodenum, including pancreatic juice from the pancreas and bile from the
liver (stored in the gall bladder). Bile is an alkaline, greenish liquid without digestive enzymes.

When chyme enters the duodenum, hormones stimulate the pancreas and gall bladder to release their
digestive juices. Pancreatic juice contains three crucial enzymes: amylase breaks down starch into maltose,
trypsin digests proteins into polypeptides, and lipase breaks down fats into carboxylic acids and glycerol. All
these enzymes require an alkaline medium to work.

Although bile lacks digestive enzymes, it serves essential roles. It adds water to chyme, neutralizes
hydrochloric acid, and emulsifies fats, breaking them into tiny droplets for more extensive enzyme action.
As chyme progresses through the duodenum, it becomes waterier and is called chyle. Intestinal juice
produced in the ileum contains enzymes working in an alkaline medium, completing digestion.

ABSORPTION OF DIGESTED FOOD

The small intestine efficiently absorbs glucose, amino acids, fatty acids, glycerol, vitamins, mineral salts,
and more. Its walls have folds, furrows, and villi (finger-like projections) to maximize surface area. The
inner surface layer of each villus facilitates absorption through diffusion or active transport. A rich network
of blood vessels and lymphatic vessels carries absorbed food substances. The hepatic-portal vein transports
these substances to the liver for processing and distribution throughout the body.

Undigested food passes into the large intestine (colon), where water absorption occurs, concentrating waste
products into semi-solid faeces. Faeces then move into the rectum and exit through the anus. Dietary fibre or
roughage aids faecal movement by providing resistance for gut muscles to squeeze against, preventing
constipation. The entire digestive process typically takes about one and a half days from ingestion to faecal
elimination.

WORK OF THE LIVER

The liver, the largest organ in the body, regulates glucose and amino acid levels in the blood. Excess glucose
is converted to glycogen and stored, while glycogen is converted back to glucose when needed, regulated by
hormones. The liver also releases the necessary amount of amino acids into the blood and breaks down
excess amino acids.

LESSON EVALUATION
1. List 6 enzymes produced in the human body during digestion and their purposes.
2. What is the purpose of dilute HCL and in what part of the body is it produced?
3. In the mouth, chewed and broken-down food is called what?
4. Which organ coverts glucose to glycogen?
5. Intestinal juice is secreted in what part of the small intestine?

PERIOD: 2
SUB-TOPIC: Digestive System.
SPECIFIC OBJECTIVES: By the end of the lesson, students should be able to explain the modification and
mechanism of feeding in some organisms.

BOARD SUMMARY
MODIFICATION AND MECHANISM OF FEEDING IN SOME ORGANISMS

ABSORBING MECHANISM
Endo-parasites, such as tapeworms, employ a unique mechanism for parasitic feeding within their host's
intestine. They lack a mouth and rely on absorbing digested food from the host (usually humans). The
adaptation of their body for this purpose includes:
1. HOOK AND SUCKER ATTACHMENT: Tapeworms possess specialized structures like hooks and
suckers that allow them to firmly attach themselves to the host's intestinal walls.
2. PROTECTIVE CUTICLE: Their body is equipped with a thick cuticle that shields them from digestion
by the host's enzymes.
3. FLAT BODY: Tapeworms have flat bodies, which provide a large surface area for efficient absorption of
digested food. Nutrients can permeate through their body surface, facilitating the absorption process.

2. BITING AND CHEWING MECHANISM

The method is adopted by insects such as grasshopper and cockroach. They have different mouth parts
which are modified and adapted for biting and chewing:
1. MANDIBLE: Heavy, toothed, jaw like structure to cut and crush food substances.
2. MAXILLA: Directs food to the mandibles and also cuts and grinds food.
3. LABRUM: Helps to hold food material.
4. LABIUM: Prevent food materials from wasting.

3. SUCKING MECHANISM
The popular organism that feed in this manner are mosquito, butterfly and housefly. These insects
have different modification of mouth parts for their feeding through sucking.

MOSQUITOES

Fig. Mouth parts of a female mosquito.

The mouth part of mosquitoes is modified into proboscis. The male mosquitoes feed on nectar and plant
juices so the proboscis is used for sucking only. However, the female mosquitoes feed on the blood of
animals and so their proboscis is used for both piercing and sucking. The proboscis of the female mosquito
is made up of four sharp stylets that serve as the mandible and maxilla and is used for piercing the surface of
the skin, a hypopharynx that serves as a channel and injects saliva into the pierced skin to prevent blood
from clotting, and the labium which hold the different part of the proboscis.

4. GRINDING AND CHEWING MECHANISM

This method is common among mammals e.g., man, cattle, sheep, dog, etc. These animals are capable of
grinding their food before swallowing. The grinding is aided by the presence of hard and strong teeth make
up of enamel and dentine. Mammal like man has four different types of teeth mainly incisor, canine,
premolar and molar. The incisor has a sharp edge that is used to cut food, the canine is pointed and they are
used for tearing of flesh or other material. The premolars and molars are flat teeth with cusps that grind and
mash food. The molars are for vigorous chewing.

DENTAL FORMULA
The Dental formula shows the number and types of teeth an animal has in one half of each jaw.
HUMANS: Incisor =2/2, Canine =1/1, Premolar =2/2, Molar=3/3 = 16
total number of teeth = 2×16= 32.
DOG: Incisor =3/3, Canine =1/1, Premolar =4/4, Molar =2/3=21
total number of teeth= 2×21=42.
SHEEP & GOATS: Incisor =0/4, Premolar =3/3, Molar =3/3= 16
total number of teeth= 2×16 = 32

STRUCTURE OF HUMAN TEETH.

Fig. Structure of the Human Teeth.

The human teeth are divided into 3 sections.

1. CROWN: The crown is the visible part of the tooth that protrudes above the gums.
2. ROOT: The root is the part of the tooth that is embedded within the jawbone.
3. NECK: The neck is the junction where the crown and root meet.
INSIDE THE TOOTH
PULP CAVITY: At the centre of the tooth is the pulp cavity, which contains blood vessels and nerves.
These are highly sensitive to temperature changes, such as heat and cold.
DENTINE: Surrounding the pulp is dentine, a hard and bone-like material that contains some living
cytoplasm. Small openings at the tips of the roots allow connections between the blood vessels and nerves of
the pulp, gums, and bones.
ENAMEL: The dentine is covered by a white layer known as enamel, which is the hardest substance
produced by animals. Enamel protects the pulp and dentine, but it's not present in the root area.
CEMENTUM: In the root region, a thin layer of cement covers the dentine.
PERIODONTAL MEMBRANE: The tooth is fixed to the jawbone by the periodontal membrane, which
surrounds the cement. Importantly, the tooth is not rigidly fixed and can have slight movement during biting
and chewing.
LESSON EVALUATION
1. Explain the sucking mechanism. State one organisms under sucking mechanism and its modifications.
2. What is the Dental formula of man.
3. What layer is responsible for covering the pulp cavity in the human teeth.