Thomas malthus’s contribution to natural selection is: a. the binomial taxonomic system of naming species. b. the theory that events like warfare, disease, and famine are necessary to control population size and thereby reduce the risk of depleting resources. c. the theory that dna makes up the building blocks of life. d. the theory that the earth’s old age is based on geologic evidence resulting from cataclysmic events.

15 ! come and answer! a(n) disease is caused by a pathogen and can spread among organisms. a infectious b noninfectious c toxic d contaminated

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water

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.