"essay on the principle of population", written by thomas malthus in 1798, influenced darwin's thoughts as he struggled to understand what mechanisms could be at work to produce evolution. malthus proposed that populations of animals and plants, including humans,

a. increased arithmetically in numbers while the nutrients available only increased geometrically
b. increased geometrically in numbers while the nutrients available only increased arithmetically
c. decreased arithmetically in numbers while the nutrients available increased geometrically
d. evolved from mainland to islands, thus explaining why the island flora and fauna resembled the mainland species so closely

1. label high-pressure areas with the letter h. 2. label low-pressure areas with the letter l. 3. over which area(s) would you expect to see rain or snow? 4. over which area(s) would you expect to see clear skies? 5. draw arrows around the h on the map to show the wind direction. 6. draw arrows around the l on the map to show the wind direction. 7. imagine that you live in maine. currently there is a high-pressure area over maine. if a low-pressure area moves in, how will the direction of the wind change? 5. draw arrows around the h on the map to show the wind direction. 6. draw arrows around the l on the map to show the wind direction. 7. imagine that you live in maine. currently there is a high-pressure area over maine. if a low-pressure area moves in, how will the direction of the wind change? 8. imagine that you live in colorado. currently there is a low-pressure area over colorado. if a high-pressure area moves in, how will the direction of the wind change? 9. according to the map, where would the strongest winds be expected? (refer to the lesson if needed.)

Drag each tile to the correct box. the body monitors the levels of oxygen in the blood to regulate breathing. isabel is running in a marathon and is near the finish line. she feels out of breath. how will her nervous system work to generate a reaction? arrange the tiles in chronological order. isabel's breathing rate increases. sensory receptors in the arteries detect low oxygen levels. the brain sends signals through motor neurons. sensory neurons generate an impulse. the central nervous system relays an impulse to certain brain regions.

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.