Study

Question 1

Nervous System Purpose

Answer 1

Coordinates rapid responses to stimuli; controls and integrates body functions

Question 2

CNS vs PNS

Answer 2

CNS: Brain and spinal cord; processes information

PNS: Peripheral nerves; transmits signals to/from CNS

Question 3

Neuron Structure

Answer 3

Cell body, dendrites (receive signals), axon (transmits signals), myelin sheath, axon terminals

Question 4

Brain Regions

Answer 4

Cerebrum: Thinking, memory, sensory processing, voluntary movement

Cerebellum: Balance, coordination, posture

Brain stem: Basic life functions (heartbeat, breathing)

Hypothalamus: Homeostasis, links to endocrine system

Question 5

Receptor Types

Answer 5

Chemoreceptors (chemicals), Mechanoreceptors (pressure/touch), Thermoreceptors (temperature), Photoreceptors (light)

Question 6

Endocrine System Purpose

Answer 6

Chemical communication via hormones for slower, longer-lasting responses

Question 7

Endocrine System- Key Glands & Hormones

Answer 7

Pituitary: Growth hormone, controls other glands

Thyroid: Thyroxine (metabolism)

Pancreas: Insulin, glucagon (blood glucose)

Adrenal: Adrenaline (stress response)

Gonads: Sex hormones (reproduction, development)

Question 8

What is homeostasis?

Answer 8

Maintenance of stable internal environment despite external changes

Question 9

What are pathogens?

Answer 9

Disease-causing microorganisms (bacteria, viruses, fungi, protozoans)

Question 10

Three Lines of Defense

Answer 10

First: Physical barriers (skin, mucous membranes)

Second: Non-specific responses (inflammation, phagocytes, macrophages, neutrophil)

Third: Specific immune response (lymphocytes, antibodies)

Question 11

How are diseases prevented

Answer 11

Vaccination, hygiene, proper food handling, clean water

Question 12

Antibiotics

Answer 12

Kill bacteria but not viruses; overuse leads to resistance

Question 13

Abiotic vs Biotic

Answer 13

Abiotic: Non-living (temperature, water, soil, light)

Biotic: Living organisms (plants, animals, microbes)

Question 14

Different types of organism interaction

Answer 14

Competition: Contest for limited resources (lion/cheetah want to eat zebra)

Predation: One organism consumes another (fox eats rabbit)

Mutualism: Both benefit (bee/flower)

Commensalism: One benefits, other unaffected (remora/shark)

Parasitism: One benefits, other harmed (tapeworm/host)

Question 15

Different types of adaption examples

Answer 15

Structural (body features), Behavioural (actions), Physiological (internal functions)

Question 16

How energy flows in and out of ecosystem and how it must be retained to maintain sustainability of ecosystem

Answer 16

Enters ecosystem via photosynthesis

Transferred through food webs with -10% efficiency between levels

Must be constantly replaced from the sun

Question 17

Major glands and hormones in endocrine system

Answer 17

Pituitary: “Master gland” produces growth hormone (GH) and controls other glands via releasing hormones

Thyroid: Produces thyroxine (T4) controlling metabolism and body temperature

Pancreas: Beta cells produce insulin (lowers blood glucose); alpha cells produce glucagon (raises blood glucose)

Adrenal: Produces adrenaline/epinephrine (fight-or-flight response) and cortisol (stress response)

Gonads: Testes produce testosterone; ovaries produce estrogen and progesterone (reproduction, development)

Hypothalamus: Links nervous and endocrine systems; produces releasing hormones

Question 18

How do hormones regulate processes

Answer 18

Feedback loops

Question 19

What are hormones

Answer 19

Hormones are chemical messengers traveling via bloodstream to target cells

Question 20

What are feedback mechanisms that control hormone levels

Answer 20

Negative feedback: When hormone levels rise → signals gland to decrease production
- Example: High blood glucose → insulin released → glucose uptake increases → blood glucose decreases → insulin production stops

Positive feedback: Less common; hormone triggers more hormone production
- Example: Oxytocin during childbirth intensifies contractions

Question 21

Endocrine disorder example

Answer 21

Type 1 Diabetes
- Causes: Autoimmune destruction of pancreatic beta cells
- Symptoms: Excessive thirst, frequent urination, fatigue, weight loss
- Disruption to homeostasis: Unable to regulate blood glucose levels; glucose remains in bloodstream rather than entering cells

Question 22

CNS major components

Answer 22

o Brain:
- Cerebrum: Higher functions (thinking, memory, sensation, voluntary movement)
- Cerebellum: Coordination, balance, fine movement
- Brain stem: Vital functions (breathing, heart rate)
- Hypothalamus: Homeostasis, links to endocrine system

o Spinal cord: Neural pathway between brain and body; coordinates reflexes

Question 23

How does CNS process and respond to stimuli

Answer 23

o Receives sensory input from receptors via afferent neurons
o Integrates and processes information in interneurons in spinal cord (if a reflex arc), otherwise processes information brain
o Sends motor commands via efferent neurons
o Uses electrochemical signals (action potentials) along neurons and neurotransmitters across synapses

Question 24

Roles of neurons in transmitting signals within CNS

Answer 24

o Dendrites receive signals → cell body integrates signals → axon conducts action potentials → synaptic terminals release neurotransmitters
o Myelin sheath increases transmission speed via saltatory conduction
o Neurotransmitters cross synaptic cleft to trigger response in next neuron

Question 25

Reflex Arc components

Answer 25

o Receptor: Detects stimulus (e.g., pain receptor in skin) o Sensory neuron: Transmits signal to CNS o Interneuron: Processes signal within spinal cord o Motor neuron: Carries signal to effector o Effector: Muscle or gland that responds

Question 26

Reflex action process

Answer 26

o Stimulus activates receptor → sensory neuron transmits signal to spinal cord → interneuron processes signal → motor neuron carries signal to effector → effector produces rapid response o Bypasses brain for faster reaction time (e.g., withdrawing hand from hot surface)

Question 27

Importance of reflex arc

Answer 27

o Provides rapid protective responses without conscious thought o Maintains homeostasis (e.g., pupil reflex, maintaining balance) o Prevents tissue damage from harmful stimuli

Question 28

Major components immune system

Answer 28

o White blood cells (leukocytes): B cells, T cells, phagocytes o Lymphatic system: Lymph nodes, spleen, thymus o Antibodies: Proteins that tag pathogens for destruction o Complement proteins: Enhance antibody effectiveness, promote inflammation

Question 29

Innate vs. Adaptive immune response

Answer 29

o Innate: Non-specific, immediate response (inflammation, phagocytosis) o Adaptive: Specific to particular pathogens, develops memory cells - Humoral immunity: B cells produce antibodies against extracellular pathogens - Cell-mediated immunity: T cells attack infected cells directly

Question 30

How does immune system respond to pathogens in body

Answer 30

o Recognition of pathogen via antigens o Activation of appropriate immune cells o Elimination through phagocytosis, antibody neutralization, or destruction of infected cells o Development of immunological memory for faster future response

Question 31

3 lines of defense

Answer 31

First line (external barriers): - Skin: Physical barrier, acidic environment (pH 4-5) - Mucous membranes: Trap pathogens - Chemical barriers: Lysozyme in tears, stomach acid, antimicrobial peptides Second line (non-specific internal): - Inflammation: Increased blood flow, swelling, pain - Phagocytes: Neutrophils and macrophages engulf pathogens - Natural killer cells: Destroy virus-infected or cancerous cells - Complement system: Enhances phagocytosis, forms membrane attack complexes Third line (specific immune response): - B lymphocytes: Produce specific antibodies - T lymphocytes: Helper T cells coordinate immune response; cytotoxic T cells destroy infected cells - Memory cells: Provide long-term immunity

Question 32

How does immune system distinguish between harmful pathogens and body’s own cells

Answer 32

• Cell ID markers: Your cells have special proteins (MHC) on their surfaces that work like ID cards saying "I belong here" • T-cell training: During development, T-cells that would attack your own cells are eliminated in the thymus gland • Pattern recognition: Your immune cells can identify specific patterns on bacteria and viruses that healthy human cells don't have • Danger signals: Damaged cells release alarm chemicals that tell the immune system "something's wrong here"

Question 33

Parasitism

Answer 33

One organism benefits while harming another. Examples: tapeworms in intestines, ticks on mammals.

Question 34

Mutualism

Answer 34

Both organisms benefit. Examples: bees pollinating flowers, clownfish and sea anemones.

Question 35

Commensalism

Answer 35

One organism benefits, the other unaffected. Examples: orchids on trees, remora fish on sharks.

Question 36

Food chain and food web

Answer 36

A food chain is a linear sequence showing how energy and nutrients transfer from one organism to another in an ecosystem. For example: Grass (producer) → Grasshopper (primary consumer) → Frog (secondary consumer) → Snake (tertiary consumer) → Hawk (quaternary consumer) A food web is an interconnected network of multiple food chains. Food webs more accurately represent ecosystem complexity by showing how species interact through multiple feeding relationships. For instance, a hawk might eat snakes, frogs, and mice, while frogs might consume grasshoppers and beetles, creating a complex network rather than a simple chain.

Question 37

Decomposers and Detritivores

Answer 37

Decomposers: Break down dead material into inorganic compounds. Fungi, bacteria. Detritivores: Consume decomposing matter. Earthworms, millipedes. Importance: Release nutrients back to soil, prevent waste accumulation, complete nutrient cycles, enhance soil fertility.

Question 38

Role of chlorophyll in photosynthesis

Answer 38

• Absorbs light energy (blue and red wavelengths) • Converts light to chemical energy • Forms photosystems I and II • Enables water molecule splitting

Question 39

Equation for photosynthesis

Answer 39

Word equation: Carbon dioxide + Water + Light energy → Glucose + Oxygen Symbol equation: 6CO₂ + 6H₂O + Light energy → C₆H₁₂O₆ + 6O₂

Question 40

Cellular respiration equation

Answer 40

Word equation: Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP) Symbol equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)

Question 41

How do photosynthesis and cellular respiration contribute to the cycling of energy and matter in ecosystems

Answer 41

Energy flow: Photosynthesis converts solar energy into chemical energy stored in glucose. This energy transfers through trophic levels via food chains. Carbon cycle: Photosynthesis removes CO₂ from the atmosphere and incorporates it into organic compounds. Respiration returns CO₂ to the atmosphere, completing the cycle. Oxygen cycle: Photosynthesis releases O₂ as a byproduct, which organisms use for aerobic respiration. Respiration consumes O₂ and produces CO₂, creating a cyclic relationship. Water cycle: Plants absorb water for photosynthesis and release it through transpiration, contributing to atmospheric water vapor that eventually returns as precipitation.