IB Bio ULTIMATE Processes- High Yield

Outline the steps of insulin action (7)

Released when blood glucose is TOO HIGH IN BLOOD (moves glucose OUT blood into cell)

1. Blood glucose rises after eating carbohydrates

2. B cells in the islets of Langerhans detects increase and secretes insulin into blood

3. Insulin binds to receptors on target cells (liver/muscles/fat cells)

4. Insulin receptors activate a signal transduction pathway where vesicle containg glucose transporter proteins move to the cell surface membrane

5. Glucose enters cells by faciliated diffusion

6. Liver and muscle cells convert excess glucose → glycogen in a process called glycogenesis

7. Cells use glucose + blood glucose level decreases

Outline the steps of glucagon action (6)

Released when blood glucose is too LOW

1. Blood glucose falls from fasting/excerise

2. Alpha cells in pancreas detects low blood glucose → releases glucagon

3. Glucagon travels to blood → liver cells

4. Liver cells brakd down glycogen → glucose (glycogenesis)

5. Glucose released into blood

6. Blood glucose levels = normal

Define osmosis and detail its process in hypertonic and hypotonic solutions (9)

Osmosis is the passive movement (no energy required) of water from an area of high water potential to low water potential.

Hypotonic solution: Interior of the cell has lower solute concentration

1. Water diffuses from out → in

2. Cell lysis (animal) or turgid (plant)

3. Cell volume increases

4. For plants, rigid cell wal provides resistance to internal pressure = prevents cell from bursting

Hypertonic solution: Exterior of the cell has a higher solute concentration

1. Water diffuses in → out

2. Cell crenatioin (animal) or plasmolysed/flaccid (plant)

3. Cell volume decreases and may lead to cell death if prolonged

Explain ‍the role of water potential in the ‍uptake of water by plant roots.

1. Water potential determines the direction water moves. High → low via osmosis

2. Soil water has HIGHER water potential than root hair cells (has high solute concentration) → water enters root hair cells via osmosis

3. Water moves across root cortex moving across water potential gradient. This gradient is maintained by ion transport (root cells actively transport mineral ions → xylem which requires ATP)

4. Water enters xylem (has very LOW water potential) aka ROOT PRESSURE

5. Transpiration creates tension in the xylem = negative pressure → pulls water upward from the roots

6. Cohesion and Adhesion helps maintain water coloumn (adhesion= water + xylem walls, cohesion = water molecules to eachother via H-bonds)

Outline the steps of the menustral cycle (8)

• Hypothalamus secrets GnRH which stimulates anterior pituitary gland to secrete LH and FH

• Ovaries secrete progesterone and estradiol (estrogen)

• 1. Menustral Phase/Early Follicular Phase

  • Corpus luteum breaks down from previous cycle

  • Low progesterone and estradiol levels → breakdown of the uterine lining (endometrium) results in menses (period)

  • Low progesterone/estradiol stimulates GnRH which increases LH and FH → increase progesterone/estradiol (negative feedback loop)

• 2. Late Follicular Phase

  • FH promotes growth of follicles (membranes that surrounds ovaries)

  • One follicile = DOMINANT follicile

  • Increased progesterone levels → FH/LH increase (LH SURGE)= increase progesterone (positive feedback loop)

  • LH Surge → ovulation trigger = follicile ruptures + releases egg.

• 3. Luteal Phase

  • Leftover folicile = corpus luteum

  • Corpus luteum → secretes progesterone + estradiol → builds up endometrium for blastocyst implantation

  • If NO blastocyst= corpus luteum breaks down → low progesterone/estrogen (step 1 all over)

  • If YES blastocyst = no menustral cycle = pregnancy

Outline the kidney’s role in urination

• 1. Ultrafilteration

  • Where? Glomerulus and Bowman’s capsule (in cortex)

  • Blood from afferent ateriole enters glomerulus which increases blood pressure since glomerlus has a narrow lumen

  • Blood leaves through efferent arteriole (affert > efferent)

  • Bowman’s capsule has a filtiration barrier so only small molecules like ions/glucose/urea/amino acid/etc. can pass through

  • Fluid is now called a filtrate

• 2. Selective Reabsorption

  • Where? Proximal convoluted tubule (in cortex)

  • Why? Reabsorb useful nutrients such as oxygen, glucose, protein → capillary. Only waste product like urea filtered out

  • Na⁺ ions in tubule cells → diffuse into blood capillary via active transport

  • Since there is now a lower Na⁺ concentration, glucose and amino acids are co-transported with Na⁺ from filtrate (inside tubule LUMEN) into the tubule cell (WALL of tubule) → facillitated diffusion to blood

• 3. Secretion

  • Where? Loop of Henle, distal convoluted tubule, and collecting duct (in medulla)

  • Why? Reabsorbs water from fluid so less water is loss to urine (more concentrated urine)

  • Filtrate enters thin descending limb= permeable to water but impermeable to salts. Water leaves to capillary but Na⁺ and Cl^- stays inside filtrate.

  • Thus medulla now has low water potential and high solute concentration → water leaves filtrate to medulla → capillary (vasa recta) via osmosis

  • Filtrate moves to thick ascending limb = impermeable to water → Na⁺ and Cl^- leaves the filtrate → actively transported out → medulla

  • Filtrate becomes more dilute (salt leaves but water stays inside)

Outline the kidney’s role in osmoregulation

Where: Distal convoluted tubules + Collecting Duct

1. Osmosreceptors in hypothalamus detects low/high water potential in blood → signals posterior pituitary → releases ADH into blood

2. ADH travels to kidneys → DCT + collecting ducts

3. Low water blood content: HIGHER levels of ADH secreted → higher amounts of aquaporines inserted via vesicles containing aquaporins→ more permeable to water → water leaves filtrate into capillary via osmosis

4. High water blood content: LOWER levels of ADH secreted → opens less aquaporins for water to flow in from tubule → less water leaves filtrate into capillary via osmosis

Outline the reason and process of thermoregulation in humans

Reason: Human enzymes needs to work at specific temeperature (37˚C) → kinetic energy for successful collision required. Too high = denature

How? Thermoreceptors detects change (skin thermoreceptors detects external temperature and hypothalamus detects blood temperature) → effectors respond for negative feedback loop


Increase body temp:

• Vasodilation: muscles in arteriole walls relax → arterioles dilate/widen → more blood flows through capillaries near skin → heat transferred to skin surface → heat lost by radiation

• Sweating: Sweat glands secrete more swewat → sweat spreads over skin surface → evaporates (requires Heat energy) => heat energy taken from skin → cools down

• Hair flattens: Hair erector muscles relax → lies flat against skin → less air trapped under skin → less insulation → more heat exacpe

Decrease body temp:

• Vasoconstriction: muscles in arteriole walls constrict → arterioles narrow → less blood flows through capillary near skin → heat retained in body and less heat loss via radiation

• Hair stands up: Hair erector muscles contracts → stands upright → air is trapped under hair → air acts as insulating layer → less heat loss from skin

• Shivering: Muscles contract/relax rapidly → generates heat energy → harms blood → core body temp increases

• Brown adipose tissues: lipids in brown adipose tissues= metbolizes → respiration releases heat instead of making ATP

Outline the role of chemoreceptors

Define and outline summation and its different types

Outline the role of melatonin in circadian rhymths

Distinguish between type I and type II diabetes

Outline the process of tissue fluids and role of lympathic system

Outline the role of haemoglobin in oxygen dissociation curve + Bohr shift and fetal hemolglobins

Outline the process of HIV infection

Outline the process of seed germination

Outline the process of cell elogation and distinguish between auxin and cytokin

Outline the process of a reflex arc

Outline the roles of hormones in labour and birth and after birth

Outline the energy flow/nutrient cycling through an ecosystem (9)

1. Sunlight is the main source of energy in an ecosystem

2. Producers/autotrophs convert sunlight and inorganic substances into chemical energy via photosynthesis (stores biomass w/chem energy)

3. Primary consumers eat producers

4. Secondary consumers eat primary consumers

5. Energy is transfered between trophic levels via feeding

6. Energy is loss between each trophic level via heat loss from cellular respiration/undigested or consumed biomass/movement/waste product

7. Decomposers break down dead orgaisms + waste

8. Nutritents are recycled but energy is NOT

9. Energy flow = one way

Outline the process of eutrophication

1. Pesticides with nitrates and phosphates applied to farmland

2. Rain falls → leaching and runoff (downward movement of dissolved nutrents to bodies of water)

3. Influx of nutrients causes algae to grow rapidly → algae bloom forms on water surface

4. Algae prevents sunlight from reaching aquatic plants → decrease photosynthesis → death

5. Dead algae/plants consumed by bacteria → bacteria population increase

6. Bacteria carries out aerobic respiration → uses dissolved oxygen in water → oxygen concentration decreases → biochemical oxygen demand (BOD) increases (measure of dissolved oxygenn required by aquatic organisms) → fish and aquatic invertebrates die due to lack of oxygen

Outline the process of biomagnification

1. Persistent pollutant enters ecosystem → pollutant does not break down easily

2. Small organisms absorbs/ingests pollutations → builds up in tissues (bioaccumulation)

3. Primary consumers eat many contaminated organisms → secondary consumers eat primary = pollutant conc. increaces at each trophic level (biomagnification)

4. Top predators recieve highest pollutant concentration = reduces survival/reproductive failure

Outline the process of DDT as a biomagnification, using bird eggshell as an example

1. DDT = insecticide

2. DDT enters food chains → accumulates in tissues of organisms. This accumulations is magnified as trophic level increases as DDT becomes more concentrated

3. Birds (top predator) recieves highest DDT concentration → bird produces thin eggshells → more easily break → fewer chick survives → reproductive success declines → bird populations decline

Outline the process of primary and secondary succession

PRIMARY: Creation of new community from lifeless area

1. Pioneer species (first species that inhabits area) like lichens and mosses colonize surface

2. Pionneer species can survive harsh conditions → more tolerant + allows for growth

3. Withering/decomposing → soil formation → Soil deph gradually increases → small plants/grass grows

4. More organic matter added whenver organism dies → nutrient availability increases → shrubs continue to grow

5. Small trees establish → larger trees → biodiversity increases

6. Food webs becomes more complex + stable climax community (final, stable stage of succession) reached

SECONDARY: Creation of new community from previously existing community that has been removed by disturbances

1. Distrubance affects existing ecosystem (ex: volcanic eruptions, wildfire, abandoned farmland, deforestration)

2. Original community damanged/removed but soil remains present

3. Seeds/roots/nutrients remain in soil → grasses/small plants grows → small trees/shrubs grow → trees begin to grow

4. Species diversity increases and food webs become more complex until mature community is developped

Outline the process of climate change

1. Anthropogenic change (environmental changes by human activity) such as fossil fuels, deforestration, landfills, peat degration → global warming + biodiversity loss + ecosystem loss

2. Human activity → increases greenhouse gases (carbon dioxide, methane, water vapour)

3. Greenhouse gases absorbs IR light emited by sun and re-emits them to Earth’s surface → increases temperature of atmosphere → global average temperature increases = global warming

4. Climate patterns thus change and become more violent → disrupts enviornments → climate change

Outline the process of postive feedback (Ice-Albedo Effect)

1. Global temperature increases

2. Ice and snow melts (which has high albedo → reflects sunlight)

3. Ice melt → darker surface like ocean water/rock exposed

4. Darker surface → less albedo → less sunlight reflected → more solar radiation absorbed by Earth’s surface → further warming

5. More ice melet (positive feedback loop)

Outline the process of permafrost melting

1. Global temperature increases

2. Permafrost which traps organic matter → melts → decomposers

3. Decomposers breaks down organic matter → releases CO2

4. In anerobic conditions + waterlogged conditions, methanogenic archea releases CH4 (methane) → increases greenhouse gas concentration → global temperature increases (positive feedback loop)

Outline the process of phenological mismatch as a result of climate change

1. Climate change alters temperature + seasonal timing

2. Species respond to enviornmental cues at different timing → biological event mismatched

3. Another dependent species = does not shift at same rater

4. Food avaialbility and matches no longer at peak demand → survival/reproductive decline → decrease population

Outline the process of climate change’s attribution to natural selection using the tawny owl as an example

1. Climate change = new enviornmental conditions → new selection pressures

2. Individuals with adv. traits = survive better and more likely to reproduce

Tawny owls:

1. Can be both grey/both but in snowy winters → grey owls better camouflaged

2. Climate change → less snow → grey owls traits less advantageous (less camouflage) whereas brown owls have more camouflage → increased survival

3. Brown alleles increase in frequency → population shifts towards more brown owls

Outline the different types of natural selection and its reason

Directional Selection (environmental change)

• One end of phenotype favoured

Stabilising Selection (stabilised environment)

• Average phenotypes favored

Disruptive Selection (speciation)

• Extreme phenotypes favored

Outline the process of ecosystem restoration and methods of conserving biodiversity

Outline the process of peristalis

Outline the cardiac cycle

Outline the process of cell respiration (aerobic)

1. Glyco

Outline the process of cell respiration (anerobic) in animals and plants

1. Glycolysis

Animals: Lactate production

Plants: Ethanol production

Outline the process of photosynthesis

Outline the process of nerve propagation and saltatory conduction

Outline the feedback control of heart rate

Outline the feedback control of ventillation rate

Outline the process of G-protein and epinephrine

Outline the process of acetylcholine neurotransmitters

Outline the effects of cocaine/nicotine

Outline competitive and non-competitive inhibitors using lactate as an example

Outline the developments in microscopy

Outline the evidence of virus origin

Outline the structure and function of the nucleus

Outline the structure and function of the golgi apparatus

Outline the structure and function of the ribosome

Outline the structure and function of the vesicle

Outline the process of IVF (in virto ferilisation)

Outline the process of spermatogenesis

Outline the adaptations of egg cells

Outline the process of blood clotting

Outline the process of innate and adaptive immune system

Innate Immune System:

• Phagocytosis

Adaptive Immune System:

Outline the adaptations of light harvesting in trees,lianas, epiphytes, strangular epiphytes, and shade tolerant herbs/herbaceous plants

Distinguish between primary and secondary production