Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
what is osmosis |
the passive movement of WATER from a dilute solution to a high concentration across a SEMI-PERMEABLE MEMBRANE until a DYNAMIC EQUILIBRIUM is reached |
|
what is active transport |
the ACTIVE movement of particles from an area that is LOW in concentration to an area of HIGH conc (against conc gradient) - requires energy |
|
what do dissolved substances move with |
diffusion and active transport |
|
if water and ions are not replaced into the body after a workout what happens |
ion/water imbalance of the body is disturbed |
|
explain how the exchange surface of the lungs (alveoli) is adapted for efficient exchange of molecules |
-thin walls so diffusion is across a smaller surface -large S/A for diffusion -moist lining -cell wall = 1 cell thick |
|
explain how the exchange surface of the small intestine (microvilli) is adapted for efficient exchange of molecules |
- inner surface has many villie (small folds) meaning large s/a best for diffusion & absorbtion - each villi is v. thin so food molecules diffuse across a small distance into the blood -lots of mitochondria -1 cell thick |
|
explain the process of breathing in |
-diaphragm contracts, flattens and moves down - intercostal muscles contract -ribs lift upwards and outwards -larger volume in thorax = lower pressure & fresh air drawn in |
|
explain the process of breathing out |
-diaphragm relaxes & moves upwards - intercontinental muscles relax -rib cage drops down & in -lower vol. in thorax so air pushed out |
|
exchange systems in plants |
- co2 leaves & enters via diffusion - water & mineral ions absorbed by roots |
|
water flow through plants |
-phloem transport food (mainly dissolved sugars) UP & DOWN -xylem take water UP (water & minerals) - lose water vapor from leaves - takes place through stomata |
|
stomata |
-take in co2 in atmosphere and to remove oxygen produced in photosynthesis - size controlled by guard cells |
|
s/a increased where and by |
-large s/a in roots bc of root hairs - large s/a bc of flat leaves & internal air spaces |
|
water loss in plants |
- evaporation bigger in hot, dry & windy conditions - if water lost faster than replaced by roots, stomata can be closed to prevent wilting |
|
what doe the circulatory system do |
transports substances around the body |
|
what is the heart |
- organ & pumps blood around the body - wall made of muscle tissue - 4 main chambers: 1. pulmonary artery 2. aorta 3. right atrium 3. left atrium |