When large numbers of organisms share limited space and resources, the immediate result is

Step 1: Analyze the question The question asks about the immediate result when many organisms share limited space and resources. This is an ecology question about population interactions.

Step 2: Explain the concept When a habitat has limited resources (food, water, shelter, mates, light), and the number of organisms grows, individuals need the same resources. This leads to competition, which is a struggle between organisms for resources that are in short supply. It can be:

• Intraspecific: between members of the same species
• Interspecific: between different species

Step 3: Evaluate each option

• A. Extinction: This is the complete disappearance of a species. It is a possible long-term outcome, not the immediate one.
• B. Emigration: This is organisms moving out of an area. It may happen later as a response to competition, but it is not the first result.
• C. Competition: This happens straight away, since organisms must contend for the same limited resources. ✔
• D. Immigration: This is organisms moving into an area. Overcrowding would discourage this, not cause it.

Step 4: Answer The immediate result is competition, which is option C.

Exam tip: Watch for words like "immediate" or "direct". Competition is the first effect of overcrowding. Emigration, population decline, or extinction are later consequences. Remember the chain: Overcrowding → Competition → Migration/Death → Possible extinction.