Biology is a fascinating and essential subject that helps us understand life and its processes. This comprehensive guide focuses on the second-term revision and examination for SS 2 Biology, covering topics ranging from excretion to the mechanism of transport in higher plants. Each topic is analyzed in detail, providing explanations and likely examination questions to ensure students are well-prepared.
Week 1: Excretion
Excretion is the process by which organisms remove metabolic waste products to maintain internal balance. Waste products include urea, carbon dioxide, and excess salts. Organs involved in excretion in humans are the kidneys, lungs, skin, and liver.
Key Processes:
- Kidney Function: Filters blood, forms urine.
- Lungs: Expels carbon dioxide during respiration.
- Skin: Removes water and salts through sweat.
Likely Questions:
- Define excretion.
- Explain the importance of excretion in maintaining homeostasis.
- Name the excretory organs in humans and their functions.
Week 2: Tissues and Supporting Systems
Tissues are groups of cells that perform specific functions. In animals, there are four main types: epithelial, connective, muscular, and nervous tissues. Supporting systems in mammals include the skeletal and muscular systems, which provide structure and enable movement.
Likely Questions:
- What are tissues? Give examples of animal tissues.
- Describe connective tissue and its role.
- Explain how the skeletal system supports the body.
Week 3: Components of the Mammalian Skeleton
The mammalian skeleton consists of bones and cartilage that provide support and protection. It is divided into:
- Axial Skeleton: Skull, vertebral column, and ribcage.
- Appendicular Skeleton: Limbs and girdles.
Likely Questions:
- Name the two main parts of the mammalian skeleton.
- What is the function of the ribcage?
- Distinguish between the axial and appendicular skeleton.
Week 4: Joints
Joints are connections between bones that allow for movement. Types include:
- Fixed Joints: Immovable, e.g., skull.
- Slightly Movable Joints: Allow limited movement, e.g., vertebrae.
- Freely Movable Joints: Permit a wide range of movements, e.g., ball-and-socket joints.
Likely Questions:
- Define a joint and list its types.
- Explain the structure of a ball-and-socket joint.
- State the differences between fixed and movable joints.
Week 5 & 6: Alimentary Canal/Digestive System
The alimentary canal is a continuous tube running from the mouth to the anus, where digestion and absorption occur. Major parts include the mouth, esophagus, stomach, intestines, and anus.
Processes:
- Digestion: Breakdown of food into simpler forms.
- Absorption: Nutrient uptake in the intestines.
Likely Questions:
- What is the alimentary canal?
- Describe the role of the stomach in digestion.
- How does the small intestine facilitate absorption?
Week 7: Feeding Habits
Feeding habits refer to the various methods organisms use to obtain food. They are classified as:
- Herbivores: Plant-eaters, e.g., cows.
- Carnivores: Meat-eaters, e.g., lions.
- Omnivores: Eat both plants and animals, e.g., humans.
Likely Questions:
- Define feeding habits and give examples.
- Differentiate between herbivores and carnivores.
- Why are humans classified as omnivores?
Week 8: Feeding in Amoeba, Hydra, and Man
- Amoeba: Engulfs food via pseudopodia (phagocytosis).
- Hydra: Captures prey with tentacles and digests it in the gastrovascular cavity.
- Man: Uses mechanical and chemical digestion.
Likely Questions:
- How does Amoeba obtain its food?
- Explain the feeding mechanism in Hydra.
- Compare the feeding process in Hydra and humans.
Week 9: Transport Systems
Transport systems ensure the movement of nutrients, gases, and waste within an organism. In mammals, the circulatory system plays this role. Plants rely on xylem and phloem for transport.
Likely Questions:
- Why are transport systems essential in living organisms?
- Name the main transport system in mammals.
- Explain the role of xylem and phloem in plants.
Week 10: Circulatory System in Mammals
The circulatory system comprises the heart, blood vessels, and blood. It is responsible for transporting oxygen, nutrients, and waste products.
Key Concepts:
- Heart: Pumps blood.
- Blood Vessels: Arteries, veins, and capillaries transport blood.
Likely Questions:
- What are the components of the circulatory system?
- How does the heart function?
- Differentiate between arteries and veins.
Week 11: Mechanism of Transport in Higher Plants
Higher plants transport water, minerals, and nutrients through xylem and phloem.
- Xylem: Conducts water and dissolved minerals.
- Phloem: Transports food substances.
Likely Questions:
- Explain the function of xylem in plants.
- How does phloem transport food?
- What is the importance of the vascular system in plants?
This guide provides an in-depth look at key topics for SS 2 Biology second-term revision and examination. By understanding these concepts, students can confidently tackle examination questions and excel in their studies.