Midlatitude lakes undergo mixing more than equatorial lakes because
(a) the midlatitude lakes turn over twice a year.
(b) midlatitude lakes develop a thermocline.
(c) water is densest at 4 ̊c.
(d) all of the above.
(e) they don’t—equatorial lakes have more mixing

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.