unit 6 pt 2 Flashcards
asexual vs sexual reproduction
asexual: 1 parent, identical offspring, meiosis doesn’t happen, mitosis happens, only get variation from mutations
sexual: 2 parents, non identical offspring,meiosis happens, mitosis happens, genetic variation from crossing over and random orientation, more likely to go through natural selection
asexual organisms
prokaryotes, plants, bacteria
meiosis advantage
increases variation
asexual advantage
being able to reproduce quickly and creat exact copy that’s already adapted to environment
what is male and female based off in humans
gametes
male vs female gametes
male: travels toward female, smaller, only holds nutrients for energy to move, more of them
female: doesn’t move, bigger, holds lots of nutrients, less of them
how are gametes produced
produced by meiosis, combined by fertilization, make genetic variation
male reproductive system
-2 testis sperm-also produce testosterone
-scrotum holds testis outside body
-epidymus stores sperm
-sperm travels through sperm duct when ejaculated
-seminal vesicle and prostate gland produce semen to increase sperm’s speed
-sperm goes out uretha
-penis is for penetrating female reproductive system
female reproductive system
egg is produced in 2 ovaries
egg travels down oviduct-site of fertilization
egg reaches uterus-stays if fertilized
egg passes through cervix
egg passes through vagina
vagina is protected by vulva on the outside
menstrual cycle order
menstruation, follicular phase, ovulation , luteal phase
follicular phase
FSH produced by pituitary gland
follicle produces estrogen causing follicle to have more FSH receptors-positive feedback
ovulation
when estrogen peaks in follicular phase, LH is produced by pituitary gland
causes release of egg from LH peak
LH peak causes estrogen to go back down
luteal phase
LH at peak turns follicle into corpus luteum
corpus luteum makes progesterone which builds lining of uterus with the help of some estrogen
LH and FSH go back down
if there’s no embryo, egg passes out body
progesterone and estrogen go back down and uterus lining sheds since its not needed-menstruation
FSH produced-cycle restarts
fertilization in humans
-egg releases hormones that tell sperm where it is
-when sperm reaches egg, it releases enzymes to dissolve outer layer of the egg
-sperm releases nucleus into egg
-rest of sperm dissolves including mitochondria
-after sperm dissolves, the outside of egg hardens to keep other sperm out
-for awhile, nuclei stay separate until mitosis I when nuclei dissolve in prophase
in vitro fertilization steps
-get control of mothers menstrual cycle by giving her drugs to decrease almost all of the 4 hormones
-high amounts of FSH and LH are injected
-many eggs released
-eggs then removed and place in petri dish and mixed with fathers sperm
-eggs can be put back in mothers uterus or put in surrogate
-wall must be built up by estrogen and progesterone
possibilities of vitro fertilization
high chance of problems or twins
surrogates immune system can attack new cells
blood glucose
moves around for cell repsiration
controlled by pancreas
what are islets of Langerhans
cells that regulate blood sugar
alpha cells
islets that make hormones when glucose is too low
-produce glucagon which breaks down glycogen which releases glucose into blood
beta cells
islets that produce hormones(insulin) when glucose is too high
-insulin stimulates cells that absorb glucose causing it to go down
diabetes type 1
comes from DNA mutation in gene for insulin-glucose is too high
-treated by being given insulin
diabetes type 2
develops over time usually from poor health
-insulin produced too much so now insulin receptors break down
- much harder to treat
thermoreceptors
monitor body temp
skin cells have many to monitor temp outside body
chemical regulation of body temp
-thermoreceptors send signals to the hypothalamus in brain
-TRH is released in response to low temperature and targets pituitary gland
-pituitary gland sends out TSH which targets thyroid gland in neck
-thyroid gland releases thyroxin which releases all cells which make heat as by product of the increased cell respiration
physiological responses to cold
vasoconstriction
shivering
uncoupled respiration
hair erection
how does vasoconstriction regulate body temperature
makes blood vessels more narrow to get blood away from skins surface so it isn’t releasing heat
-happens in arterioles
how does shivering regulate body temperature
involuntary muscle contractions and relaxations producing a lot of heat
how does uncoupled respiration regulate body temperature
only breaks down sugar for releasing heat not for energy
-brown adipose
how does hair erection regulate body temperature
traps heat in animals
why we have goosebumps, but they dont trap heat
physiological responses to heat
vasodilation: blood vessels widen and are closer to skin to release heat
sweating: produces water which absorbs heat because of its hydrogen bonds and then evaporates
what is a pathogen
any living thing that causes disease
-causes inability to maintain homeostasis
3 main causes of disease
pathogens
genetic mutations
environment
pathogens vs parasites
pathogens cause disease, parasites can cause other problems
parasites have to have host to get nutrients
5 major types of pathogens
- virus: DNA looking for host to replicate inside
- bacteria: prokaryote, no nucleus, not always pathogen
- fungus: rarely a pathogen
- protists: eukaryote- rarely a pathogen
- prions: like viruses
what is the first line of defense in immune system
skin
thick line of dead cells-chemical and physical barrier
how do sebaceous glands defend
produce moisture and lower pH of skin by sebum
-lower pH prevents bacteria growth
how are body openings protected
mucus to prevent pathogens from entering
blood clotting defense
gel barrier created by blood cells to keep from letting blood out and keeps pathogens from getting in
blood clot cascade(thrombosis)
- blood cells and platelets aggregate at cut
- sends out “clotting factor” signals
- signals cause cells to make group of enzymes called thrombin
- thrombin changes fibronogen(weak, liquid) into fibrin(strong, catches blood cells)
- more aggregation- positive feedback
second line of defense
white blood cells destroy pathogens
-specifically phagocytes/macrophages
how do white blood cells move
amoeboid movement(expanding and contracting)
how do white blood cells destroy pathogens
engulfing
what is endocytosis
formation of vesicle by bringing pathogen into white blood cells using enzymes
-lysosomes
what is pus
phagocytes trying to get rid of infection
what is the innate immune system
born knowing how to destroy pathogens
(not born knowing how to recognize)
what is the adaptive immune system
learns about and identifies pathogens
-done by lymphocytes by looking for antigens
what are antibodies
molecules produced by immune system that help phagocytes destroy pathogens
what are b cells(plasma cell)
type of lymphocyte that produces antibodies
where are lymphocytes mainly
lymph nodes-travel in blood stream
what are antigens
molecules on surface of cell that are used to identify it
-usually made of glycoproteins and plysaccharides
antigen functions
-connecting to host cell
-infecting host cell
-destroying host cell
-basic functions like sending and receiving signals
what is an allergy
when the immune system responds to pathogen that isn’t actually there
what defines blood cells
glycoproteins
-sometimes with blood transfusions the immune system cant recognize new cells
adaptive immune response steps
- phagocytes find pathogen and engulfs and destroys it
-antigen is saved - phagocyte displays antigen on its surface
- helper t cells recognizes antigen and is activated
- B cell sees same pathogen
- b cell and t cell bind together activating the b cell
- b cells divides by mitosise into many cells
- cells make and release antibodies
- antibodies destroy pathogens or help phagocytes destroy pathogen
- antibodies and b cells all dissolve except some b cells
what are memory cells
the surviving b cells after adaptive immune response
-second time being infected is much faster response
what does immunity mean
cant get sick from same pathogen again
what is HIV
human immunodeficiency virus
attacks and destroys helper t cells
cant make antibodies or memory cells
death can occur from any disease in someone with this
what is aids
acquired immunodeficiency syndrome
collection diseases/negative effects caused by HIV
under threshold of white blood cells count
how is HIV spread
unprotected sex, sharing needles, nursing
what is an antibiotic
any chemical that inhibits the growth of a living pathogen
how does a antibiotic stop pathogen
blocking processes unique to prokaryotes so we don’t kill our own eukaryotic cells
what is the main process blocked by antibiotics
cell wall formation since eukaryotes don’t have cell walls
where do most antibiotics come from
fungi so they destroy bacteria and limit competition
why don’t antibiotics work for viruses
viruses use our cells to do living processes since they aren’t alive. it would hurt our cells
what is an anti viral
targets proteins and enzymes unique to viruses
what is antibiotic resistance
a bacteria is exposed to antibiotic, most die, surviving ones have a mutation, they pass mutation on
what is multiple/pan resistant bacteria
a bacteria that is resistant to all antibiotic- bad when it’s in deadly bacteria
examples of multiple resistant bacteria
MRSA and tuberculosis
measures to avoid antibiotic resistance
- doctors need to be sure of what disease it is and prescribe only when absolutely needed
- if a patient is prescribed, patient must finish entire course
- better hygiene in hospitals
- farmers not overuse antibiotics on animals
- pharmaceutical companies develop new antibiotics
what is zoonosis
how disease moves from animals to people- infrequent
3 main ways of zoonosis
- living in close proximity
- eating unsterilized food
- disturbing natural areas
zoonosis disease examples
- tuberculosis- mainly from cattle
-drinking unpasteurized milk
-airborne - rabies- passed through saliva into wound
3.japanese encephalitis- brain swells
-mosquitos get from pigs and birds and give to us - covid 19
-bats maybe - ebola - virus destroys every cell
-maybe from apes
-transferred by blood
-caused by disturbing wild areas
what is a vaccine
part of a virus that doesn’t make you sick but triggers immune response to get memory cells
-must have antigen
what is a attenuated vaccine
weakened or dilute form of a virus- most of the virus but without a couple parts
-ex: measles
what is a killed vaccine
virus has its DNA or RNA moved so virus can’t make you sick
-ex: flu
what is a subunit vaccine
small part of virus inserted(antigen)
-hepatitus
what is a mRNA vaccine
mRNA is turned into proteins from translation
the vaccine sequences DNA so that our cells have antigen to make fast immune response and antibodies
-flu and covid
what does herd immunity mean
significant portion of population is immun which prevents spread of the disease
-protects those with weakened immune responses
what are the 2 ways of becoming immune
vaccine or getting the disease
what does herd immunity depend on
how easily spread the disease is
what is an r value
how many 1 person would infect on average
formula for how many people need vaccinated for herd immunity
1-1/R
