Part 1 SBL 100

Index
1. Why Biology for Engineers? — Overview & Exam-ready summary

2. MCQs — Why Biology for Engineers (15 Qs)

3. Applications of Biology for Engineers — Notes & MCQs

4. Short-notes: Neurons & Brain; DNA & Inheritance

5. Bio-mimetic & Bioengineered World — Notes & MCQs

6. MCQs — Biological Terms & Organisms (10 Qs)

7. Bio-inspired Robotics & AI — Notes, Table & MCQs

8. What is Life? — Levels of life, Summary & MCQs

9. Goal of Life — Explanation, Entamoeba example & MCQs

10. Amoebiasis — Summary table & MCQs

11. Consciousness — Notes & MCQs

12. Simple Reflex Action — Explanation & examples

13. Goal of Human Life, ET Life, Inner Life of a Cell — Notes & MCQs

14. Breaking the barrier with technological advances (Cell imaging) — Notes &
MCQs

15. Fibroblast & Cytoskeletal Elements — Notes & MCQs

16. Cell as a Factory — Organelles explained & MCQs

17. Four important organelles (ER, Lysosomes, Golgi, Ribosomes) — Details &
MCQs

18. The Crowded Cell — Unicellular vs Multicellular, MCQs

19. Cell Membrane Properties & Types of Cells (Excitable vs Non-excitable) —

Notes & MCQs

20. Central Dogma of Biology (DNA → RNA → Protein) — Notes & MCQs

21. Somatic Cells, Transcription, Translation, Reverse Transcription — Notes

22. Ion Homeostasis & Cell Signaling — Notes, Ion concentrations & MCQs

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 23. Why & How Ion Homeostasis works — Mechanisms & analogies

24. Equivalent Circuit Model of the Cell Membrane — Notes & MCQs

25. Lipid Bilayer role — Notes & analogy

26. Genome Organization & Genome Size examples — Notes & MCQs

27. What is a Genome — Notes

28. DNA Structure — beginning note (continues)

1. Why Biology for Engineers? — Overview

& exam-ready summary
Greater Philosophical & Open Questions

What is life? Who are we? → Biology helps explore meaning of life.

Where is our origin? What is our fate? → Evolution + genetics give answers
to where humans came from and where we are going.

Are there others like us? → Search for extraterrestrial life, synthetic life.

Are we parasitic/commensals/symbiotic? → Our relationship with

microorganisms and environment.

Practical Importance for Engineers

Healthcare & Medicine: engineers design medical devices, prosthetics,

drug-delivery systems; biology helps understand human body → better
innovations.

Biological WMD (Weapons of Mass Destruction): viruses, genetic

engineering → ethical responsibility; “gain-of-function” research =
modifying viruses → risk and ethics.

Engineering Marvel

The human body itself is the greatest engineering marvel; complex systems
inspire bio-inspired engineering (robotics, AI, nanotech).

Interdisciplinary Relevance

Biology + Engineering = solutions for modern challenges.

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 Applications: Biotechnology (genetic engineering, CRISPR), Artificial Life
(Alife research → simulations), Bio-inspired design (Velcro from burrs).

Famous References

Dan Brown’s Inferno — bioengineering + ethical dilemmas.

Feynman quote: “What I cannot create, I cannot understand.” → Engineers

must understand biology to recreate life-like systems.

Star Trek reference → imagining life beyond Earth.

Exam-ready summary (short answers)

Engineers study biology to answer philosophical (life, origin, future) and

practical (medicine, biotechnology, environment) questions.

Biology provides models for engineering designs (bio-inspired).

Helps in healthcare innovation, understanding threats (bioweapons), and

ethical responsibilities.

Ultimately, the human body is the greatest engineering marvel.

2. MCQs — Why Biology for Engineers?

(15 Qs — answers + short explanation)
1. The main reason engineers study biology is to:
B. Answer philosophical and practical questions.Explanation: Engineers
use biology for both philosophical (life, origin) and practical (healthcare,
biotech) reasons.

2. “What is life? Who are we?” refers to:

B. Fundamental philosophical questions.

3. “Where is our origin? What is our fate?” connects to:

B. Alife Research (Artificial Life).

4. Which is considered the greatest engineering marvel?

C. Human body.

5. Healthcare and medicine require biology because:

B. Understanding the body helps design medical technologies.

6. Which of the following can be a Biological WMD?

B. Gain-of-function viruses.

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 7. Dan Brown’s Inferno relates to biology because it discusses:
B. Genetic modification and bioethics.

8. “What I cannot create, I cannot understand.” is by:

C. Feynman.

9. “Are we parasitic, commensal, or symbiotic?” refers to:

A. Our relationship with microorganisms and environment.

10. The study of whether “there are others like us” links to:
A. Astronomy and space biology.

11. Which field combines biology and engineering for new materials and
devices?
A. Biotechnology.

12. Bio-inspired engineering means:

B. Copying nature’s principles to solve engineering problems.

13. Which area directly benefits from engineers understanding biology?

B. Prosthetics and medical devices.

14. “Star Trek: USS Enterprise” in the slide refers to:

A. Space exploration and extraterrestrial life possibilities.

15. The human body inspires engineers because:

C. It is highly complex and efficient.

3. Applications of Biology for Engineers —

Notes & MCQs
Biology is a molten pot

Biology mixes ideas from physics, chemistry, computing, and life sciences.

Bio-inspired Design

Engineers copy nature to solve problems. Examples:

Bullet train nose inspired by kingfisher beak (reduces noise & splash).

Prosthetics inspired by human limbs.

Mechanical/artificial heart — under development.

Synthetic & Chemical Biology

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 Creating artificial life forms or molecules for drug design, vaccines,
biomaterials.

Blue Brain Project

Simulate the human brain on a supercomputer to understand memory,

decision-making.

Next-Generation Sequencing (NGS)

Fast DNA sequencing → personalized medicine, genomics.

Exam-ready short summary

Biology inspires designs; engineering builds tools (instruments, algorithms)

to apply biology.

MCQs — Applications (10 Qs)

1. “Molten pot” means: B. Biology mixes ideas from different fields.

2. Bullet train nose design inspired by: B. Kingfisher bird’s beak.

3. Mechanical limbs are: B. Bio-inspired prosthetics.

4. Mechanical heart status: B. Hypothetical / under development.

5. Synthetic biology aims at: B. Creating artificial life forms and molecules.

6. Blue Brain Project: B. Simulating the human brain on a supercomputer.

7. NGS is used for: B. Reading DNA quickly and cheaply.

8. Personalized medicine is possible because of: C. Next-Generation DNA

sequencing.

9. Bio-inspired design principle: B. Copy nature’s solutions.

10. Non-example of bio-inspired design: D. Highway construction material.

4. Short-notes: Neurons & Brain; DNA &

Inheritance
Neurons & Brain — short notes

1. Neuron basics: dendrites (input), cell body (processing), axon (output),

synapse (gap). Signal = electrical impulse + neurotransmitters.

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 2. Brain functions: reflexes, learning (plasticity), decision-making, emotions
(amygdala).

3. Memory & learning: patterns of connections; practice strengthens

synapses.

4. Brain mapping & AI: MRI, fMRI, EEG; BCI (brain-computer interfaces); ANNs
inspired by neurons.

DNA & Inheritance — short notes

1. DNA basics: double helix of nucleotides (sugar + phosphate + base). Bases

pair A–T, G–C.

2. Central Dogma: DNA → RNA (transcription) → Protein (translation).

3. DNA decides functions via protein sequences; mutations cause disease.

4. Inheritance: 23 chromosomes from each parent; dominant vs recessive;

crossing-over creates uniqueness.

Comparison table (DNA vs Neuron vs AI) — high-level mapping:

DNA: code (A,T,G,C) → proteins → traits.

Neuron/Brain: signals, synapses → memory & action.

AI: inputs + weights → learning algorithms.

5. Bio-mimetic & Bioengineered World —

Notes & MCQs
Examples

1. Self-healing cement: Bacillus cohnii spores + calcium lactate → CaCO₃

precipitate fills cracks.

2. Biocouture (microbial leather): Acetobacter xylinum produces cellulose

sheets → leather-like materials.

3. Chlorella Pavilion (oxygen bar): Chlorella microalgae photosynthesize →

produce O₂, absorb CO₂.

4. Algeavator: rooftop microalgae farms for biomass & CO₂ capture.

5. Fungus chair: mycelium + corn stalk waste grown in molds →

biodegradable furniture.

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 6. Mycoform museum (NYC): mycelium + agricultural waste as building
material.

7. Abu Dhabi Towers: movable shades inspired by sunflower phototropism for

energy saving.

Exam-ready summary

Bio-mimetic design solves sustainability problems using bacteria, algae,

fungi, and plant-inspired architecture.

MCQs — Bio-mimetic Designs (10 Qs)

1. Bacillus cohnii role in self-healing cement: B. Produce CaCO₃ to seal

cracks.

2. Healing agent in bio-cement: B. Bacillus spores + calcium lactate.

3. Biocouture aims at: B. Producing leather without animals.

4. Microalgae in Chlorella Pavilion: B. Chlorella.

5. Benefit of Chlorella Pavilion: B. Air purification and oxygen supply.

6. Algeavator uses rooftops to: B. Grow microalgae.

7. Fungus Chairs made from: A. Mycelium + corn stalk waste.

8. Mycoform project uses: B. Fungal mycelium + agricultural waste.

9. Abu Dhabi Towers inspired by: C. Sunflower phototropism.

10. Shading system helps: B. Save cooling energy by reducing heat.

6. MCQs — Biological Terms & Organisms

(10 Qs)
1. Which bacteria used in self-healing cement? B. Bacillus cohnii.

2. “Spores” in bacteria refers to: B. Dormant, resistant bacterial form.

3. CaCO₃ is main component of: B. Limestone and seashells.

4. Organism used in biocouture: A. Acetobacter xylinum.

5. Structural polymer secreted by microbes for microbial leather: C. Cellulose.

6. Microalgae used in Chlorella Pavilion: B. Chlorella.

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 7. Process in algae to absorb CO₂ and release O₂: B. Photosynthesis.

8. Root-like network of fungi: B. Mycelium.

9. Biological waste used with mycelium: B. Corn stalks.

10. Abu Dhabi Towers based on: B. Sunflower phototropism.

7. Bio-inspired Robotics & AI — Notes,

Table & MCQs
Robots & inspirations

HRP-2 (Japan): humanoid — walking, standing, assist in tasks.

KISMET (MIT): social robot for emotional interaction; Cynthia Breazeal.

PARO (Japan): therapeutic baby-seal robot for elderly care.

Snake-mimetic robots: crawl through narrow spaces — rescue &

inspection.

Fish-mimetic robots: marine research & pollution monitoring.

Capsule endoscopy robot: swallowed camera for GI tract imaging.

Summary table (Robot → Inspiration → Purpose)

HRP-2 → Human → daily tasks, disaster response

KISMET → Human emotions → social interaction research

PARO → Baby seal → therapy, emotional support

Snake robot → Snake movement → rescue/inspection

Fish robot → Fish swimming → marine study/pollution monitoring

Capsule endoscopy → Swallowing → non-invasive medical diagnosis

MCQs — Bio-inspired Robotics & AI (10 Qs)

1. HRP-2 developed in: B. Japan.

2. KISMET focus: B. Social interaction and emotions.

3. Cynthia Breazeal associated with: C. KISMET.

4. PARO used for: B. Therapy in hospitals and elderly care.

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 5. Snake-mimetic robots inspired by: C. Snake.

6. Fish-mimetic robots mainly used for: B. Underwater research and pollution

monitoring.

7. Capsule endoscopy robots designed to: B. Travel through digestive

system and capture images.

8. Bio-inspired robotics means: A. Copying natural systems to design robots.

9. Seal-shaped therapy robot: B. PARO.

10. Capsule endoscopy studies: B. Digestive tract.

8. What is Life? — Levels, Summary &

MCQs
Levels of life (smallest → largest)

1. Atoms → 2. Molecules (DNA, proteins) → 3. Cells (basic unit of life) → 4.

Networks (cell networks, e.g., neurons) → 5. Organs → 6. Organism → 7.
Cognition & Behavior (highest level).

Key points

Cells are the basic units of life; molecules (DNA/proteins) store & perform
functions; cognition emerges from complex networks.

MCQs — What is Life? (10 Qs)

1. Smallest unit of life: C. Cell.

2. DNA and proteins belong to: B. Molecule.

3. Neurons forming memory pathways represent: A. Network.

4. The brain is an example of: C. Organ.

5. Atoms forming glucose is an example of: A. Molecule formation.

6. “What is Life?” best explained as: B. Emergence from atoms → … →

cognition.

7. Level responsible for thinking and behavior: D. Cognition & Behavior.

8. Heart pumping due to cardiac networks is example of: B. Organ-level

function.

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 9. Who said “What I cannot create, I cannot understand.”: C. Feynman.

10. Correct order smallest → largest: B. Atom → Molecule → Cell → Network →

Organ → Organism → Cognition.

9. Goal of Life — Explanation, Entamoeba

example & MCQs
Goal of Life

Core: passing information (DNA) to next generations — propagation.

Environment matters: favorable → growth/reproduction; unfavorable →

dormancy or survival forms.

Example: Entamoeba histolytica

Parasite causing amoebiasis.

Two stages: trophozoite (active, multiplies in intestine) and cyst (dormant,

survives outside host until new host found).

Summary table

Goal: passing genetic information (DNA).

Favorable environment → life propagates (seeds sprout; trophozoites

multiply).

Unfavorable environment → dormancy (seeds dormant; Entamoeba cyst).

MCQs — Goal of Life (10 Qs)

1. Ultimate goal of life: B. Passing knowledge/information to next

generations (DNA).

2. Genetic information stored in: B. DNA.

3. Life propagates when: B. Environment is conducive/favorable.

4. Example organism for propagation vs dormancy: B. Entamoeba histolytica.

5. Disease caused by Entamoeba histolytica: B. Amoebiasis (dysentery).

6. Active stage in humans: B. Trophozoite.

7. Cyst stage represents: B. Dormancy in unfavorable conditions.

8. Seeds dormant is similar to: C. Unfavorable environment stalling life.

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 9. Biological “knowledge” refers to: B. DNA code.

10. Survival strategy in unfavorable environments: C. Dormancy or protective

structures.

10. Amoebiasis — Summary & MCQs

Amoebiasis (Amoebic dysentery)

Organism: Entamoeba histolytica (protozoan).

Transmission: fecal–oral (contaminated food/water).

Infective stage: cyst.

Pathogenic stage: trophozoite (damages intestine → ulcers).

Symptoms: diarrhea, abdominal pain, dysentery (blood + mucus).

Complication: liver abscess.

Treatment: metronidazole, rehydration.

Prevention: clean water, sanitation, hygiene.

MCQs — Amoebiasis

1. Amoebiasis caused by: B. Entamoeba histolytica.

2. Infective stage: C. Cyst.

3. Site of infection: B. Large intestine (colon).

4. Dysentery due to: B. Ulcers in intestinal wall caused by trophozoites.

5. Severe complication: C. Liver abscess.

11. Consciousness — Notes & MCQs

What is Consciousness?

Awareness of self + environment; thinking, feeling emotions, making

decisions, reflecting.

In humans arises from complex brain networks (billions of neurons).

What makes humans different?

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 Self-awareness, emotions, abstract thinking, language → cognition +
consciousness.

Sentient AI

AI today: powerful at data processing but lacks true awareness/feelings.

Sentient AI (hypothetical) would have emotions and self-awareness.

Natural Language Perception

Humans use context, culture, emotion; AI uses pattern recognition and

algorithms.

MCQs — Consciousness & AI

1. Consciousness best described as: B. Awareness of self and surroundings.

2. Unique to humans vs machines: A. Self-awareness and abstract thinking.

3. Sentient AI refers to: B. AI with emotions and self-awareness like humans.

4. Part generating consciousness: B. Neurons and brain networks.

5. Main difference NLP vs human language: C. Humans use context, culture,

emotions; AI uses algorithms.

6. Which is NOT a feature of consciousness: D. Simple reflex action.

7. AI chatbot answering Qs is example of: B. Natural Language Processing

(NLP).

8. “Who we are” biologically: A. Genes + Consciousness + Environment.

9. “I think, therefore I am” — who: B. Descartes.

10. Main debate around sentient AI: A. Can machines ever achieve true self-
awareness like humans?

12. Simple Reflex Action — Explanation &

examples
Definition

Quick, automatic response to stimulus; involuntary; does not involve

conscious decision (spinal cord mediated).

Reflex arc pathway

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 Stimulus → Receptor → Sensory neuron → Relay neuron (spinal cord) →
Motor neuron → Effector (muscle) → Response.

Brain is informed after action.

Examples

Withdraw hand from hot object; knee-jerk reflex; blinking; sneezing;

coughing.

Exam phrasing

Simple reflex action = automatic, quick, involuntary response to a stimulus,

controlled by spinal cord without conscious brain involvement.

13. Goal of Human Life, ET Life, Inner Life

of a Cell — Notes & MCQs
Goal of human life (various perspectives)

Religious: serve God.

Philosophical: seek truth, happiness.

Scientific: survival, reproduction, passing on knowledge.

Modern: self-created purpose (growth, society, impact).

Exploration of ET life

Reasons: Are we alone? How does life start?

Methods: examine Mars, Europa, Enceladus; look for biosignatures (water,

oxygen, methane); SETI radio; James Webb observations.

Inner life of a cell

Nucleus = DNA (control), mitochondria = energy, ribosomes = protein

factories, membrane = control of entry/exit.

Studying cells helps medicine and biotech.

MCQs

1. Scientific goal of human life: B. Passing on knowledge and survival.

2. Planet most studied for life: B. Mars.

3. Possible biosignature for ET life: B. Oxygen & methane.

Part 1 SBL 100 13

 4. Nucleus main responsibility: C. Storing DNA and giving instructions.

5. Mitochondria called: B. Power house.

6. Telescope used for ET signals: B. SETI Radio Telescopes.

14. Breaking the barrier with technological

advances (Cell imaging) — Notes & MCQs
Advances

Improved imaging (super-resolution) allows visualization of fibroblasts,

cytoskeleton, nucleus organization, even chromatin.

Examples

Fluorescent imaging (GFP) lights up specific parts; cytoskeletal elements

(actin, microtubules, intermediate filaments) visible in detail; nucleus & DNA
visualized at micron scale (scale bar: 2 µm).

MCQs

1. What allowed clearer visualization in last decade? B. Technological

advances in imaging.

2. Fibroblast function: B. Collagen production and wound healing.

3. GFP useful because: C. Glow under special microscopes to label cell

parts.

4. Structure giving shape and movement: C. Cytoskeleton.

5. Nucleus contains: B. Genetic material (DNA).

6. Cytoskeleton made of: B. Actin, microtubules, and intermediate filaments.

15. Fibroblast & Cytoskeletal Elements —

Notes & MCQs
Fibroblast

Common connective tissue cell; spindle-shaped; makes collagen and ECM;

essential in wound healing.

Cytoskeleton

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 Network inside all cells: actin filaments (movement, shape), microtubules
(tracks for transport, cell division), intermediate filaments (mechanical
strength).

Analogy

Fibroblast → construction worker; Cytoskeleton → skeleton + railway

system.

MCQs (sample)

(Would create dedicated MCQs — user already has requests earlier; core
Qs included above.)

16. Cell as a Factory — Organelles

explained & MCQs
Organelles and analogies

Plasma membrane = signal relay station / security guard.

Nucleus = central command; DNA = blueprint.

RNA (mRNA) = job order.

Ribosome = forge and machine (protein synthesis).

Golgi apparatus = warehouse & shipping.

Mitochondria = power generator.

ER (RER & SER) = QC center.

Lysosomes = recycle bin.

Peroxisomes = detox units.

Cytoskeleton = structural framework & transport.

MCQs (selected)

1. Nucleus compared to: B. Central command.

2. Organelle producing energy: B. Mitochondria.

3. Ribosome role: B. Forge and Machine.

4. Golgi apparatus: B. Golgi Apparatus (warehouse).

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 5. Lysosomes: C. Recycle bin and recycling plant.

17. Four important organelles — Details &

MCQs
Endoplasmic Reticulum (ER)

Rough ER (RER): ribosomes attached, protein synthesis & folding.

Smooth ER (SER): lipid synthesis, detoxification.

Lysosomes

Contain hydrolytic enzymes, break down waste, role in apoptosis.

Golgi Apparatus

Modifies, sorts, packages proteins (cis face receives from ER, trans face
sends out).

Ribosomes

rRNA + proteins; translate mRNA using tRNA; located free or on RER.

Quick MCQs

Transcription = DNA → mRNA (RNA polymerase).

Translation = mRNA → protein (ribosome + tRNA).

Reverse transcription exists in some viruses (RNA → DNA via reverse

transcriptase).

18. The Crowded Cell — Unicellular vs

Multicellular, MCQs
Single-cell organisms

Complete beings (e.g., bacteria, amoeba) — perform all life functions

independently.

Personality in microbes

Bacteria show behavioral variations (“mood swings”).

Multicellular organisms

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 Cells specialize, sacrifice individual autonomy for the whole organism
(nerve cells, RBCs, muscle cells, bone cells, fibroblasts, intestinal epithelial
cells).

Key idea

Unicellular = independence; Multicellular = cooperation & specialization.

MCQs

1. Unique about single-cell organisms: B. Perform all life functions

independently.

2. “Cells sacrifice their selfishness” means: B. Cells specialize and work for
the body as a whole.

3. RBC function: B. Carry oxygen.

4. Osteocytes found in: B. Bone tissue.

5. Absorption of nutrients: B. Intestinal epithelial cells.

19. Cell Membrane Properties & Types of

Cells (Excitable vs Non-excitable)
Excitable cells

Can generate action potentials: neurons, cardiomyocytes, smooth muscle

cells. Produce distinct field potentials.

Non-excitable cells

Cannot generate electrical signals: stem cells, fibroblasts, many somatic

cells.

Key idea

Excitable = signaling; Non-excitable = structural/support.

20. Central Dogma of Biology (DNA →

RNA → Protein)
Central Dogma

DNA → RNA (transcription) → Protein (translation).

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 Reverse transcription (RNA → DNA) occurs in retroviruses (e.g., HIV).

MCQs

Which cells are excitable? Neurons and cardiomyocytes.

Non-excitable example: Stem cell.

Role of excitable cells: Conduct electrical signals.

21. Somatic Cells, Transcription,

Translation, Reverse Transcription
Somatic cells

All body cells except sperm & egg; divide by mitosis.

Transcription

DNA → mRNA in nucleus by RNA polymerase.

Translation

mRNA read in codons; tRNA brings amino acids; ribosome synthesizes

protein.

Reverse transcription

RNA → DNA via reverse transcriptase in retroviruses.

22. Ion Homeostasis & Cell Signaling —

Notes, Ion concentrations & MCQs
Ion homeostasis

Cells maintain Na⁺, K⁺, Ca²⁺, Cl⁻ gradients using channels & pumps.

Typical mammalian cell size & volume

Diameter: ~10–30 µm. Volume: ~1 pL (10⁻¹² L).

Approximate ion concentrations (inside vs outside)

Na⁺: inside ~10–15 mM, outside ~145 mM.

K⁺: inside ~140 mM, outside ~5 mM.

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 Ca²⁺: inside ~100 nM, outside ~1.8 mM.

Cl⁻: inside ~5–15 mM, outside ~110 mM.

How many K⁺ ions in cytoplasm (approx)

Rough calculation: ~80 billion K⁺ ions per mammalian cell.

MCQs

1. Typical size: B. 10–30 µm.

2. Approx volume: C. 1 picoliter.

3. Ion highest inside: B. K⁺.

4. Ion lowest inside: D. Ca²⁺.

5. Ion channels allow ions to move: B. Down concentration gradient.

6. Rough number of K⁺ ions: C. 80 billion.

23. Why & How Ion Homeostasis works —

mechanisms
Why

To maintain membrane potential (voltage) used for nerve impulses, muscle

contraction, transport.

How

Ion channels (passive, selective) allow flow down gradients.

Pumps (active, use ATP) like Na⁺/K⁺ ATPase pump 3 Na⁺ out, 2 K⁺ in to
maintain gradients.

Roles in signaling

Neurons: voltage-gated Na⁺ & K⁺ channels produce action potentials.

Heart: rhythmic Na⁺/Ca²⁺ influx and K⁺ efflux produce heartbeat.

Muscle: Ca²⁺ acts as switch for contraction.

Analogies

City gates & guards = channels & pumps; metro turnstiles = selectivity
filters; membrane potential = rechargeable battery.

Part 1 SBL 100 19

 24. Equivalent Circuit Model of the Cell
Membrane — Notes & MCQs
Circuit components

Rm (membrane resistance) — depends on open channels.

Em (membrane potential) — voltage difference due to ion distribution.

Cm (membrane capacitance) — lipid bilayer acts as capacitor storing

charge.

Ion channels

Act as short-circuits (reduce resistance when open). Without ΔVm, cell

cannot survive.

MCQs

1. Cm represents: B. Membrane capacitance.

2. Rm depends on: C. Number of open ion channels.

3. Ion channels called “short circuits” because: B. They allow ions to bypass
membrane resistance.

4. Without ΔVm: B. The cell cannot survive.

5. Lipid bilayer resembles: B. Capacitor.

25. Lipid Bilayer role — Notes & analogy

Structure

Two phospholipid layers: hydrophilic heads outward, hydrophobic tails

inward → barrier.

Role in circuit model

Acts as electrical insulator (capacitor, Cm). Ion channels are resistors;

electrochemical gradients behave like batteries.

Analogy

Wall with gates: wall = bilayer (capacitor), gates = ion channels (resistors),
battery = ion gradient.

Part 1 SBL 100 20

 26. Genome Organization & Genome Size
examples — Notes & MCQs
Genome

Complete set of DNA in an organism (genes + non-coding DNA). Measured

in base pairs (bp).

Examples

Human: ~3.1 × 10⁹ bp.

Mexican axolotl: ~32 × 10⁹ bp (~10× human).

Loblolly pine (Pinus taeda): ~23 × 10⁹ bp.

Paris japonica (flowering plant): ~150 × 10⁹ bp (one of largest known).

C-value paradox

Genome size ≠ organismal complexity.

MCQs

1. Human genome size approx: B. 3.1 × 10⁹ bp.

2. Largest genome among list: D. Paris japonica (~150 × 10⁹ bp).

3. Axolotl genome ~ how many times human: C. 10×.

4. C-value paradox: B. Genome size does not directly reflect organism

complexity.

5. Which ~23 × 10⁹ bp: C. Pinus taeda.

27. What is a Genome — Notes

DNA = molecule of life; genome = whole DNA content (genes + non-
coding).

Genome size = number of base pairs (bp). More base pairs = more letters in
the “book of life”, but not necessarily more complexity.

28. DNA Structure — (starts)

Double helix

Part 1 SBL 100 21

 Two antiparallel strands (5′→3′ and 3′→5′).
Components

Sugar-phosphate backbone (phosphodiester bonds).

Bases: A, T, G, C. Pairing: A–T (2 H bonds), G–C (3 H bonds).

Grooves and other structural features — (text continues in your original
content).

Part 1 SBL 100 22