Lesson Notes By Weeks and Term - Senior Secondary 3

TERM – 1^ST TERM

WEEK EIGHT

Class: Senior Secondary School 3

Age: 17 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Biology

Topic: Evolution

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Discuss the progressive change in structure and anatomy of organisms
2. Identify the structural Adaptation of living organisms.
3. Identify castles of termite and their functions.

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

EVOLUTION

Progressive change in structures and anatomy of organism

Progressive changes in the structures and anatomy of organisms occur through the process of evolution. Over time, most species undergo modifications in their anatomy to adapt to environmental conditions or respond to selective pressures. For instance, the transition from water to land involves significant adaptations in structures and anatomy. Fish, for example, have gills for underwater respiration, while amphibians, transitioning to land, develop lungs for breathing air. Limbs evolve for weight-bearing and movement, replacing fins. Skin thickens to prevent desiccation, and in some cases, scales are replaced by more impermeable skin. Additionally, the shift from external to internal fertilization often occurs to protect eggs from drying out on land. These adaptations illustrate the progressive changes organisms undergo during the water-to-land transition.

Structural Adaptation

Adaptive coloration and functions in Chameleon

Camouflage in chameleons is a remarkable structural adaptation. Chameleons possess specialized cells called chromatophores in their skin that allow them to change color rapidly. This adaptation serves various functions:

1. Predator Avoidance: Chameleons can blend into their surroundings, making it challenging for predators to spot them. This helps them avoid being detected and attacked.
2. Ambush Hunting: When hunting for prey, chameleons can use their color-changing ability to match the colors of the background, providing effective camouflage as they wait for unsuspecting prey to approach.
3. Communication: Chameleons also change color as a form of communication. They may display bright colors during courtship rituals or to establish territory, signaling their intentions to other chameleons.

Adaptive coloration and functions in green snake

The adaptive coloration of a green snake, blending with green grass, serves several crucial functions:

1. Camouflage: The primary purpose is to camouflage and avoid detection by predators or prey. By matching the color of its surroundings, the snake becomes less visible, enhancing its ability to ambush prey or evade predators.
2. Ambush Predation: Green snakes often use their cryptic coloration to lie in wait for prey. This ambush strategy allows them to surprise and capture prey more effectively.
3. Protection from Predators: The camouflage helps protect the snake from potential predators by making it harder to spot. This is particularly important for species that rely on concealment rather than active defense.
4. Survival Advantage: The ability to blend into the environment provides a survival advantage by increasing the snake's chances of avoiding threats and successfully hunting for food.

 Adaptive coloration and  functions in flowers

The bright coloration of flowers is a structural adaptation that serves the essential function of attracting pollinators. Here are the key functions:

1. Pollinator Attraction: The vibrant colors of flowers, such as reds, blues, pinks, and yellows, act as visual signals to attract pollinators like bees, butterflies, and hummingbirds. These animals are drawn to the colorful blooms while foraging for nectar.
2. Reproductive Success: Pollination is a crucial step in the reproductive process of flowering plants. By attracting pollinators with bright colors, flowers increase the likelihood of pollen transfer between male and female reproductive organs, leading to successful fertilization and seed production.
3. Nectar Guides: Some flowers have specific patterns or markings, known as nectar guides, that guide pollinators toward the nectar-rich parts of the flower. This enhances the efficiency of pollination

Structural Adaptation for obtaining food

Structural adaptations for obtaining food showcase the diverse strategies organisms employ:

1. Proboscis for Sucking Cell Sap: Aphids for example have specialized mouthparts, called stylets, adapted for piercing plant tissues and extracting cell sap. This proboscis allows aphids to feed on plant fluids, obtaining nutrients directly from the host plant.

2. Insect Mimicry: The viceroy butterfly mimics the appearance of the toxic monarch butterfly. Mimicry serves as a defense mechanism, deterring predators by resembling a harmful or unpalatable species.

3. Colors for Security: The vibrant colors of poisonous dart frogs in tropical rainforests. Bright colors act as a warning signal to predators, indicating toxicity and discouraging potential attacks.

4. Mates for Regulating Temperature: Desert-dwelling beetles engaging in "mate shielding," where one beetle shelters its mate from extreme temperatures.

This behavior helps regulate the temperature of the mating partner, improving their chances of successful reproduction in harsh environments.

Termites

Termites live in colonies that consist of different castes, each with specific roles. The main castes are:

1. Worker Termites: Workers are the most numerous and are typically blind and sterile. They are responsible for building and maintaining the nest, foraging for food, and feeding other castes.
2. Soldier Termites: Soldiers have large mandibles for protection, and they rely on workers for feeding. They defend the colony against predators, primarily ants, and other threats.
3. Reproductive Termites (King and Queen): Queens are usually larger and have an elongated abdomen for egg production, while kings are smaller and serve the queen. The king and queen are the primary reproductive members, responsible for laying eggs and starting new colonies.
4. Alate Termites (Winged Reproductives): Alates have both male and female reproductive organs and lose their wings after mating.These are winged reproductive termites that leave the colony in swarms to mate and establish new colonies.
5. Nymphs: Nymphs resemble smaller versions of adults and undergo molting to reach maturity. Immature termites that develop into workers, soldiers, or alates.

EVALUATION: 1. Discuss the progressive change in structure and anatomy of organisms during evolution.

2. Identify the functions of adaptive coloration of a green snake
3. Identify 4 structural Adaptation for food exhibited by living organisms.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively