DISEASE
Q: Define pathogen
A: A disease-causing agent (e.g. bacteria, viruses, protozoa, fungi)
Q: Contrast infectious vs non-infectious disease
A: Infectious = caused by pathogens, can be passed person-to-person. Non-infectious = not caused by pathogens, cannot be passed (except genetic diseases)
Q: Compare bacteria and viruses
| Bacteria | Viruses | |
|---|---|---|
| Cell type | Prokaryotic | Genetic material only |
| Treatment | Antibiotics | Vaccines |
| Example | Staphylococcus | COVID-19 |
Q: Compare protozoa and fungi
| Protozoa | Fungi | |
|---|---|---|
| Cell type | Eukaryotic | Eukaryotic |
| Habitat | Moist environments, inside organisms | Almost everywhere, body |
| Treatment | Medication | Antifungal creams/medication |
| Example | Plasmodium (malaria) | Tinea Pedis (athlete’s foot) |
Q: What causes cystic fibrosis?
A: Genetic — both parents must carry the gene (1 in 4 chance if both carriers)
Q: What are the symptoms of cystic fibrosis?
A: Increased mucus in respiratory system → reduced ability to breathe and do daily activities
Q: How is cystic fibrosis treated?
A: No cure. Managed with chest therapy (hitting front/back of chest to loosen mucus). Many patients die before age 30.
THE IMMUNE SYSTEM
Q: What is the first line of defence?
A: Physical/chemical barriers that stop pathogens entering the body — skin, mucous membranes, cilia, chemical secretions (saliva, tears, stomach acid)
Q: How does the skin prevent infection?
A: Physical barrier — prevents bacteria from entering the body
Q: How do mucous membranes prevent infection?
A: Both physical and chemical — mucous contains enzymes that break down some bacteria and physically trap pathogens
Q: How do cilia prevent infection?
A: Hair-like structures that move trapped pathogens in mucus up and out of the lungs (out through nose or into stomach acid)
Q: What is phagocytosis?
A: Large white blood cells envelope pathogens and destroy them via enzymes. Think “Pac-Man”
Q: What happens during inflammation?
A: Redness, heat, swelling at the affected area. Capillaries dilate, permeability increases, clotting elements and phagocytic cells are delivered to the area
Q: What does fever do?
A: Increases body temperature, quickens tissue repair, facilitates phagocytosis, inhibits growth of some microorganisms
Q: What is the lymphatic system’s role in infection?
A: Lymph vessels drain fluid from body → passes through lymph nodes where macrophages filter out waste and destroy foreign particles. Swollen lymph nodes = sign of infection
Q: Define antigen
A: A molecule capable of inducing an immune response. Antigens identify cells as FOREIGN
Q: How do B cells produce antibodies?
A: 1. WBCs detect antigen inside you
2. B cell matches antigen → produces antibodies
3. Antibody binds antigen (antigen-antibody complex), inactivates invader and “marks” it for destruction
4. B cells make memory B cells that stay in blood for faster response if same antigen returns
Q: Define immunity
A: The body’s ability to resist and fight off infection
Q: How does vaccination produce long-term immunity?
A: Vaccine introduces weakened/antigenic material → immune system makes memory cells → if you encounter the real disease later, memory cells respond so fast you may not even know you had it
Q: Why are childhood vaccinations essential?
A: They create herd immunity — enough people immune that disease can’t spread dangerously, causing it to die out
REPRODUCTION
Q: Define asexual reproduction
A: One parent creates identical copies. Fast, but if environment changes the offspring may not survive
Q: Define sexual reproduction
A: Gametes (sperm + egg) combine to create a zygote. Creates genetic variety but is slower and more complicated
Q: Examples of asexual reproduction
A: Binary fission, budding, spores
Q: Examples of sexual reproduction
A: Syngamy (two gametes combine), conjugation (organisms fuse to share genetic material)
Q: Define gamete
A: Cells containing half the DNA needed for offspring (e.g. sperm and egg)
Q: Define zygote
A: The product of combining two gametes
Q: Define embryo
A: Cloned zygotes (early stage of development)
Q: Functions of female reproductive organs
| Organ | Function |
|---|---|
| Ovary | Produces and stores ova (eggs × 40,000), releases one per month after puberty |
| Fallopian tube | Carries egg to uterus |
| Uterus | Where fertilised egg implants and baby develops |
| Cervix | Secretes mucus that varies through menstrual cycle — at ovulation it’s clear/runny for sperm |
| Vagina | Muscle dense area for penis insertion, birth canal |
Q: Functions of male reproductive organs
| Organ | Function |
|---|---|
| Testicle | Generates sperm |
| Scrotum | Keeps sperm below body temperature |
| Epididymis | Fluid for sperm to sit in |
| Vas deferens | Carries sperm from testicles to penis |
| Seminal vesicle | Produces ejaculate fluid (minus sperm) |
| Urethra | Removes urine OR expels ejaculate |
| Penis | Encases urethra and nerves |
Q: Changes during puberty in females
A: Ovaries produce oestrogen → breast tissue develops → fat stores around hips/buttocks → secondary hair (armpits/groin)
Q: Changes during puberty in males
A: Voice deepens → secondary hair (armpits/groin) → oil production increases (acne) → sperm production begins, testes/scrotum enlarge → involuntary erections and wet dreams
Q: Define copulation
A: Sexual intercourse — introduction of penis into vagina followed by semen discharge
Q: Define fertilisation
A: Union of male (sperm) and female (ovum) gametes (each with haploid set of chromosomes) to produce a diploid zygote
Q: Pregnancy milestones — Month 0-2
A: Month 0: Fertilisation → zygote implants in uterine wall
Month 1: Egg grows, amniotic fluid and placenta form
Month 2: Facial features, arms/legs begin forming → at end of month called a fetus
Q: Pregnancy milestones — Month 3-6
A: Month 3: All organs and extremities formed and working, ears/teeth forming
Month 4: Heartbeat detectable, can suck thumb, ultrasound can determine sex
Month 5: Mother feels movement, hair grows on baby
Month 6: Skin reddish/wrinkled, veins visible, toe/fingerprints visible, baby reacts to sounds
Q: Pregnancy milestones — Month 7-9
A: Month 7: Body fat reserves develop, responds to sound/pain/light, amniotic fluid diminishes
Month 8: Baby kicks more, brain develops quickly
Month 9: Lungs nearly fully developed, reflexes developing
COORDINATION SYSTEMS
Q: Define coordination
A: Various systems in living things working together so they function effectively
Q: How does the nervous system coordinate the body?
A: Sends fast electrical messages (impulses) along neurones — coordinates immediate responses like reflex actions and walking
Q: How does the endocrine system coordinate the body?
A: Releases hormones into bloodstream — coordinates slower, longer-lasting changes like growth, blood sugar control, puberty
Q: How do nervous and endocrine systems work together?
A: Nervous system can trigger hormone release (e.g. stress/fear activates hormone pathways). Hormones can adjust how the nervous system controls the body
Q: What is homeostasis?
A: Both systems maintain stable internal conditions (body temperature, heart rate, energy use) so cells function properly
Q: What happens in a stress response?
A: Nervous system rapidly reacts to danger → hormones (adrenaline and cortisol) sustain the fight-or-flight response over a longer period
THE NERVOUS SYSTEM
Q: Roles of brain, spinal cord, and nerves
| Structure | Role |
|---|---|
| Brain | Process information from nerves, decide responses |
| Spinal cord | Connects nerves and brain |
| Nerves | Gather information, sense the world |
Q: Functions of brain areas
| Area | Function |
|---|---|
| Cerebrum | Higher-order thinking, language, stimulus interpretation |
| Cerebellum | Balance, posture, coordinating voluntary movements |
| Medulla/Brain stem | Survival mechanisms, breath rate, heart rate, lower-order thinking |
Q: Functions of cerebrum lobes
| Lobe | Function |
|---|---|
| Frontal | Higher order thinking: maths, creativity, language, logic |
| Parietal | Sensory information: spatial processing, body position, navigation |
| Temporal | Speech, hearing, smell |
| Occipital | Sight |
Q: Animal cell organelle functions
| Structure | Function |
|---|---|
| Cell membrane | Controls what enters/leaves, maintains cell shape |
| Cytoplasm | Supports cell structures, medium for energy transportation |
| Nucleus | Stores and protects cell DNA |
Q: Parts of a neuron and their roles
| Part | Role |
|---|---|
| Dendrites | Receive impulses from other neurons |
| Cell body | Contains nucleus, processes impulses |
| Axon | Carries impulse away from cell body |
| Axon terminals | Release neurotransmitters to next neuron |
Q: How does a synapse work?
A: Small gap (synapse) between neurons. Axon terminals release neurotransmitters (e.g. dopamine, histamine, endorphin). Chemicals reach dendrites of next cell → next neuron fires. Signal is electrical along neuron, chemical at synapse = electro-chemical response
Q: Compare sensory, connecting, and motor neurons
| Neuron | Role |
|---|---|
| Sensory | Convert external stimuli into nervous impulses |
| Connecting | Form connections between sensory and motor neurons |
| Motor | Control muscles |
Q: What is a reflex arc?
A: Stimulus → sensory neuron → spinal cord (interneuron) → motor neuron → muscle/response. Bypasses the brain for fast, automatic responses (e.g. pulling hand away from hot surface)
Q: Example reflexes
| Sense | Stimulus | Response |
|---|---|---|
| Sight | Bright light | Pupils shrink |
| Touch | Something hot | Hand moves away |
| Smell | Something foul | Gag/dry heave |
ENDOCRINE SYSTEM
(from Coordination Systems Map — content to expand from vault if available)
Q: What does the endocrine system do?
A: Releases hormones into the bloodstream to coordinate slower, longer-lasting changes in the body
Q: Examples of endocrine control
A: Growth and development (pituitary hormones), blood sugar control (insulin/glucagon), puberty
Created from: School/Science/Biology/2025 - Getting it Together/