BIOA11
Quantitative Genes
Diversity
Inheritance of Genes
[Intelligence, weight, eye colour]
Continuous Variation
influenced by many genes
Transcription regulators
proteins that choose which gene is expressed and when
Heritability
Environment
Identical Twins Case [smoke & tanning]
Correlation *between groups not individuals
Probability
Normal Distribution Graph
Bell Curve
Mean (top) & Variability (width)
Flip flop tan
Nature vs Nurture
Natural Experiments
human twins
dizygotic
monozygotic
Pleiotropy
shown by gene which influences several unrelated traits
Both desirable and undesirable traits
click to edit
Qualitative Genes
on / off
wrinkled / round
Genetics
Codominance
Incomplete dominance
RR x rr = Rr (pink flower)
R1R1 x R2R2 = roan cow (both dom)
Pedigree
DNA Profiling
STRs (short tandem repeats)
PCR (polymerase chain reaction)
Test tube, heat, machine
ABO blood
multiple allelism
only used to eliminate, not confirm relationships
RH factor (+) or (-)
Step 1: components are put in a test tube and put in a thermal cylinder
Step 2: DNA is heated and strands separate into single strands. Then the primer binds with the complementary sequences.
Step 3: TAQ polymerase used the free nucleotides to start DNA synthesis (primer is used as a start)
Step 4: The two stranded DNA molecules are produced from one original DNA molecule
Step 5: the process gets repeated many times. Each time, the DNA is doubled.
Protein Synthesis
Transcription
Protein Synthesis
Baking a cake
consult a recipe book (genome)
Find the recipe (gene) to make the cake (protein)
Make a copy of the recipe (mRNA)
leave the original book (genome) on the shelf (nucleus) os the recipe (gene) doesn't get dirty
Place the copy (mRNA) on the kitchen counter (ribosomes)
Gather all the ingredients (amino acids)
get measuring cups and spoons too (tRNA)
Mutations
changes to DNA sequence (during translation
may result in a nonfunctional protein or a different one than you wanted
Neutral Mutation
has no effect
may not be able to perform the job
Frame Shift Mutation
can cause codons to form in different groups
click to edit
Gene Expression
control gene expression (use of proteins called activators)
differs from cell to cell
Regulated through rate of transcription or translation
done by blocking transcription (or translation) via proteins called repressors
Cloning
making many copies of the gene
(Cow example)
- remove the gene from the chromosome
- Insert BGH gene into Bacterial Plasmid
- Insert recombinant plasmid into a bacterial cell.
GMOs
Gene gun is used to move genes
Transgenic organism
resistant to herbicides and pesticides
'super weeks' evolve
Pharming (goats and milk for treating human clotting)
Stem Cells
totipotent (cells that have the potential to become any cell)
Gene Therapy
Somatic Gene Therapy
replacing dysfunctional cells with functional cells
Human Cloning
Reproductive Development
Asexual Reproduction
Not sexual
Reproducing by yourself
cells divide through binary fission
Budding
Sexual Reproduction
creating offspring through fusion of sex cells
male and female required
gonads (gamete producing structures)
ovaries are female gonads
testes are male gonads
zygote (offspring) 2n
Hermaphrodites (animals that have both male and female reproductive systems)
Internal fertilization (leaving sperm in/near the female reproductive system)
External Fertilization (egg laid in water and male sperm released over the egg) **no physical contact needed
First step in P.S.
copying process
occurs in the nucleus
Some DNA is unzipped so that mRNA can be made
(mRNA is made from a DNA template)
Nucleotides of RNA match w/ one strand of DNA and make mRNA
RNA polymerase unzips the DNA & puts RNA nucleotides into the right place (C&G, T&A, A&U) Uracil bonds with A in RNA
After mRNA is formed, it moves out of the nucleus & goes into the cytoplasm to find a ribosome
Ribosomes are protein making machines (they read mRNA codes and add the right amino acid using tRNA) to build a protein
tRNA has an anticodon on one end (which matches with mRNA) and an amino acid on the other end
Translation
- mRNA attaches to a ribosome & a start codon must be read (AUG)
tRNA brings in the 1st amino acid
anti codon matches up with the codon on mRNA
- The next tRNA molecule moves in & matches with the mRNA codon
- Amino Acids form a peptide bond
- The 1st tRNA can detach & mRNA moves over for the next tRNA to come in
- The protein grows until a stop codon is reached
- The protein is formed and ready to finish folding to become functional
Reproductive Systems
Male
Female
Anatomy
Ovary
Oviduct/fallopian tubes (released egg goes here) Uterus (fertilized egg implants here (or not)
Vagina (site of semen reception)
Cervix (blocking of vagina, dialates when baby's born)
Ovulation (inside an ovary where all the eggs are) once a month, 1 egg is chosen to develop into a follicle. Egg is released. Remainder of follicle is called the corpus lutem (gives chemical support to egg. [progesterone and estrogen]
Anatomy
- Vas Defernes (tube where sperm moves out of for ejaculation)
- Testes (secretes sex hormones & site of sperm formation)
- Epididymis (sperm develops here)
- Penis (to deliver into the vagina)
click to edit
Menstrual Cycle (FSH & CH released from petuitary gland) blastula & gastula = baby
Nervous System
CNS (central nervous system)
PNS (peripheral nervous system)
radiates out from brain and spinal cord
brain and spinal cord
gathers info and goes back to the CNS
Effectors (body tissues)
Nerve Impulses (electrical charges)
Neurotransmitters (charges in an ion concentration / chemicals released from nerve cells)
Types of Neurons
- Sensory Neurons (carry info to CNS)
- Motor Neurons (carry info away from CNS)
- Interneurons (located between sensory and motor)
Sensory Receptors (sensory input if detected by these)
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The General Senses
pain, touch, temperature (skin -- nerve endings can moderate their response based on the intensity of the stimulus) [touching snow or a hot stove]
body position (proprioception) muscle -- special neurons sense joint position, tension and muscle contraction [my leg popping out of place]
The Senses
The Special Senses
Smell (receptor in the nasal cavity)
Taste (taste buds: sweet, salty, sour, bitter, urnami)
Vision (Retina -- receptors in the retina allow sight and mediate responses to changes in amounts of light)
Hearing/Equilibrium (receptors in inner ear -- determine the position in the body in space and interpret sound waves)
Smell, taste, vision, hearing/equilibrium
Sensory information is passed to your brain through the spinal cord
Spine protects spinal cord with bones called vertebrae
*Also known as a reflex center
Reflexes are automatic responses to a stimulus
*they're prewired in a circuit of neurons called reflex arc (sensory neurons that receive info from a sensory receptor, and interneuron that passes the information along and a motor neuron that sends a message to the muscle that needs to respond).
Amphetamines
heightens CNS response
causes increased alertness, focus and euphoria
can lead to permanent changes in the CNS function and control (depression, anxiety)
mixing amphetamines and alcohol can lead to heart attack or stroke **long term use can lead to psychosis
**those with ADD are much less likely to experience side effects than their non-ADD peers
The Brain
decisions are made here, bodily activities are directed here 100 - 200 billion neurons found here
brain sits in liquid bath called cerebrospinal fluid
Right hemisphere of the brain controls the left and vice versa
The Left Hemisphere (controls: speech, reading, math problem solving)
The Right Hemisphere controls spacial perceptions, music and art creation)
Glial Cells Supply nutrients to neurons, help repairing brain after injury and attacking bacteria *don't carry messages
Other parts of the brain (Cerebrum, thalamus, hypothalamus, cerebellum, brain stem)
Cerebrum fills the whole upper part of the brain
Parts of the cerebrum:
Parietal Lobe processes information about touch and is involved in self-awareness
Frontal Lobe voluntary muscle movements, planning, memory, impulse control
Temporal Lobe processing sound and smell; good for memory and emotion
Occipital Lobe processes visual information
Cerebral Cortex wrinkly part; outer surface of cerebrum
conscious activity and higher thoughts
Corpus Callosum links the hemispheres; allows communication between the different sides of the brain
Thalamus main relay between spinal cord and cerebrum; first one to receive messages signaling pain, pressure, temperature.
Hypothalmus control center for many sensations (special senses: pleasure, sex drive, hunger, thirst)
Cerebellum controls balance, muscle movement and coordination
Brain Stem controls reflexes and spontaneous functions
Midbrain adjusts sensitivity of the eyes and ears
Pons relay messages between spinal cord and brain
Medulla Oblongata controls heart rate and sends info to spinal cord and brain
Neurons
Dendrites (collect electrical signals)
Cell Body contains a nucleus and organelles
Axon delivers electrical signals to dendrites of another cell or to an effector cell
Terminal Boutons
Action Potential
a nerve impulse
Digestive System
Pharynx
Epiglottis (stops food from going into the lungs)
Esophagus brings food into the stomach, peristalis (muscle contraction which moves food down)
Mouth (mechanical digestion, chemical digestion through salivary glands i.e. sugars broken down), bolus created (ball of food)
Stomach bolus is turned into chyme
gastrin hormone produced by stomach
- stimulates upper part of stomach
- produces acidic gastric juices
- facilitates digestion
- triggers production of secretin and CKK
(which causes pancreas and gallbladder to increase output of digestive juices)
Small Intestine chemical digestion, absorption of nutrients, chyme exposed to bile (liver synthesizes it)
- substances absorbed through "villi"
- blood and lymphatic vessel
Microvilli
- smaller villi
- increases surface area
- transports nutrients into blood vessels inside each villus
Pancreas digestive enzymes are produced here
Liver Metabolizes toxins
Gallbladder stores and concentrates bile
released into the small intestine to help dissolve fats
Alcohol and the Digestive System
Stomach small % of alcohol is metabolized here.
Eating
- presence of food in stomach causes pyloric sphincter to stay closed
- stomach does not absorb alcohol as readily as the small intestine so it prevents alcohol from reaching the small intestine thus slowing the rate at which the alcohol reaches the blood stream
Alcohol Dehydrogenases
- enzyme secreted by epithelial cells lining the stomach
- help metabolize alcohol
*special variant of Al. Dehyd. "Acetaldehyde"
- differs by 1 amino acid
- popular in East Asian descent
- causes a more slowly metabolization of alcohol breakdown
- causes an increase in dizziness, flushed face, irregular heartbeat, nausea
If chyme has a high alcohol level
- stomach lining becomes irritated
- vomiting relfex
Small Intestine - majority of alcohol is broken down here - moved here by pyloric sphincter
- alcohol relaxes muscles involved with peristalis
- therefore, food spends more time in the digestive tract
- therefore, increased exposure to digestive enzymes
therefore, diarrhea
alcohol can interfere with the absorption of nutrients by damaging intestinal villi
Liver heavy drinking - leads to healthy liver tissue being replaced by scar tissue
condition called cirrhosis
progressive, irrversible process
scar tissue prevents proper blood flow through the liver and can result in liver failure
Pancreas inflammation caused by excessive alcohol consumption
- pancreatitis prevents pancreas from secreting digestive enzymes
- thus disrupts digestion which can lead to life-threatening complications
Alcohol leaves the intestine and goes into the bloodstream.
- process to remove it from the body begins
important to prevent damage i.e. decrease level of testosterone production thus, erectile dysfunction and lower sperm production
removed by urinary system
unabsorbed materials pass through the large intestine (colon) and into the rectum and anus
Urinary System
removes waste & retains valuable materials for reuse and recycle
Kidneys filter & cleanses circulating blood
- sit behind the liver and stomach
densely packed with looped tubules nephrons (1,250,000/kidney)
capillaries surround nephrons
- lets waste diffuse out of blood & into tubules for excretion
- all blood is filtered 100s of times/day
Renal Arteries bring blood to kidneys
Sends waste through the ureters, bladder and stores urine in the urinary bladder then expelled via urethra
Waste Processing
- Filtration occurs with in Bowman's capsule
- at the head of the nephron
- encloses the glomerulus
- Blood pressure forces plasma into nephron through tiny holes in the adjacent capillaries
- Reabsoption
- sugars, amino acids and water are reabsorbed into the kidney tissue across the nephron loop
- salt actively removed from the filtrate on the ascending limb of the nephron loop becomes concentrated in the interior of the kidney causing water to flow out
- Secretion
- waste low in concentration in the blood is actively secreted into the far end of the nephron.
- waste then flows into the collecting duct
- Excretion
- After the filtrate is further concentrated as the collecting duct extends into the salty tissue of the kidney, urine is excreted into the bladder.
Micturition
- Alcohol promotes formation of urine, increases volume released by the bladder
Functions of the Urinary System
-regulates blood volume, acidity and salt balance
- waste management
*When BP is low, ADH is released by the petuitary gland which increases permeability of the collecting duct to water; thus lets increased amount of water from the filtrate return into the blood stream.
*When BP is high, ADH release is curtailed and more water is excreted
Infectious Agents
pathogens disease causing organisms [different types: viruses, bacteria, eukaryotic etc.]
parasites organisms that develop on another organism [contagious, host organisms]
microbes microscopic organisms
*only seen with a microscope
Bacteria
a single cell,
prokaryotic,
no nucleus -- nucleolid region,
double-stranded DNA
plasmids dna separate from chromosomes (carry genes and pass them)
cell wall (capsule helps attach and escape)
flagella movement
pili attach
3 types of Bacteria
rod (bacilli)
spherical (cocci)
spiral (spirochetes)
Infections
toxins
- molecules causing symptoms treated with antibiotics
- causes resistance
Anthrox
- lives in soil
- exists as a spore
- lethal if inhaled
- infections *not contagious
Botulism
- nervous system
- paralysis of facial and respiratory muscles
- botox (injections of the toxin produced by this bacterium)
- canned foods
E. Coili
- bacteria lives in the intestines of humans
- uncooked meat, bad milk
Staph
- bacteria on human skin and mucous membrane
- invades and destroys tissue
Vaccines - needed for school
DPT
- diptheria (respiratory)
- pertussis (respiratory)
- Tatnus (nervous/muscuar)
Bacterial Meningitus
- inflammation of membranes surrounding the brain
- death (10%) & disability
- spread through sneezes & coughs
- givevn to teens (spread through res)
Viruses
- packs of DNA or RNA w/ protein coat (capsid)
- not living
- can't replicate w/o help of a host cell
- not made of cells - no enzymes for metabolism
- no ribosomes (can't make its own proteins)
- no cytoplasm or membrane-bound organelles (can't produce toxins like bacteria can)
- genome (genetic material) is DNA or RNA, circular or linear, circular or single stranded
- genes code for production of proteins needed to make more viruses inside of a host cell
RNA viruses called "retroviruses" (packed with enzyme reverse transcriptase-- synthesize DNA from RNA)
Animals
- extra structure outside capsid called "viral envelope"
- viruses surrounded by envelope called "enveloped viruses"
Viral Infection
animals - enveloped virus
- virus fuses its envelope with host cell's membrane *access granted
- humans unenveloped virus
- capsid proteins used to bind to receptor proteins in the plasma membrane of the host cell
- *viral genome enters cells
- once inside the host cell, capsid is removed
- Enter (genome --> host cell)
- Replicate (copied)
- Exit (new virus leaves & leaves behind some viral proteins in host's cell membrane)
- Spread (new viruses move to other cells and spread and infect)
Latent Virus
- dormancy i.e. herpes
- present but no symptoms for a while
Vaccines against Virus
- hepititus B (sexually transmited)
- babies vaccinated
attacks the liver
polio
kids vaccinated, paralysis, death
MMR (mumps, measles and rumbella)
Chicken Pox
- causes brain swelling (encephalitis) & pneumonia
- older kids are affected
Gardasil
- college students
- protects HPV (causes reproductive cancer)
Flu Shot
Vaccines reduce the total number of susceptible individuals so disease doesn't spread as easily
Diseases Caused by Viruses
AIDS
- HIV is transmitted only through direct contact with bodily fluids
- [blood, semen, vaginal fluid]
- not tears, sweat or coughing, contact with clothes, phone or toilet seat
- Spread through needle sharing, unprotected sex, oral sex with infected partner
Common Cold
- 200 viruses cause colds
- rhinovirus most common cause
- Spread through droplets from sneezes or coughs or on objects i.e. utensils, doorknobs
Ebola
- Infected through wild animals or exposure to secretion of animals
- Spread through bodily fluids (even if dead)
- Exposure to medical supplies used to treat infected person
Mononucleosis
- affects young adults
- Symptoms: fever, fatigue, weakness, sore throat (1-2 months)
- transmitted in saliva when kissing, coughing or sneezing or touching contaminated objects
Rabies
- viral disease
- Spread through bite from infected animal
- Flu symptoms to paralysis, convulsions, hallucinations.
- Pets get the vaccine
- Spread through wild animals
West Nile
- transmitted to humans through bite of mosquito
- brain and spinal cord can become inflamed
- results in paralysis and death
Eukaryotic Pathogens
- single-cell protozoans & worms & fungi
- Spread by water and food contaminated with animal poop
Worms
- Worms gain access to body because of poor sanitation or eating contaminated meat / fish
- Worms live in the intestines or other organs
- Cause damage to internal tissues
Fungi
- cause diseases of the skin and internal organs
- damage tissue by secreting disgestive enzymes into it and absorbing products of digestion
Eukaryotic Pathogen Diseases
Giardiasis
- waterborne
- cyst
- enters water and food supplies in contaminated feces
- completes life cycle in intestines of infected person
- causes severe diarrhea and gas
Malaria
- caused by protozoans transmitted through mosquito bites in humans
- kills 2 million people / year
Schistosomiasis
- fresh water snails carry it
- caused by flatworms
- spread through contaminated water
- found in Asia, Africa, South America
Tapeworm
- caused by eating raw pork or beef
- worm lives in intestine
- causes abdominal pain and diarrhea
Athlete's foot & Jock Itch
- affect skin between toes, genitals, inner thighs
- Spreads easily through public places (locker rooms, pools, communal showers)
- Sweat can wash away naturally occuring fungus
- Athletes have more exposure to communal environments * more prone
The Immune System
First Line of Defense
- Skin and Mucous Membranes
- physical, chemical barrier
- don't distinguish pathogens
Skin
- sheds pathogens along with skin
- low pH *repels microorganisms
- glands in the skin secrete chemicals that slow the grow of bacteria
- [tears and saliva have enzymes that break down bacterial cells. Earwax traps microorganisms]
Mucous Membranes
- lining the respiratory, digestive, reproductive and urinary tracts
- Secretes mucous that traps pathogens which are coughed or sneezed away, destroyed in the stomach, excreted in urine or feces
- Digestive secretions including acids, kill many microorganisms
- vomitting can get rid of toxins or infectious agents
Second Line of Defense: Phagocytes & Macrophages, Inflammation, Defensive Proteins & Fever
Phagocyctes & Macrophages
- Phagocytes are white blood cells that attack and ingest invaders
- Macrophages are one type of phagocytic white blood cell that move throughout the lymphatic fluid, engulfing dead and damaged cells
- Enzymes inside the macrophage help destory the invader
- Macrophages clean up old blood cells, ddead tissue fragments and debris
- They release chemicals that stimulate the production of more white blood cells
- Mostly occurs within the lymph nodes
- If an invader is too big, white blood cells surround it and secrete digestive enzymes to irritate and destroy the invader
- natural killer cells extra white blood cells that circulate through blood and lymph destroying invaders
- attack tumour cells and viruses
- they release chemicals that break apart plasma membranes of invaders * they burst
- Fluid, dead cells and microorganisms = pus
- if pus can't drain, it becomes an abscess
Inflammation
- Responds to tissue injury
- Damaged cells release chemicals that stimulate special cells to release histamine
- Histamine promotes bigger blood vessels near the injury
- extra blood flow brings oxygen and nutrients for tissue to heal
Defensive Proteins
- Interferons (proteins prduced by virus infected body cells to help resist infection)
- When infected cells die, they release interferons (which bind to receptors on uninfected cells and stimulate the healthy cells to produce proteins that inhibit viral reproduction)
- Complement Proteins (circulate in the blood and help/complement other defence mechanisms)
- They coat the surface of microbes, making them easier for macrophages to engulf.
- They can poke holes in membranes causing them to break apart and increase inflammatory response
Fever
- normal range 97 - 99 F
- Macrophages release chemicals called pyrogens that cause fever
- Slight fever causes less bacteria to grow and increases rate of metabolic healthy cells
- Lets tissue to repair faster
- when the infection is controlled, the macrophages stop releasing pyrogens and body temperature goes back to normal
Third Line of Defense: Lymphocytes
- Specific Defense System has millions of white blood cells called lymphocytes
- they travel throughout the body by moving through spaces between cells and tissues
- transport via blood or lymphatic system
- triggered response by proteins or carbohydrates on the surface of pathogens or cells that have been infected
- Antigens molecules that stimulate and react to the immune system
- [found on invading viruses, bacteria, fungi, protozoans,worms, dust, pollen, transplanted tissues]
- When antigen is present in the body: production of 2 types of lymphocytes is enhanced 1. B cells 2. T cells
- they move through the ciruclatory and lymphatic system
- they are concentrated in the spleen and lymph nodes
- display specificity they recognize specific antigens
- Antigen Receptors proteins that make lymphocytes specific
- their shape fits perfectly into foreign molecule and they bind like a key into a lock
- B cells recognize small, free living organisms [bacteia and toxins]
- T cells recognize larger, body cells that have gone wild [cancer cells, cells invaded by viruses]
- B & T cells both help recognize and get rid or antigens but in different ways
- B cells secrete antibodies (proteins that bind and inactivate antigens)
- T cells directly attack invaders
Antibodies
- found in the blood, lymph, intestines and tissue fluids
- found in breast milk
- passive immunity transferring antibodies from mother to child (short term)
- Active Immunity Exposure to antigens and antibodies created by child
Allergy
- immune response that occurs when no pathogen is present
- body reacts to nonharmful substance as if a pathogen is present
- possible connection to allergies and vaccinations
Anticipating Infection
- Stem Cells produce lymphocytes
- bone marrow has a supply of stem cells
- Bone marrow cells can enable the bone marrow to produce blood cells over a life time
- Thymus Gland (stimulates T cells)