Module 7
Class 1: Introduction to Animals
Characteristics of Animals:
Multicellular, eukaryotic organisms with no cell walls.
Heterotrophic (consume organic material).
Most have specialized tissues for movement and response (e.g., muscle and nerve cells).
Sexual reproduction is common, with embryonic development proceeding through distinct stages like blastula.
Symmetry in Animals:
Radial Symmetry: Body parts arranged around a central axis (e.g., jellyfish).
Bilateral Symmetry: Divisible into mirror-image halves along one plane (e.g., humans).
Three Germ Layers:
Ectoderm: Forms the skin and nervous system.
Mesoderm: Forms muscles, bones, and circulatory system.
Endoderm: Forms the digestive tract and associated organs.
Body Cavities:
Coelom: A true body cavity within the mesoderm (e.g., mammals).
Pseudocoelom: A cavity between mesoderm and endoderm (e.g., roundworms).
Acoelomate: No body cavity (e.g., flatworms).
Advantages: Body cavities allow for organ movement, cushioning, and development.
Segmentation and Cephalization:
Segmentation: Division of the body into repeated parts (e.g., earthworms). Provides flexibility and efficient movement.
Cephalization: Concentration of sensory and neural organs in the head. Increases coordination and processing.
Animal Phylogenetic Tree:
Traces evolution from simple organisms (sponges) to complex ones (vertebrates).
Includes transitions to bilateral symmetry, coelom, and segmentation.
Four Tissue Types:
Epithelial: Covers surfaces, lines cavities (e.g., skin).
Connective: Supports, binds, stores energy (e.g., bone, blood).
Muscle: Produces movement (skeletal, cardiac, smooth).
Nervous: Transmits signals (neurons, glial cells).
Tissues, Organs, and Systems:
Tissues form organs (e.g., stomach), and organs combine into organ systems (e.g., digestive system).
Homeostasis and Feedback Mechanisms:
Homeostasis: Maintenance of stable internal conditions.
Negative Feedback: Reverses changes (e.g., body temperature regulation).
Positive Feedback: Amplifies responses (e.g., blood clotting).
Animal Diversity and Evolution:
Compare structural and functional traits across species to understand evolutionary adaptations.
1. Characteristics that distinguish animals from other types of organisms:
Eukaryotic: Cells contain a nucleus and organelles.
Multicellular: Composed of multiple cells.
Specialized Tissues: Have tissues with specific functions.
Motility: Mobile during at least one stage of their life cycle.
Heterotrophic: Obtain energy by ingesting organic matter.
Reproduction: Most reproduce sexually with offspring passing through developmental stages; some reproduce asexually (e.g., budding, fragmentation, parthenogenesis).
2. Radial vs. Bilateral Symmetry:
Radial Symmetry: Body parts arranged around a central axis; can be divided into similar halves along multiple planes (e.g., sea anemones).
Bilateral Symmetry: Body has left and right sides that are mirror images; divided by a single vertical plane (e.g., humans, goats).
3. Germ Layers and Their Derived Tissues:
Ectoderm: Develops into the epidermis, nervous system, lens/cornea of the eye.
Mesoderm: Forms muscles, bones, blood vessels, kidneys, and the dermis.
Endoderm: Becomes the lining of the digestive tract, liver, and pancreas.
4. Types of Body Cavities:
Acoelomate: No body cavity (e.g., flatworms).
Pseudocoelomate: Fluid-filled cavity between endoderm and mesoderm, but mesoderm only lines the ectoderm side (e.g., nematodes).
Coelomate: Fully lined cavity within the mesoderm that surrounds and supports organs (e.g., arthropods, chordates). Advantages of Body Cavities: Provide space for organ development, cushioning, and better mobility.
5. Segmentation and Cephalization:
Segmentation: Division into repeated sections (e.g., earthworms); provides flexibility, mobility, and specialization.
Cephalization: Concentration of sensory organs and nervous tissue at the head; facilitates efficient environmental interaction and processing.
6. Basic Phylogenetic Tree and Evolutionary Features:
Radial symmetry evolved in diploblastic animals.
Bilateral symmetry, cephalization, and segmentation evolved in triploblastic animals.
Acoelomate, pseudocoelomate, and coelomate body plans developed within bilateral animals.
Protostomes (mouth forms first) and deuterostomes (anus forms first) diverged among coelomates.
7. Four Types of Animal Tissues and Functions:
Epithelial: Covers surfaces; aids in absorption, secretion, and protection (e.g., skin, lung linings).
Connective: Supports and binds other tissues (e.g., bone, cartilage, blood).
Muscle: Produces movement; types include skeletal, smooth, and cardiac.
Nervous: Transmits signals; consists of neurons and glial cells.
8. Tissues, Organs, and Organ Systems:
Tissues: Groups of similar cells with specific functions.
Organs: Structures with specific functions made of multiple tissue types.
Organ Systems: Groups of organs working together for larger functions (e.g., circulatory system).
9. Homeostasis, Negative Feedback, and Positive Feedback:
Homeostasis: Maintenance of stable internal conditions.
Negative Feedback: Reverses changes (e.g., insulin regulates blood glucose levels).
Positive Feedback: Amplifies changes (e.g., oxytocin in childbirth).
10. Animal Diversity and Evolution:
Similarities: Eukaryotic, multicellular, heterotrophic, and use tissues/organs for specialized functions.
Differences: Body plans, symmetry, germ layers, reproductive methods, and habitat adaptations demonstrate evolutionary diversity.
Leeches belong to what group of animals? – Annelida
What are tetrapods? – animals with four limbs
Which of the following is not a characteristic of all chordates? – exoskeleton
An organism that has no body cavity is called – acoelomate
All animals have cells that are – eukaryotic
Class 2: Material Acquisition and Transport
Aerobic Respiration:
Inputs: Oxygen (O₂), glucose.
Outputs: Carbon dioxide (CO₂), water, ATP.
Transport relies on the circulatory system.
Digestive Systems:
Incomplete: Single opening (e.g., jellyfish).
Complete: Separate mouth and anus (e.g., mammals).
Mammalian Digestive System:
Components: Mouth, esophagus, stomach, intestines, liver, pancreas.
Functions: Digestion, absorption, waste elimination.
Processes in Digestion:
Mechanical (chewing) and chemical (enzyme action).
Absorption in intestines via villi.
Fat Digestion:
Bile: Emulsifies fats.
Lipase: Breaks down fats into fatty acids and glycerol.
Vitamins and Minerals:
Essential for enzyme function, bone health, and metabolism.
Adaptations for Diets:
Herbivores have specialized teeth and long digestive tracts; carnivores have sharp teeth and shorter guts.
Gas Exchange Adaptations:
Gills, lungs, skin for O₂ intake and CO₂ release.
Breathing and Cellular Respiration:
Breathing supplies O₂ for ATP production; CO₂ is a waste product.
Circulatory Systems:
Open: Blood bathes organs directly (e.g., insects).
Closed: Blood confined to vessels (e.g., vertebrates).
Heart and Blood Flow:
Pathway: Right atrium → right ventricle → lungs → left atrium → left ventricle → body.
Blood Components:
Erythrocytes: Carry oxygen.
Leukocytes: Fight infection.
Thrombocytes: Clotting.
Which of the following is true about saliva? – It inhibits the growth of bacteria
Peristalsis is not under voluntary control.
What type of blood is monocyte? – White blood cell
What is the count of chambers in the heart of an amphibian? – two atria and one ventricle
What structure in the respiratory system is responsible for gas exchange between blood and tissues? – alveoli
Class 3: Internal Communication and Coordination
Nervous System:
Central (CNS): Brain and spinal cord.
Peripheral (PNS): Nerves outside the CNS.
Neuron Types:
Sensory: Detect stimuli.
Motor: Trigger responses.
Interneuron: Connect sensory and motor neurons.
Neuron Structure:
Axon: Transmits signals.
Dendrites: Receive signals.
Synapse: Gap between neurons for signal transmission.
Resting Potential and Action Potential:
Resting potential maintained by ion gradients.
Action potentials propagate signals.
Endocrine System:
Hormones like insulin regulate processes like blood sugar.
1. Subdivisions of the Human Nervous System
Central Nervous System (CNS):
Composition: Composed of the brain and spinal cord.
Function: Processes and integrates information, controls thought, movement, memory, and sensory processing.
Peripheral Nervous System (PNS):
Composition: Includes all nerves outside the CNS, such as sensory and motor neurons.
Function: Connects the CNS to the limbs and organs, enabling sensory input and motor output. It is divided into:
Somatic Nervous System: Controls voluntary movements.
Autonomic Nervous System: Regulates involuntary functions like heartbeat and digestion.
2. Types of Neurons and Their Functions
Sensory Neurons:
Function: Transmit sensory information (e.g., temperature, pain) from sensory receptors to the CNS.
Location: Found in sensory organs (skin, eyes, ears).
Motor Neurons:
Function: Carry signals from the CNS to muscles and glands to provoke action (e.g., muscle contraction).
Location: Found in the CNS and extend to muscles and organs.
Interneurons:
Function: Process information between sensory and motor neurons, and are involved in reflexes and higher brain functions (e.g., thinking, learning).
Location: Found entirely within the CNS.
3. Parts of a Neuron and Synaptic Transmission
Cell Body (Soma): Contains the nucleus and is responsible for the general metabolic functions of the neuron.
Axon: Transmits electrical signals (action potential) away from the cell body toward other neurons, muscles, or glands.
Dendrites: Receive electrical signals from other neurons and transmit them to the cell body.
Synapse: The gap between two neurons where communication occurs via neurotransmitters. Electrical signals are converted into chemical signals for transmission across the synapse.
4. Resting Potential and Signal Initiation
Resting Potential: The charge difference across the neuron's membrane when it is not actively transmitting a signal. Inside the neuron is negatively charged relative to the outside.
Molecular Basis: Maintained by the sodium-potassium pump, which pumps out 3 sodium ions (Na⁺) and pumps in 2 potassium ions (K⁺), creating a negative charge inside the cell.
Action Potential:
When a signal is triggered, sodium channels open, and Na⁺ rushes in, causing the inside of the cell to become more positive (depolarization).
Potassium channels then open, and K⁺ leaves the cell, restoring the negative charge (repolarization).
The action potential propagates along the axon to the next neuron.
5. Signal Conduction (Action Potential and Synaptic Transmission)
Action Potential: An electrical impulse that travels along the axon, triggered when the threshold is reached. It travels as a wave of depolarization and repolarization.
Synaptic Transmission: When the action potential reaches the axon terminal, it triggers the release of neurotransmitters into the synaptic cleft. These neurotransmitters bind to receptors on the next neuron, transmitting the signal.
6. Neurotransmitters and Hormones
Neurotransmitter: Chemical messengers that transmit signals across synapses between neurons.
Examples: Dopamine, serotonin, acetylcholine.
Receptors: Located on the postsynaptic neuron’s dendrites or cell body.
Hormones: Chemical messengers secreted by endocrine glands, influencing organs and tissues to regulate physiological processes (e.g., growth, metabolism).
Receptors: Found on or inside target cells, depending on whether the hormone is lipid-soluble or water-soluble.
7. Human Endocrine System Components
Glands: Key endocrine glands include the pituitary gland, thyroid, adrenal glands, pancreas, and gonads (ovaries/testes).
Functions: These glands secrete hormones that regulate metabolism, growth, reproduction, and response to stress, among other functions.
8. Regulation of Blood Sugar (Endocrine Homeostasis)
Pancreatic Hormones:
Insulin: Secreted by the pancreas when blood sugar levels are high. It promotes the uptake of glucose into cells, lowering blood sugar.
Glucagon: Secreted when blood sugar is low. It signals the liver to release stored glucose, raising blood sugar levels.
Target Tissues: Insulin affects cells throughout the body (muscle, fat, liver), while glucagon primarily affects the liver.
9. Endocrine System and Reproductive System
Males:
Testes: Produce testosterone, which regulates male reproductive functions and secondary sexual characteristics.
Females:
Ovaries: Produce estrogen and progesterone, which regulate the menstrual cycle, pregnancy, and female secondary sexual characteristics.
Both systems are regulated by hormones from the hypothalamus and pituitary gland.
10. Asexual vs. Sexual Reproduction
Asexual Reproduction: Involves one parent and results in genetically identical offspring (e.g., binary fission, budding).
Advantages: Faster reproduction, no need for mates.
Disadvantages: Lack of genetic diversity.
Sexual Reproduction: Involves two parents and results in genetically diverse offspring.
Advantages: Greater genetic diversity, better adaptation.
Disadvantages: Slower reproduction, requires mates.
11. Regulation of Digestion (Endocrine and Nervous Systems)
Endocrine Control:
Gastrin: Stimulates gastric acid production.
Insulin: Aids in glucose metabolism after eating.
Nervous Control: The autonomic nervous system (ANS) regulates digestion by influencing smooth muscle activity and enzyme secretion.
Homeostasis: These systems work together to maintain balance, ensuring proper nutrient absorption and metabolic regulation.
12. Endocrine System and Other Organ Systems
The endocrine system interacts with the nervous system, cardiovascular system, and digestive system, among others, to regulate processes such as metabolism, growth, stress response, and homeostasis.
For example, thyroid hormones influence metabolic rate, while insulin interacts with the circulatory system to regulate blood glucose levels.
The brain and spinal cord make up the – central nervous system
What type of hormone can pass through a plasma membrane to bind with a receptor inside the cell? – steroid
During the resting potential, the inside of a neuron is more negative than the outside.
Hermaphrodites are animals that have both male and female reproductive systems.
What general type of neuron detects information from the environment? – sensory neurons
Class 4: External Communication and Coordination
Integumentary System:
Skin protects and regulates temperature.
Senses:
Chemoreceptors (taste, smell), photoreceptors (vision), mechanoreceptors (touch, hearing).
Immunity:
Innate (general defense) and adaptive (specific targeting).
Vaccines:
Stimulate immunological memory.
1. Integumentary System
Description: Includes skin, hair, nails, sweat glands, and sebaceous glands.
Functions:
Protection against pathogens, injury, and UV radiation.
Regulates body temperature.
Sensory reception.
Vitamin D synthesis.
Excretion of waste (sweat).
2. Five Major Human Senses and Their Receptor Types
Senses & Classifications:
Sight (Vision): Photoreceptor (eyes).
Hearing: Mechanoreceptor (ears).
Touch: Mechanoreceptor (skin).
Smell (Olfaction): Chemoreceptor (nose).
Taste: Chemoreceptor (tongue).
3. Reflex Arc
Components:
Receptor: Detects stimulus.
Sensory Neuron: Sends signal to spinal cord.
Integration Center: Processes signal in the spinal cord (interneurons).
Motor Neuron: Sends response signal to effector.
Effector: Executes response (e.g., muscle or gland).
Function: Provides rapid, involuntary response to stimuli (e.g., knee-jerk reflex).
4. Immunity
Definition: The body’s ability to resist disease.
Types of Defense Mechanisms:
Innate (Non-specific): Immediate defense (skin, mucus, phagocytes).
Adaptive (Specific): Slower but targeted (antibodies, T-cells).
5. Characteristics of Viruses
Key Features:
Non-living particles with genetic material (DNA or RNA).
Cannot reproduce independently; require a host cell.
No metabolism or cellular structure.
6. Viral Replication and Evolution
Replication Steps:
Attachment to host cell.
Entry of genetic material.
Use of host machinery for replication and protein synthesis.
Assembly of new viruses.
Release of viruses from the host cell.
Evolution: Rapid due to mutations during replication.
7. Effects of Viruses on Humans
Harmful Effects:
Cause diseases (e.g., COVID-19, flu, HIV).
Beneficial Effects:
Used in gene therapy and vaccines.
Important in research and biotechnology.
8. Components of Innate Immunity
Physical Barriers: Skin, mucus membranes.
Internal Defenses:
Phagocytes (e.g., macrophages, neutrophils).
Natural killer cells.
Inflammatory response.
Antimicrobial proteins (e.g., interferons, complement system).
9. Antibodies (Humoral Response)
Definition: Proteins produced by B-cells to neutralize pathogens.
Function: Bind to antigens, marking them for destruction.
Production Site: Bone marrow and lymphatic tissue.
10. Cell-Mediated Response
Process:
Involves T-cells targeting infected or abnormal cells.
Cytotoxic T-cells kill directly.
Helper T-cells coordinate immune responses.
11. Immunological Memory and Vaccines
Immunological Memory: Adaptive immunity retains memory of pathogens for faster future responses.
Vaccines: Mimic infection to train the immune system without causing disease.
12. Leukocytes (White Blood Cells)
Types:
Innate Immunity: Neutrophils, macrophages, dendritic cells, natural killer cells.
Adaptive Immunity: B-cells, T-cells (Helper and Cytotoxic).
Function: Defend against pathogens and coordinate immune responses.
13. Lymphatic System
Components:
Lymph, lymph nodes, lymphatic vessels, thymus, spleen, bone marrow.
Functions:
Transport lymph and immune cells.
Filter pathogens.
Aid in fat absorption.
14. Daphnia Experiment
Objective: Study heart rate changes in response to environmental factors (e.g., temperature, chemicals).
Key Findings: Analyze class data to understand the physiological responses of the organism.
What happens in the lysogenic cycle of viral infection? – Viral genes are incorporated into the host genes
Antibodies are produced by B cells in response to antigens.
The spleen is part of what organ system? – the lymphatic system
Which of the following is a human disease caused by an RNA virus? – Covid-19
What gland secretes oil to lubricate and waterproof the skin? – sebaceous
Class 5: Adaptation to Land
Challenges:
Water retention, movement, reproduction, and respiration.
Skeletal Systems:
Hydrostatic (worms), exoskeletons (insects), endoskeletons (vertebrates).
Muscles:
Smooth (organs), cardiac (heart), skeletal (movement).
Sliding Filament Theory:
Actin and myosin filaments slide using ATP.
1. Challenges of Living on Land and Adaptations
Challenges:
Desiccation (Water Loss): Need to prevent dehydration.
Gravity: Support and movement without buoyancy.
Gas Exchange: Efficient respiration in air.
Reproduction: Protection of gametes and developing embryos.
Adaptations:
Skin & Exoskeletons: Prevent water loss.
Skeletal Systems: Provide structural support.
Lungs & Tracheae: Adapted for air breathing.
Amniotic Eggs & Internal Fertilization: Protect reproduction.
2. Skeletal Systems
Types:
Hydrostatic Skeleton:
Structure: Fluid-filled cavity (e.g., jellyfish).
Advantages: Flexible, good for movement in aquatic environments.
Disadvantages: Limited support on land.
Exoskeleton:
Structure: Hard outer covering (e.g., insects).
Advantages: Protection, prevents water loss.
Disadvantages: Limits growth, requires molting.
Endoskeleton:
Structure: Internal bones or cartilage (e.g., vertebrates).
Advantages: Supports larger body size, grows with organism.
Disadvantages: Less external protection.
3. Types of Muscles
Smooth Muscle:
Location: Walls of organs (e.g., stomach, intestines).
Function: Involuntary movement (e.g., digestion).
Cardiac Muscle:
Location: Heart.
Function: Pumps blood, involuntary, rhythmic.
Skeletal Muscle:
Location: Attached to bones.
Function: Voluntary movement, posture.
4. Sarcomere: Basic Functional Unit of Muscle Contraction
Key Structures:
Actin Filaments (Thin): Pulled during contraction.
Myosin Filaments (Thick): Pull actin using cross-bridges.
Z-lines: Define boundaries of sarcomere.
Role: Contracts muscles by shortening.
5. Sliding Filament Theory
Steps:
Signal: Nerve impulse triggers calcium release.
Calcium: Binds to troponin, exposing actin sites.
Myosin Heads: Attach to actin, forming cross-bridges.
ATP: Powers myosin to pull actin (contraction).
Reset: ATP breaks cross-bridge for relaxation.
6. Systems Working Together
Integration:
Nervous System: Sends signals.
Sensory Organs: Detect stimuli.
Muscular System: Responds via contraction.
Skeletal System: Provides support for movement.
Example: Reflex to move away from danger.
7. Regulation of Water and Solutes
Importance: Maintain homeostasis in varying environments.
Strategies:
Osmoregulators: Actively regulate water/solute balance.
Osmoconformers: Match external osmotic conditions.
8. Osmotic Regulation Organs
Organs:
Kidneys (mammals).
Malpighian tubules (insects).
Gills (fish).
Function: Control water balance and excretion.
9. Mammalian Kidney Functions
Functions:
Osmotic Regulation: Adjusts water/solute levels.
Acid-Base Regulation: Maintains blood pH.
Nitrogenous Waste Excretion: Removes urea.
10. Urinalysis
Uses: Detects abnormalities in kidney function.
Examples:
High glucose: Possible diabetes.
High protein: Kidney damage.
Blood: Injury or infection.
11. Nephron Structure
Components:
Bowman’s Capsule: Filters blood.
Proximal Tubule: Reabsorbs nutrients.
Loop of Henle: Concentrates urine.
Distal Tubule: Regulates ions.
Collecting Duct: Final water reabsorption.
12. Nephron Processes
Key Processes:
Glomerular Filtration: Filters blood into nephron.
Tubular Reabsorption: Returns useful substances to blood.
Tubular Secretion: Removes wastes into nephron.
Mechanisms:
Active transport (energy required).
Passive transport (diffusion).
13. Reproduction on Land
Adaptations:
Internal Fertilization: Protects gametes.
Amniotic Eggs: Provides a self-contained environment.
Protective Structures: Nests, shells, or parental care.
Which of the following animals have a hydrostatic skeleton? – Octopus
What is the functional unit of the kidney? – the nephron
What are tetrapods? – animals with four limbs
In what sort of environment would a fish drink little water and excrete a high volume of dilute urine? – hypotonic environment
The thick filaments of myofilaments are made of the protein myosin
Class 6: Homeostasis
Integration of Systems:
Systems work together to maintain stable environments for temperature, pH, and hydration.
What structure in the brain secretes antidiuretic hormone (ADH)? – pituitary
What is the main function of the nervous and endocrine systems in the maintenance of homeostasis? – To send signals between the receptors, coordination centers, and effectors.
What structure in the brain detects the concentration of water in blood? – hypothalamus
What part of an automatic control system detects a change from optimal conditions? – receptors
The endocrine system relies on chemical messengers called hormones that travel throughout the body but only affect cells with the correct receptor .
During the process of reabsorption , molecules that the body needs (like glucose) return to the blood.
The first thing that happens during the automatic control of homeostasis is the detection of a change from optimal.
Choose all that apply: Some of the things regulated by the kidneys include – ions and water