Exam 3 Flashcards
Bio 130 unit 3
What is the single most important aspect of animal form?
Size, mostly because of surface area
What are the two resources an organism requires?
Materials and energy
Why is efficient form important for animals?
Because resources are scarce and difficult to acquire and process
What type of form determines most things about an organism? (Such as metabolism & lifespan)
Size
What function does size impact?
Diffusion- things diffuse better through thinner/smaller surfaces
What has more surface area, a large animal or a small animal?
The small animal
Regulation is best for:
Conformation is best for:
Regulation is best for high performance
Conformation is best for high efficiency
How do organs/organisms increase surface area?
folds, Fingerlike projections called villae, epithelial cells with microvillae
Why is regulation important?
Our bodies function over narrow limits, so regulation is necessary for survival
What is homeostasis?
The regulation of an endothermic organism’s body temperature within a narrow range
is homeostasis negative or positive feedback?
Negative
Why does it matter what temperature something is?
If our internal temperature is too high, things start to break down. If we are too cold, things slow down. both inhibit chemical reactions and general function
Where does heat come from?
metabolism or environment
What is conduction?
“heat diffusion” through an object on a molecular level, felt via physical contact
What is convection?
Macroscopic motion of a substance, such as fire, or heat movement through air or water current. No physical contact needed
(pain wizard)
What is evaporation?
Water transports heat well, and takes a lot with it when it converts to vapor
What is radiation?
Everything emits radiation always forever, and it travels until it hits another object (like you)
What are three methods of thermoregulation?
Physical, physiological, and behavioral
Explain physical thermoregulation
A physical trait that is always present that contributes to thermoregulation
(EX: feathers, hair, blubber)
Explain physiological thermoregulation
Short term, toggled, methods of thermoregulation such as vasodilation (bring heat to skins surface) vasoconstriction (keeps heat close) or evaporative cooling (releases heat via evaporation)
Explain behavioral thermoregulation
Instinctual behaviors done by animals, such as evaporative cooling (panting/use of external water), increase in surface area to gather solar radiation, increase or decrease to sun/air exposure
define endothermic
The body produces and regulates its own heat, energetically expensive, good for high performance
define ectothermic
Heat is gained from external sources and conforms to its surroundings, good for high efficiency
what are regional and seasonal regulation?
Regional: warm up certain parts of the body
Seasonal: employ regulation during certain seasons, such as incubation periods for snake parents
Are larger or smaller animals going to stay warmer?
Larger, because they have less relative surface area to lose heat from, and a lower temperature regulation cost
How does size relate to overall metabolism?
bigger things and ectotherms have a higher lifespan and a lower metabolism, so its not quite as energetically expensive to exist. Smaller endothermic things have short lifespans, fast metabolism, and a high cost
where does the energy in a burning candle come from?
from the stored energy in the carbon-carbon bonds within the fatty wax
What are the three steps of nutrition acquisition?
Mechanical breakdown, chemical breakdown, and absorbtion
What is mechanical breakdown?
the first step of nutrition acquisition, food is torn, chewed, and squished in the mouth (teeth) and by stomach muscles
What is chemical breakdown?
enzymes in the stomach and small intestine break down food compounds so they can be absorbed
What is absorption?
after everything is broken down, resources are absorbed into the small intestine lining
What are the main materials we need in food?
fats, carbs, and proteins. all of these are broken down by hydrolysis
what are essential amino acids?
a set of 9 amino acids that humans cannot create, and must acquire elsewhere
where does digestion begin?
in the mouth, chomp chomp
Explain the process of digestion to me :)
-mouth (mechanical and chemical digestion)
-food forms a bolus and is swallowed
-travels down esophagus into stomach
-chemical and mechanical digestion continue in stomach, converting food to chyme with gastric juices
-Small intestine further breaks chyme down with enzyme hydrolysis in three sections
-small intestine uses folds, villi, microvilli to absorb resources
-left over water and waste processed in the large intestine
-colon completes reabsorption of water
-waste is excreted
what are gastric juices
one of the few positive feedback cycles:
pepsinogen and HCL secreted into lumen (stomach lining)
HCL converts pepsinogen to pepsin
pepsin activates pepsinogen to be secreted into the lumen
cycle continues
what are the three sections of the small intestine?
the duodenum, trypsyn and bicarbonate from pancreas
jejunum, bile and fat emulsification from gallbladder
illeum, liver stores and filters
Why is regionality important?
because different foods/compounds require different digestive methods and enzymes, which can’t often coexist
Where does water reabsorption happen?
the large intestine and colon
Where does the majority of chemical digestion and absorption occur?
the Small intestine
Insulin induces the [ ]; to uptake [ ]; via [ ] feedback
Insulin induces the liver; to uptake glucose from the bloodstream; via negative feedback
what digestive method do herbivores use?
fermentation, the process by which microbes/bacteria break down plant matter into alcohols
There are two types of rumination, what are they and how do they differ?
The rumen is an organ without acid that uses microbes to break down plant matter
foregut rumination is where the rumen is near the front of the animal, and processes the food before the small intestine
hindgut rumination is where the rumen is near the back of the animal, and processes the food after the small intestine
in ruminants, how does the animal get the most nutrients out of the plant matter?
by processing the plant matter more than once, either through regurgitation or coprophagy (eating fecal matter)
How do digestive products get directed?
the liver’s hepatic portal vein
what happens to blood sugar after eating food?
it rises, the speed and amount depends on what was eaten though
define glucose homeostasis
insulin and glycogen being produced in response to rise/fall in blood sugar in order to bring it back to even levels
what is a feedback circuit?
a negative feedback loop where proper levels are maintained
What are the two types of diabetes?
type 1: pancreas sends no signal, leading to insufficient insulin
type 2: liver doesn’t receive any signal, insulin is produced but not responded to
where are nucleic acids digested?
small intestine only
Where are proteins digested?
stomach and small intestine
Where are fats digested?
by the gall bladder in the small intestine
Where are carbohydrates digested?
mouth, stomach, and small intestine
explain the difference between ventilation and respiration
Ventilation: bringing air (o2) in contact with the body’s exchange surfaces
Respiration: bringing air into the body
Define Ventilation
bringing a fluid in contact with the respiratory surfaces of a body
Define Respiration
getting oxygen from fluid into bloodstream, releasing co2 as a byproduct
Define Circulation
moving oxygenated blood around the body
Active or passive transport:
oxygen transport across a membrane
passive, via diffusion along a transportation gradient
Active or passive transport:
oxygen transport around the body
active, using circulation
which is better for transport over long distances: diffusion, or convection?
Convection, its faster
Respiratory surfaces vary, name the surface for each of the following:
Insects
Fish & Crustaceans
Bony fish and amphibians
Crocodiles
Birds and mammals
Insects: cell surface
Fish & Crustaceans: Gills
Bony fish and amphibians: Buccal pump
Crocodiles: hepatic piston
Birds and mammals: Lungs
Define tidal flow
back and forth (in and out through the same structure) ventilation
Define unidirectional flow
air flows through the body
what is the purpose of Alveoli?
to increase surface area in the lungs (respiratory structure)
Explain how counter current exchange works
-new blood comes in contact with depleted respiratory fluid, maintaining concentration gradient
- oxygenated blood comes in contact with fresh respiratory fluid, maintaining gradient
-outgoing blood is higher in concentration than outgoing respiratory fluid
what is the most effective form of gas exchange?
countercurrent exchange
how is oxygen transported through the body (on a molecular level)?
Oxygen is carried by hemoglobin
what is the speed of diffusion?
the speed of diffusion is directly proportional to the difference in concentration, and the difference in distance
Where in our body has the lowest oxygen concentration and why?
in our mitochondria, the oxygen concentration is the lowest because it has the highest demand (O2 is absolutely necessary to make ATP)
What is Hemoglobin?
Carrier of oxygen that is housed in blood cells. Each molecule of hemoglobin is made of four globins, which can each carry one oxygen molecule
How does hemoglobin help with circulating oxygen?
Hemoglobin works very quickly, it binds with O2 molecules which then “don’t count” towards the concentration gradient, allowing respiration to continue to occur via diffusion
what kinds of Globin are there, and what do they do?
hemoglobin (globin in blood) myglobin (globin in muscles) maternal and embryonic globins. all forms of globin help maintain polarity of O2 diffusion in the proper direction
What purpose does the circulatory system serve?
it links respiratory gas sources (lungs) to respiratory gas sinks (tissues)
Describe the four chambers of the heart and what they do
Left and right atria: thin walled, collects blood that is returning to the heart
Left and right ventricles: Thick walled, pump blood from atria to other places
Which tubes take blood away from the heart, and which take blood to the heart?
Arteries take blood Away from the heart, they are more muscular and elastic to withstand and regularize blood pressure
Veins take lower pressure blood back to the heart
What is the difference between single and double circulation?
mainly, how many times the circulatory system cycles.
single:
heart -> gills -> body -> heart
double
heart -> lungs -> heart
heart-> body -> heart
Define carrying capacity:
the number of individuals in a population that an environment can support over the long term
How do population numbers change?
Populations grow by births and immigration, and shrink by deaths and emigration
what is population density?
a measure of population that indicates the number of individuals per unit area (aka volume)
describe a population’s growth in a limited environment
the population would grow exponentially until it hits carrying capacity, and then level off and remain at equilibrium (sometimes, this isn’t an immediate effect, because the negative feedback isn’t felt until the population reaches adulthood)
define survivorship and the three types of survivorship curves
Survivorship: how long an organism lives
Type 1: low death early/mid life, increase in death in older individuals
Type 2: constant death rate
Type 3: high death early/mid life, low death in late life
what is r-selection?
a life history strategy where an organism has lots of small offspring, maximizing per-parent growth rate, linked with type 3
what is k-selection?
a life history strategy with one/few large babies, maximizes per-offspring competitive advantage, linked with type 1
define fecundity
the number of offspring produced in an organisms lifespan
describe the growth rate of the human population and how that relates to carrying capacity
the human population has stopped growing exponentially, but is still growing. It is unclear if we have hit carrying capacity yet, but there are a few theoretical ways we could extend carrying capacity (lower birthrate, better use of existing carrying capacity, emigration)
Describe the positive feedback loop in human childbirth
Estradiol (released by ovaries) causes the release of oxytocin, which stimulates contractions, which causes the placenta to make prostaglandins which stimulate more contractions and also more oxytocin
What is asexual reproduction?
called budding, where one individual creates another genetically identical individual on its own
what is sexual reproduction?
(usually) two individuals contribute to the genetics of the offspring, is metabolically expensive and requires the creation of more offspring to replace parents, but is valued because of recombination
what is the beginning step in sexual reproduction?
fertilization (when sperm and egg unite)
What are the two types of fertilization?
Internal (energetically expensive, linked to higher offspring survival) and external (requires a wet environment, linked to lower offspring survival)
Describe the reproductive process in females
make gametes, which develop first during puberty and are released monthly after. -> ovum comes from ovaries, is fertilized in fallopian tube -> duplicates via cleavage, implants in vascular endometrium
Describe the reproductive process in males
sperm is created in the epididymis, matures in testes, travels through vas deferens, ejaculatory tissues and urethra
What are the roles and names of hormones in reproduction?
Hormones regulate and direct reproduction. they’re secreted by the hypothalamus (Gonadotropin-releasing hormone) then the anterior pituitary (FSH and LH) which go to the gonads, the gonads also secrete sex hormones (either estrogens or androgens)
What are the two cycles in the female reproductive system?
the ovarian cycle and the uterine cycle
what are oogenesis and spermatogenesis?
the respective terms for gametogenesis of either eggs or sperm
what are the phases in the ovaries?
follicular: Sex hormones build up, stimulate egg development, ends with ovulation mid-cycle
luteal: corpus luteum (short term structure after ovulation) secretes hormones, triggering secretory phase where the endometrial wall thickens and preps for a zygote
regulation is [ ] in females; and [ ] in males
regulation is cyclical in females; and constant in males
describe the gestation process
1st trimester- embryo grows organs and develops placenta. all major structures visible by week 8
2nd trimester - fetus grows, high activity period, placenta produces progesterone
3rd trimester - fetus grows more
birth occurs at the end of the 3rd trimester
describe the process of labor
three stages:
-thinning/expansion of cervix– dialation
-expulsion/delivery of baby
-expulsion of placenta
birth is one of the few positive feedback loops in biology
What is the point (and types) of contraceptives
the point is to prevent unwanted pregnancy by interrupting a normal chain of events in fertilization. this can be done by preventing egg and sperm release, keeping gametes separate, or preventing zygote implantation
