In a science experiment, equal-sized populations of two species of earthworms are placed in a terrarium filled with soil. abiotic factors such as temperature and water supply are kept constant in the terrarium, as is food in the form of bread scraps. the population of each species is observed and counted each day. in agreement with the competitive exclusion principle, what is the most likely outcome of the experiment over time? a. only one population will thrive; the other population will decrease to zero. b. both populations will reach the same size, which is the carrying capacity of the terrarium for earthworms. c. one population will be about twice the size of the other. d. both populations will reach the same size, which is about half the carrying capacity of the terrarium for earthworms

A. Only one population will thrive; the other population will decrease to zero.

The competitive exclusion principle also known as Gause's law , states that two species which thrive for the same resources cannot coexist. Out of the two species one has extra advantageous characteristics to survive for long than the other. For survival   species undergo evolutionary adaptations and increases chances of survival. Here, abiotic factors such as temperature and water supply are kept constant therefore has no affect on populations growth and extinction but food in the form of essential requirement for survival can be a competing factor for both species. Species with more adaptation and higher competing tendency will survive and weaker competing species will extinct.

good one: produce hormones that plants grow.

bad one: the problem with organic matter is that while plant nutrients are needed for crop growth, they can also stimulate excessive growth of the wrong plants – mainly, algae.