CSEC Human & Social Biology Exam Revision Checklist Notes
EXAM REVISION CHECKLIST
This checklist is designed to highlight the main topics for the CSEC Human & Social Biology syllabus. It serves as a study guide to help track progress through the syllabus sections. It is advised to print the PDF and tick off topics as they are completed.
SECTION A: LIVING ORGANISMS & THE ENVIRONMENT
Characteristics of Living Organisms:
Understanding the key features that define life, such as respiration, nutrition, excretion, growth, reproduction, movement and sensitivity.
Cell Structure & Function:
Plant vs. Animal Cells: Comparing and contrasting the structures and functions of plant and animal cells, including organelles like the nucleus, mitochondria, chloroplasts (in plant cells), cell wall (in plant cells), and vacuoles.
Structure of Microbes:
Virus: Non-cellular structures consisting of nucleic acid (DNA or RNA) enclosed in a protein coat. They require a host to replicate.
Bacteria: Unicellular prokaryotic organisms with a cell wall, cytoplasm, and genetic material (DNA) but lacking a nucleus. They reproduce through binary fission.
Fungi: Eukaryotic organisms that can be unicellular (yeasts) or multicellular (molds and mushrooms). They have cell walls made of chitin and obtain nutrients through absorption.
Select Cells:
Egg Cell (Ovum): Female reproductive cell, large and non-motile, containing nutrients for the developing embryo.
Sperm Cell: Male reproductive cell, small and motile, with a flagellum for swimming to the egg.
Epithelial Cell: Cells that line surfaces and cavities in the body, providing protection, absorption, and secretion. Examples include skin cells and cells lining the digestive tract.
Neuron (Nerve Cell): Cells specialized for transmitting electrical and chemical signals, consisting of a cell body, dendrites, and an axon.
Muscle Cell: Cells specialized for contraction, enabling movement. There are three types: skeletal, smooth, and cardiac muscle cells.
Cell Specialization & Levels of Organization:
Cell Specialization: The process by which cells become specialized to perform specific functions in multicellular organisms. (e.g., red blood cells for oxygen transport, nerve cells for signal transmission).
Levels of Organization: Cells -> Tissues -> Organs -> Organ Systems -> Organism
Cell Transport:
Diffusion: The movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached. It does not require energy.
Osmosis: The movement of water molecules from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration) through a semi-permeable membrane.
Active Transport: The movement of particles against their concentration gradient (from low to high concentration), requiring energy (ATP) and carrier proteins.
Photosynthesis:
Equation: (Carbon dioxide + Water + Light Energy -> Glucose + Oxygen)
Test a Leaf for Starch: Testing for the presence of starch in a leaf involves killing the leaf in boiling water, extracting the chlorophyll using ethanol, and then adding iodine solution. A blue-black color indicates the presence of starch.
Food Chains and Food Webs, Biomass:
Food Chains: Linear sequence of organisms through which nutrients and energy pass as one organism eats another
Food Webs: Interconnected network of food chains, showing the complex feeding relationships in an ecosystem.
Biomass: The total mass of organisms in a given area or volume.
Effects of Bioaccumulation on Humans:
Bioaccumulation: The accumulation of toxic substances in the tissues of living organisms. These substances become more concentrated at each successive trophic level in a food chain, leading to harmful effects on top predators, including humans.
Processes in the Carbon Cycle:
Photosynthesis: Plants and other photosynthetic organisms remove carbon dioxide from the atmosphere and convert it into organic compounds.
Respiration: Organisms release carbon dioxide into the atmosphere as they break down organic compounds for energy.
Decomposition: Decomposers break down dead organisms and organic waste, releasing carbon dioxide into the atmosphere and soil.
Combustion: Burning of fossil fuels and biomass releases carbon dioxide into the atmosphere.
SECTION B: LIFE PROCESSES
1. NUTRITION
Macronutrients vs. Micronutrients:
Macronutrients: Nutrients required in large amounts, including carbohydrates, proteins, and fats. They provide energy and building blocks for the body.
Micronutrients: Nutrients required in small amounts, including vitamins and minerals. They are essential for various physiological processes.
Deficiency Diseases:
Diseases caused by the lack of specific nutrients in the diet (e.g., scurvy due to vitamin C deficiency, rickets due to vitamin D deficiency).
Performing Food Tests:
Tests to identify the presence of specific nutrients in food samples (e.g., iodine test for starch, Biuret test for protein, Benedict's test for reducing sugars).
Functions of Water and Dietary Fiber:
Water: Essential for hydration, temperature regulation, nutrient transport, and various biochemical reactions.
Dietary Fiber: Important for digestive health, promoting regular bowel movements, and preventing constipation. It also helps regulate blood sugar and cholesterol levels.
Causes and Effects of Constipation & Diarrhea:
Constipation: Infrequent or difficult bowel movements, caused by insufficient fiber intake, dehydration, lack of physical activity, or certain medications. Effects include abdominal discomfort, bloating, and straining during bowel movements.
Diarrhea: Frequent, loose, and watery stools, caused by infections, food poisoning, food intolerances, or certain medications. Effects include dehydration, electrolyte imbalance, and abdominal cramps.
Importance of a Balanced Diet and Malnutrition:
Balanced Diet: A diet that contains all the essential nutrients in the right proportions to meet the body's needs for growth, maintenance, and repair.
Malnutrition: A condition caused by a deficiency or excess of nutrients, leading to health problems. It includes undernutrition (deficiency of nutrients) and overnutrition (excess of nutrients).
Calculate the Body Mass Index (BMI):
Types of Teeth; Tooth Structure; Tooth Decay:
Types of Teeth: Incisors (for cutting), canines (for tearing), premolars (for grinding), and molars (for grinding).
Tooth Structure: Enamel (outer protective layer), dentin (inner layer), pulp (contains nerves and blood vessels).
Tooth Decay: The breakdown of tooth enamel caused by acids produced by bacteria in the mouth, leading to cavities.
Role of Enzymes in Digestion:
Enzymes: Biological catalysts that speed up chemical reactions in the digestive system. (e.g., amylase breaks down starch, protease breaks down proteins, lipase breaks down fats).
Effects of Temperature & pH on Enzymes:
Temperature: Enzymes have an optimal temperature at which they function best. High temperatures can denature enzymes, reducing their activity.
pH: Enzymes also have an optimal pH at which they function best. Extreme pH levels can denature enzymes.
Structure & Functions of the Digestive System:
Mouth: Mechanical digestion (chewing) and chemical digestion (saliva).
Esophagus: Transports food from the mouth to the stomach.
Stomach: Mechanical digestion (churning) and chemical digestion (acid and enzymes).
Small Intestine: Digestion and absorption of nutrients.
Large Intestine: Absorption of water and formation of feces.
Anus: Elimination of feces.
Distinguish Between Egestion & Excretion:
Egestion: The removal of undigested waste from the digestive system (e.g., feces).
Excretion: The removal of metabolic waste from the body (e.g., urine, sweat).
Blood Glucose Regulation (Pancreas & Liver):
Pancreas: Secretes insulin and glucagon to regulate blood glucose levels.
Liver: Stores glucose as glycogen and releases glucose into the blood when needed.
2. THE RESPIRATORY SYSTEM
Importance of Breathing; Breathing Mechanism:
Breathing: The process of moving air into and out of the lungs, allowing for gas exchange (oxygen intake and carbon dioxide removal).
Breathing Mechanism: Inhalation (diaphragm contracts, rib cage expands) and exhalation (diaphragm relaxes, rib cage contracts).
Factors Affecting Breathing Rate:
Exercise: Increases breathing rate to meet the body's increased oxygen demand.
Altitude: Lower oxygen levels at high altitudes increase breathing rate.
Carbon Dioxide Levels: High carbon dioxide levels in the blood increase breathing rate.
Label a Diagram of the Respiratory System:
Nose/Mouth, Pharynx, Larynx, Trachea, Bronchi, Bronchioles, Alveoli, Lungs, Diaphragm
Define Vital Capacity:
Vital Capacity: The maximum amount of air a person can exhale after a maximum inhalation.
Compare Gaseous Exchange to Breathing:
Breathing: The physical process of inhaling and exhaling air.
Gaseous Exchange: The diffusion of oxygen from the alveoli into the blood and carbon dioxide from the blood into the alveoli.
Gaseous Exchange Across an Alveolus:
Oxygen diffuses from the alveoli (high concentration) into the blood (low concentration), while carbon dioxide diffuses from the blood (high concentration) into the alveoli (low concentration).
Characteristics of Gaseous Exchange Surfaces:
Large Surface Area: To maximize gas exchange.
Thin: To minimize the diffusion distance.
Moist: To allow gases to dissolve.
Good Blood Supply: To maintain concentration gradients.
Aerobic vs. Anaerobic Respiration:
Aerobic Respiration: The breakdown of glucose in the presence of oxygen to produce energy (ATP), carbon dioxide, and water. It occurs in the mitochondria.
Anaerobic Respiration: The breakdown of glucose in the absence of oxygen to produce energy (ATP) and either lactic acid (in animals) or ethanol and carbon dioxide (in plants and yeast). It occurs in the cytoplasm.
In Animals: (Glucose -> Lactic Acid + Energy)
In Yeast: (Glucose -> Ethanol + Carbon Dioxide + Energy)
The Role of ATP in Energy Transfer:
ATP (Adenosine Triphosphate): The main energy currency of the cell, providing energy for various cellular processes.
Steps to Perform Cardiopulmonary Resuscitation (CPR):
Check for responsiveness and breathing.
Call for help or ask someone to call emergency services.
Perform chest compressions (30 compressions followed by 2 rescue breaths).
Continue CPR until help arrives or the person shows signs of recovery.
Effects of Smoking (Cigarette, Marijuana, Vaping, Hookah):
Cigarette Smoking: Increases the risk of lung cancer, heart disease, emphysema, and other respiratory problems.
Marijuana Smoking: Can cause respiratory problems, impaired cognitive function, and psychological effects.
Vaping: Can cause lung damage, nicotine addiction, and exposure to harmful chemicals.
Hookah: Poses similar health risks to cigarette smoking, including exposure to toxins and carcinogens.
3. THE CIRCULATORY SYSTEM
The Need for a Transport System in the Body:
A transport system is needed to distribute nutrients, oxygen, hormones, and other substances to cells throughout the body and to remove waste products.
Substances Transported in the Body:
Oxygen, carbon dioxide, nutrients, hormones, waste products, immune cells.
Components of the Blood:
Red Blood Cells (Erythrocytes): Transport oxygen.
White Blood Cells (Leukocytes): Fight infection.
Platelets (Thrombocytes): Aid in blood clotting.
Plasma: The liquid component of blood, carrying nutrients, hormones, and waste products.
Blood Groups (ABO System & Rhesus Factor):
ABO System: Blood groups A, B, AB, and O, based on the presence or absence of A and B antigens on red blood cells.
Rhesus Factor (Rh): Positive or negative, based on the presence or absence of the Rh antigen on red blood cells.
Importance & Process of Blood Clotting:
Blood Clotting: The process of forming a blood clot to stop bleeding and prevent infection.
Process: Platelets aggregate at the site of injury, forming a plug. A cascade of clotting factors leads to the formation of fibrin, which strengthens the clot.
Concept of Blood Pressure:
Blood Pressure: The force exerted by the blood against the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is expressed as systolic pressure (when the heart contracts) over diastolic pressure (when the heart relaxes).
Structure & Functions of Arteries, Veins & Capillaries:
Arteries: Carry blood away from the heart, have thick, elastic walls to withstand high pressure.
Veins: Carry blood back to the heart, have thinner walls and valves to prevent backflow.
Capillaries: Tiny vessels that connect arteries and veins, allowing for the exchange of nutrients, oxygen, and waste products between the blood and tissues.
Label Diagram of the Human Heart:
Right Atrium, Right Ventricle, Left Atrium, Left Ventricle, Aorta, Pulmonary Artery, Pulmonary Vein, Vena Cava, Valves
Cause and Effects of Heart Disease:
Heart Disease: A range of conditions that affect the heart, including coronary artery disease, heart failure, and arrhythmia.
Causes: High blood pressure, high cholesterol, smoking, obesity, diabetes, and family history.
Effects: Chest pain, shortness of breath, fatigue, and heart attack.
Structure & Function of the Lymphatic System:
Lymphatic System: A network of vessels and tissues that help remove waste and toxins from the body. It includes lymph nodes, lymph vessels, and lymphoid organs (spleen, thymus).
Functions: Draining excess fluid from tissues, transporting fats, and playing a role in immune defense.
Formation of Tissue Fluid and Lymph:
Tissue Fluid: Fluid that surrounds cells in tissues, formed by filtration of plasma from capillaries.
Lymph: Tissue fluid that enters lymphatic vessels, carrying waste products and immune cells.
4. THE SKELETAL SYSTEM
Label Main Bones of the Human Skeleton:
Skull, Mandible, Clavicle, Scapula, Sternum, Ribs, Humerus, Radius, Ulna, Vertebral Column, Pelvis, Femur, Patella, Tibia, Fibula, Tarsals, Metatarsals, Phalanges
Functions of the Human Skeleton:
Support: Provides a framework for the body.
Protection: Protects vital organs (e.g., skull protects the brain, rib cage protects the heart and lungs).
Movement: Provides attachment points for muscles, enabling movement.
Storage: Stores minerals (e.g., calcium and phosphate) and fat.
Blood Cell Production: Red bone marrow produces blood cells.
Structure of a Long Bone:
Diaphysis: The long, cylindrical shaft of the bone.
Epiphysis: The rounded ends of the bone.
Compact Bone: The dense, outer layer of the bone.
Spongy Bone: The porous, inner layer of the bone.
Medullary Cavity: The hollow space in the diaphysis, containing bone marrow.
Periosteum: The outer membrane covering the bone.
Distinguish Between Tendons and Ligaments:
Tendons: Connect muscles to bones.
Ligaments: Connect bones to bones at joints.
Types of Joints (Fixed, Hinge, Ball & Socket):
Fixed Joints: Immovable joints (e.g., sutures in the skull).
Hinge Joints: Allow movement in one plane (e.g., elbow and knee joints).
Ball & Socket Joints: Allow movement in multiple directions (e.g., shoulder and hip joints).
Types of Muscles (Smooth, Cardiac, Skeletal):
Smooth Muscle: Found in the walls of internal organs and blood vessels, involuntary control.
Cardiac Muscle: Found in the heart, involuntary control.
Skeletal Muscle: Attached to bones, responsible for voluntary movement.
The Role of Antagonistic Muscles in Limb Movement:
Antagonistic Muscles: Muscle pairs that work opposite each other to produce movement (e.g., biceps and triceps).
Identify the Biceps and Triceps in the Upper Arm:
Biceps: Flexes the forearm.
Triceps: Extends the forearm.
Importance of Locomotion in Humans:
Locomotion: The ability to move from one place to another, essential for obtaining food, escaping danger, and finding shelter.
Factors Affecting the Skeletal System:
Nutrition: Calcium and vitamin D are essential for bone health.
Exercise: Weight-bearing exercise promotes bone density.
Hormones: Hormones such as estrogen and testosterone play a role in bone growth and maintenance.
Age: Bone density decreases with age, increasing the risk of osteoporosis.