Relationships and Population

• Population: the number of a particular species in a particular ecosystem
• Competition: when two or more organisms fight for a resource that is in short supply
• Contest competition: the struggle between two organisms in which only one wins the resource
• Scramble competition: a struggle between organisms for a scarce resource in which each organism gets some of the resource
• Predation: the act of hunting, killing and eating prey
• Predator: the organism that hunts, kills and eats its prey
• Prey: the organism that is eaten by the predator
• Parasitism: a relationship between two organisms of different species living together where one benefits and does harm to the other