week 4 quiz Flashcards
chapters 37, 41, 42
what causes opening and closing of stomata?
-blue light
-co2 depletion
-h2o availability
-circadian rhythm
what does nitrogen fixing bacteria do?
turn nitrogen into NH3 or ammonia
what does nitrifying bacteria do to ammonium
turn it into NO2- or nitrite
what does H+ from the soil water do to NH3
produce NH4+ or ammonium
what does nitrifying bacteria do to nitrite?
turn it into NO3- or nitrate
what happens to nitrate
1) dentrifying bacteria turns it back into N2 and it is released into the atmosphere
2) turns into NH4+ and goes into xylem of the roots
what does dead organic material produce
decomposition-> amino acids-> ammonifying bacteria-> ammonium
the root nodules of legumes
have a mutualistic relationship with nitrogen-fixing bacteria(Rhizobium) because they produce usable N2 at the root and bacteria gets sugar in the root
Mycorrhizae
has a mutualistic associations of fungi & roots; the host plant gives the fungus a steady supply of sugars; fungus(long-tubular extension) increases the SA:V for water uptake
two types of Mycorrhizae
-ectomycorrhizae-> blue sheaths around root; don’t penetrate cells
-arbuscular mycorrhizae-> go into root and penetrate cells
hydra animal digestion
gastrovascular cavity= intracellular digestion (cells themselves engulf tiny molecules)
what are more complex animals’ digestive tracts called?
alimentary canals
what do complex animals do
extracellular digestion
what do earthworms and birds have to aid in digestion
gizzards
epiglottis up
trachea open
epiglottis down
esophagus open, trachea closed
how is the digestive tract compartmentalized
sphincters
what is peristalsis
wave-like contractions of whatever tube is moving; way that we move things through digestive tract
why are the small intestines efficient?
-tube shape increases SA:V ratio
-folds increases SA:V ratio
-vili increases SA:V ratio
-microvili increases SA:V ratio
what do large intestine do?
reabsorbs water from feces
what do small intestines do?
digestion & absorption;
where is glucagon produced?
the pancreas increases it and it tells the liver to break down glycogen to release glucose into blood
how is insulin produced?
the pancreas secretes it and it enhances the transport of glucose & makes the liver store glucose as glycogen
what does the gallbladder do?
it stores bile; balloon type structure
blood glucose homeoestasis cycle: blood glucose level increases(such as after eating)
1) increases
2) beta cells of the pancreas secrete the hormone insulin into the blood
3) insulin enhances the transport of glucose into body cells and stimulates the liver to store glucose as glycogen
4) blood glucose level falls
blood glucose homeoestasis cycle: blood glucose level decreases(such as after fasting)
1) decreases
2) alpha cells of the pancreas secrete the hormone glucagon into the blood
3)glucagon promotes the breakdown of glycogen in the liver and the release of glucose into the blood
4) blood glucose level rises
what is bile?
*made in the liver
*released into small intestine & emulsifies fats; breaks them down into small droplets=easier digestion
when and why is gastrin released?
released when food enters the stomach and it stimulates the production of gastric juices
what happens when chyme enters the duodenum?
1)CCK is released and causes the pancreas to stimulate the release of bile from the gallbladder
2)secretin is released and stimulates the pancreas to release bicarbonate which reduces the acidity of chyme
what happens if the chyme is rich in fats?
the high levels of secretin and CCK released inhibits peristalsis which slows the movement of chyme and allows it to digest properly
what is gas exchange?
the uptake of O2 from the environment and the discharge of CO2 to the environment
what is partial pressure?
the pressure exerted by a particular gas in a mixture of gases; also applies to gases dissolved in liquids such as water
is O2 less soluble in water than in air
yes
is O2 concentration in air?
30x stronger in air than in water since diffusion is harder in air
what are respiratory surfaces?
*gas exchange across respiratory surfaces(have to be moist) takes place by diffusion
* respiratory surfaces vary by animal and can include the skin, gills, trachae, and lungs
how are the gills in aquatic animals?
*outfoldings of the body that create a large SA for gas exchange
*ventilation moves the rspiratory medium over the respiratory surface
*aquatic animals move through water or move water over their gills for ventilation
how do fish get oxygen?
countercurrent exchange in fish gill; 2 types of liquid move in opposite direction
how do insects get oxygen?
*tracheal system in insects: consists mostly of network of branching tubes throughout the body
- the tracheal tubes supply O2 to body cells
-the respiratory and circulatory systems are separate
-larger insects must ventilate their tracheal system to meet O2 demands
how do the lungs work?
*lungs are the infolding of the body surface
*the circulatory system transports gases between the lungs and the rest of the body
*the size & complexity of lungs correlate with an animal’s metabolic rate
*gas exchange takes place in alveoli, air sacs at the tips of bronchioles
*oxygen diffuses through the moist film of the epithelium and into capillaries
*carbon dioxide diffuses from the capillaries across the epithelium and into the air space
how does a bird breathe?
*birds have air sacs that function as bellows that keep air flowing through the lungs
*air passes through the lungs in one direction only
*passage of air through the entire system of lungs and sir sacs requires two cycles of inhalation and exhalation
*ventilation in birds is highly efficient
why is bird breathing more efficient?
one way breathing means no exhalation of valuable gases, like humans do
