It is not just the environment that affects the chances of a ❌ surviving. Organisms are also dependant on other ❌ for their survival. They may depend on other species for food or for their habitat. Many species of insect, for example, have habitats within or on particular ❌.
In a particular habitat there will be competition between species for resources. ❌ may compete for breeding sites or territories, food, mates or living space. Plants may compete for space, ❌, nutrients and water.
A food web shows the feeding ❌ of some of the species within a habitat. Because species depend on each other in many ways, any impact on one species within a food web will have a ❌ on many of the other species that are part of the same food web. Food webs are extremely useful because they give us a visual representation of ❌.

Organisms can be ❌ in many different ways. In the past, organisms were classified mainly by their ❌. Today, we have a much more ❌ way of classifying organisms, based on their DNA ❌. Organisms with more similar DNA are likely to be more ❌ species. Classifying organisms in this way helps us to see how they ❌. A ❌ ancestor is the most recent individual from which all organisms in a group are descended. Organisms with the most similar DNA have more ❌ common ancestors than those with ❌ similar DNA.