Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: HUMAN BIOLOGY REVISON NOTES
Description: literally just 47 pages of human bio notes covering everything from: Chemical messengers Hormones secreted from organs other than your pituitary Parts of a neuron and their functions Structural types of neurons and their processes Divisions of the nervous system The CNS in depth How the body detects and regulates internal changes Disruptions to homeostasis Protections against invaders Specific resistances to infection Mutations and gene pools Biotech Evolutionary mechanisms Evidence for evolution (broad) Fossil evidence for evolution (narrow) Evolutionary trends in hominins Human ancestors and Cultural trends in Humans
Description: literally just 47 pages of human bio notes covering everything from: Chemical messengers Hormones secreted from organs other than your pituitary Parts of a neuron and their functions Structural types of neurons and their processes Divisions of the nervous system The CNS in depth How the body detects and regulates internal changes Disruptions to homeostasis Protections against invaders Specific resistances to infection Mutations and gene pools Biotech Evolutionary mechanisms Evidence for evolution (broad) Fossil evidence for evolution (narrow) Evolutionary trends in hominins Human ancestors and Cultural trends in Humans
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
1
...
3
...
2
...
Endocrine Glands (ductless) – Secrete hormones into the extracellular fluid that surrounds the cells that make up a
gland – secretion then passes into the capillaries to be transported by the blood
...
Paracrines or (local) hormones are secreted by cells in order to communicate with other cells in the same tissue
...
PROTEIN AND AMINE HORMONES (water soluble) – attach to receptor proteins in the membrane of the target cell –
causes a secondary messenger substance to diffuse through the cell and activate particular enzymes
...
E
...
STEROID HORMONES (lipid soluble) – enter target cells and bind to receptor proteins on the inside (this may be on
the mitochondria or in the nucleus)
...
* HORMONES MAY CHANGE THE FUNCTION OF A CELL BY CHANGING THE TYPE, QUANTITY OR ACTIVITY OF THE
PROTEINS PRODUCED – THEY ARE NOT ENZYMES BUT CAN EXERT INFLUENCE BY CHANGING THE ENZYME ITSELF
OR THE CONCENTRATION OF THE ENZYME *
HORMONES MAY:
Activate certain genes in the nucleus so that a particular enzyme or structural protein is produced
...
Change the rate of production of an enzyme or structural protein by changing the rate of transcription/translation
during protein production
...
Bind to a receptor within a cell and block the endogenous hormone from binding
...
Examples
of
3
...
3
...
-‐
-‐
1
...
HYPOTHALAMUS AND PITUITARY:
The hypothalamus is located at the base of the brain – regulates many of the basic functions of the body such as C
...
T,
water balance and heart rate – many of these functions are carried out through the pituitary gland (hypophysis –
approx
...
The
pituitary gland is separated into 2 sections – posterior and anterior:
POSTERIOR PITUITARY (neurohypophysis) – not a true gland because it does NOT secret hormones – connected to
the hypothalamus by nerve fibres that travel through the infundibulum
...
Oxytocin = stimulates contraction of uterine and mammary muscles, is the ‘happy hormone’/evokes feelings of
contentment and joy and is believed to have a role in the healing of external wounds by regulating inflammation of
tissues (decreases certain cytokines)
...
ADH production can be inhibited by the consumption of alcohol
...
g
...
BUT WAIT! You have a bottle of whiskey with you (60%
water) – do you drink the whiskey or not? Why?
~ YOU DON’T DRINK THE WHISKEY!
Whiskey acts as a diuretic – inhibits the secretion of ADH from the posterior lobe which means that when you’re super
dehydrated and the body needs to conserve all the water it has, ADH isn’t able to do its job and stimulate the
reabsorption of excess water from your urine AND as alcohol is a diuretic (from Greek word diouretikos – to urinate),
you basically just pee out all the water your body needs (hence term ‘going out on the piss’ when getting drunk)
...
Alcohol is also an irritant to the stomach – especially when the volume of water in
the body is depleted – causes the drinker to vomit – 2 things can come of this:
Dehydration – many side effects = drowsiness, confusion, decreased CBT – hypothermia, fainting and death
...
ANTERIOR PITUITARY (adenohypophysis) – has no nerves connecting it to the hypothalamus – it is connected by a
complex set of blood vessels
...
THYROID GLAND
Located in the neck, just below the larynx and consists of two lobes that sit on either side of the trachea
...
Thyroxine is involved in body metabolism and regulates reactions in which complex molecules are broken down to
release energy
...
B
...
~ A person who is physically deformed and has learning difficulties due to a congenital thyroid deficiency
...
Cretinism is therefore
most probably due to a diet deficient in iodine
...
If
untreated, it results in mild to severe impairment of both physical and mental growth and development
...
Adult stature without treatment ranges from 1 to 1
...
3
to 5
...
In adults, Cretinism results in mental deterioration, swelling of the skin, loss of water and hair
...
Ovulation is impeded, and infertility is common
...
Cognitive impairment may also range from mild to so severe that the person is nonverbal and dependent on
others for basic care
...
Other signs may include thickened skin, enlarged tongue, or a
protruding abdomen
...
This type of cretinism has been almost completely eliminated in developed countries by early
diagnosis by newborn screening schemes followed by lifelong treatment with thyroxine
...
In the case of dosing infants, the T4 tablets are generally crushed and mixed with breast milk,
formula milk or water
...
Iodized salt is
usually the preferred prophylactic vehicle, but iodized vegetable oil, iodized water, and iodine tablets are also
occasionally used
...
Your doctor might need you to fast, take medication, or eat particular foods for a brief period
prior to your blood test
...
Doctors may also try
screening/imaging tests to locate or pinpoint a nodule/tumour
...
) to the
central nervous system (brain and spinal cord)
-‐ Motor/effector – carry messages from the CNS to the muscles and glands (the effectors)
-‐ Interneurons/association/connector/relay – located in the CNS and are the link between sensory and motor
neurons
PARTS OF A NEURON
PART OF THE NEURON
Soma
Nucleus
Axon
Myelin sheath
Node of Ranvier
WHAT IS IT MADE OF
Nissl granules –
composed mainly of
rough ER and free
polyribosomes
Genetic material in the
form of chromosomes
and the nucleolus, which
is made up of RNA and
protein
...
Archivist and architect –
it contains the DNA,
which keeps the cell
history and synthesizes
RNA from DNA and ships
it to the cytoplasm for
protein synthesis
...
Electrical insulation –
protect the axon from
electrically charged ions
found in the fluid
surrounding the entire
nervous system and
increase speed at which
impulses propagate
along the myelinated
fibres
...
Receives electrical
impulses from other cells
Synaptic contact with
other nerve
cells/effectors and to
communicate
neurotransmitters
1
...
3
...
Bipolar neurons – Have one axon and one dendrite that may have many branches on either end – may be found in eye,
ear and/or nose – they take messages from receptor cells to other neurons
...
The soma is to one side of the axon – most sensory neurons that
carry messages to the spinal cord are of this type
...
When an action potential is stimulated,
sodium ion channels and sodium from the inside floods the outside and the neuron depolarizes as the impulse travels
down the axon
...
The refractory period is during the time just before hyperpolarization to the neurons
return to resting potential -‐ It is at this point, that no other action potentials can pass through the axon
DEPOLARIZATION ONLY OCCURS IF AN IMPULSE CAN STIMULATE A CHANGE OF AT LEAST 15mV – this is an all-‐or-‐
nothing response
...
Slow depolarization of the membrane brings
the potential to the threshold
...
Sodium channels in the membrane open;
sodium floods into the membrane and the
membrane becomes depolarized/membrane
voltage increases
...
Sodium channels close and membrane
repolarizes
...
Membrane returns to resting state
...
Once this impulse has been sent, an enzyme called acetylcholinesterase
attaches to the acetylcholine and breaks it down in order to allow the muscle/organ to relax
...
g
...
This causes a build up of the acetylcholine within the synaptic cleft, which
continues to act, so that any nerve impulses are continually transmitted and muscle contractions do not stop
...
TTX binding physically
blocks the flow of sodium ions through the channel, thereby preventing action potential
(AP) generation and propagation
...
CHAPTER 4 -‐ DIVISIONS OF THE NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM
(brain and spinal cord)
PERIPHERAL NERVOUS SYSTEM
(12 pairs of cranial nerves and 31
pairs of spinal nerves)
AFFERENT DIVISIONS –
Carries shit TO the CNS
Somatic division –
carries messages
to the skeletal
muscles
EFFERENT DIVISION –
Carries shit AWAY from
the CNS
Sympathetic NS
Somatosens
ory neurons
from skin
and muscle
Visceral sensory
neurons from
internal organs
-‐
-‐
-‐
-‐
o
o
Parasympathetic
NS
Autonomic division – carries
messages t the
o
heart/involuntary muscles and
glands
THE AUTONOMIC NERVOUS SYSTEM
~ It is studied as a separate system to the PNS but it is actually structurally and functionally part of the same system ~
Controls: Heart rate, blood pressure, body temperature, digestion, release of energy, pupil diameter, airflow to the
lungs and excretion
...
CORPUS CALLOSUM
A large bundle of nerve fibres that connects the two hemispheres – it cannot be seen outside the brain
...
Surface is folded into convolutions (gyri – above and sulci – below = used to
further divide the 4 lobes of the brain)
...
It contains the:
Cardiac centre – regulates rate and force of heartbeat
Respiratory centre – control rate and depth of breathing
Vasomotor centre – Regulates diameter of blood vessels
CEREBELLUM
Underneath the rear part of the brain – less prominent folds than those of the cerebrum – exerts control over posture,
balance and fine control over voluntary muscle movement
...
Functions of the hypothalamus include regulation of:
The ANS – regulation of heart rate, blood pressure, secretion of digestive juices, pupil of the eye and movements of the
alimentary canal
...
FUNCTIONS OF THE CEREBRUM
Thinking
Reasoning
Learning
Memory
Intelligence
Sense of responsibility
Three types of functional areas in the cerebral cortex:
Sensory areas – receive and process nerve impulses from the senses
Motor areas – send impulses to muscles, especially for voluntary movement
Association areas – interpret information from the senses and make it useful
PRIMARY MOTOR CORTEX – Frontal lobe (reasoning, planning, higher order though processes, emotions, movement
and balance)
PRIMARY SENSORY CORTEX – Parietal lobe (touch, pressure, temperature and pain)
PRIMARY VISUAL CORTEX – Occipital lobe (visual-‐spatial processing, colours and movement discrimination)
PRIMARY AUDITORY CORTEX – Temporal lobe (perception, recognition and processing of auditory stimuli – key in the
comprehension of speech)
-‐
-‐
CHAPTER 6 – DETECTING AND REGULATING CHANGE
Receptors:
A receptor is a structure that is able to detect the changes in the internal and external environment of the human body
...
e
...
Other receptors a simply nerve endings -‐ possibly spread throughout the parts of the body/ whole body as is the case
of pain and temperature receptors in the skin
...
This information is received by the hypothalamus/cerebrum so that we are constantly
consciously aware of our surrounding temperature
...
Temperature inside the body (core temperature) is monitored and regulated by the hypothalamus – the
thermoreceptors within the hypothalamus are able to detect changes in the temperature of the blood flowing around
our brain – using its own thermoreceptors as well as the receptors in our skin, the hypothalamus is able to regulate
body temperature (maintaining homeostatic temperature of 37 degrees)
...
Central thermoreceptors – hypothalamus – the main temperature regulating centre – detect changes in CBT and
process and respond to external changes
...
1
...
3
...
1
...
3
...
5
...
2
...
4
...
-‐
-‐
-‐
-‐
-‐
-‐
Chemoreceptors:
Stimulated by particular chemicals – found within the nose (sensitivity to smell) and on the tongue (sensitivity to
tastes) – also found within the body (sensitive to the composition and concentration of body fluids)
...
Touch receptors:
Found mainly in the skin – when they are closer to the surface of the skin then they are more sensitive to very light
touches i
...
in the lips, finger tips, eyelids, external genitals and hair follicles (these respond to very small movements
that bend the hair)
...
They
are especially concentrated in the skin and mucous membranes – can be found in nearly every organ in the body
except the brain – pain receptors adapt very little (if at all) so pain remains present until the stimulation stops with
prolonged exposure to stimulus making the pain worse
...
Reflexes have 4 important,
distinctive properties:
A stimulus is required to trigger a reflex – it is not spontaneous
A reflex is involuntary – no conscious thought involved
A reflex is rapid – only a small amount of neurons involved
It is stereotyped – occurs in the same way each time
BASIC COMPONENTS OF A REFLEX ARC:
A receptor is either the ending of a sensory neuron or a specialized cell associated with the end of a sensory neuron
...
A motor neuron carries the impulse to an effector
...
Sensory neuron conducts the impulse from the receptor to the spinal cord
...
One or more interneurons pass the message to the appropriate motor neuron
...
RESPONSE: The effector (in the case of sticking hand on a thumb prick – the biceps muscle) contracts removing hand
from painful stimulus
...
Important aspects of the internal environment that need to me maintained:
CBT
PH and concentrations of dissolved substances in the blood
Concentrations of glucose in the blood
Concentrations of O2 and CO2 in the blood and other body fluids
Blood pressure
Concentration of metabolic wastes
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
•
•
•
•
•
NEGATIVE FEEDBACK LOOPS:
Stimulus – change in environment that prompts a response
Receptor – detects the change
Modulator – control centre responsible for processing information from receptor and sending out information to the
effector
...
CHAPTER 7 – THERMOREGULATION
“Maintaining the balance between heat production and heat loss/expenditure” – HEAT GAIN MUST = HEAT LOSS
Heat input:
Body processes (metabolism) especially respiration of muscle and liver cells
...
Heat output:
Radiation, conduction and convection to surroundings
...
WHAT FACTORS INCREASE HEAT PRODUCTION:
Metabolism of lipids, proteins and carbohydrates releases energy – some used by the muscles and cells for respiration
– most is lost as heat waste
...
Stress (activation of the sympathetic nervous system and release of norepinephrine)
CBT increase – for every degree increase, metabolic rate increases by about 10%
PREVENTING BODY TEMP FROM FALLING:
Vasoconstriction
Stimulation of the adrenal medulla to secrete adrenaline and release noradrenaline – increases metabolic rate
Shivering – oscillating muscle tremors – 10 to 20 per second
Stimulation of the anterior pituitary lobe to secrete TSH – causes the thyroid gland to release thyroxine into the blood
– slower to act but longer lasting
Behavioural response – putting more clothes, reducing body surface area by curling into a ball or turning the heater on
PREVENTING BODY TEMP FROM RISING
•
•
•
•
•
•
Vasodilation
Sweating (only applicable in places that are hot and ARID (not humid) – sweat has to be able to evaporate for their to
be a cooling effect
Decreased metabolic rate – reduction in the secretion of thyroxine (long term response)
Increasing body surface area – spreading out
Decreasing voluntary activity – the less you move, the less hot you become
Behavioural response – removing clothing, turning on fan/AC
TEMPERATURE TOLERANCE:
42c – dangerous level
45c – death usually occurs
33c – hypothermic level
32c < -‐ death usually occurs but people can survive at lower temperatures
HEAT STROKE -‐ body temperature rises and regulatory mechanisms cease – VERY SERIOUS – treatments include
immersing person in cold water to rapidly decrease CBT
...
5L per/day)
Food (700mL)
Metabolic water – by product of metabolism of cells (200mL)
Drink (1600mL)
Water loss (2
...
2
...
4
...
2
...
4
...
6
...
8
...
2
...
4
...
6
...
2
...
4
...
6
...
(Faeces from undigested food is not considered to be a part of excretion because it was not
produced by the cells)
Kidneys – THE MAIN EXCRETORY ORGAN – involved in maintaining a constant concentration of materials in the body
fluid – most important substance excreted by the nephrons is urea which is produced in the liver during the
breakdown of proteins
THE KIDNEYS:
Renal vein – takes blood away from the kidney
Renal artery – takes blood to the kidney
Ureter – a tube that drains urine away from the kidney
Bladder – a muscular bag that holds urine until it is passed from the body
Urethra – a tube from the bladder that opens to the outside
PROCESS OF THE NEPHRON:
Blood enters the glomerulus under high pressure
FILTRATION – The high blood pressure forces water and small dissolved molecules out of the blood and into the
glomerular capsule – large molecules are retained in the blood and pumped back into the body systems
REABSORPTION – The filtrate passes into the proximal convoluted tubule where water, ions and all organic
substances are reabsorbed into the bloodstream
...
URINE – The water and dissolved substances that remain make up urine – which is carried by the collecting ducts to
the bladder
...
Water concentration of blood plasma decreases; osmotic pressure is increased
Osmoreceptors in the hypothalamus are stimulated
Posterior pituitary is stimulated to release ADH
Permeability to water in the DCT and collecting ducts are increased
Increased amount of water is reabsorbed into blood plasma
Water concentration of blood plasma is increased; osmotic pressure is decreased
IN ADDITION TO ADH, ALDOSTERONE IS SECRETED BY THE ADRENAL CORTEX – IT ACTS ON THE NEPHRONS TO
INCREASE THE AMOUNT OF SODIUM (AND WATER) REABSORBED AND THE AMOUNT OF POTASSIUM EXCRETED IN
URINE – INCREASING WATER ABSORPTION ALSO INCREASES BLOOD VOLUME WHICH INCREASES BLOOD
PRESSURE THUS ALDOSTERONE INDIRECTLY AFFECTS BLOOD PRESSURE
...
CELLULAR RESPIRATION EQUATION
Glucose + oxygen = carbon dioxide + water + energy
C6H12O6 + O2 = CO2 + H2O + energy
Glycogen – the form in which carbohydrates are stored in the body (mainly in the liver (100g) and muscle cells (the
rest up to 400g))
Glucagon – hormone secreted by the pancreas to break down glycogen to glucose to increase blood sugar levels
Insulin – secreted by pancreas to build glucose back up to glycogen and reduce blood sugar levels
...
ADRENAL MEDULLA –
Synthesizes epinephrine and norepinephrine
Stimulate the breakdown of glycogen in liver and release of glucose into blood
Stimulates the production of lactic acid from glycogen in muscle cells – which can then be used by the liver to
manufacture glucose
EFFECTS OF CAFFEINE ON THE BODY:
Increased alertness – high concentrations of caffeine mobilize the calcium in cells and inhibit specific enzymes,
increasing energy metabolism throughout the brain while decreasing cerebral blood flow
...
Caffeine antagonizes the adenosine receptors in the brain which control the activity of neurotransmitters such as
dopamine and serotonin – by blocking the action of adenosine, caffeine constricts the cerebral blood vessels and
increases the release of excitory hormones
...
These nerves have their origins in the spinal cord – if these nerves are injured or the area from which these nerves
originate then the result is complete paralysis of the of the muscles that move air in and out of the lungs
...
OXYGEN CONCENTRATION:
If concentration of oxygen in blood plasma decreases while everything else remains constant then breathing rate
increases (this is only a very slight increase – oxygen concentration has to fall dramatically for their to be a noticeable
change in breathing rate
...
CARBON DIOXIDE CONCENTRATION:
Concentration of CO2 in the blood plasma has a major effect in the regulation of breathing – a relatively small increase
in CO2 levels creates a significant change in breathing rate (increase)
An increase in CO2 levels also increases levels of hydrogen ions – this increase is detected by chemoreceptors (inside
the medulla) which in turn transmit nerve impulses to the respiratory centre, stimulating an increase in breathing
rate
...
The immediate increase in breathing rate is produced by stimulation of the aortic and carotid bodies from the increase
in hydrogen ions
...
VOLUNTARY CONTROL OF BREATHING:
By passes the respiratory centre of the medulla oblongata – protective device preventing irritating gases and water
into the lungs – only viable for a limited time as the eventual build up of carbon dioxide in the lungs stimulates an
autonomic reflex kick-‐starting the respiratory centre to send impulses to the inspiratory muscles – forcing us to take a
breath
...
Cardiac output (mL/min) = heart rate (b/pm) x stroke volume (mL)
As cardiac output increases so does blood pressure
Vasodilation = decrease BP / vasoconstriction = increase BP
CHAPTER 9 – DISRUPTIONS TO HOMEOSTASIS
HORMONAL CAUSES OF DISRUPTIONS:
Diabetes:
DIABETES MELLITUS (TYPE 1 – INSULIN DEPENDANT) VS DIABETES TYPE 2 (METABOLIC DISORDER)
TYPE 1 DIABETES – (usually begins in between adolescence and early adulthood / 10-‐25) -‐ results from the
autoimmune destruction of the insulin producing beta cells of the pancreas
...
In people with type 1 diabetes,
they have absent or malfunctioning beta cells so the hormones insulin and amylin (released with insulin to decrease
glucagon levels) are missing which means the hormone GLP-‐1 (glucagon-‐like peptide 1) cant work properly
...
Organs involved:
Pancreas
Liver
Kidneys
Treatments:
Low carbohydrate diet
Insulin injections/pump – 4 types of insulin; rapid/short/intermediate/long acting
Pancreas transplant
Islet cell transplant
TYPE 2 DIABETES – (usually occurs in the middle aged / 45+) -‐ a metabolic disorder characterized by high blood
sugar, insulin resistance and a relative lack of insulin
...
It has also been linked to a
lack of sleep – decreases metabolism
...
Treatments:
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
Exercising – high resistance and aerobic exercise are generally the most successful
Diabetic diet that promotes weight loss
...
e
...
O
...
D)
SIGNS AND SYMPTOMS:
Chronic cough
Sputum production
Shortness of breath
Barrel chest
High pressure on lung arteries – strains R
...
PATHOGENS:
Disease causing organisms – most commonly viruses/bacteria – sometimes fungi or parasites
...
WHATS ON/IN BACTERIA?
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
1
...
3
...
5
...
7
...
-‐
-‐
-‐
-‐
Slime layer – around the outside of some bacteria
Cell wall – often made of peptidoglycan – a combined carb/protein
...
New viral genes are produced by the host cell and so hundreds of new virus particles are formed
...
TRANSMISSION BY PATHOGENS:
By contact – direct (touching infected) / indirect (touching something the infected touched)
By body fluids – STI’s, Hep B/C and HIV from shared needles
By droplets -‐ sneezing/coughing around non-‐infected
By ingestion – contaminated food/drink – salmonella and typhoid fever
By air – moisture in exhaled droplets
By vectors – on animals such as household flies, fleas and mosquitoes
NON SPECIFIC DEFENSES
Work against all pathogens -‐ first line of defense
EXTERNAL:
Skin – sweat, sebum and low pH
Mucous membranes
Hair – nose, eyelids and ears (trap 90% of foreign bodies)
Acids
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
1
...
3
...
1
...
3
...
5
...
7
...
9
...
MACROPHAGES ARE LARGE PHAGOCYTES THAT DEVELOP FROM SOME LEUCOYCTES – SOME WANDER, LOOKING
FOR PATHOGENS WHILE OTHERS ARE FIXED IN PLACE AND DEAL WITH PATHOGENS THAT COME TO THEM
...
ANTIBODIES:
A blood protein produced in response to and counteracting a specific antigen
...
Y in shape
Disulphide bond connecting the constant and variable portions
Lower ¾ is the heavy chain
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
1
...
3
...
5
...
7
...
B CELLS
Humoral and antibody mediated immunity
Educated in bone marrow
Chemical based system
Produce antibodies (Ig – immunoglobulin)
Effective against extracellular bacteria and some viruses
T CELLS
Cellular and cell mediated immunity
Educated in thymus
Cell based system
Produce killer, memory and helper cells
Effective against intracellular viruses, cancer and some bacteria
KILLER T (CYTOTOXIC) CELLS – destroy body cells infected by viruses or transformed by cancer
HELPER T CELLS – perform many immune functions – they are essential for activating killer cells and B cells
MEMORY CELLS -‐ remain in the body and enable the immune system to react rapidly should it encounter the same
antigens again
CYTOKINES – stimulate T cells to divide and differentiate into killer, helper or memory cells
ANTIBIOTICS – chemicals specifically designed to kill a certain bacteria – produces by fungi or other microorganisms
(penicillin)
AGGLUTINATION -‐ a reaction in which particles (as red blood cells or bacteria) suspended in a liquid collect into
clumps and which occurs especially as a serological response to a specific antibody
...
Internal cell infection is displayed on the cell surface by MHC class one
2
...
Costimulation occurs with helper T cells and CD8
4
...
Some T cells differentiate into cytotoxic T cells
6
...
Cytokines kill the cell
8
...
Memory T cells remember the antigen and produce faster immune response during
subsequent exposures
ACTIVE IMMUNITY:
(antigen activated)
immune system activated
memory cells produced = immunity acquired
-‐
-‐
-‐
-‐
-‐
-‐
-‐
-‐
protection slow to develop but permanent
NATURAL – involves B and T cells (natural contact w/disease)
ARTIFICIAL – vaccines (dead, attenuated, sub unit, toxoid)
PASSIVE IMMUNITY
(antibody activated)
immune system not activated
no memory cells formed = not immunity acquired
protection immediate but only temporary
NATURAL – IgG (cross placenta) / IgA (cross breast milk)
ARTIFICIAL – serum (dose of antibody to fight infection)
CHAPTER 12 – MUTATIONS AND GENE POOLS:
Species – a group of individuals who share many of the same characteristics and are able to interbreed naturally to
create fertile offspring
...
GENE POOLS:
Population – a group of organisms of the same species living together in a particular place at a particular time –
geneticists (scientists specializing in inheritance) prefer to look at a population as a whole and not the individuals who
make up that population
...
-‐ I
...
– Cystic fibrosis is a mutation of chromosome 7 – if the allele frequency of CF is 5%, then among the members of
the population, 5 in every 100 people will have cystic fibrosis
...
e
...
MUTATIONS:
Offspring may show variations that do not resemble either parent and have never occurred before in the history of the
family – they may occur quite suddenly of by pure chance – these are called MUTATIONS
...
There are 2 main types of mutations:
Gene mutations – changes in a single gene so that traits normally produced by that gene are changed or destroyed
...
When it was recognized that genetic information is carried in the sequence of bases in the DNA, it became possible to
understand the chemical nature of gene mutations
...
1
...
2
...
DMD becomes apparent at 3-‐5 years old and results in the wasting of muscles in the legs, arms,
shoulders and chest
...
3
...
Without the correct protein the affected person suffers from symptoms: salty
tasting skin, persistent coughing, wheezing or pneumonia and digestive problems
...
Chromosomal mutations – where all or parts of a chromosome are affected – therefore affect not just one but a
number of genes
...
Deletion – part of a chromosome is lost
2
...
Inversion – breaks occur in a chromosome and the broken piece joins back in but the wrong
way around – this changes the order of the genes on the chromosome and may disrupt the
pairing of homologous chromosomes during meiosis
4
...
Non-‐disjunction – during meiosis, a pair of chromosomes does not separate and so one
daughter cell has an extra chromosome and one daughter has one less chromosome –
sometimes referred to as ANEUPLOIDY – a change in chromosome number
Chromosomal mutations cause abnormalities so severe that miscarriage often occurs during early pregnancy
...
Patau syndrome is trisomy on the 13th chromosome and produces individuals with mental
retardation, a cleft lip/palate, malformations of the ears and eyes and an extra finger on each hand – it occurs in
1/5000 live births though more than 80% of affected people die within a month of birth
...
Trisomy can also occur in the sex chromosomes -‐ non disjunction
may occur during the 1st/2nd meiotic division resulting in individuals with one extra x (XXY) or one extra y (XYY)
chromosome – trisomy XXY sufferers are normal boys but develop Klinefelters syndrome as adults – the have small
testes that do not produce sperm, enlarged breasts and sparse body hair – occasionally they may be mentally retarded
...
If the
entire autosome is missing, this generally produces severe malformations that end in spontaneous miscarriage; if only
part of the chromosome is missing, this is referred to as partial monosomy – part of the chromosome has two copies
but part only has one – i
...
Cri du Chat (cry of the cat) syndrome – missing portion of chromosome 5 that results in
problems with the larynx and nervous system AND monosomy X in females where they only have one x chromosome 0
these females will generally be short in stature, lack secondary sexual characteristics and be infertile
...
LETHAL RECESSIVES:
Most gene mutations produce a recessive allele because they prevent the gene from producing a protein able to
function in the body
...
Some recessive mutations are lethal if they are not masked by a dominant normal allele –
these lethal recessives generally cause the early death of the embryo or foetus (miscarriage or spontaneous abortion)
...
MUTAGENS:
(AKA mutagenic agents) – things that are known to increase the rate at which mutations occur – i
...
mustard gas,
formaldehyde, sulfur dioxide, ultraviolet light, x-‐rays, cosmic rays and radiation
...
SOMATIC AND GERMLINE MUTATIONS:
1
...
3
...
5
...
2
...
Somatic – the body cells are involved – only the individual with the mutation is affected
...
Germline – reproductive cells are affected – the mutation can then occur in the gametes and thus be passed onto
subsequent generations – in this case, the individual with the original mutation may not be affected
...
If reproduction occurs directly on one of those affected gametes, the
pregnancy is often aborted naturally
...
CHAPTER 13 – BIOTECH:
Genome: the complete set of genetic information of an organism – for humans this is the full sequence of approx
...
DNA: Deoxyribonucleic acid – made up of a double helix w/ alternating steps of sugars (deoxyribose) and
phosphate groups, with pairs of nitrogenous bases forming cross links between the strands (Adenine/Thymine
and Cytosine/Guanine)
~ The order/sequence of these bases is the genetic information that determines the structure of the cell and the
way it functions
...
~ SANGER METHOD – in building a DNA sequence, each new nucleotide is bonded to the hydroxyl group (-‐OH) of
the previous nucleotide
...
Sanger method requires:
Multiple copies of single stranded DNA
A suitable primer
DNA polymerase (DNA copier – adds new nucleotides to the 3” end of the template strand
A pool of normal nucleotides
A small portion of ddTTP’s labeled in some way – radioactively/fluorescent dye
...
G – Spastic paraplegia – symptoms show between 20-‐50 – segment of chromosome 2 was searched for affected
point mutation by comparing to non-‐affected members of the family
...
DNA profiling depends on regions of non-‐coding DNA that is polymorphic – shows great variability between
individuals – uses STR’s
...
Larger pieces
are heavier and thus travel less that lighter/smaller pieces of DNA – this creates a distinctive banding pattern
that varies from person to person allowing the difference sequences to be compared
...
9% of different people’s DNA is common
The other 0
...
These are called
Short Tandem Repeats (STR)
Due to random mutation these STR areas vary between individuals
The length of specific STR sections can be compared to create an individual DNA profile
...
1
...
3
...
2
...
4
...
PCR – Polymerase chain reaction – used to amplify minute amounts of DNA using an enzyme called DNA
polymerase (developed my Kary Mullis)
...
HYBRIDISATION: Primers (short synthetic DNA fragments) are added to the DNA -‐ they bind to the strand of
separated DNA acting as a starting point for replication
...
RECOMBINANT DNA TECHNOLOGY: (genetic engineering): involves the introduction of DNA into cells where the
DNA is foreign or has been modified in some way
...
Stanley Norman Cohen and Herbert Boyer invented the recombinant DNA technique in 1973 – it involves the
isolation and amplification of genes or DNA segments to insert them into a bacterial cell – creating a
TRANSGENIC BACTERIUM
...
BACTERIOPHAGES/PHAGES – Viruses that infect bacteria cells
Certain enzymes in bacteria are able to restrict the duplication of infecting viruses by cutting them up – scientists
discovered that such an enzyme ALWAYS cuts the DNA at a point where there is a specific sequence of bases –
this is known as the recognition site while the enzyme that cuts the DNA is a restriction enzyme
...
A
straight cut is when the restriction enzyme makes a clean break across the two strands of DNA to make a blunt
end
...
Restriction enzymes that produce a staggered cut
create a sticky end
...
DNA ligase – found in the E
...
PROCESS OF RECOMBINANT DNA:
Isolate the gene and cut it out using a restriction enzyme
Isolate a plasmid from a bacterial cell and cut it with the same R
...
RECOMBINANT DNA TECH HAS BEEN USED TO CREATE:
Insulin – the human gene that contains the code for insulin production was inserted into bacterial cells – these
bacterial cells became insulin factories that are now cultured in vats – it is identical to human insulin because the
human gene was engineered into the bacteria
...
CYSTIC FIBROSIS:
Most common life threatening disease in Australians of European descent
...
Cystic fibrosis transmembrane regulator was identified in 1989, and in 1991 scientist successfully corrected the
faulty gene in cultured cells by adding normal copies to the culture
...
The first experimental CF gene treatment was given to a man in 1993 – scientists modified a rhinovirus cell to act
as the vector to carry normal genes to the CFTR cells in the lungs
...
CELL REPLACEMENT THERAPY AND TISSUE ENGINEERING:
Stem cells are undifferentiated cells that are capable of repeated mitotic divisions and if given the right
conditions, specialization
...
I
...
Stem cells are also increasingly being used for tissue engineering – the primary objective of T
...
TISSUE ENGINEERING:
Requires an abundant supply of disease free cells of specific types
...
Tissue scaffolds serve as a template
for tissue growth and need to have high pore sizes that enable the cells to grow while at the same time allowing
for the diffusion of nutrients through the whole structure
...
Once a scaffold has been devised, stem cells need to be cultured
...
As the new cells continue to grow and divide, the material making up the scaffold
begins to degrade or get absorbed
...
CHAPTER 14 – EVOLUTIONARY MECHANISMS:
Random assortment – of chromosomes during meiosis results in gametes that have a huge number of possible
number combinations of the chromosomes that originally came from the male parent and the female parent
...
Non-‐disjunction – BITCH I ALREADY EXPLAINED THIS IN CHAPTER 13
Random fertilization – each person produces a huge number of different sperm or eggs (in relation to potential
variations in alleles) and because any sperm can fertilize any egg, there is almost an infinite number of possible
allele combinations
...
RANDOM GENETIC DRIFT (Sewall Wright effect) - The occurrence of characteristics in a population as a result
of chance rather than natural selection – occurs only in small groups
...
Genetic drift takes place when the occurrence
of variant forms of a gene, called alleles, increases and decreases by chance over time
...
Typically, genetic drift occurs in small populations, where infrequently occurring alleles face a greater
chance of being lost
...
Both possibilities
decrease the genetic diversity of a population
...
In these cases, genetic drift can result in the loss
of rare alleles and decrease the gene pool
...
I
...
the Dunkers of Pennsylvania that originally came from Hesse Germany – their religion does
not allow them to marry outside of their group – in terms of various physical characteristics such as, the
frequency of ABO, Rh and MN blood groups, attached or free earlobes, mid-‐digital hair and left or right-‐
handedness, the Dunkers varied in allele frequency from modern day Hesse Germans and also from the
surrounding population (whose environment was the same ruling out natural selection)
...
The blood group frequencies of both Bentinck and Bayley point of the mainland have been compared – the
occupants of Bentinck island show a very high proportion of the Ib allele and a complete absence of the Ia
allele – direct opposition to the Bayley point inhabitants who have high proportion of the Ia allele and low
proportions of the Ib allele – thus the blood group frequencies of the Bentinck islanders fall outside the
range for Aborigines in the rest of Australia
...
THE FOUNDER EFFECT – similar to genetic drift, the founder effect occurs when a small group of people
moves away from its homeland to a totally new area and establishes a community which later expands
...
This new community therefore generally shows features that are not typical of the original
homeland population
...
E
...
Among the
survivors was a person heterozygous for a form of recessive total colour blindness – ACHROMATOPSIA -‐
today after a number of generations, the frequency of achromatopsia in Pingelap is 5% of the population,
compared to the 0
...
Furthermore, 30% of the population are
carriers for the disorder
...
MIGRATION – gene flow from one population to another – if immigrants to a certain country bring alleles
that are not already in the population, the frequencies for the alleles of that gene will be altered
...
E in the
past the Chinese population was RH+ -‐ when European countries began trading with China, they introduced
the RH-‐ blood group allele into the population – frequency of the RH-‐ blood group is still comparatively low
in China compared to other countries
...
Prior to british colonization in
1788, the indigenous pop of Australia had no contact with European diseases such a chickenpox, small pox
and influenza and thus had very little genetic resistance
...
4
...
As no two environments are exactly the same, the environmental pressures on
one may be different to the pressures of another – this results in slightly different characteristics being
favoured in one population compared to the other – these changes in each population over many
generations result in the populations becoming less and less alike as they develop characteristics better
suited to their respective environments
...
Geographical barriers include: oceans, mountain ranges, large lake systems, deserts and expansive ice
sheets
...
The Basque people of the Pyrenees in France and Spain have a language that appears unrelated to any other
...
GENETIC DISEASES – The allele that causes tay-‐sachs is an example of how genetic diseases affect allele
frequencies in gene pools
...
It affects around 1/500000 births worldwide, but around 1/2500 births in Ashkenazi jews
...
Another reason is that those
who are heterozygous for Tay-‐sachs have a selective advantage/resistance to tuberculosis – that is, that
people who are homozygous for the dominant normal allele (TT) are susceptible to TB, those who are
homozygous for the recessive lethal allele (tt) are likely to die very young due to the disease but those who
are heterozygous -‐ that is the lethal recessive is masked by the dominant normal allele (Tt), they are not
affected negatively by the disease, but still have a specific resistance to TB – and are thus more likely to
reproduce and pass their genes on to subsequent generations
...
It is interesting to note that the same disorder has been seen in the Cajun population of southern
Louisiana – Cajuns are an ethnic group that have been reproductively isolated for several hundred years
because of language differences – the mutation may have been introduced when an Ashkenazi family
integrated into the society who were carriers/affected – if this was the case it is another example of how
migration affects allele frequencies in populations
...
THE THEORY OF EVOLUTION THROUGH NATURAL SELECTION:
*Evolution is the gradual change in the characteristics of a species (Charles Darwin and Albert Wallace in 1858)*
Darwins theory of natural selection was based on three observations:
1
...
It is
because of variation that survival of the fittest (more organisms with favourable characteristics suitable to
survival in their environment survived long enough to reproduce and pass those characteristics on to their
children)
...
Birth rate – all living organisms reproduce at a rate which exceed the rate at which their food and resource
supply increase – creates a struggle for existence with favourable variations being preserved
...
Natures balance – although birth rate was high, each species numbers tended to remain at a relatively
constant level
...
Those organisms that survive will pass on their favourable alleles to their offspring with the
characteristics of a population over an extended period of time changing to be better suited to their
environment
...
shortlimbed/longbodied people of the
Inuit (eskimo)
...
SPECIATION:
-‐
-‐
-‐
-‐
-‐
-‐
Isolation was mentioned earlier as a barrier to gene flow – reproductive isolation may lead to the development of
separate gene pools
...
Thus the two populations
would be considered two separate species
...
1
...
2
...
SELECTION – different selection pressures act on each of the two populations over a number of generations
...
SPECIATION – Over a long period of time the changes in the gene frequencies may become great enough that
production of fertile offspring from interbreeding can NEVER AGAIN OCCUR – at this point, two separate
species occur
CHAPTER 15 – EVIDENCE FOR EVOLUTION:
SPECIATION: When an ancestral species gives rise to two or more species – the new species would have very
similar DNA with these similarities decreasing as the species gradually change and mutate
...
Examples of non-‐functional DNA are endogenous retro viruses (ERV)
...
The DNA then
becomes inserted into one of the host cells chromosomes
...
Scientists have found 16 instances of the exact same retrovirus in the same places in both humans and
chimpanzees – short arms of chromosomes 10, 1 and 6 and the long arm of chromosome 9 – this is compelling
evidence of shared ancestry as any retrovirus inserted into the genome of a common ancestor would be
inherited by subsequent species branches on the exact same arm of chromosomes
...
Most of the cells DNA is found in the nucleus, but a small amount is found in the mitochondria – mtDNA
mtDNA is found in the form of small circular molecules – there are 5-‐10 of these molecules in each
mitochondrion
...
The other 13 have instructions for making some of the enzymes necessary for cellular respiration
reactions
Some rare diseases are caused by mutations in the mtDNA
Most cells contain large numbers of mitochondria and therefore around 500-‐1000 copies of mtDNA molecule –
this makes it a lot easier to find and extract than DNA from the nucleus so smaller samples can be used
...
DNA found in the mitochondria also has a higher rate of mutation than
nuclear DNA – meaning that human mtDNA has been slowly diverging from the mtDNA of our original female
ancestor – scientists are thus able to use the similarities between the mtDNA of any 2 individuals to estimate
their genetic closeness
...
PROTEIN SEQUENCES:
-‐
-‐
-‐
-‐
Proteins consist of long chains amino acids (from a few hundred – thousands) -‐ linking together particular
amino acids in a precise order determined by DNA creates these proteins – thousands of types of proteins exist
in all living things created from 20 kinds of amino acids
...
The
longer the period of time involved since two given species have evolved from a common ancestor, the more
differences there should be in their amino acid sequences
...
Cytochrome C is one such example of a ubiquitous protein – human cytochrome has 104 amino acids –
regardless of the species tested, 34 of these have been found in the same positions in every cytochrome C
molecule that’s been sequenced – strongly suggesting that these proteins have descended from an ancestral
cytochrome C molecule found in a primitive microbe that existed more than 2000 million years ago
...
The cytochrome C of chimps and gorillas is the same
as that for humans while for rhesus monkeys, it differs by only one amino acid
...
COMPARATIVE GENOMICS:
Is a relatively new field of bio-‐research where the genome sequences of different species are compared – by
comparing the sequence of the human genome with the genomes of other organisms, researchers are able to
identify regions of similarity and difference
...
By analyzing the genomic features of different species that have been preserved for millions of years, researchers
are beginning to be able to tease apart the subtle differences between animal species – it has also been used to
reveal the diversity of gene composition in different evolutionary lineages
...
EMBRYOLOGY:
Comparing the very early stages of development of organisms
...
Fish, reptiles, birds, pigs and humans all have gill pouches and arches as early embryos despite the latter four
having lungs for breathing air and no aquatic larvae in later life – the presence of these structures is significant if
they are viewed as an evolutionary series that began with fish hundreds of millions of years ago with evolution
resulting in their divergence later
...
-‐
Common to all vertebrate embryos too are two chambered hearts and similar brain development – adding up to
striking evidence for common ancestry with later evolution along different pathways
...
These similarities are evidence that life on Earth has a common ancient ancestor that the diverse species have
evolved from over time
...
The more closely the organisms are related, the more similar the homologous structures between organisms
...
The bone
structure within those limbs are similar between closely related species
...
The flipper of a whale, the wing of a bat, and the leg of a cat are all
very similar to the human arm
...
All of the species also have a collection of
smaller bones in the "wrist" area (these are called carpal bones in humans) that lead into the long "fingers" or
phalanges
...
The homologous limbs can be used for flying, swimming, walking, or everything humans do with
their arms
...
Whales were once classified as a fish
since they live in the water and have flippers
...
In fact, it seems whales are much more closely related to hippos than fish
...
Everything with
wings were put into the same branch of the phylogenetic tree
...
Even though they have the
same function, to make the organism be able to get airborne and fly, they are structurally very different
...
Therefore, bats are more closely related to humans than birds or insects and were moved to their corresponding
branch on the phylogenetic tree of life
...
e
...
2
...
4
...
6
...
8
...
Nictitating membrane (pinkish membrane found in inner corner of eye)
Muscles to move ears
Pointed canine and wisdom tooth
Hair on body
Nipples on male
Segmentation of abdominal muscles
Appendix
Pyramidalis muscles above pubic area
Coccyx (fused tail bone area)
They are what remains of organs that were functional in ancestral forms – over time and with changing
environmental conditions, such organs were no longer essential to survival and gradually reduced to vestigial
remnants; however as they are not harmful in any way, they have not been completely eliminated
...
CHAPTER 16 – FOSSIL EVIDENCE FOR EVOLUTION:
One of the crucial pieces of evidence for evolution, the gradual change in characteristics of organisms over time,
is the record of those changes left in the form of fossils
...
Other material associated with the bones, such as the rock they were found in and fossils
of other plants and animals allows the scientist to develop a picture of life in the past – what they ate, what other
things existed at the same time and sometimes even what the climate was like
...
FOSSILFORMATION:
Normally dead organisms are decayed by micro-‐organisms and no trace of their existence is left
...
In wet, acid soils, the minerals of the bone are dissolved and no fossilisation occurs, however if such soil contains
no oxygen (i
...
peat) complete preservation of the soft tissues and bones of the organism may occur
...
FOUR CONDITIONS REQUIRED FOR FOSSIL FORMATION:
1
...
3
...
A quick burial of the material
The presence of hard body parts
An absence of decay organisms
A long period of stability – the organism needs to be left undisturbed
DISCOVERY OF FOSSILS:
Small hand tools are used to gently remove the soil so as not to damage any of the material (the soil is usually
then sieved)
...
In the
laboratory, fossils are carefully scraped clean , broken parts are pieced together, measurements are made and
plaster casts/latex moulds may be made
...
Some methods of dating provide absolute dates – the actual age of the specimen in years
– or relative dates – which tell us if one sample is older/younger than another
...
Potassium is a mixture of three
different forms with atomic weights 39, 40 and 41
...
P-‐A dating has limited usefulness however as not all rock
types are suitable for this method of dating and it can only date rocks older than 100 000 – 200 000 years (at the
earlier date of 100 000 years, only 0
...
To determine the age of a fossil using this method, a suitable rock of
the same age must be available – this occurs when rocks produced in volcanic eruptions bury bones
...
Carbon 14 is produced in the
upper atmosphere by the action of cosmic radiation on nitrogen at about the same rate that it decays
...
When plants use atmospheric carbon dioxide in photosynthesis, one atom in every trillion of the
carbon atoms incorporated is carbon-‐14
...
With death, an organisms intake of carbon 14 ceases, but the carbon 14 already in the tissues
continues to decay at a fixed rate – by measuring the amount of radiation liberated by a sample, the ratio of
carbon 14 – carbon 12 can be estimated and from this, the age of the sample can be calculated
...
A more refined technique called the ACCELORATOR MASS SPECTROMETRY (AMS) RADIOCARBON DATING can
be used to date a sample as small as 100micro grams by breaking the sample up into its constituent atoms so
that the number of atoms of each isotope of carbon can be counted
...
DATING METHOD
MATERIAL USED
Tree growth rings
Wood
Up to 9000
Carbon -‐14
Carbon compounds
Up to 60 000
Protactinium
Sea sediments
Up to 250 000
Uranium-‐thorium
Sea sediments, coral
Up to 600 000
Potassium-‐argon
Volcanic deposits
200 000 and earlier
Electron spin resonance
Fission tracks
Thermoluminescence
USEFUL RANGE (YEARS BP)
Calcium carbonate, quartz
and flint
Between 100 000 and 300 000
Minerals and glass
100 years ago to 4550 million
Sediments, lava, ceramics
300 years ago to 100 000
After about 70 000 years radiocarbon dating is null and void because the amount of carbon 14 left is negligible –
therefore radiocarbon dating cannot be used to date back more than 60000 years – another limitation is that
material to be dated must contain organic carbon compounds
...
2
...
The correlation of rock strata – involves matching layers of rock from different areas – matching can be done by
examining the rock itself and also by studying the fossils it contains
...
Certain fossils are of great value in correlation studies as they are widely
distributed and present for only a limited period of time – they are called index fossils (i
...
a trilobite fossil)
...
All the fossil bones in a particular deposit should have the same
amount of fluoride and so fossils that have been displaced can be detected – the older the fossil, the more
fluoride it should contain and so the relative ages can be established
...
Closely related groups are placed on branches close to eachother – keep in
mind however that these are only inferred relationships; different researchers may come up with different trees
to fit their interpretation of the data
...
In studying the origins of
humans, we are only interested in the Cainozoic era as this is when the primates (the group modern humans
belongs to) started to evolve
...
-‐ interesting – the ancestors of modern humans that made those footprints were walking much the same way as
we do now – BIPEDAL LOCOMOTION – or walking upright on 2 legs – differs from other great apes who used
QUADRAPEDAL LOCOMOTION
...
2
...
4
...
6
...
Humans as such are classified as HOMININS, belonging to the tribe HOMININI
...
FAMILY
HYLOBATIDAE
SUBFAMILY
PONGINAE
GIBBONS AND
THEIR EXTINCT
ANCESTORS
FAMILY
HOMINIDAE
SUBFAMILY
HOMININAE
ORANGUTANS
AND THEIR
EXTINCT
ANCESTORS
TRIBE
GORILLINI
GORILLAS
AND THEIR
EXTINCT
ANCESTORS
TRIBE
PANINI
CHIMPANZEES
AND THEIR
EXTINCT
ANCESTORS
TRIBE
HOMININI
HUMANS AND
THEIR
EXTINCT
ANCESTORS
EVOLUTIONARY TRENDS:
Apes and humans share a common ancestor – an ape like creature – from these the first hominins evolved –
AUSTRALOPITHECINES – hominins classified in the genus Australopithicus
...
ADAPTIONS FOR ERECT POSTURE:
An adaption is any characteristic that helps an organism survive and reproduce in its natural environment – erect posture
helped our human ancestors survive
...
POSITION OF THE FORAMEN MAGNUM – where the brain meets the spinal cord, there is a hole in the skull called the
foramen magnum – in quadrupeds, its situated in the centre back of the skull (creates c shaped spine), whereas in
humans its gradually moved forward (to centre bottom of skull) so that the skull can be balanced ON TOP of the
vertebral column -‐ gorillas need large neck muscles to hold the head in place as it overhangs the chest whereas in
humans, the weight of the skull is borne by the vertebral column and so large neck muscles are not required
...
CURVATURE OF THE SPINAL COLUMN – humans have a double curvature giving the spine its distinctive ‘s’ shape
...
3
...
4
...
The pelvis in humans is broader and
shorter – from top to bottom – than in apes and bowl shaped
...
5
...
This allows the weight to be transferred from the pelvis to the legs
...
Because the pelvis is broad, the hip sockets are far
apart, but the femurs tend to converge inwards at the knee – this arrangement of the femurs forms an angle to the
vertical (carrying angle) which ensures that weight distribution remains close to the central axis of the body when
walking – this arrangement also allows for greater stability when walking as it enables the body to be rotated around
the lower leg and foot AND for each footstep to follow a more-‐or-‐less straight line (enabling humans a striding gait
rather than the swaying gait of chimps and gorillas)
...
7
...
9
...
The knee is a 2 part
hinge joint – because the weight is transmitted to the outer hinge – it is bigger and stronger than the inner hinge
...
THE FOOT – from the knee joint most of the weight of the body is transmitted through the tibia (the larger and
stronger of the 2 lower leg bones) to the ankle
...
We have developed the transverse arch (side to side) that apes do not have in
addition to the longitudinal arch of all apes (front to back)
...
STANCE AND LOCOMOTION – striding gait = walking upright with the hip and knee fully straightened – apes when
walking upright push their hips forward and bend their knees to counter balance and lower centre of gravity
...
e
...
CHAPTER 19 – HUMAN ANCESTORS:
AUSTRALOPITHICUS AFARENSIS
AUSTRALOPITHECUS AFRICANUS
PARENTHROPUS AETHIOPUS
HOMO
HABILIS
HOMO RUDOLFENSIS
PARENTHROPUS
ROBUSTUS
PARENTHROPUS
BOISEI
HOMO ERGASTER
HOMO ERECTUS
HOMO
HEIDELBERGENSIS
HOMO
SAPIENS (in
Africa)
HOMO
NEANDERTHALUS
(in Europe)
ADVANTAGES OF BIPEDAL LOCOMOTION:
1
...
Increased size, deterring predators
3
...
Higher reach when picking fruit from trees
5
...
FEATURES OF AUSTRALOPITHICENES (TAUNG MAN
EXAMPLE)
1
...
Skull w as more rounded
3
...
More forward position of the foramen magnum
5
...
More prognathic than modern humans
7
...
7
...
9
...
Africanus/Afarensus – Lucy)
• 120-‐140 cm tall
• 25-‐35kgs
• teeth were more in proportion to eachother
• jaw muscles were smaller
HOMO HABILIS (HANDY MAN)
~ thought to be the earliest tool user
~ taller than gracile forms
~ stood more erect
~ belonged to the homo genus and existed/lived along side robust australopithicenes (1
...
600-‐775 cm3
HOMO ERECTUS (UPRIGHT MAN)
~ thought to be the first species to use fire
~ average brain size 1075 cm3
~ dental arcade was shorter and more rounded in shape (apes are parabolic)
~ jaw was shorter and more compact w/ evidence of a developing chin
FOOTPRINTS IN ILERET KENYA – OLDEST RECORDED FOSSILS OF MODERN HUMAN FOOTPRINTS – BELONGED
TO HOMO ERGASTAR 1
...
8-‐1
...
6-‐1
...
8MYA – 250 000 YA
HOMO ANTECESSOR = 750 000 YA
HOMO HEIDELBERGENSIS = 450 000 YA
DENTITION OF THE AUSTRALOPITHICENES:
1
...
The first premolar was typically more ape like – some specimens only had one cusp rather than two
3
...
the femur of the australopithecine was angled so the foot was under the centre of gravity
2
...
5m tall
• barrel chest
• slightly larger brain (1485 cm3 compared to our 1350 cm3)
CROMAGNON PEOPLE:
• one of the earliest examples of homo sapiens
• stone tools (AURIGNACIAN TOOLS)
• 40 000-‐12 000 ya
• skulls were shorter from front-‐back, higher in the top region of the skull and rounder at the back
• less prominent brow ridges, smaller jaw and less projected
• teeth were smaller and chin had developed
CHAPTER 20 – CULTURAL EVOLUTION:
AUSTRALOPITHECINE CULTURE:
• OLDOWAN period
• Home bases
• Range of pebble tools dating back 2
...
Early homo had a bulge in the speech production centre of the brain – larynx may not have been capable of making
complex sounds
...
Keeps away predators
2
...
Cooking away germs – digestible and taste better
4
...
6-‐1
...
7 MYA-‐200 000 YA – ACHEULIAN
NEANDERTHAL – 200 000-‐40 000 YA – MOUSETTARIAN (FLAKE TOOLS)
CROMAGNON – 43 000 -‐26 000 – AURIGNACIAN (BLADE TOOLS)
-‐ 22 000-‐19 000 – SOULTERIAN (PRESSURE FLAKING)
-‐ 18 000-‐12 000 – MAGDALENIAN (BONE AND ANTLER TOOLS/ARTWORK)
THE BEGINNINGS OF AGRICULTURE:
-‐ Neolithic revolution
-‐ Domestication of plants and animals – sheep were domesticated first – 11 000 ya and the
hybridization of wild goat grass and wild wheat to create the fertile Emmer was the first
domesticated plant
Title: HUMAN BIOLOGY REVISON NOTES
Description: literally just 47 pages of human bio notes covering everything from: Chemical messengers Hormones secreted from organs other than your pituitary Parts of a neuron and their functions Structural types of neurons and their processes Divisions of the nervous system The CNS in depth How the body detects and regulates internal changes Disruptions to homeostasis Protections against invaders Specific resistances to infection Mutations and gene pools Biotech Evolutionary mechanisms Evidence for evolution (broad) Fossil evidence for evolution (narrow) Evolutionary trends in hominins Human ancestors and Cultural trends in Humans
Description: literally just 47 pages of human bio notes covering everything from: Chemical messengers Hormones secreted from organs other than your pituitary Parts of a neuron and their functions Structural types of neurons and their processes Divisions of the nervous system The CNS in depth How the body detects and regulates internal changes Disruptions to homeostasis Protections against invaders Specific resistances to infection Mutations and gene pools Biotech Evolutionary mechanisms Evidence for evolution (broad) Fossil evidence for evolution (narrow) Evolutionary trends in hominins Human ancestors and Cultural trends in Humans