Biology Flashcards
How often does menstruation occur?
One egg per month ovulated into peritoneal sac
- Drawn into fallopian tube
- Fallopian tubes have cilia which propel egg forward to uterus
Portal system definition
Two capillary beds in series through which blood travels before returning to the heart
Paracrine signals
Signals act on cells in a certain area
Calcitonin effect
Dec. Ca absorption from gut, inc storage of Ca in bone, inc Ca excretion from kidneys
Hook (flagella)
Connects filament and basal body so that as basal body rotates, it exerts torque on filament and spins/propels bacterium forward
Apoptosis
Programmed cell death
How are primary germ layers formed?
When cells migrate from blastocoel remains
Binary fission
Asexual reproduction of prokaryotes
- Circular chromosome attaches to cell wall while replicating
- Produces two identical daughter cells
Founder effect
extreme case of genetic drift when smalll population finds itself in reproductive isolation from other populations
-Inbreeding leads to homozygosity and inc prevalence of homozygous dominant and recessive genotypes
Function of cell wall
Forms outer barrier of cell
- Provides structure
- Controls movement of solutes in/out
WHat are fingerhails and nails composed off
Keratin
Mineralcorticoids function
Salt and water homeostasis in kidneys
Dizygotic Twins process of fertilization
Two different eggs released during one ovulatory cycle
-Fertilized by two different sperm
Where do solutes reabsorbed in PCT go?
They enter the insterstitium then pass through the vasa recta and return to the bloodstream
What hormone affects TSH release?
TRH
How is fertilzation by multiple sperm stopped?
After penetration by a sperm, cortical reaction occurs -> release of Ca2+ ions
- Depolarizes membrane
- Inc metabolic rate of newly formed diploid zygote
What are the three processes kidney uses to regulate blood volume and osmolarity
filtration, secretion, reabsorption
Pleural Cavity of Lungs
Filled with lubricating fluid secreted by the membranes
How to germ cells divide?
Meiosis
What type of cells are germ cells?
Haploid
Luteal phase
LH causes ruptured follicle to form corpus luteum
- Prog levels start to rise
- Prog maintains uterine lining for sperm implantation
- Estrogen levels remain low
- High levels of prog cause negative feedback of GnRH, LH, FSH -> prevents ovulation of multiple eggs
Differences between oogenesis and spermatogenesis
- limited supply of stem cells
- By birth, all oogonia are primary oocytes and arrested in prophase1 - oogeneis creates one oocyte instead of four mature spermatocytes
- Secondary oocyte arrested in metaphase II until fertilization
When is the second checkpoint of the cell cycle and what is checked?
End of G2
- Ensures DNA replication had no errors
- Ready to enter mitosis
How do viruses reproduce?
After infection, translation of viral genetic material must occur for reproduction
- DNA viruses have to enter nucleus before transcription and translation
- Positive sense viruses stay in cytoplasm for direct translation
- Once viral genome is replicated, can be packaged in capsid to infect other cells
Adrenal glands location
On top of kidney
Prostate gland and seminal vesicles work together to?
Give seminal fluid mildly alkaline properties so sperm can survive in relative acidity of female reproductive tract
Death phase of bacterial growth
Once bacteria have exceeded ability/resources of environment to support them
-Mass death of cells
What causes parturition/pregnancy
Accomplished by rhythmic contractions of uterine smooth muscle and coordinated by prostaglandins and oxytocin
Loop of henle located in what region of kidney?
Descends and ascends in outer/inner medulla
What vascular structures are contained in the umbilical cord?
Two arteries and one vein
- Arteries carry deoxygenated blood and waste back to mother
- Vein carries oxygenated blood and nutrients to baby
What do FLAT and PEG mean in FLAT PEG
FLAT: tropic hormones
PEG: direct hormones
Neo-darwinism changes to include recombinatino
Differential reproduction: populations evolve not individuals
-When recombination or mutation results in favorable change, change is more likely to be passed on to next generation
What is Oogenesis
Production of female gametes
What hormone does the heart release
Atrial natriuretic peptide
Equations of harvey weinberg equilibrium
p+q=1 p^2 + 2pq + q^2 = 1 -p=dominant allele freq -q=recessive allele freq -p^2 = freq of homozygous dominant -2pg = freq of heterozygote -q^2 = freq of homozygous recessive -p^2 + 2pq = freq of dominant phenotype
Internal urethral sphincter
Composed of smooth muscle
- Contracted in normal state
- Under involuntary control
How does mitosis occur in germ cells
Mitosis only occurs in somatic cells
Senescense
Biological aging
-Occurs at cellular and organismal levels
Plasmids
Carry DNA not necessary for survival of prokaryotic cell but can help with antibiotic resistance
-Could carry virulence factors that increase pathogenecity
Dermis def
Contains Papillary layer and reticular layer of skin
Papillary: Composed of loose connective tissue
Reticular layer: Below papillay and much denser
Cortisol function
Raise blood gluc by inc gluconeogenesis and dec protein synthesis
-Dec inflammation and immunologic response
What are the female gonads
Ovaries: produce estrogen and progesterone
Calcitonin produced by?
Follicular cells produce parafollicular cells in thyroid
What energy source do the use sperm use?
fructose
Where are the ovaries located?
Thousands of follicles located in pelvic cavity
How does growth hormone perform its function?
Prevents glucose uptake in some tissues and stimulates fatty acid breakdown
Speciation def
Formation of a new species via evolution
-Could occur based on isolation of two populations
Amnion
Surrounds allantois
-Thin tough membrane filled with amniotic fluid
Chorionic villi
penetrate endometrium and support maternal-fetal gas exchange
Neurulation
Development of nervous system
- Rod of mesodermal cells called notochord forms along axis of organism
- Neural folds grow towards each other and form neural tube = CNA
- Neural crest cells at tip of folds migrate outwards to form PNS and specific cell types
- Ectodermal cells migrate to neural tube to cover nervous system
Stratum granulosum def
Keratinoctytes die here and lose their nuclei
How long is the effects of steroid hormones?
Slower but longer-lived effects than peptide hormones
Asters
Anchor centrioles to cell membrane
Ascending loop of henle permeability
Only permeable to salts
-Impermeable to water
Function of amniotic fluid
Shock absorber for maternal motion
What is gastrulation?
Generation of three distinct cell layers
-Forms primary germ cell layers
Gram negative cell wall
Thin layer with peptidoglycan
- Cell walls separated from membrane by periplasmic space
- Outer membrane has phospholipids and lipopolysaccharides
- Stain pink
Where are parathyroid hormones located?
On top of posterior surface of thyroid
Islates of langerhan function
Small clusters of hormone producing cells grouped together
Seminal vesicles
Contribute fructose to nourish sperm
What are the three types of hormones released by pancreas
Alpha, beta and delta cellls
When is erythropoietin protein secreted
In response to low O2 levels in blood
Angiotensin aldosterone system steps
- Dec BP-> juxtaglomerular cells in kidney secrete renin
- Renin cleaves inactive angiotensinogen into active angiotensin I
- Angiotensin I converted into angiotensin II by angiotensin-converting enzyme
- Angiotension II stimulates adrenal cortex to secrete aldosterone
- Once BP restored, Renin no longer released
- Negative feedback
What are starling forces
Govern movement of fluid into Bowman’s space
-Account for H-static and oncotic pressure differentials between blood and Bowman’s space
Indeterminate vs determinate cleavage
Determinate: cells are already determined
-COmmitted to differentiations into a certain cell type
Indeterminate: Cells can still develop into complete organisms
Parallel evolution
When related species evolve in a similar way for a long period of time
How do X-linked diseases work?
If recessive, female needs allele on both X chromosomes
- If only have allele on one X chromosome -> carrier
- For males, only have one X chromosome so if they carrier the allele, have disease
Genetic drift def
Changes in gene pool due to chance
-More pronounced in small populations
How does the hypothalamus regulate pituitary gland?
Via tropic hormones
-Paracrine release into portal system
What phenomenon is melatonin related to
Circadian rhythms
What stimulates calcitonin secretion?
High levels of Ca2+ in blood
Reticular Fibers
Made of collagen proteins
- Arranged in thin networks
- Net arrangement as a support network
Menstruation steps
- Corpus luteum loses stimulation from LH
- Prog levels decline
- Uterine lining sloughed off
- Lower levels of estro/prog allow GnRH to be released and next cycle to begin
Vaginal birth alternate name
Parturition
Osmotic pressure vs oncotic pressure
Osmotic: sucking pressure that draws water into vasculature
Oncotic: Osmotic pressure attributable to dissolved proteins specifically
Micturition reflex
- When bladder full, stretch receptors tell nervous system to empty it
- Parasympathetic neurons fire causing dtrusor muscle to contract
- Internal sphincter relaxes
- Individual then has choice to mtaintain tone of external to prevent urination
Complete dominance def
When only one dominant and one recessive allele exist for a gene
Regenerative capacity
Ability of an organism to regrow certain parts of the body
-Stem cells can migrate to appropriate part of body to initiate regrowth
What does GnRH trigger during puberty
Triggers anterior pituitary to synthesize and release FSH and LH
Type I Alveolar Cell
Simple Squamous Epithelial
-Main site of gas exchange
What hormone affects ACTH release?
CRH
What process does zygote undergo during its travel to uterus?
Rapid cell division -> cleavage
-Oficially creates embryo
Protein fibers vs Ground substance
Protein fibers: Strengthen and Support tissue -Secreted by connective tissue cells —Collagen —Elastic —Reticular
Ground substance:
- Material between cells and fibers
- Supports and bind cells
- Stores water
- fluid, semi-fluid, gelatinous, calcified
- Contains Glycosaminoglycans
Chromosomal mutations insertion
When a segment of DNA is moved from one chromosome to another
Obligate aerobes
Require O2 for metabolism
Totipotent stem cells
Can divide into any cell type
-Prior to formation of germ layers
What does fewer sequence repeats of an allele indicate?
reduced, low or non penetrance
Constant vs variable expressivity
COnstant: All inviduals with same genotype express same phenotype
Variable: Individuals with same genotype can have different phenotypes
Microfilaments
Made of actin -> organized into bundles
- Resist compression/fractre -> protection
- Role in cytokinesis -> contained in cleavage furrow
Stationary phase of bacterial growth
As number of bacteria inc, resources are reduced
-Reproduction slows
What is the functional unit of the kidney
The nephron
Penetrance def
Population metric that measures proportion of individuals carrying a certain allele who actually express the phenotype
-Probability that given a particular genotype, person expresses the phenotype
Type II Alveolar Cell
Simple Cuboidal Epithelial
-Secretes Alveolar fluid and surfactant
Alveolar fluid: keeps surface between cell and air moist
Surfactant: Prevents alveolar collapse -> keeps alveoli open
How do peptide hormones signal for cellular change?
After bidning to extracellular receptor, induce signaling cascade
- 1st messenger is peptide hormone that binds to receptor
- Trasmission of 2nd signal/messenger triggered
- 2nd messenger affects the intended change
Long term stress hormone vs Short term stress
Cortisol = long term Catecholamines = short term (epi/norepi)
Functions of excretory system
Regulation of blood pressure
Reulgation of blood osmolarity and acid-base balance
Removal of nitrogenous waste
Function of ascending vs descending loops of henle
Descending: Maximizes water reabsorption
Ascending: max salt reabsorption
What cortical sex hormones released by adrenal glands
Androgens and estrogens
How do T3 and T4 affect change?
Make energy production more/less efficient and alter utilization of glucose and fatty acids
-Higher T3 = more cellular respiration
ER
SEries of interconneted membranes continuous with nuclear envelope
Genes
DNA sequences that code for heritable traits passed from generation to the next
-Organized on chromosomes
G2 Postsynaptic Gap phase
Further protein syntehsis and rapid cell growh
- Microtubules being to reorganize to form a spindle
- Second checkpoint
Parts of a mature sperm
Head: cap with acrosome
Mid piece: filled with mitochondria to generate ATP for swimming through reproductive tract
Flagellum: motility
What mutations occur in species well suited to their habitat
No changes ar elikely to occur
What Is Mendel’s 2nd Law and what aspect of meiosis explains it?
INheritance of one allele has no effect on likelihood of inheriting alleles for other genes
-Explained by crossing over
Chromosomal mutations Deletion
Large segment of DNA lost from chromosome
Full penetrance sequence repeats
40 sequence repeats
100% of individuals with allele show phenotype
Where does fertilization occur?
Widest part of fallopian tube -> ampulla
Puncuated equilibrium
Change in some species occurs in rapid bursts instead of gradually over time
Prolactin function
Stimulates mmilk production in mammary glands
-Smooth muscles in breast contract
Stratified Squamous Epithelium
First line of defense against microbes -> protection against abrasion of water loss
- Nonkeratinized: Mouth, tongue, pharynx, esophagus, vagina
- Keratinized: Superficial layer of skin
Tight Junctions vs Adherens Junctions
Tight: Form fluid-tight seals between cells
- Preventing substances from passing through -> no leaky organs
- Lining of stomach, intestines, bladder
Adherens: Help epithelial surfaces resist separation during movement
-Connect actin cytoskeleton of cells together
Blastula structure
Hollow ball of cells in fluid-filled cavity
Bacterial shapes
Spherical = cocci
Rod-shaped bacteria = bacilli
Spiral-shaped = spirili
Zona Pellucida
Surrounds oocyte and a cellular mix of glycoproteins to protect oocyte and compounds needed for sperm binding
Where do spermatozoa gain mobility
Sperm are passed to epididymis where they gain mobility
What substances are always reabsorbed
Glucose, vitamins, amino acids
What drugs inhibit ADH release and what are their effects
Caffeine and alcohol inhibit ADH release
-Lead to freq urination of dilute urine
Law of Segregation
Either chromosome can end up in either daughter cell
Directional selection ef
Emergence and dominance of initially extreme phenotype
what hormones does adrenal medulla release
Promote sympathetic hormones epi and norepi
Cowper’s/Bulbourethral Gland
Produces clear viscous fluid that clears out remnants of urine and lubricates urethra during sexual arousal
Areolar Connective tissue
Strength, elasticity, support
- In and around nearly every structure
- Packing material
Facultative Anaerobes
Can toggle between anaerobic and aerobic metabolism based on O2 concentration
Direction of genetic info transfer in conjugation
Male donor to recipient female
-Male donor needs plasmids for sex factors
Where are the testis located
In the scrotum (external pouch below penis)
Peroxisomes
Contain hydrogen peroxide
-Break down of long chain fatty acids via beta oxidation
Types of amino acid derivatives?
Epi and norepi
-Catcholamines
Punnet square variables
P generation = parent -> gets crossed
F1 generation = their offspring
F2= offpsring of the offspring
When does menstruation occur
Only if implantation doesn’t occur
Transitional Epithelium
Allows urinary organs to stretch
- Maintains protective lining without rupturing
- Urinary bladder and portions of ureters and urethra
High penetrance sequence repeats
Fewer sequence repeats
Most with allele show phenotype
Filtration steps
- Fluid moves into Bowman’s spaces based on Starling forces
2, Hydrostatic pressure in glomerulus much higher than that in Bowman’s space so fluid moves into nephron
-This diff in H-static pressure overrides higher osmolarity of blood in Bowman’s space that opposes fluid movement into nephron
Structure of Bacteriophages?
Tail sheath: syringe that injects genetic material into bacteria
Tail fibers: help bacteriophage recognize and connect to correct host cell
Contrast R from L Lung
R lung:
-Shorter, wider, 3 lobes
L lung:
-longer, narrower, two lobes, cardiac notch
Erythropoietin function
Stimulates bone marrow to inc erythrocyte production
What is descending loop of henle mostly permeable to?
Primarily permeable to water
Juxtacrine
Involve a cell directly stimulating receptors of an adjacent cell
What does respiratory system do if blood pH too high
Decreases respiratory rate
-Increased conversion of CO2 and water in forward direction of equation to create more H+ and HCO3-
How does ADH affect kidney function
Only in colelcting duct
- Inc reabsorption of water
- Greater water retention/more concentrated urine
Yolk sac function
Site of early blood cell development
Conjugation
Bacterial mating/sexual reproductions
- Two bacterial cells form conjugation bridge: facilitates transfer of genetic material
- Transfer is unidirectional
- Bridge made from sex pili from donor male
- Copy of genome attempted to transfer but usually not completed
Where do peptide hormones bind?
They are charged so they cannot pass through the phospholipid bilayer
-Bind to extracellular ligand
How is viral progeny released?
Released when cell death initiated by virus
- Spills progeny
- Could also result from host cell lysing by large numbers of virion
- Can also be by fusing with cell membrane -> productive cycle
What system controls aldosterone secretion
angiotensin aldosterone system
Episomes
Plasmids capable of integrating into genome of bacteria
Glucocorticoids function
Steroid hormones that regulate glucose levels
Negative sense single stranded virus RNA
Strand is template for synthesis of complementary strand
- Complementary strand used as template for protein synthesis
- Must have RNA replicase to ensure complementary strand synthesized
Hypothyroidism effects
Lethargy, dec body temp, slowed respiration, low HR
Presygotic mechanisms of speciation
Pre: prevent formation of zygote completely -Temporal behavioral reproductive genetic isolation
G0 stage
Cell not carrying out functions in preparation for division
Anaerobes
Do not require oxygen by using fermentation for metabolism
Ovulation
Eventually estrogen reaches concentration threshold that results in positive feedback of GnRH, LH, FSH to spike
- Surge in LH induces ovulation
- Release of ovum from ovary into peritoneal cavity
Hypodermis def
subcutaneous layer below dermis
Induction
Process of groups of cells to influence nearby cells
-Ensures different cell types work together within an organ
3rd trimester
Continued rapid growth
-more brain development
antibodes transported from mother to fetus
-Growth rate slows and fetus is less active because less room
Retrovirus mechanism
DNA integrates into host cell genome and is replicated/transcribed
- Cell is infected indefinitely
- Only way to remove infection is to kill cell
Pluripotent stem cells
Can differentiate into any cell type not in placental structures
-After formation of the three germ layers
How do viruses reproduce?
Cannot reproduce independently
- Obligate intracellular parasites
- Must express and replicate genetic info within host cell
- Replicate and produce virions to infect additional cells
Role of blastocyst in fertilization
- Secretes hCG -> analog of LH
- Maintains corpus luteum
- Critical during 1st trimester
What results from fertilization
Zygote develops into blastocyst and implants into uterine lining
Pulmonary Respiration is -____
gas exchange in alveoli
Translocation Chromosomal mutations
Segment of DNA from one chromosome swapped with a segment of DNA from another
Autocrine signals
signals act on same cell that secreted the signal
What is the first checkpoint of the cell cycle and during what phase is it locarted?
End of G1 phase
-Checks if cell is ready to commit to cell division and replicate DNA
Trachea Composition
Contains hyaline cartilage
Has pseudostratified columnar epithelial cells
Also contains goblet cells
Vas deferens
Layer of muscle that regulates temp of sperm development
How does the pineal gland know to release melatonin
Receives projections from retina by responding to intensity of sunlight
Prophase
Condensation of chromatin into chromosomes
- Centrioles pair and separate to opposite side of cell
- Centrioles begin to form spindle finbers
Simple columnar epithelium
Nonciliated: More secretion and absorption than cuboidal
-GI tract -> stomach, gallbladder, ducts of glands
Ciliated: Moves particles away
-Bronchioles of respiratory tract, uterine fallopian tube
Microtubules
Hollow polymers of tubulin proteins
-Primary pathway for motor proteins like kinesin and dynein to carry vesicles
Three layers of wall of heart
Epicardium, myocardium and endocardium
Gene pool def
All alleles that exist within a species
-New genes added via mutations or gene leakage
What are cycline
Bind to cyclin-dependent kinases CDKs that can phosphorylate transcription factors’
-Promote transcription of genes required for the next cell cycle
Anaphase
Centromeres split so each chromitd has own centromere
-Sister chromatids separate -> pulled to opposite sides
Stabilizing selection def
Keeps phenotypes within specific range by selecting against extremes
Ex: gestational weight can’t be too much or too little
Stem cells
Cells not yet differentiated or that give rise to other cells that will differentiat
Tissue
Group of cells with common function that carry out specialized activities
List the 5 strata of the epidermis in order from deepest to shallowest
Stratum basale Stratum spinosum Stratum granulosa Stratum lucidum Stratum corneum
Who discovered transformation in bacteria
Griffith experiement -> frederick griffith
Bowman’s capsule definition
Encases glomerulus leads to PCT
Aldosterone kidney pathway
- Dec BP -> renin released from juxtaglomerular cellls
- Renin cleaves angiotensinogen to form angiotensin I
- Angiotensin-convertin enzyme metabolizes angiotensin I to angiotensin II
- Angiotensin II promotes release of aldosterone form adrenal cortex
- Aldosterone inc Na+ reabsorption in DCT and water reabsorption in collecting duct
- Aldosterone also inc K+ and H+ excretion
Bone Tissue
Support, protection, storage
- Houses blood forming tissues
- Exc. Matrix: calcified
Structural components of flagella
Filament, basal body, hook
What mutations are larger scale than nucleotide mutations
Chromosomal mutations
-Affects large segments of DNA
Renal hilum
Deep slit in center of medial surface of kidney
Treatment for type I diabetes
Regular injections of insulin required
Functions of TSH
- Set basal metabolic rate -> T3 and T4
2. Promote calcium homeostatsis -> Clacitonin release
Neo darwinism inclusive fitness
Inclusive fitness: measure of organism’s success in populations based on number of offspring, success in supporting those offspring, ability of offspring to support others
- Darwin did not look at behaviors of population in relation to protecting offspring
- this includes parents nature of endangering self to protect offspring
What chromosomes determine 23rd Choromosomes
Biological sex
What happens during fertilization to secondary oocyte?
Undergoes meiosis II and splits into mature ovum and another polar body
-Consists of large quantities of cytoplasm and organelles
Inbreeding depression def
Loss of genetic variation may cause reduced fitness of a population
Endoderm
Innermost layer
-Epithelial linings of digestive and respiratory tracts, pancreas, thyroid, bladder parts of liver
How long are cells usually in interphase?
For about 90% of the time
Basal body (flagella)
Anchors flagellum to cytoplasmic membrane and is motor for flagellum
What happens when blood osmolarity is high
Water reabsorption inc and solute excretion inc
Errector pilli function
Contract and cause hairs on skin to stand up
-Traps layer of heated air near skin
Pulmonary Ventilation is _____
Breathing
Codominance def
When more than one dominant allele exists for a given gene
Levels of human chorionic gonadotropin hCG
- Levels decline during 2nd trimester bc placenta sufficient in size to secrete prog/estro by itself
- Inhibited by high levels of prog/estro
Cell Junctions:
Hold individual cells together
-Contact point between plasma membrane of neighboring cells
Where do renal arteries, renal veins and ureters enter and exit kidney?
Through the renal hilum
What type of muscles line the bladder and what division of nervous system controls them
Detrusor muscles and are controlled by parasympathetic activity
Postzygotic mechanisms of speciation
ALlow for gamete fusion but lead to nonviable/sterile offspring
Hybrid invariability
Hybrid sterility
Hybrid breakdown
Anaphase I
Homologous chromosomes pulled to opposite pulls via disjunction
-Explain’s Mendel’s 1st law that each chromosome of paternal origin separates from its homologue of maternal origin
Example of tropic hormone pathway
GnRH and LH don’t directly induce change
-Make gonads release testosterone in males
What dynamics do expressivity and penetrance reflect?
Expressivity reflects genetics at an individual level
Penetrance: population level
What is the countercurrent miltiplier system in kidneys
Flow of filtrate in loop of Henle oposite direction from flow of blood in vasa recta
-Filtrate constantly exposed to hypertonic blood -> maximal reabsorption of water
Distal convoluted tubule function
Responds to aldosterone which promotes Na+ reabsorption
-Waste product secretion like PCT
Nervous Tissue
Neurons + Neuroglia: Contact nerve impulses
- Brain, spinal cord, nerves
- Neurons & muscle cells are excitable
Function of hormones
Bind to receptors of tissues and induce changes in gene expression or cellular functioning
What type of blood carried in pulmonary venules/arterioles?
Pulmonary arteriole: deoxygenated blood -> blood coming from heart to lungs
Pulmonary Venule: Oxygenated blood from lungs to the heart
Effect of parathyroid hormones
Dec excretion of Ca by kidneys, inc abosrption by Ca in gut
-Also promotes phosphorus homeostatsis by inc resorption of phosphate of bone and reduced reabsorption of phosphate in kidneys
Stratum spinosum def
Conencted to each of the other strata
Determination stage of cell specialization
Cell irreversibly commits cell to a specific lineage
Convergent evolution def
Independent developkent of similar characteristics in two or more lineages not sharing a common ancestor
-Analagous structures
Ex: fish and dolphins resemble each other but from different classes of vertebrates
What hormones increase reabsorption of water
aldosterons and ADH
When does transduction occur in the lysogenic cycle?
If extracts portions of bacterial DNA when leaving
What do cells of Leydig do
Secretes testosterone and other male sex hormones (androgens)
What tissue is hypodermis composed of
Connective tissue connnects it to skin and rest of body
-Composed of fat and fibrous tissue
Ex of selective transcription
Pancreatic islet cell has genes on to produce hormones but other cells would have these genes turned off
Cortex vs medulla of kidney location
Cortex: outermost
Medulla: within cortex
Telophae I
Nuc membrane reforms, each chromosome still has two sister chromatids at centromere
-Cells are now haploid
Species def
Largest group of organisms capable of breeding to form fertile offspring
Genetic leakage def
Flow of genes between species
- When individuals of different but closely related species mate to produce hybrid offspring
- WHen these hybrid offspring can reproduce -> gene flow
Transposons def
Can insert and remove themselve from genome
-Can disrupt a gene if inserts into its sequence
Mesoderm
Musculoskeletal, circulatory, most of excretory, gonads,
-Moveoderm
Natural selection theory and creator
Certain characteristics/traits possed by individuals within a species may help them have greater reproductive success and pass traits off to offspring
-Charles darwin
Where are androgens primarily released from
Mostly from testes, some released by adrenal glands
Chemotaxis
Ability of cell to detect stimuli and move toward/away it
Hyperthyroidism
Excess of thyroid hormone
-Opposite effects of hypothyroidism
What are trophoblast cells
Surround and give rise to chorion and placenta
-Protudes into blastocoel annd gives rise to organism itself
Gap Junctions
Fluid-filled tunnels -> connexons between cells
- Allows cells to rapidly communicate with each other
- Enable impulses to travel quickly from cell to cell
Found in:
Cardiac muscle tissue
Smooth of intestines/uterus
Nervous tissue
Where are steroid hormones produced
Gonads and adrenal cortex
Teratogens
Substances that interfere with development
-Can cause defects or death of embryo
Dense regular vs irregular connective
Regular: Withstands pulling/tension along axis
Irregular: Tensile pulling strength in many directions
Types of hormones
Peptides, steroids, amino acid derivatives
Locus def
Location on a specific chromosome
Allele freq def
How often an allele appears in a population
-Evolution results from changes in gene freq of reproducing poulations over time
What is the epidermis divided into
Strata
Growth hormone function
Promotes growth of bone and muscle
What type of hormones are epi and norepi
Amino-acid derivative hormones
-Bigger group: catecholamines
HOw long is the duration of effect of peptide hormones?
Usually rapid effect but short-lived
-Need constant stimulation for effect to last
Chorion
Extraembryonic membrane that develops into placenta
Responder cell
Cell that is induced into developing into a type of cell
Aerotolerant Anaerobes
Unable to have O2 for metabolism
-Not harmed by presence of O2 in enviornment
If blood volume is low and blood osmolarity is high what does urine composed of
Urine would be highly concentrated with low water volume
Golgi apparatus
Materials from ER transferred to golgi via vesicles
- MOdified with addition of carbs, phosphates sulfates, etc
- Repackages modified products into vesivles
- Vesicles released via exocytosis
Glucagon function
Inc gluc production by triggering glycogenolysis and gluconeogenesis and degradation of protein/fat
What gland releases melatonin
Pineal gland
Tenets of Mendel’s 1st law of segregation
- Genes exist in alrenative forms -> alleles
- An organism has two alleles for each gene -> one inherited from each parent
- Two alleles segregate during meiosis
- Gametes carry only one allele for any inherited trait - If two alleles are different, only one is fully expressed while the other is silent
- Recessive allele is silent
- This segregation occurs in anaphase I of meiosis
What happens if person decides not to urinate with Micturition reflex?
After a few moments of discomfort, the reflex dissipates
-Reflex begins again shortly thereafter
Alveolar Macrophages
Phagocytes -> Remove debris
Adrenal glands components
medulla and cortex
What organ converts ammonia to urea and why does this conversion happen
The liver converts
-Necessary because ammonia is a basic compiund that could mess up pH of blood and cells and urea is a neutral compound
What type of change does steroid hormones do?
Binding leads to conformational change of receptor which can bind to DNA
What does respiratory sytem do if blood pH is too low
Inc respiratory rate to blow off more CO2
Also converts H+ and HCO3- to water and CO2 to inc pH
-Bicarbonate goes in reverse direction
What are the four stages of regular cell cycle?
G1, S, G2, M
Anterior pituitary mnemonic
FLAT PEG F: follicle stimulating hormone L: Leuteinizing hormone A: Adrenocorticoptropic hormone T: Thyroid-stimulating hormone P: Prolactin E: Endorphins G: Growth hormone
What do the equations of hardy weinberg equil tell us
1st: freq of alleles in a population
2nd: genotype and phenotype freqs in a population
Competent cell
When responder is able to respond to an inducing signal
Spermatogenesis
Formation of haploid sperm via meiosis
Incomplete dominance
When heterozygote expresses phenotype that is intermediate between the two homozygous genotypes
Stratum basale def
Stem cells that proliferate into keratinocytes
-Keratonicoytes produce keratin
When are amino acids, gluc vitamins excreted
In secretion stage
-Allos secretion of molecules to large for glomerular pores
Lytic cycle
Bacteriophage maximizes use of cell’s machinery with little regard for host cell survival
- Once cell swelling with new virion, cell lyses and other bacteria can be infected
- Viruses in this phase -> virulent
Where does all connective tissue originate from?
Originates from mesenchymal cells in embryo
Oxytocin affects
- Stimulates uterine contraction
- May be involved in bonding behavior
Morula
Sold mass of cells of embryo
-Undergoes blastulation to form a blastula
What hormome affects prolactin release?
PIF
Mutation def
Changes in DNA sequence that result in mutant allele
Outbreeding def
Introduction of unrelated individuals into breeding group
-Could result in inc variation and inc fitness of population
Capsid
Protein coat surrounded by envelope of phospholipids and virus-specific proteins
Hemizygous def
ONly one allele present for a gene
Ex: On X chromosome only in males
Differences. between cellular and organismal level senescense
Cellular: results in failure to divide
Organismal Level: represents changes in body’s ability to respond to changing environment
Lobule Breakdown
Single compartment respiratory unit
Respiratory bronchioles -> Alveolar ducts -> Alveolar sacs -> Alveoli
What type of cells are autosomal cells?
Diploid
Cellular Respiration is ____
gas exchange in the tissues
Multipotent cells
More specialized
-Can differentiate into multiple types of cells within a certain group
External urethral sphincter
Composed of skeletal muscle -> voluntary control
What is a test cross
When one of the parents has an unknown genotype, cross it with a homozygous recessive genotype
Steps of sperm binding with secondary oocyte?
Binds and releases acrosomal enzymes to enable it to penetrate corona radiata and zona pellucida
- Forms tube-like acrosomal apparatus to penetrate cell membrane
- Pronucles freely enters oocyte
Simple Squamous Epithelium
- Sites of filtration and diffusion
- Lungs, lining of heart, blood vessels, endothelium
- Epithelial layer of serous membranes
What is recombination frequency (represented by theta)
Likelihood of two alleles separated from each other during crossing over
-Roughly proportional to distance between genes on chromosome
Cytokinesis
Right after telophase
-Separation of cytoplasm and organelles
What form is DNA stored in in viruses?
Could be circular, linear, single or double stranded
Effects of menopause
Menstruation stops
- Estro and Prog levels drop
- Endometrium atrophies
Endoprhins function
Dec percetion of pain
Collagen
Made of collagen protein
- Often in large bundles
- Very strong, resist pull or stretch
- Act like glue but also flexible
When is GnRH released?
Once puberty has started
How many copies of each chromosome does each person have
Two -> homologous
What is the product of mitosis
Two identical daughter cells
Role of estrogens
- Secreted in response to FSH and result in development/maintenance of female reproductive system and secondary sex characteristics
- Stimulates development of reproductive tract
How do steroid hormones interact with blood and the membrane
Derived from a nonpolar molecule so can easily cross membrane
-Cannot freely travel through bloodstream so must be carried via carrier proteins
Log/exponential phase of bacterial growth
Bacteria adapts and rate of division inc
-Exponential inc in number of bacteria
WHat genetic info does the Y chromosome carry?
-Has SRY gene which codes for transcription factor of testis differentiation and formation of male gonads
How does CV system regulate BP
Vasoconstriction and vasodilation to maintain blood pressure
=Constriction -> lower BP in glomeruli -> inc BP in general
Cytoskeleton
Provides structure to cell and helps it maintain shape
- COnduit for transport of materials around cell
- Broken up into microfilaments, microtubules, intermediate filaments
Function of acrosome
Penetration of ovum
Epiglottis Function
Prevents swallowed food from entering the trachea
Diploid vs Haploid
Diploid: Two copies of each chromosome
Haploid: One copy of each chromosome
Prolactin inhibited by?
Release of DA from hypothalamus dec secretion
Hypoglycemia definition
Low blood gluc concentration
Stratum corneum def
Several dozen layers of dead, flattened keratinocytes
- Prevents loss of fluids/salts
- Protects against Microbial production
ADH function
Reabsorption of water in collecting ducts of kidneys
- Inc. plasma osmolarity
- Inc. conc of solute in blood
- Inc permeability of collecting duct
Meiosis II
Similar to mitosis in that siter chromatids are separate
-Different because end result is two haploid daughter cells
Elastic Fibers
Made of elastin protein
-Can be stretched up to 150%
Return to normal shape after stretch
-Give structures elasticity
Layer after the cell wall
Plasma membrane
Molecular clock model def
Degree of genomic similarity with amount of time some two species are split from a common ancestor
-More time = less similarity
Where are sperm stored prior to ejaculation?
In the epididymis
Selective transcription
Allows for formation of distinctive cell types
-Only genes needed for particular cell types are transcribed
Portal system steps
- Artery branches into medulla and enters cortex as afferent arterioles
- Tufts of glomeruli connect to afferent arterioles
- Blood passess through glomerulus and efferent arterioles to form 2nd capillary bed
- Leads into loop of henle
- Travels back into body
Collecting duct function
Responsive to both aldosterone and ADH for permeability
- If permeability inc, water is reabsorped and urine is concentrated
- If impermeable, low concentrated urine
Melanocytes functino
In stratum basale, produce melanin
-Melanin transferred from melanocytes to kertainocytes
Somatostatin
Inhibitor of both insulin and glucagon secretion
-Stimulated by high blood gluc and amino acid concentration
Desmosomes vs Hemidesmosomes
Desmo: Link cytoskeletons of adjacent cells together
- Stability of cells and tissue
- Prevent then from separating under tension
Hemi: Connect cells to extra cellular material
-Anchor cells to basement membrane
Genetic map def
Can be created representing relative distance between genes on a chromosome
-One map unit equals 1% chance of recombination between two genes
Thymus releases what hormone
Thymosin: proper T-cell development and differentiation
How can peptide hormone effects be amplified?
Each step of the peptide hormone signaling pathway can be amplified by binding of hormone to multiple receptors
-Each receptor could also activate multiple enzymes and create more 2ndary messengers
Proximal COnvoluted Tubule function
Amino acids, gluc, water-soluble vitamins and most salts reabsorbed with water
-Secretion of waste products: K+, H+, urea
Recombination frequencies of tightly vs weakly linked genes
Tightly: Theta close to 0%
Loosely: theta close to 50%
Simple Cuboidal Epithelium
Secretion and Absorption
-Kidney Tubules, ducts of glands like in thyroid
Phases of bacterial growth
Lag, log/exponential, stationary, death phases
Fitness def
Individual’s level of reproductive success
How are peptide hormones directed to their intended location?
Smaller units are transported to the Golgi body and modified/activated and directed to location of effect
-Released by exocytosis into bloodstream
Where do tropic hormones originate?
In brain/anterior pituitary
Mendel’s Second law of segregation
Law of independent assortment
Inheritance of one gene does not affect inheritance of another gene
Cell wall + cell membrane = ?
Envelope
Reticular connective Tissue
Stroma of organs
- Filters blood cells in spleen & microbes in lymph nodes
- Found in stroma of liver, spleen, lymph nodes
How do kidneys contribute to the bicarbonate buffer system
Can selecitvely inc or dec secretion of H+ ions or bicarbonate
- If blood pH too low, kidneys excrete more H+ ions and increase reasborption of bicarbonate -> higher pH
- If blood pH too high vice cersa
Reabsoprtion kidney definition
Some compounds filtered or secreted may be taken up for use
What connects the embryo to the placenta?
Umbilical cord
INsulin function
Antagonistic to glucagon and secreted when blood gluc levels are high
- INduces muscle and liver cells to take up gluc and store as glyocgen for later use
- Stimulates fat and protein synthesis
FSH and LH roles in males
FSH: stimulates ser toil cells and triggers sperm maturation
LH: induces interstitial cells to produce testosterone
Fat ufunction of thermoregulation
Adipose tissue -> white fat -> insulation
Brown fat: produces a lot of heat energy in in fants
WHat structures are found on microtubules?
Cilia: project from cell and involved in movement of material along its surface
Flagella: involved in movement of cell itself
-Centrioles: create spindle fibers during mitosis
Adipose Connective Tissue
Energy reserve, supports and protects
- Reduces heat loss
- Located anywhere where areolar tissue is
- Subcutaneous, heart, kidneys, yellow bone marrow
What does nephron secrete into tubules?
Salts, acids, bases and urea
-Quantity of substances secreted related to bod’s needs at the time
What stimulates Parathyroid hormone secretion
Low blood Ca levels
Mutagens def
Substances that cause mutations
Peptide hormones are made of?
Made of amino acids and derived from larger precursors of polypeptides that have been cleaved posttranslationally
Renal pelvis location
Spans almost entire witdth of renal hilum
What hormone affects GHRH?
GH
What is the problem with Mendel’s second law of segregation
linked genes
G1: Presynaptic Gap phase
Cells create organelles for energy/protein production and increase in size
- Replicate mitochondria, ribosomes, ER
- First restriction point
Centrosome definition
Contains chromatids
Criteria for gene pool stability/Hardy-weinberg equilibrium
- Population very large -> no genetic drift
- No mutations occur that affect gene pool
- Mating between individuals in population is random
- No migration of individuals in or out of population
- Genes in population are equally successful at being produced
Alternative name for pituitary gland?
Hypophysis
How does the skin perform thermoregulation
Sweating, arrector pilli, arterioles near the skin constriction, shiver, fat insulation
Menopause
Ovaries become less esnstive to FSH and LH as women age
- Ovaries begin to atrophy
- Usually between 45-55
First trimester of pregnancy
Major organs start to develop Heart begins to beat Eyes, gonads, limbs, and liver start to form 5 weeks: embryo = 10 mm in length 8 weeks: embryo becomes fetus
Retroviruses enzymes for translation/replication
Carry reverse transcriptase that synthesizes DNA from single-stranded RNA
Divergent evolution
Independent development of dissimilar characteristics in two or more lineages
-They share a common ancestor
-Homologous structures
Ex: seals and cats both in carnivora order but very diff
Filament (flagella)
Hollow helical structure made of flagellin
Endocrine signals
Involve secreted hormones that travel through the bloodstream to a directed tissue
Which types of cells commonly use transformation
Gram-negative rods
Lag phase of bacterial growth
Bacteria first adapts to new local environment
-Growth but not rapid
Hematopoesis
Formation of blood cells
- Starts in red bone marrow
- ALl cells derived from heamtopoietic stem cell
What do parathyroids produce?
Paratyroid hormones
amino acid derivative hormones structure
Composed of less amount of aa’s than other two
What term is given to mutations with a negative selective advantage
Deleterious mutations
Where does spermatogenesis occur
In the seminiferous tubules
Disruptive selection def
Two extreme phenotypes selected over the norm
- No animals have intermediate phenotype
- Facilitated by polymorphisms -> difference between members of the same population
Direct hormones definition
Secreted and act direcly on target tissue
Viroids
Small pathogens with very short circular single-stranded RNA that infect plants
- Can bind to large numbers of RNA sequences and silence genes in plant genome
- Prevents synthesis of necessary proteins
Chromosomal mutations inversion
When a segment of DNA is reversed within a chromosome
Shivering function
Contractions of skeletal muscles to produce heat
Aldosterone function
Inc BP by inc Na reabsorption in DCT and collecting duct
-Also dec reabsoprtion of K and H+ ions in DCT and collecting duct
Kinetochores
Attachment points for fibers of the spindle apparatus
Filtration kidney definition
Movement of solutes from blood to filtrate at Bowman’s capsule
What is the bicrabonate buffer system equation
CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO3-
Bacteriophages definition
Viruses that infect bacteria
Pseudostratified Ciliated Columnar Epithelium
-Secretes mucus that trap particles
-Cilia sweeps away particles
-Airways of upper respiratory tract
—Trachea
What is a spermatogonium?
A male diploid stem cell
Prions
Infectious proteins: non living things that cause disease by triggering misfolding of other proteins
- Usually via conversion from alpha-helice to beta-pleated sheet
- Reduces solubility and ability of cell to degrade it
- Cell aggregates form and interferes with cell function
Stratum lucidum
Only found in thick hairless skin
What type of feedback affects oxytocin level?
Positive feedback loop:
- Release promotes uterine contraction and oxytocin release
- More oxytocin release leads to stronger contractions
Steroid Hormones are derived from what compounds?
Derived from cholesterol
Virus composition
Genetic material, protein coat, and envelope with lipids
What are symptoms of diabetes in general
Hyperglycemia
- Overwhelms nephron ability to reabsorb gluc and leads to gluc in urine
- Leads to excess excretion of water and dramatic inc in urine volume
Ectoderm
Outermost layer
=Integument, nervous system, adrenal medulla, inner ear, eye lens
Where does zygote travel after fertilization?
Has to travel to uterus for implantation
Tropic hormones
Require an intermediary to act
Brown vs white adipose
Brown: More blood vessels, more mitochondria, heat production, infants
White: More fat storage, adults
Vulva
General term for external female anatomy
Langerhans cells function
Special macrophages in stratum spinosum
-Presents antigens ti T-cells and activates immune system
How permeable is skin to H20
Matinatins blood osmolarity with this impermeability to H20
-Prevents water loss of H20 entering through skin
Steps of Mendel’s Second law of segregation
- Small segments of DNA swapped between homologous chromosomes during Prophase I -> novel combos of alleles now present -> recombination
- Inc genetic diversity of gametes and offspring
Passage of urine through excretory system
Nephron -> renal pelvis -> urter -> bladder -> urethra
Where are norepi and epi secreted
Directly into bloodstream
Positive sense single stranded virus RNA
Genome directly translated to functional proteins by ribosomes of host cell
-Similar to mRNA
Sweating function
Cooling mechanism and controlled by autonomic NS
- Postganglionic sympathetic secretion of water from sweat glands
- Heat absorbed from body and evaporates
- Large quantitiy of blood borught to surface of blood which leads to evaporation of sweat
Where are the receptors for steroid hormones typically found?
Typically intracellular or intracnuclear
Telophase
Spindle apparatus disappears, nuclear membrane reforms around chromosomes, chromosomes uncoil
Hypothyroidism definition
Deficiency of iodine or inflammation of thyroid
Skeletal vs Cardiac vs Smooth Muscle tissue
Skeletal: Motion, posture, heat production
Cardiac: pumps blood to all parts of body
Smooth: Motion
-Iris,blood vessels, stomach, airways, intestines, bladder
Follicular phase
- GnRH secretion inc. response to dec. concentration of estro/prog
- GnRH causes secretion inc of FSH/LSH -> develop several ovarian follicles
- Follicles produce estrogen that cause FSH, LH, GnRH levels to fall off
- Estrogen stimulates regrowth of endometrial lining
Two components of the testis
seminiferous tubules and interstitial cells of Leydig
What do determination and differentiation depend on?
Depends on cellular location and identity of surrounding cells
What happens if the celll does not meet the criteria of a checkpoint during the cell cycle?
Cell goes into arrest until DNA is repaired
Type I diabetes
Low or no insulin production
-Result of autoimmune destruction of beta islet cells
Type II diabetes
Receptor-level resistance to effects of insulin
-Partially inherited and partially due to environmental factors
What is the product of spermatogenesis
Four functional sperm for each spermatogonium
What hormones does Posterior pituitary release?
Oxytocin and ADH
Carrier definition
When someone carries a diseased allele but doesn’t exhibit disease
When is glucagon released
During times of fasting or when blood glucose is low
Intermediate filaments
Cell-cell adhesion of cytoskeletons
-Anchor organelles
Secretion definition kidney
Movement of solutes from blood to filtrate in PCT and descending loop of henle
Steps of parturition
- cervix thins out and amniotic sac ruptures
- Strong uterine contractions result in birth of fetus
- Placenta and umbilical cord expelled (afterbirth)
Filtrate composition
Similar to blood but no cells or proteins
-Isotonic to blood
Viruses binding to receptors mechanism
Viruses must bind to specific receptors
- Once binding, virus and cell can do additional interactions
- Enveloped viruses fuse with plasma membrane
- Virion enters host cell
- Depending on virus, different, portions of virion inserted into host cells
Function of endocrine system
Has organs/glands that secrete hormones directly intobloodstream to distant tissues
What do excess and deficicient amounts of GH lead to
Excess: gigantism
Deficit: Dwarfism
What are calluses made out of
Excessive keratin due to repeated strain of an area of skin
Estrogen role in adults
Leads to thickening of endometrium each month in preparation of implantation of zygote
- Secreted by corpus luteum in response to LH
- Supplied by placenta in 1st trimester of pregnancy
What are follicles (female gonads)
Multilayered sacs containing, nourishing, protecting immature eggs/ova
Incomplete regeneration
newly formed tissue is not identical in structure/function to tissue host
Second trimester of pregnancy
Tremendous growth
- Fetus begin to move in amniotic fluid
- Embryo begins to look human
Where is sperm produced
Seminiferous tubules
Differentation stage of cell specialization
Changing structure, function and biochem of celll becoming its determined cell type
Connective Tissue + composition
Most abundant tissue in body
-Basic components: cells & exc. matrix
FLAMMP: Fibroblast, Leukocytes, Adipocytes, Macrophage, Mast Cell, Plasma Cell
Fibroblast: Secrete fibers and matrix material
Macrophage: Digests foreign material
Plasma Cell: Produces antibodies -> inflammatory response
Mast Cell: Produces histamine -> inflammatory response
Adipocytes: Fat cells -> store energy in form of of fat
Leukocytes: WBCs -> immune/allergic response
What type of disease is color blindness
X-linked recessive
How does aldosterone affect kidney function
DCT: promotes Na+ reabsorption
Collecting: Inc reabsorption of water
-Greater water retention/more concentrated urine
Analagous structures associated with which type of evolution
Convergent evolution\
-SImilar features but not derived from common ancestor
Metaphase I
Held by one intead of two spindle fibers
Allantois
Early fluid exchange between embryo and yolk sac
Types of WBC and functions
Neutrophil: acute bacterial Eosinophil: Parasitic Basophil: Allergic reactions Lymphocyte: Viral -> T-cells/B-cells Monocyte: Viral Chronic
Homologous structures are associated with which type of evolution
Divergent
- Indicate species deriving from same ancestor
- Do not need to have same function as ancestor
Flow of blood through valves from body
Blood from body enters through superior/inferior vena cavae
Right Atrium -> Right ventricle through Tricuspid valve
Right Ventricle -> Lungs through pulmonary valves that connect to pulmonary arteries
Lungs to pulmonary veins to L Atrium
L atrium to L ventricle through mitral/bicuspid valve
L ventricle to aorta via aortic valve -> pumped to rest of body
What stages of cell cycle are interphase?
G1, S, G2
What are heterozygous females of x-linked traits called
Carriers
Why does the blastula need to burrow into the endometrium
Creates interface for maternal blood supply
Prophase I
Homologous chromosomes come together and intertwine
- Crossing over: between homologus chromosomes
- Leads to genetic recombination and inc variety of genetic combinations
Where do sperm travel during ejaculation?
Travels through vas deferens and enter ejaculatory duct at posterior edge of prostate gland
-Two ejaculatory ducts fuse to form urethra
How do peptide hormones travel through the bloodstream?
They are water-soluble so travel quickly through the bloodstream without needing carrier proteins
Obligate anaerobes
Cannot survive in oxygen-containing enviornment
What is the main protein associated with control of checkpoints
p53
-Common mutation target for cancer -> unchecked cell division
Morphogens
Can cause neighboring cells to follow certain developmental pathway
Rough ER vs SMooth ER
Rough: studded with ribosomes
-Translation of proteins
Smooth: no ribosomes
-Lipid synthesis and detox of drugs/poisons
Cervix
Lower end of uterus
- Connects to vaginal canal
- Where sperm are deposited
Lysogenic cycle
Virus does not lyse bacterium but integrates into host genome as provirus/prophage
- Virus replicated as bacterium reproduces as part of genome
- Infection with one strain of phase makes bacterium less susceptible to infection
Tenets of natural selection theory
- Organisms produce offpsring but few survive to reproductive maturity
- Chance variations within individuals can be heritable
- Individuals with greater preponderance for favorable mutations are more likely to survie to reproductive age
- Leads to higher freq of these traits in future generations
Effects of melatonin
Sleepiness sensation
Prokaryotic DNA characteristics
Located in nucleoid region
- Carried on single circular chromosomes
- Can also be carried on plasmids
Chromosomal mutations duplication
Segment of DNA copied multiople times in a genome
Where does anything not reabsorbed by collecting duct go?
It collcets in renal pelvis -> flows through ureter to bladder
-Stored in bladder until excreted via urination
Lysosomes
Membrane-bound structures with hydrolytic enzymes
S: Synthesis Phase
Cells replicate genetic material and have exactly identical copies
-Two identical chromatids bound together by centromere
What hormone induces FSH and LH levels?
GnRH
Function of melanin
Protects skin from UV radiation
- Levels of melanin results from activity levells of melanocytes
- Skin color produced by varying levels of melanin
Flagella function
Long, whip-like structures used for propulsion
-Can be used to move toward or away from food/toxins
Menstrual cycle
Rising and falling of estrogen/progesterone in female reproductive years
What situation induces ADH release
Low blood volume
-Want greater retention of H20
Gonads of males
Testes
Arteroiles constriction function for thermoregulation
Blood near skin is limited by this constriction
Path from spermatogonium to spermatozoa?
Spermatogonium replicated: diploid primary spermatocytes
- After first meiosis, haploid secondary spermatic
- After second meiosis, haploid spermatids
- Spermatids undergo maturation and become mature spermatozoa
Benefits of conjugation
Allows for rapid acquisition of abx resitance or virulence factors throughout the colony
What is adaptive radiation
Rapid rise of number of diff species from a common ancestor
-Alllows for various species to occupy diff niches
Punnet square ratios for mendel when crossing homozygous dominant and recessive parents
F1 genotypic ratio: 100% Pp heterozygous
-Phenotypic: 100% purple
F2 genotypic ratio: 25% PP, 50% Pp, 25% pp
-Phenotypic: 3 purple 1 white
Expressivity def
Varying phenotypes depite identical genotypes
-Constant or variable
Metaphase
Kinetochore fibers align chromosomes at metaphase plate
Retrovirus structure
Enveloped, single-stranded RNA viruses with virions of two identical RNA molecules
Specification stage of cell specialization
Cell reversibly designated as specific cell type
Connective vs Epithelial Tissue
Connective: More extracellular matrix
- Lots of blood vessels
- Underlying surface layers
Epithelial: More cells
- No blood vessels
- Form surface layers
Function of ANP (atrial natriuretic peptide)
Regulates salt and H20 balance
- Promotes excretion of Na+ and inc in urine volume
- Antagonistic to aldosterone
Interkinesis
Ocassional short rest period between meiosis I and II
Monozygotic twins fertilization process
When zygote splits into two
Apoptosis steps
Cells divide into self-containted protrusions called apoptotic blebs
-Can be further divided into apoptotic bodies and digested by other cells
Gram positive cell wall characteristics
Thick layer of peptidoglycan
- Cell wall contains lipotechoic acid
- Purple stain
Why aren’t there cells or proteins in filtrate
The glomerular pores are too small for these molecules to fit so they remain in the blood
Type II diabetes treatment
Req insulin only when body can’t control gluc levels
Corona radiata
Outside of zona pellucida and layer of cells adhered to oocyte during ovulation
Transduction (prokaryotic)
Requires a vector: virus that carries genetic material from one cell to another
- Performed by bacteriophages
- Bacteriophage infects host genome and incorporates a segment of its DNA
- When it infects another bacterium, can release this DNA into new host cell
Difference between meiosis one and two
Reductional division: Meiosis I reults in haploid daughter cells from a diploid parent cell
vs equational division: Meiosis II results in haploid daughter cells from haploid parent cells
-No change in ploidy
What stimulates prolactin secretion?
Estrogen and progesterone
What type of system typically regulates endorcine system
Negative feedback: hormone later in pathway inhibits hormones earlier in pathway
Transformation
Integration of foreign genetic material into host genome
-After lysing, contents spilled into vicinity of a bacterium capable of transformatino
Transposons
Genetic elements capable of inserting and removing themselves from genome
-Disrupts affected gene
Absorption GI System def
Involves tranposrt of products of digestion from digestive tract into circulatory system to distribute into tissue and cells
Path of food in and out of body
Oral cavity -> phaynx, esophagus, stomach, small intestine, large intestine, rectum
Enteric nervous system
Neurons that govern function of GI system
- Do not need to send messages to brain to do stuff
- Triger peristalsis
Peristalsis def
Rhythmic contractions of gut tube that moves materials through the system
What types of digestion does the oral cavity do?
Both mechanical and chemical digestion of food
What type of digestion is chewing
Mastication -> mechanical
Function of chewing/mastication
Inc. surface area-to-volme ratio of food
- Creates more surface area for enzymatic digestion
- Allows food to enter esophagus
Chemical digestion of oral cavity
Saliva produced by three pairs of salivary glands
-Salivary amylase, lipas
functions of sailvary amylase and lipase
Lipase: hydrolyzes lipids
Amylase: hydrolyzes starch into smaller sugars
Sections of the pharynx
Nasopharynx: behind nasal cavity
oropharynx: at back of mouth
Laryngopharynx: above the vocal cor
Pharynx function
Connects mouth to larynx
Epiglottis
Prevents food from entering larynx during swallowing
Esophagus function
Connect pharynx to stomach
Is the esophagus under voluntary control
Only the top third, the rest is under involuntary control
rugae def
Folds in the stomach
What do mucous cells produce
bicarbonate
What do chief cells produce
Pepsinogen
What is pepsinogen and what is proudced by
inactive form of pepsin
-Produced by chief cells
What do G cells produce
Gastrin
Function of gastrin
Released from stomach in response to food
- Causes parietal cells to secrete HCl and chief cells to release pepsinogen
- Inc gastric emptying and send chyme to the duodenum
Function of HCl
Cleaves pepsinogen into its active form pepsin
What do parietal cells produce
HCl
-Also intrinsic factor: leads to absorption of vitamin B12
Why is secretin released
because of the acidity of the stomach when food/chyme enters into the small intestine
What is the role of bicarbonate in the GI system
It neutralizes the chyme in the duodenum
Role of secretin
Inhibit’s gastric effects
-Slows gastric emptying
Cholecystokinin CCK functions
Causes:
- Release of pancreatic enzymes -> lipase
- Cause gall bladder to contract -> release bile
- Dec stomach motility
- Inhibits somatostatin -> promotes satiety
What releases CCK
Small intestine
What causes CCK to be released
Presence of fat
Exocrine functions of pancreas
Acinar cells produce pancreatic juices
-Use for digestion
Function of pancreatic amylase and lipase
Amylase: Breaks down large polysaccharides into small dissacharides
Lipase: Breaks down fats into free fatty acids and glycerol
Enteropeptidase function
Master switch
- Converts trypsinogen to trypson
- Activates other zymogens and activates carboxypepidases
Where is the liver located
RUQ of abdomen
What are the bile ducts
Contains bile and connects liver with gallbladder with small intestine
Where does liver receive blood from
Hepatic portal vein
Where does blood in the liver drain to
Inferior vena cava
Function of liver
Produce glucose via
glycogenolysis and
gluconeogenesis
Sugar converted to glycogen
Fats stored as triacylglycerols
Detoxifies ammonia into urea
Detoxifies alcohol and meds
Produces bile
Creates bilirubin which breaks
down Hb
Synthesizes albumin
Synthesizes clotting factorswhat is bile made of
Bilirubin -> byproduce of hemoglobin breakdown
-Bile salts and cholesterol
When does jaundice occur
Yellowing of skin caused by liver inability to process/excrete bilirubin
What is albumin
Maintains plasma oncotic pressure and carrier for drugs/hormones
Where is the gallbladder
Under liver
Function of gallbladder
Stores/concentrates bile
When is bile released
CCK is present
-Site of cholesterol/bilirubin stone formation
Jejunum and ileum function
Involved absorption of nutrients
-Contain villi
Function of villi/microvilli
increase surface area for absorption
Components of villi
Capillary bed for water soluble nutrient absorption and a lacteal which takes up fats and transports them into lymphatic system
Pathway of fat soluble vitamin absorption
Fat soluble vitamins dissolve directly into chylomicrons to enter lymphatic circulation
Pathway of water soluble vitamin absorption
Taken up with water/aa’s/carbs across endothelial cells and directly into plasma
Function of cecum
Accepts fluid from small intestine and attaches to appendix
- Reabsorbs water
- Concentrates remaining material to form feces
Function of anus
Opening through which wasters are eliminated
Internal vs external anal sphincter
Inner is involuntary, outer is voluntary
Role of bacteria in GI system
Produce vitamins
- Outcompete foreign bacteria
- In return,a re fed steady source of food
Does ADH/aldosterone promote thirst?
yes
Which hormones promote hunger
Glucagon and ghrelin
Which hormones promote satiety
Leptin and CCK
Red fibers def
slow-twitch fibers
- High myoglobin and primaryily do aerobic energy
- COntain lots of mitochondria
White fibers def
Fast-twitch fibers
- Much less myoglobin
- Appear lighter because less myoglobin
Why do red twitch fibers look red
Because when iron binds to myoglobin, the heme group is red
-Red twitch fibers have a lot of Myoglobin
Tonus def
Constant state of low level contraction of muscles
How are cardiac muscles connected
Via intercalated discs containing a lot of gap junctions
Function of gap junctions
Allow for rapid/coordinated depolarization of muscle cells and efficient contractions
Pathway of electrical conduction in heart
Depolarization spread from Sinoatrial node to atrioventricular node to Bundle of His to Purkinje Fibers
M-line
Center of sarcomere through middle of myosins
I-Band
exclusively thin filaments
H-zone
Only thick filaments
A-Band
Thick everywhere but some overlap with thin filaments
Which areas of sarcomere don’t shorten during contraction
A-band
myofibrils def
Mutliple sarcomeres attached end to end
What surrounds the myofirbils
Sarcoplasmic reticulum
Function of sarcolasmic reticulum
High concentration of Ca2+ ions
Sarcolemma
Cell membrane of a myocyte
-
sarcomere
Can propagate action potential to all sarcomeres within a myofibril via T-tubules
What is a myocyte composed of
Many myofibrils arranged in parallel
Composition of muscles
Myocytes in parallel
How does the nervous system communicate with muscles
Via motor/efferent neurons
What happens when a signal reaches a nerve terminal
Acetylcholine is released into synapse
Motor unit composition
Nerve terminal and its myocytes
Nerve terminal def
Controls group of myocytes
Depolarization propagation steps in sarcomeres
Spreads down sarcolemma to T-tubiules
-Reaches sarcoplasmic reticulum and Ca2+ released
Function of Ca2+ in depolarization of muscles
Binds to regulatory subunit in troponin
- Tropomyocin undergoes conformation change
- Myosin-binding sites now exposed on actin
Sliding filament model steps
- ATP hydrolysed to ADP+Pi
- Ca2+ binds to troponin, myosin binds to actin
- Powerstroke occurs, sarcomere contracts,
- ADP + Pi dissociate from myosin - New ATP binds to Myosin
- myosin detaches from actin - Cycle repeats
How is acetylcholine broken down
In synapse by acetylcholinesterase
-Terminates signal at neuromuscular junction
What happens when acetylcholine is broken down
Sarcolemma repolarizes
- Ca2+ stops being released
- Sarcoplasmic reticulum takes Ca2+ back up from sarcoplasm
- No Ca2+ -> myosin-binding sites once again covered by tropomyosin
What dictates the strength of a response for muscles
The number of motor units that reach the threshold volume of an action potential
